studies on forms and transformation of sulphur and response of rice to sulphur application in rice

STUDIES ON FORMS AND TRANSFORMATION OF

SULPHUR AND RESPONSE OF RICE TO SULPHUR

APPLICATION IN RICE-RICE CROPPING SEQUENCE

Thesis submitted to the University of Agricultural Sciences, Dharwad

in partial fulfillment of the requirements for the Degree of

DOCTOR OF PHILOSOPHY

in

SOIL SCIENCE AND AGRICULTURAL CHEMISTRY

By

D. N. SAMARAWEERA

DEPARTMENT OF SOIL SCIENCE AND AGRICULTURAL CHEMISTRY

COLLEGE OF AGRICULTURE, DHARWAD

UNIVERSITY OF AGRICULTURAL SCIENCES,

DHARWAD – 580 005

SEPTEMBER, 2009

ADVISORY COMMITTEE

DHARWAD SEPTEMBER, 2009 (H. T. CHANNAL) MAJOR ADVISOR

Approved by : Chairman :

Members : 1.

2.

3.

4.

5.

(G. S. DASOG)

(A. R. ALAGAWADI)

(B. I. BIDARI)

(B. N. PATIL)

(H. T. CHANNAL)

(M. HEBBAR)

CONTENTS

Sl. No. Chapter Particulars

CERTIFICATE

ACKNOWLEDGEMENT

LIST OF TABLES

LIST OF FIGURES

LIST OF PLATES

LIST OF APPENDICES

1. INTRODUCTION

2. REVIEW OF LITERATURE

2.1 Status and distribution of different forms of sulphur in soils

2.2 Relationship between forms of soil sulphur and some soil properties

2.3 Role of sulphur in plants

2.4 Transformation of sulphur in soils

3. MATERIAL AND METHODS

3.1 Survey and characterization

3.2 Incubation study

3.3 Field experiment

4. EXPERIMENTAL RESULTS

4.1 Status and distribution of different forms of sulphur in intensive rice grown areas

4.2 Incubation study on the transformation of different sources and levels of sulphur in soil

4.3 Direct and residual effects of sulphur fertilization in rice-rice cropping sequence

5. DISCUSSION

5.1 Status and distribution of different forms of sulphur in intensive rice cropping areas


5.3 Direct and residual effects of sulphur fertilization on rice-rice cropping sequence

6. SUMMARY AND CONCLUSIONS

REFERENCES

LIST OF TABLES

Table No.

Title

1. Locations of soils collected for survey and characterization in farmers’ fields

2. Physico-chemical properties of soils of rice fields of different locations in rice growing areas of North Karnataka

3. Weather data of Agricultural Research Station, Gangavati, 2007

4. Physico-chemical properties of the soil used for incubation study and field experiment

5. Details of field experiment

6. Methods of analysis of soil and plant samples

7. Estimation of different soil sulphur fractions

8. Methods of recording observations of different growth, yield and quality parameters

9. Distribution of different sulphur fractions (mg kg-1

) in soils of rice fields of different locations in rice growing areas of North Karnataka

10 Percentage contribution of sulphur fractions to total sulphur in soils selected from rice fields of different locations in rice growing areas of North Karnataka

11. Correlation coefficients between different forms of sulphur and soil properties

12. Effect of different levels and sources of sulphur on sulphate sulphur (mg kg

-1) at different days after incubation

13. Effect of different levels and sources of sulphur on water soluble sulphur (mg kg


14. Effect of different levels and sources of sulphur on organic sulphur (mg kg


15. Effect of different levels and sources of sulphur on non-sulphate sulphur (mg kg


16. Effect of different levels and sources of sulphur on total sulphur (mg kg


17. Effect of different sources and levels of sulphur on plant height (cm) at different growth stages of rice

18. Effect of different sources and levels of sulphur on number of tillers per hill at different growth stages of rice

19. Effect of different sources and levels of sulphur on dry matter production (q ha

-1) of rice

20. Effect of different sources and levels of sulphur on number of panicles per m

2

21. Effect of different sources and levels of sulphur on panicle length, number of grains per panicle and 1000 grain weight of rice

22. Effect of different sources and levels of sulphur on grain yield, straw yield and harvest index of rice

Contd….

Table No.

Title

23. Effect of different sources and levels of sulphur on grain protein (%) and methionine content (mg g

-1)

24. Effect of different sources and levels of sulphur on plant nitrogen (N) content (%) and uptake (kg ha

-1) by rice

25. Effect of different sources and levels of sulphur on plant phosphorus (P) content (%) and uptake (kg ha

-1) by rice

26. Effect of different sources and levels of sulphur on plant potassium (K) content (%) and uptake (kg ha

-1) by rice

27. Effect of different sources and levels of sulphur on plant sulphur (S) content (%) and uptake (kg ha

-1) by rice

28. Effect of different sources and levels of sulphur on plant Zn content (mg kg

-1) and uptake (g ha

-1) by rice

29. Effect of different sources and levels of sulphur on plant Cu content (mg kg


-1) by rice

30. Effect of different sources and levels of sulphur on plant Fe content (mg kg


-1) by rice

31. Effect of different sources and levels of sulphur on plant Mn content (mg kg


-1) by rice

32. Effect of different sources and levels of sulphur on pH at different growth stages of rice

33. Effect of different sources and levels of sulphur on EC (dS m-1

) at different growth stages of rice

34. Effect of different sources and levels of sulphur on sulphate sulphur (mg kg

-1) in soil

35. Effect of different sources and levels of sulphur on water soluble sulphur (mg kg

-1) in soil

36. Effect of different sources and levels of sulphur on organic sulphur (mg kg

-1) in soil

37. Effect of different sources and levels of sulphur on non-sulphate sulphur (mg kg

-1) in soil

38. Effect of different sources and levels of sulphur on total sulphur (mg kg

-1) in soil

39. Effect of different sources and levels of sulphur on DTPA-extractable Zn (mg kg

-1) in soil

40. Effect of different sources and levels of sulphur on DTPA-extractable Cu (mg kg

-1) in soil

41. Effect of different sources and levels of sulphur on DTPA-extractable Fe (mg kg

-1) in soil

42. Effect of different sources and levels of sulphur on DTPA-extractable Mn (mg kg

-1) in soil

43. Residual effect of different sources and levels of sulphur on plant height (cm) at different growth stages of rice

44. Residual effect of different sources and levels of sulphur on number of tillers per hill at different growth stages of rice

Contd….

Table No.

Title

45. Residual effect of different sources and levels of sulphur on dry matter production (q ha

-1) of rice

46. Residual effect of different sources and levels of sulphur on number of panicles per m

2

47. Residual effect of different sources and levels of sulphur on panicle length, number of grains per panicle and 1000 grain weight of rice

48. Residual effect of different sources and levels of sulphur on grain yield, straw yield and harvest index of rice

49. Residual effect of different sources and levels of sulphur on grain protein (%) and methionine content (mg g

-1)

50. Residual effect of different sources and levels of sulphur on plant nitrogen (N) content (%) and uptake (kg ha

-1) by rice

51. Residual effect of different sources and levels of sulphur on plant phosphorus (P) content (%) and uptake (kg ha

-1) by rice

52. Residual effect of different sources and levels of sulphur on plant potassium (K) content (%) and uptake (kg ha

-1) by rice

53. Residual effect of different sources and levels of sulphur on plant sulphur (S) content (%) and uptake (kg ha

-1) of rice

54. Residual effect of different sources and levels of sulphur on plant Zn content (mg kg


-1) by rice

55. Residual effect of different sources and levels of sulphur on plant Cu content (mg kg


-1) by rice

56. Residual effect of different sources and levels of sulphur on plant Fe content (mg kg


-1) by rice

57. Residual effect of different sources and levels of sulphur on plant Mn content (mg kg


-1) by rice

58. Residual effect of different sources and levels of sulphur on pH at different growth stages of rice

59. Residual effect of different sources and levels of sulphur on EC (dS m

-1) in soil at different growth stages of rice

60. Residual effect of different sources and levels of sulphur on sulphate sulphur (mg kg

-1) in soil

61. Residual effect of different sources and levels of sulphur on water soluble sulphur (mg kg

-1) in soil

62. Residual effect of different sources and levels of sulphur on organic sulphur (mg kg

-1) in soil

63. Residual effect of different sources and levels of sulphur on non-sulphate sulphur (mg kg

-1) in soil

64. Residual effect of different sources and levels of sulphur on total sulphur (mg kg

-1) in soil

65. Residual effect of different sources and levels of sulphur on DTPA-extractable Zn (mg kg

-1) in soil

66. Residual effect of different sources and levels of sulphur on DTPA-extractable Cu (mg kg

-1) in soil

Contd….

Table No.

Title

67. Residual effect of different sources and levels of sulphur on DTPA-extractable Fe (mg kg

-1) in soil

68. Residual effect of different sources and levels of sulphur on DTPA-extractable Mn (mg kg

-1) in soil

69. Effect of different sources and levels of sulphur on economics of first rice crop

70. Effect of different sources and levels of sulphur on economics of succeeding rice crop

LIST OF FIGURES

Figure No.

Title

1. Plan of layout of the field experiment

2. Average per cent contribution of different forms of sulphur to total sulphur in various soil bodies

3. Effect of different levels and sources of sulphur on sulphate sulphur at different days after incubation

4. Effect of different levels and sources of sulphur on water-soluble sulphur at different days after incubation

5. Effect of different levels and sources of sulphur on organic sulphur at different days after incubation

6. Effect of different levels and sources of sulphur on total sulphur at different days after incubation

7. Effect of different sources and levels of sulphur on grain and straw yield of rice

8. Effect of different sources and levels of sulphur on grain protein and methionine content of rice

9. Effect of different sources and levels of sulphur on nitrogen content at different growth stages of rice

10. Effect of different sources and levels of sulphur on nitrogen uptake at different growth stages of rice

11. Effect of different sources and levels of sulphur on phosphorus content at different growth stages of rice

12. Effect of different sources and levels of sulphur on phosphorus uptake at different growth stages of rice

13. Effect of different sources and levels of sulphur on potassium uptake at different growth stages of rice

14. Effect of different sources and levels of sulphur on sulphur content at different growth stages of rice

15. Effect of different sources and levels of sulphur on sulphur uptake at different growth stages of rice

16. Effect of different sources and levels of sulphur on sulphate sulphur content at different growth stages of rice

17. Effect of sulphur nutrition on water-soluble sulphur content at different growth stages of rice

18. Effect of different sources and levels of sulphur on organic sulphur content at different growth stages of rice

Figure No.

Title

19. Residual effect of different sources and levels of sulphur on grain and straw yield of rice

20. Residual effect of different sources and levels of sulphur on grain protein and methionine content of rice

21. Residual effect of different sources and levels of sulphur on nitrogen content at different growth stages of rice

22. Residual effect of different sources and levels of sulphur on nitrogen uptake at different growth stages of rice

23. Residual effect of different sources and levels of sulphur on phosphorus content at different growth stages of rice

24. Residual effect of different sources and levels of sulphur on phosphorus uptake at different growth stages of rice

25. Residual effect of different sources and levels of sulphur on potassium uptake at different growth stages of rice

26. Residual effect of different sources and levels of sulphur on sulphur content at different growth stages of rice

27. Residual effect of different sources and levels of sulphur on sulphur uptake at different growth stages of rice

28. Residual effect of different sources and levels of sulphur on sulphate sulphur content at different growth stages of rice

29. Residual effect of different sources and levels of sulphur on water-soluble sulphur content at different growth stages of rice

30. Residual effect of different sources and levels of sulphur on organic sulphur content at different growth stages of rice

LIST OF PLATES

Plate No.

Title

1. Random assignment of treatments in incubation study

2. General view of the experiment at active tillering stage – first rice crop

3. Direct effect of sulphur nutrition at active tillering stage

4. General view of the experiment at grain filling stage – first rice crop

5. Direct effect of sulphur nutrition at grain filing stage

6. General view of the experiment at harvest – first rice crop

7. General view of the experiment at active tillering stage – succeeding rice crop

8. Residual effect of sulphur nutrition at active tillering stage

9. General view of the experiment at grain filling stage – succeeding rice crop

10. Residual effect of sulphur nutrition at grain filling stage – succeeding rice crop

11. General view of the experiment at harvest – succeeding rice crop

LIST OF APPENDICES

Appendix No.

Title

1. Price of inputs and returns used in calculating cost of cultivation

2. Cost of different operations used in calculating cost of cultivation

1. INTRODUCTION

Sulphur, one of the most important nutrients for all plants and animals, is considered as the fourth major nutrient after nitrogen, phosphorous and potassium for agricultural crop production. Sulphur is a structural constituent of organic compounds, some of which are uniquely synthesized by plants, providing human and animals with essential amino acids (methionine and cysteine). It is involved in chlorophyll formation, activation of enzymes and is a part of vitamins biotin and thiamine (B1) (Hegde and Sudhakara Babu, 2007). There are many other sulphur containing compounds in plants which are not essential, but may be involved in defense mechanisms against herbivores, pest and pathogens, or contribute to the special taste and odour of food plants. Sulphur improves oil and protein contents, flour quality for milling and baking, marketability of copra, quality of tobacco and nutritive value of forages, etc.

Role of sulphur in Indian agriculture is now gaining importance because of the recognition of its role in increasing crop production, not only of oil seeds, pulses, legumes and forages but also of many cereals (Singh et al., 2000). Sulphur deficiency in crops is gradually becoming widespread due to continuous use of sulphur free fertilizers, high yielding crop varieties, intensive multiple cropping systems coupled with higher productivity.

Among the cereals, rice (Oryza sativa L.) is an important food crop which ranks second after wheat in the world. Rice is the major staple food of 70 per cent of the Indian population and being cultivated all over the country under varying agro-climatic regions. It occupies 44.6 million hectares which is 36.58 per cent of the net cultivated area contributing 40 per cent of country’s food production (Anon., 2005). To meet the demand of increasing population and to maintain the self sufficiency, the present production of 86 million tones needs to be increased to 120 million tones by the year 2020 (Mishra, 2003).

There has been quantum jump both in production and productivity of rice in past few decades which occurred mainly under irrigated ecosystems. The transformation from traditional internal input-based agriculture to the present day external input-based agriculture has caused wide spread deficiency of sulphur. With the adoption of intensive farming, the farmers have shifted from using organic to inorganic high analysis sulphur-free fertilizers leading to more widespread and more intense sulphur deficiencies in Indian soils. In early 1990s, sulphur deficiencies in Indian soils were estimated to occur in about 130 districts (Tandon, 1991). Singh (2000) reported that about 45 per cent districts of the country showed more than 40 per cent sulphur deficiency.

In Karnataka, rice is grown under a variety of soils and wide range of rainfall and temperature regimes. Forty four per cent of the total acreage is under irrigation while the rest is under monsoon. The unique feature of rice culture in the state is that either sowing or transplanting is seen in all seasons of the year. Rice being the most important staple food of the state is cultivated under six different ecosystems over an area of about 14.5 lakh hectares (2003-2004) with an annual production of about 33.3 lakh tones with productivity of 2.30 tonnes per ha (Anon, 2005). Major rice area of the state is broadly classified into two seasons, viz., kharif and summer. Irrigated maidan area (north) occupies an area of 0.21 million hectares, with the productivity of 2.53 tonnes per hectare (Anon, 2005). In Karnataka, sulphur deficiency problem appears to be acute in Bangalore, Dakshina Kannada, Malnad areas (Ananthanarayana et al., 1986) and Malaprabha command area (Balanagoudar and Satyanarayana, 1990a).

As plants take up sulphur only in the sulphate form, the oxidation state of the sulphur present in the rice soil is important. Although a great deal is known about the sulphur status of soils and sulphur containing fertilizers under aerobic soil conditions, few studies have been conducted under flooded soil conditions. The flooding of an aerobic soil brings about a variety of chemical, biological and electrochemical changes due to decrease in oxygen supply and the consequent changes in redox (reduction-oxidation) potential, pH, ionic strength and mineral equilibria. Under these conditions, plant available sulphate (SO4

2-) is reduced to non-

available sulphide (S2-

) when the redox potential reaches approximately -220 mV (Ponnamperuma, 1979). Such transformations result in a lower plant uptake of sulphur in rice.

Thus, sulphate-sulphur containing fertilizers applied to flooded rice may undergo reduction to sulphide in submerged fields with the consequent problem of plant unavailability and/or H2S production.

Large number of field experiments conducted in the past was mostly confined to direct effect of sulphur on crops by changing experimental sites in every season. In this way no due importance was given to residual value of sulphur on succeeding crops. On the other hand, response of crops to sulphur fertilization has mainly been investigated using only inorganic sulphur sources and there has been only few studies on integrated use of organics with inorganic sulphur on crops especially rice. In order to make economical use of sulphur in crop production, it seems desirable to monitor the residual value of applied sulphur on crops grown in succession. The present investigation was, therefore, initiated to study the direct effect of applied sulphur on rice crop and also to evaluate the persistence of residual effect on succeeding rice crop of where rice-rice is very common cropping sequence with the following objectives.

1) To study the status and distribution of different forms of sulphur in intensive rice cropping areas of zone 3,

2) To study the transformation of different sources and levels of applied sulphur in soil and,

3) To investigate the direct and residual effect of sulphur fertilization on rice-rice cropping sequence.

2. REVIEW OF LITERATURE

Sulphur responses have been reported in a wide range of crops in many parts of the world. Until recent past, fertilizer studies on rice have concentrated primarily on N, P and K and there are few reports of experiments where the response of this crop to sulphur has been studied. There have been indications that many rice growing soils in Asia are becoming deficient in sulphur. The increased occurrence of sulphur deficiencies has been largely attributed to the increasing use of high analysis fertilizers, increase in yields obtained as a result of technological advances, decreasing use of sulphur containing pesticides and fungicides and environmental control of sulphur emissions.

The literature on the integration of different sources and levels of sulphur with organic manures on rice is scanty. Hence literature pertaining to rice as well as other crops has been reviewed and presented in this chapter under the following headings.

2.1 Status and distribution of different forms of sulphur in soils

2.1.1 Water soluble sulphur

2.1.2 Sulphate sulphur

2.1.3 Organic sulphur

2.1.4 Non-sulphate sulphur

2.1.5 Total sulphur

2.2 Relationship between forms of soil sulphur and some soil properties

2.2.1 Water soluble sulphur with some soil properties

2.2.2 Sulphate sulphur with some soil properties

2.2.3 Organic sulphur with some soil properties

2.2.4 Non-sulphate sulphur with some soil properties

2.2.5 Total sulphur with some soil properties

2.3 Role of sulphur in plants

2.3.1 Effect of sulphur on growth and growth parameters

2.3.2 Effect of sulphur on yield and yield components

2.3.3 Effect of sulphur on quality parameters

2.3.4 Effect of sulphur on nutrient uptake

2.4 Transformation of sulphur in soils

2.1 STATUS AND DISTRIBUTION OF DIFFERENT FORMS OF SULPHUR IN SOILS

Knowledge of different forms of sulphur throughout root zone is essential for improving sulphur nutrition of crops. Sulphur status varies with depth depending upon particle size distribution, soil reaction, redox potential, free iron and aluminium oxides, moisture regime, bio mass content etc. In addition, physiography through its influence on drainage, leaching, type of vegetation and profile development play an important role towards sulphur availability.

Sulphur in soils is present in both inorganic and organic forms and the proportion of inorganic to organic sulphur varies widely depending upon the nature of soil, its depth and management factors to which the soil is subjected. The common forms of inorganic sulphur in soils are (1) water soluble sulphur (2) adsorbed sulphate (3) insoluble sulphates of Ca, Ba, Fe etc. and (4) sulphides or other reduced forms of sulphur. Distribution of different forms of sulphur and their interrelationship with some important soil characteristics decide the sulphur supplying power of a soil by influencing its release and dynamics in soils. Several soil factors influence the availability of sulphur and hence the status of different forms of sulphur in soils varies widely with soil type.

2.1.1 Water soluble sulphur

The water soluble sulphur fraction mostly contains free inorganic and some organically bound SO4

2- (Williams and Steinbergs, 1959). The sulphur that is soluble in water

or other extractants like 1 per cent NaCl is referred to as water soluble sulphur or readily available sulphur. Water soluble sulphur accounts for only a small fraction of total sulphur and it gives an indication about available sulphur status of soil (Setia and Sharma, 2005b). Although the level of soluble sulphate in the soils of humid regions is generally below 10 ppm, considerable fluctuations may occur. These variations are the result of mineralization of organic matter, leaching of soluble sulphate, uptake by plants and sulphate addition from applied fertilizers and irrigation water.

Bhan and Tripathi (1973) observed that water soluble sulphur in terai, alluvial, Bhundelkhand and Vindhyan soils of Uttar Pradesh was on an average, 25.7 and 21.3 ppm for surface and subsurface soils, respectively. The water soluble sulphur was found to be more in surface soils compared to subsurface soils. However, Sharma and Dev (1976) observed a higher content of water soluble sulphur in subsurface horizons of some Inceptisols and Alfisols of Punjab wherein its content ranged from 52.4 to 112.0 ppm.

Lande et al. (1977) found that water soluble sulphur from representative surface soil samples of Marathwada region in Maharashtra was found to vary from 5.4 to 21.1 ppm with an average of 10.7 ppm in normal soils whereas in saline soils it varied from 46.2 to 159.72 ppm with an average of 119.84 ppm.

Ruhal and Paliwal (1978) noticed that the water soluble sulphur in medium black soils and red and yellow soils of arid and semi-arid regions of Rajasthan was 9.8, 32.6 and 10.1 ppm respectively.

Singh et al. (1981) reported that water soluble sulphur in surface and profile soils of Bhundelkhand region of Uttar Pradesh ranged from 11.3 to 55.0 ppm and 8.8 to 26.3 ppm, respectively and water soluble sulphur was slightly higher than sulphate sulphur.

Dwivedi et al. (1983) observed that water soluble sulphur in central alluvial soils of Uttar Pradesh ranged from 14.1 to 36.1 ppm with a mean value of 22.5 ppm, constituting about 15 per cent of total sulphur. Rajendra Prasad et al. (1983) reported that water soluble sulphur content ranged from 81.0 to 107.10 ppm in grape garden soils of Hyderabad.

Balasubramaniam and Kothandaraman (1985) reported that the water soluble sulphur in soils of Coimbatore varied from 2.0 to 23.0 ppm with an average value of 18.0 ppm.

Karwasra et al. (1986) reported that water soluble sulphur ranged from 14.0 to 85.6 ppm with an average value of 31.1 ppm in soils of Haryana. This was found to be higher than that obtained by other extractants except heat soluble sulphur. Sharma et al. (1986) noticed that water soluble sulphur content accounted very small fraction of total sulphur, ranging from 0.83 to 24.58 per cent with an average value of 5.79 per cent in some important soil bodies of North Western Himalaya.

Balanagoudar and Satyanarayana (1990a) reported that water soluble sulphur varied from 1.4 to 230.6 ppm with an average value of 28.7 ppm, constituting 2.3 per cent of the total sulphur in Vertisols and Alfisols in North Karnataka. The higher values of water soluble sulphur in subsurface soils was due to its dependence on clay, soluble salts and calcium

carbonate content of soils, which also increased with depth. The high content of water soluble sulphur in deeper layers in Vertisols was also due to leaching of soluble sulphate, which was precipitated as gypsum crystals. However, Tiwari and Pandey (1990) observed that amount of all forms of sulphur decreased with increase in depth of soils of Varanasi region of Eastern Uttar Pradesh.

Kher and Singh (1993) observed water soluble sulphur content constituting 12.5 per cent of total sulphur in mustard growing soils of North Kashmir.

Hari Ram et al. (1993) reported that water soluble sulphur content ranged from 13.0 to 45.0 ppm with a mean of 36.0 ppm in surface soils and from 14.0 to 38.0 ppm with a mean of 27.2 ppm in subsurface soils, respectively. In all the soils studied, the water soluble sulphur was higher in surface than in subsurface layers.

Sridhara Adiga and Ananthanarayana (1996) reported that water soluble sulphur fraction constituted in twelve base unsaturated rice fallow profiles in Karnataka constituted 1.6 per cent of total sulphur. The values decreased as depth of profiles increased.

In a long term fertilizer experiment with maize-wheat cropping system conducted in Ludhiana, Setia and Sharma (2005b) observed that water soluble sulphur in the plough layer (0-15cm) of ranged between 3.0 to 4.5 mg per kg. The minimum amount of sulphur was found in water soluble form which was attributed to the high content of sand in the experimental soil.

2.1.2 Sulphate sulphur

Sulphate is present in soil either water-soluble or adsorbed form; the latter depends on soil characteristics such as content of iron oxide/hydroxide and pH. Sulphate is the form of sulphur that is taken up by plant roots, although the sulphate fraction generally accounts for less that 5 per cent of the total sulphur in soil. Various methods have been proposed to evaluate the amounts of soil sulphur available for plant uptake. Most of the methods for soil sulphur testing involve extraction of soil with a weak salt solution, e.g. CaCl2, KCl, Ca(H2PO4)2 or KH2PO4. Phosphate containing extractants are used to extract both water-soluble and adsorbed sulphate whereas Cl-based extractants mainly for water-soluble sulphate. In calcareous soils, sulphate may also be present in insoluble form due to co-precipitation with CaCO3.

Willium and Steinbergs (1959) showed that the sulphate sulphur and heat soluble sulphur were well correlated with plant uptake of sulphur. They further observed that any one of them might prove to be an index of available sulphur.

Venkateswarlu et al. (1969) studied the vertical distribution of different sulphur fractions in fifteen rice growing soils collected from different Model Agronomic Experimental Centres. Sulphate sulphur content varied from 26.8 ppm in Varanasi soil to 143.8 ppm in Dindi soil.

Lande et al. (1977) while working on sulphate sulphur content in soils of Marathwada region reported that its content varied from 8.4 to 42.0 ppm with an average of 15.9 ppm in normal soils and 117.6 to 144.0 ppm with a mean of 132.5 ppm in saline soils. The amount of sulphate sulphur contributed very small fraction (0.92%) to total sulphur.

Dolui and Nayek (1981) found that the amount of sulphate sulphur ranged from 0.4 to 28 ppm with an average value of 7.22 ppm in some soils of West Bengal. Its content had no regular trend in its distribution throughout the individual profiles as percentages of total sulphur.

Dolui and Saha (1983) reported that sulphate sulphur in soils collected from different agro-climatic regions of West Bengal, ranged from 0.5 to 130.0 ppm with an average value of 19.0 ppm and it accounted for 0.1 to 14.4 per cent of total sulphur. The lowest values of sulphate sulphur in Jhargram and Bankura soils was accounted for their location at the tropical region where temperature and moisture conditions could possibly lead to higher

mineralization as well as initial formation of sulphides and subsequently oxidized to sulphate form which lost either due to volatilization or leaching.

Cheema and Arora (1984) reported that 82 per cent of the samples from five villages of Ludhiana under groundnut-wheat cropping system were below critical level of available sulphur. The content of available sulphur in these soils showed large variations from as low as 0.30 to as high as 56 ppm. Its content increased progressively from 0.60 to 22.5 ppm in surface layer to 6.20 to 31.9 ppm in fifth layer. The accumulation of available sulphur in subsurface layer was attributed to leaching of soluble sulphates.

Marsonia et al. (1986) observed that sulphate sulphur in seven representative soil profiles in dry farming areas of Saurashtra ranged from 4.5 to 727.5 ppm with a mean value of 97.8 ppm.

Arora et al. (1988) reported that the CaCl2 extractable sulphate sulphur ranged from 5.1 to 46.0 ppm in some Benchmark soils of Panjab. On the basis of 9 ppm as critical limit, 40, 21 and 39 per cent of soils were deficient, marginal and adequate in available sulphur, respectively.

Balanagoudar and Satyanarayana (1990a) observed that sulphate sulphur ranged from 2.8 to 250 ppm with an average of 29.3 ppm and accounted for very small fraction of total sulphur. The increase in content of sulphate sulphur regularly at lower depth was due to leaching of soluble sulphate to deeper layer and precipitation as gypsum crystals. Similar findings were reported by Mohinder Singh et al. (1990) in some soils of Haryana, wherein the content of available sulphur constituted 6.5 per cent of total sulphur.

Misra et al. (1990) noticed that sulphate sulphur extracted with 1 per cent CaCl2 from some soils of Orissa varied from traces to 64.2 ppm except the two saline soils which had very high values of 273.0 and 407.7 ppm sulphur. The content of sulphate sulphur increased with depth up to 30 cm and then decreased subsequently. The high microbial activity in surface layers probably resulted in loss of sulphur in surface layers which increased with lowering of microbial activity and organic carbon.

In some soils of Varanasi region of Uttar Pradesh, Tiwari and Pandey (1990) observed that the sulphate sulphur content varied from 6.50 to 30.00 ppm. In some representative soil groups of Himachal Pradesh, sulphate sulphur content ranged from 5.5 to 21.2 ppm and showed a decreasing trend with depth. Low content of this form of sulphur was due to natural leaching under the influence of high rainfall. Higher concentration of sulphate sulphur in surface horizon was due to greater plant and microbial activities resulting in accumulation of organic matter (Tripathi and Karan Singh, 1992).

Padmaja et al. (1993) reported that in some pedons of Vertisols of Andhra Pradesh, inorganic sulphate sulphur content ranged from 8 to 19 ppm. The available sulphur contents in these soils were marginal indicating that there is a need to apply sulphur in near future to meet the sulphur requirement of crops, particularly oilseeds.

In a study conducted on the distribution of different forms of sulphur in rice growing surface (0–25cm) soils of Uttar Pradesh, Hari Ram et al. (1993) stated that sulphate sulphur content ranged from 8 to 24 mg per kg with a mean of 15 mg per kg.

Kher and Singh (1993) noticed in mustard growing soils of North Kashmir, a very small fraction of total sulphur (5.1%) was present as sulphate sulphur which varied from 4 to 15 ppm.

Surendra Singh et al. (1993) observed that the soluble sulphate sulphur (0.15% CaCl2 extractable) in some Ranchi soils of Chotanagpur formed a small fraction (1.25%) of total sulphur. Considering 10 ppm sulphate sulphur as critical limit, nearly 60 per cent of the total soils were reported to be deficient in sulphur, which was found to increase with depth of profiles, which was due to its relationship with higher clay content at lower depths.

Arvind Kumar et al. (1994) in their communication on available sulphur status of Bihar soils observed that the 0.15 per cent CaCl2 extractable sulphur ranged from 0.85 to 34.6, 2.6

to 85.5 and 2.6 to 45.1 ppm in 3 different soil series. It was inferred that neutral to slightly alkaline soils contained higher available sulphur compared to acidic soils.

In a study on the sulphur availability of some soils of Chotanagpur region of Bihar, Ghosh and Sarkar (1994) reported that available sulphur ranged from 4.3 to 14.8 ppm with an average value of 9.3 ppm. On the basis of 10 ppm of CaCl2 extractable sulphur as threshold value, 70 to 90 per cent soils could be rated as deficient, suggesting a strong need of sulphur application in these soils. In some soil groups of Kanpur district of Uttar Pradesh, sulphate sulphur ranged from 4.5 to 29 ppm constituting about 4.2 to 20.8 per cent of total sulphur as reported by Hariram and Dwivedi (1994).

Sulphate sulphur content in some important soil series of Vertisols of Maharashtra ranged from 17.0 to 24.0 ppm with an average value of 69.9 ppm while per cent contribution of sulphate sulphur to total sulphur ranged from 0.8 to 12.5 ppm. These soils contained higher sulphate sulphur than the critical limit of 10 ppm sulphate sulphur (Dharkanath et al., 1995).

Bhogal et al. (1996) reported lower values (<10 ppm S) of available sulphur in some calciorthrents of North Bihar which were due to differences in soil, environmental conditions, high rainfall and topography which depleted sulphur in the rhizosphere. The values of 0.15 per cent CaCl2 – extractable sulphur were higher in lower depths than at surface which was due to leaching of sulphate sulphur. They reported that the contribution of free CaCO3 and Al2O3 in explaining in variations of different forms of sulphur were noteworthy. In calcareous soils which contain variable amount of free CaCO3, sulphate ions are precipitated on the surface of these particles on account of which the availability of sulphur in alkaline and calcareous soils was poor.

Sridhara Adiga and Ananthanarayana (1996) reported that sulphate sulphur fraction in twelve base unsaturated rice fallow profiles in Karnataka constituted 2.4 per cent of total sulphur. It generally decreased with increase in depth of the profiles with surface layers containing the maximum amount.

Vaneet Aggarwal and Nayar (1998) reported that available sulphur content (0.15% CaCl2 extractable) in soils collected from 22 wheat fields ranged from 14.0 to 35.2 mg per kg soil in surface layers with a mean value of 22.2 mg per kg soil whereas the contents varied from 11.5 to 28.3 mg per kg soil with an average value of 16.7 mg per kg soil, indicating the surface layers were higher in available sulphur as compared to lower layers.

Available sulphur contents (0.15% CaCl2 extractable) in rice growing Alfisols and Inceptisols of the high rainfall zone of Tamil Nadu ranged from 1.9 to 159.6 ppm with a mean of 25.0 ppm (Biju Joseph et al., 1999).

Singh et al. (2000) observed that sulphate sulphur content in soils from thirty six soil series under varying physiographies and representing four soil orders viz., Entisols, Inceptisols, Alfisols and Mollisols, varied from 9.1 to 54.3 mg per kg with a mean value of 30.1 mg per kg and constituted 2.5 per cent of total sulphur.

In a study on vertical distribution of sulphur fractions in two soils series belonging to Alfisols and Entisols of Jharkhand, Rakesh Kumar et al. (2002) noticed that 0.15% CaCl2 extractable sulphate sulphur content ranged from 2.3 to 6.7 and 23.4 to 31.7 mg per kg in soils belonging to Entisols and Alfisols, respectively.

Bhatnagar et al. (2003) reported that the calcium chloride extractable sulphate sulphur in some profiles in Madhya Pradesh ranged from 11.25 to 13.25 and 9.87 to 16.25 with mean values of 12.27 and 12.40 mg per kg in surface soils of Inceptisols and Vertisols respectively.

Jat and Yadav (2006) noticed that the sulphate sulphur content in mustard growing Entisols of Jaipur district in Rajasthan ranged from 4.10 to 39.95 mg per kg with a mean value of 14.52 mg per kg. The percentage contribution of sulphate sulphur to total sulphur was 9.41.

2.1.3 Organic sulphur

The nature and properties of organic sulphur fraction in soils are important since they govern the release of plant available sulphur. Much of the organic sulphur in soils remains uncharacterized and three broad groups of sulphur compounds are recognized. They are (1) HI-reducible sulphur (2) C-bonded sulphur and (3) residual or inert sulphur. Organic sulphur is a reserve source of sulphur for plants and must undergo mineralization before it becomes available to plants. As sulphur immobilization is microbial process, it depends on factors like moisture, aeration, temperature soil reaction etc. Organic sulphur of the soil has been designated as indicator of reserve sulphur status of soil (Kumar and Singh, 1974). An increase in content of organic sulphur with increase in altitude has been reported by Dolui and Bandyopadhyay (1983).

Venkateswarlu et al. (1969) studied the vertical distribution of different sulphur fractions in fifteen rice growing soils collected from different Model Agronomic Experimental Centres. Organic sulphur content in fifteen rice growing soils varied from 49 ppm in Gangavati soil to 99 ppm in Mankhanda soil.

Covering most of the cultivated soils of Rajasthan, Shukla and Gheyi (1971) reported that the range in organic sulphur content as 60 to 298 ppm. In heavy textured soils its content varied from 90 to 230 ppm which constituted about 60 to 70 per cent of total sulphur. Kumar and Singh (1974) observed that the fine textured soils have higher levels of organic sulphur.

Aulakh and Dev (1976) observed that except in saline-sodic soils, the content of organic sulphur was highest followed by heat soluble, water soluble and sulphate sulphur. Sulphur distribution was strongly dependent upon soil characteristics like electrical conductivity, CaCO3 and texture.

Mukhopadhyay and Mukhopadhyay (1980) noticed that organic sulphur constituted the major fraction of total sulphur except in coastal saline soils in some typical soil profiles of West Bengal. Organic sulphur in soils of Darjeeling area, West Bengal, ranged from 97 to 309 ppm with a mean of 204.1 ppm and accounted for 7.7 to 49.7 per cent of total sulphur in different profiles (Dolui and Bandyopadhyay, 1983).

Rajendra Prasad et al. (1983) reported that the organic sulphur content in some intensively cultivated grape garden soils varied from 405 to 2114 ppm with a mean of 965 ppm. In some soils of Haryana, Karwasra et al. (1986) reported that organic sulphur ranged from 25 to 125 ppm.

In some soils of West Bengal, Dolui and Saha (1983) observed that organic sulphur content ranged from 8 to 305 ppm with an average of 59.7 ppm. It accounted for 2.2 to 33.7 per cent of total sulphur. The high organic sulphur content in cultivated surface soil of Barnipur was due to either addition of organic manure and sulphur containing fertilizer during cultivation or higher plant and microbial activity and subsequent organic matter accumulation.

In some soils of Coimbatore district, Tamil Nadu, Balasubramaniam and Kothandaraman (1985) reported a range of organic sulphur content ranged from 100 to 260 ppm. In surface soils of Entisols and Inceptisols of Panjab, organic sulphur ranged from 23.7 to 105.8 ppm with an average of 49.2 ppm (Arora and Takkar, 1988). In some benchmark soils of Punjab, Arora et al. (1988) observed a range of 16.9 to 61.5 ppm of organic sulphur.

Balanagoudar and Satyanarayana (1990a) reported that the organic sulphur in soils of North Karnataka varied from 8.4 to 138.6 ppm with and average of 75.2 ppm and accounted for 0.8 to 20 per cent of the total sulphur. The lower values of organic sulphur at deeper layers were attributed to the low organic matter content at these depths.

Mohinder Singh et al. (1990) reported that organic sulphur content varied from 5.0 to 168.2 ppm in soils under different agro-climatic regions of Haryana and constituted 5 to 39 per cent of total sulphur in different horizons with an average of 15.9 per cent. The range of organic sulphur content in some soils of Varanasi region of Uttar Pradesh was between 21.45 to 70. 00 ppm (Tiwari and Pandey, 1990).

Misra et al. (1990) observed that organic sulphur in some soils of Orissa constituted 66.5 to 98.3 per cent of total and the coastal saline soils contained a relatively lower fraction of organic sulphur (66.57%) as compared to other groups (81.44 to 93.97%). Organic sulphur content decreased with depth up to 60 or 90 cm and increased at lower depth (90 - 105 cm). The sudden increase in organic sulphur at deeper layer was attributed to the increase in clay and organic carbon at this depth. Some form of illuviation of sulphur-rich organic matter was also reported under predominantly anaerobic conditions at lower depth, beyond the root zone of most of the crops cultivated in the field.

In some representative soils of Himachal Pradesh, Tripathi and Karan Singh (1992) observed that organic sulphur ranged from 65.0 to 228.5 ppm which constituted about 58 per cent of total sulphur. Its content decreased with depth and followed the trend of organic matter.

Surendra Singh et al. (1993) reported that organic sulphur in some Ranchi soils of Chotanagpur area of Bihar constituted about 77 per cent of total sulphur and its content was found to decrease with increase in depth of soil profiles. This was related to organic carbon content which decreases from surface to lower depths. In some mustard growing soils of Kashmir organic sulphur constituted 43.6 to 71.3 per cent of total sulphur and it was the major fraction of total sulphur (Kher and Singh, 1993).

Hari Ram et al. (1993) reported that organic sulphur accounted for 17 to 31 per cent of total sulphur in rice growing soils of Uttar Pradesh. Because of sulphur being one of the constituent of soil organic matter, organic form of sulphur was found to be highly correlated with organic carbon.

Organically bound sulphur in some soil of groups of Kanpur district of Uttar Pradesh varied from 2.0 to 68.1 ppm with mean of 33.5 ppm and it constituted on an average 28 per cent of total sulphur (Hariram and Dwivedi, 1994)

Dharkanath et al. (1995) observed that the organic sulphur content in some important soil series of Vertisols of Maharashtra state ranged from 17.6 to 91.4 ppm while the per cent contribution of organic sulphur varied from 1.1 to 5.5. Its content showed decrease with increase in soil depth, which was due to the high amount of organic matter in surface soil horizons.

Sridhara Adiga and Ananthanarayana (1996) noticed that organic sulphur decreased along the depth of profiles and increased subsequently. This was due to its intimate relationship with organic matter content of soils. Organic sulphur which constituted 45.6 per cent of total sulphur, correlated significantly and positively with ignition sulphur, heat soluble sulphur, available sulphur and organic matter.

Bhogal et al. (1996) reported that organic sulphur in some calciorthents of Bihar accounted for 70 to 99 per cent of total sulphur, thus forming a major fraction.

Tripathi et al. (1997) observed that organic sulphur content varied from 1.2 to 65.0 mg per kg with an average of 14.6 mg per kg while the per cent contribution of organic sulphur to total sulphur ranged from 3.1 to 15.5. Its content showed decrease with increase in depth which was attributed to the consistent decrease in organic carbon content down the depth.

Sharma and Gangawar (1997) studied ten composite surface (0 - 0.15 m) soil samples collected from Alfisols, Inceptisols and Mollisols in Uttar Pradesh. It was found that organic sulphur was the most predominant form in these soils accounting more than 60 per cent of total sulphur. The average organic sulphur values were highest in Mollisols follwed by Alfisols and Inceptisols. Since the Mollisols are moderately rich in organic matter, the high organic sulphur levels were expected in them.

Singh et al, (2000) observed that organic sulphur content in soils from thirty six soil series under varying physiographies and representing four soil orders viz., Entisols, Inceptisols, Alfisols and Mollisols, varied from 35.4 to 261.5 mg per kg and constituted on an

average of 10.3 per cent of total sulphur. Such a wide variation in its content was presumably due to variation in organic carbon content in these soils.

In a study on vertical distribution of sulphur fractions in two soils series belonging to Alfisols and Entisols of Jharkhand, Rakesh Kumar et al. (2002) noticed that organic sulphur content ranged from 221 to 446 and 76 to 665 mg per kg with mean values of 331 and 425 mg per kg in Entisols and Alfisols respectively.

Bhatnagar et al. (2003) studied the distribution of sulphur in some profiles of Shivpur district of Madhya Pradesh. Organic sulphur in Inceptisols and Vertisols accounted for 59 and 62 per cent respectively. The average organic sulphur values were higher in Vertisols (556 mg kg

-1) than Inceptisols (471 mg kg

-1) at surface and decreased with depth. A significant and

negative correlation of organic sulphur was found with pH, CaCO3, clay and CEC. It showed significant and positive correlations with organic carbon, silt and total nitrogen in both Vertisols and Inceptisols.

Jat and Yadav (2006) noticed that organic sulphur content in mustard growing Entisols of Jaipur district in Rajasthan ranged from 20.50 to 76.40 mg per kg with a mean value of 154.28 mg per kg accounting about 23.66 per cent to the total sulphur content.

2.1.4 Non-sulphate sulphur

Non-sulphate inorganic fraction of sulphur is attributable to (1) primary minerals (2) pyrites or iron polysulphides formed as a result of water logging (3) insoluble barium or strontium salts and (4) co-crystallized impurities in calcium carbonate. Appreciable amounts of soluble sulphates are often found in subsoil horizons and the occurrence of free gypsum in the deeper horizons of many semi-arid soils is a well known pedological phenomenon. Several forms of insoluble sulphates such as Ca, Ba and Sr, are associated with basic sulphates of Al, Fe and calcium carbonate. Sulphate occurring in calcareous soils as a co-crystallized impurity in the calcium carbonate is probably the most common in some soils of arid and semi-arid regions and may account for 95 per cent of the total sulphur (Williams, 1975).

Venkateswarlu et al. (1969) reported that there was considerable amount of non-sulphate inorganic sulphur up to 57 per cent in some rice growing surface soils of India, which was attributed to higher phosphates and higher pH or calcareous nature of these soils. In some soils of Uttar Pradesh, non-sulphate sulphur was reported to be 56.6 ppm (average) which contributed 49.8 per cent of total sulphur (Bhardwaj and Pathak, 1969).

In arid brown and tropical brown soils, Virmani and Kanwar (1971) observed that non-sulphate sulphur was present in excess of 50 per cent of total sulphur in some profiles of North-East India. In some medium textured soils of Rajasthan, Joshi et al. (1973) reported that most of the sulphur was present in the inorganic form.

Singh et al. (1976) noticed that non-sulphate sulphur in some soils of Himachal Pradesh was found to be 22 to 54 per cent of the total sulphur in surface soils. Mukhopadyay and Mukhopadyay (1980), in their studies on sulphur content of coastal saline soils, reported that the contribution of inorganic sulphate sulphur to total sulphur was 48 per cent.

Swarnakar and Verma (1978) found that the non-sulphate sulphur in Bundelkhand soils varied from 26.0 to 82.0 ppm. In general, this form of sulphur was found to increase with depth in all soils.

Tabatabai and Al-Khafaji (1980) observed a continuous increase in sulphur mineralization with time from some American soils. However, there was a linear release of sulphate right from the start incubation period.

Dolui and Nayek (1981) reported that non-sulphate content varied from 13.0 to 70.0 ppm with an average of 29.14 ppm accounting for 24.6 to 64.4 per cent of total sulphur in red and lateritic soil profiles of Midnapur region of West Bengal.

Singh and Sharma (1983) observed that the non-sulphate form of sulphur in surface and sub-surface layers in citrus growing soils of Agra region of Uttar Pradesh ranged from 58.9 to 127.0 ppm and constituted 45.6 to 77.5 per cent of total sulphur with an average value of 57.3 and 53.8 ppm for 0-30 and 30-60 cm depth, respectively. In some central alluvial soils of Uttar Pradesh, Dwivedi et al. (1983) observed that non-sulphate sulphur ranged from 75.5 to 100.1 ppm which constituted 61 per cent of total sulphur.

Dolui and Saha (1983) showed that non-sulphate sulphur form in different agro-climatic regions of West Bengal ranged from 230.5 to 548.0 ppm with an average of 323.0 ppm and it accounted for 51.9 to 97.6 per cent of the total sulphur. The wide range in variation of non-sulphate sulphur was due to great heterogeneity in organic matter, rainfall, altitude and parent material (Sharma et al., 1988).

In Vertisols and Alfisols of North Karnataka, Balanagoudar and Satyanarayana (1990a) reported that non-sulphate sulphur content ranged from 404.0 to 3356.0 with an average value of 1136.0 ppm and constituted 75.4 to 98.7 per cent, with an average of 89 per cent of total sulphur. Non-sulphate content generally increased with depth which was due to variations of sulphur compounds in soils. The highest non-sulphate sulphur content was observed in Bidar soil rich in iron and aluminium derived from basalt since the presence of insoluble sulphur compounds of iron and aluminium was expected.

Tiwari and Pandey (1990) observed that the non-sulphate sulphur in some soils of Varanasi region of Uttar Pradesh was in the range of 29.59 to 136.10 ppm. The non-sulphate sulphur content in various soils of Haryana ranged from 46.3 to 303.8 ppm with a mean of 153.9 ppm and 42.4 to 242.6 ppm with a mean of 129.6 ppm in surface and subsurface soils, respectively (Karwasra et al. (1990).

Mohinder Singh et al. (1990) noticed that non-sulphate sulphur content in some soils under different agro-climatic regions of Haryana varied from 80 to 462.2 ppm. Its content constituted the highest (mean 77.6 %) of all other fractions. An inconsistent distribution of this form of sulphur was due to diversified and heterogeneous parent material transported by wind or water at various periods and due to leaching from surface horizon and its subsequent precipitation in different horizons. Sharma and Dev (1976) and Singh et al. (1976) also reported non-systematic distribution of non-sulphate sulphur in soil profiles from Punjab and Himachal Pradesh, respectively.

Tripathi and Karan Singh (1992) observed that non-sulphate content in some representative soil groups of Himachal Pradesh varied from 26.8 to 107.5 ppm. Its content increased with depth in majority of soils, which was due to leaching of these compounds to underlying layers.

The presence of CaCO3, slight alkaline condition and low organic matter were the contributing factors leading to higher amount of non-sulphate sulphur in mustard growing soils of Kashmir. Non-sulphate sulphur content accounted for 25 per cent of total sulphur in these soils (Kher and Singh, 1993).

Padmaja et al. (1993) showed that non-sulphate and organic sulphur content together in some pedons of Vertisols ranged from 88 to 195 ppm. The organic and non-sulphate sulphur fractions together constituted major portion of total sulphur in all the soil profiles.

Hariram and Dwivedi (1994) reported that non-sulphate sulphur ranged from 23.8 to 98.1 ppm with an average value of 72.1 ppm which constituted approximately 61 per cent of total sulphur. Non sulphate content was found to be higher than organic sulphur which was due to rapid oxidation of organic matter and mineralization of sulphur.

Dharkanath et al. (1995) noticed that non-sulphate content in some important soil series of Vertisols of Maharashtra state varied from 1050 to 2432 ppm with an average of 1616 ppm while the per cent contribution of non-sulphate sulphur to total sulphur ranged from 85.6 to 98.4 with an average of 90.4 per cent. The results also indicated that total sulphur content behaved like the content of non-sulphate sulphur. The high content of non-sulphate sulphur in these soils was attributed to the formation of these soils from basaltic rocks.

Tripathi et al. (1997) pointed out that non-sulphate content in some Aridisols of Haryana ranged from 35 to 550 mg per kg which constituted 74 to 94 per cent of total sulphur. This form of sulphur increased with increase in depth, as at lower depths there were lower contents of organic and sulphate sulphur together.

Singh et al. (2000) observed that non-sulphate sulphur content in soils from thirty six soil series under varying physiographies and representing four soil orders viz., Entisols, Inceptisols, Alfisols and Mollisols, varied from 550 to 1376.5 mg per kg with a mean value of 1061.3 mg per kg and constituted on an average 87.2 per cent of total sulphur.

Jat and Yadav (2006) noticed that non-sulphate sulphur content in mustard growing Entisols of Jaipur district in Rajasthan ranged from 67.00 to 213.40 mg per kg with an average value of 102.12 mg per kg which constituted approximately 66.86 of total sulphur content.

2.1.5 Total sulphur

The amount of total sulphur present in soils vary depending upon its content in the primary material, organic compounds and sulphate ions adsorbed and present in the soil solution. It occurs largely in organic form in humid and sub-humid soils and in inorganic forms in arid and semi-arid regions with low rainfall where salt accumulation is high. Since India is a sub-continent with a wide variety of tropical climate, soils and different agro-ecosyetems, the sulphur contents among and within soil types as well as regions vary to a great extent.

Venkateswarlu et al. (1969) studied the vertical distribution of different sulphur fractions in fifteen rice growing soils collected from different Model Agronomic Experimental Centres. Total sulphur content varied from 112.5 ppm in Nasirpur soil to 275 ppm in Titabar soil in the surface (0-15 cm) samples.

A high content of total sulphur in soils at higher altitudes than at lower altitudes has been reported by Kanwar and Takkar (1964) and Singh et al. (1976). A general decline in total sulphur content along the depth of soils was observed in soil profiles of Bhundelkhand region (Swarnakar and Verma, 1978). Similar results were obtained by Virmani and Kanwar (1971).

Mukhopadhyay and Mukhopadhyay (1980) observed that total sulphur generally decreased with depth and varied from 18.7 to 333.2 ppm, with an average of 130.6 ppm in some typical soil profiles of West Bengal. Very high content of sulphur (2654.4 ppm) was reported in some deep black soils of Rajasthan suggesting the spatial variability of total sulphur in these soils (Ruhal and Paliwal, 1980).

Dolui and Bandyopadhyay (1983) reported that the total sulphur content in some coniferous forest soil profiles of north Bengal varied from 368 to 2206 ppm with a mean of 1017 ppm. The profiles of upland and midland soils showed increased total sulphur with depth. But in case of lowland profile, total sulphur content was found to decrease with depth. In citrus growing soils of Agra region, total sulphur content ranged from 77.5 to 187.5 ppm with a mean value of 156.0 ppm (Singh and Sharma, 1983).

Rajendra Prasad et al. (1983) observed that the total sulphur content in some intensively cultivated soils of Andhra Pradesh varied from 621 to 2310 ppm with mean value of 1303 ppm in some soils of West Bengal.

Balasubramanuim and Kothandaraman (1985) revealed that total sulphur content in soils of Coimbatore district of Tamil Nadu, ranged from 190 to 5700 ppm. It was observed that soils of Dasarapatti series (black calcareous soils) recorded highest amount of total sulphur and was observed to be due to its gypsiferous nature.

Very high values of total sulphur in excess of 1000 ppm (0.1 %) are generally encountered in problem soils such as saline and acid sulphate soils (Ganeshamurthy et al., 1989). Total sulphur is generally higher in fine textured soils than in coarse textured soils. Generally, soil sulphur content is highest in the top soil and decreases with depth following

the distribution of organic matter. However, this pattern does not occur where sulphates and carbonates get accumulated in lower layers.

Dolui and Das (1988) observed that the total sulphur content in selected soil series of terai and teesta alluvial regions of West Bengal varied from 186 to 510 ppm with an average of 351 ppm. In some benchmark soils of Punjab, total sulphur ranged from 86.6 to 222 ppm with an average of 162.1 ppm (Arora et al. (1988).

Dolui and Guhathakurta (1988) noticed that the total sulphur contents in soils from different agro-climatic region of West Bengal ranged from 77.3 to 339.0 ppm with an average of 194 ppm. Total sulphur content showed decline with depth in all the profiles.

Sharma et al. (1988) reported that the variation in the amount of total sulphur in some soils in different zones of North Western Himalayas was due to the variation in parent material and organic matter content of soils.

Balanagoudar and Satyanarayana (1990a) studied the total sulphur content in some Vertisols and Alfisols of North Karnataka and reported that total sulphur content varied from 500 to 3500 ppm with an average of 1239 ppm. Similarly, Ruhal and Paliwal (1978) reported 500 to 3250 ppm of total sulphur in fine textured soils of Rajasthan.

Misra et al. (1990) studied some soils of Orissa in relation to the forms of sulphur and soil properties and reported that the total sulphur content of all soils were in a wide range of 25.7 to 925 ppm. The light textured red, laterite and alluvial soils with low clay content contained less total sulphur as compared with the soils of other groups. The total sulphur content was found to decrease with depth up to 60 to 90 cm and increased at lower depths. The high content of total sulphur in surface layer was attributed to the sulphur fertilization in the cultivated fields.

Mohinder Singh et al. (1990) showed that the total sulphur content varied from 90.0 to 996.0 ppm in soils under different agro-climatic zones of Haryana. The content of total sulphur decreased with depth in most of the profiles which was due to the dependence of total sulphur on organic carbon, salt concentration and texture.

Total sulphur status in some soils of Varanasi region of Eastern Uttar Pradesh varied from 62.44 to 216.63 ppm (Tiwari and Pandey, 1990). In some representative soils of Himachal Pradesh, Tripathi and Karan Singh (1992) observed that total sulphur content of some surface horizons of various profiles ranged from 160.0 to 325.0 ppm. Its content decreased with soil depth in all the soil profiles, which was attributed to the decrease in organic matter content down the profiles.

Surendra Singh et al. (1993) examined one hundred eight surface soil samples (0-0.15m) belong to the great groups Hapludalf and Haplustalf in Ranchi, Chotanagpur and reported that the total sulphur content in soils had a wide variation ranging from 212 to 1841 mg per kg.

Hari Ram et al. (1993) found that the total sulphur content in rice growing soils collected from 22 fields in districts of Kanpur, Aligarth and Mathura of Uttar Pradesh ranged from 100 to 179 mg per kg with mean values of 153 and 148 mg per kg for surface and sub-surface, respectively.

Total sulphur content in some Ranchi soils of Chotanagpur area had a wide variation ranging from 212 to 1841 ppm and its content was found to decrease with increase in depth of soil profiles, which was reported to be due to its relation with organic carbon content of soils (Surendra Singh et al., 1993).

Kher and Singh (1993) reported that total sulphur content was in the range of 139 to 226 ppm with an average value of 183 ppm. The total sulphur content in soils of Kanpur district of Uttar Pradesh varied form 95.7 to 143.6 ppm with a mean of 118.8 ppm. The lowest amount of total sulphur in Vertic Ustochrepts was due to their low content of organic matter.

Dharkanath et al. (1995) observed that the total sulphur content in some important series of Vertisols of Maharashtra state varied from 125 to 2525 ppm with an average of 1788 ppm and its content was higher in surface horizons and decreased with increase in soil depth.

Sridhara Adiga and Ananthanarayana (1996) investigated vertical distribution of different forms of sulphur in twelve base unsaturated rice fallow profiles in Karnataka. Total sulphur decreased as the depth of the profiles increased with the first two layers of the profiles containing maximum amount. The decrease in total sulphur with increase in depth is mainly due to the fact that most of the sulphur present in red and lateritic is primarily organic in nature.

Bhogal et al. (1996) found that the total sulphur in calciorthents of North Bihar decreased with depth and ranged from 75 to 450 mg per kg. However, they observed higher values of total sulphur at lower depths.

Sharma and Gangawar (1997) studied the distribution of different forms of sulphur and their relationship with some soil properties in Alfisols, Inceptisols and Mollisols from Uttar Pradesh. Total sulphur content ranged from 250 to 833, 167 to 917 and 250 to 1000 mg per kg in Alfisols, Inceptisols and Mollisols, respectively. The highest average values of total sulphur were maximum in Mollisols followed by Alfisols and Inceptisols. This might be because of the Mollic epipedon present which is dark coloured and high in organic matter.

Sahoo et al. (1998) reported that total sulphur in some mangrove soils of the Sunderbans ranged from 462 to 1798 mg per kg. The higher value of total sulphur content in mangrove soils was mainly due to marine influence.

Singh et al. (2000) observed that total sulphur content in soils from thirty six soil series under varying physiographies and representing four soil orders viz., Entisols, Inceptisols, Alfisols and Mollisols of Nagaland, ranged from 600 to 1645 mg per kg with a mean value of 1217.5 mg per kg. The data revealed that total sulphur content seemed to be regulated by the bio-mass content in the soils, with acidity having some additive effect.

In a study on vertical distribution of sulphur fractions in two soils series belonging to Alfisols and Entisols of Jharkhand, Rakesh Kumar et al. (2002) noticed that total sulphur content ranged from 282 to 470 mg per kg with a mean value of 370 mg per kg in Entisols while it varied from 141 to 723 mg per kg with an average of 489 mg per kg in soils belonging to Alfisols.

Yifter Nega et al. (2001) reported that the total sulphur content in a laterite soil of sandy clay loam decreased in long-term fertilizer experiment plots with soil depth and varied from 233.4 to 704.1 ppm at surface and from 203.3 to 386.8 ppm at subsurface soil.

Studies conducted by Bhatnagar et al. (2003) on distribution of sulphur in twenty profiles of Vertisols (Kolaras and Pohri tehsils) and six of Inceptisols (Shivpuri tehsil) revealed that the total sulphur in surface soil of Inceptisols and Vertisols ranged from 790 to 813 and 798 to 987 mg per kg

with mean values of 800 and 892 mg per kg, respectively. Higher

amounts of total sulphur in surface than in sub-surface soils have resulted from its recycling over the years by plants and subsequent organic matter accumulation. Total sulphur decreased down the depth in both the orders and that was attributed to low carbon content at lower horizons.

In a study on vertical distribution of sulphur fractions in two soils series belonging to Alfisols and Entisols of Jharkhand, Rakesh Kumar et al. (2002) noticed that total sulphur content ranged from 282 to 470 mg per kg with a mean value of 370 mg per kg in Entisols while it varied from 141 to 723 mg per kg with an average of 489 mg per kg in soils belonging to Alfisols.

Hu et al. (2005) reported that 64 soils collected from ten provinces in China varied widely in the amount of total sulphur ranging from 64 to 831 mg per kg.

Jat and Yadav (2006) noticed that the total sulphur content in mustard growing Entisols of Jaipur district in Rajasthan ranged from 101.30 to 302.40 mg per kg with a mean value of 154.28 mg per kg.

2.2 RELATIONSHIP FORMS OF SOIL SULPHUR AND SOME SOIL PROPERTIES

2.2.1 Water soluble sulphur with some soil properties

In soils of five dominant series in Sangrur district in Punjab state, Aulakh and Dev (1976) reported that water soluble sulphur was significantly correlated with CaCO3 content and electrical conductivity of soils.

Lande et al. (1977) observed that water soluble sulphur in representative surface soil samples of Marathwada region was found to be positively and significantly correlated with clay content (r = 0.70**), organic carbon content (r = 0.75**) and pH (r = 0.61**) of soils.

In some intensively cultivated grape garden soils, Rajendra Prasad et al. (1983) observed a significant positive correlation between water soluble and total sulphur, which was consistent with the possibility that total and water soluble sulphur were derived from the external supply and hence associated with each other. Water soluble sulphur was also positively and significantly correlated with sulphate sulphur in these soils.

Sharma et al. (1986) in their study on status of sulphur in relation to soil properties in some important soils of Himachal Pradesh concluded that various forms of sulphur were dependent mainly on the organic carbon content of soils.

Balanagoudar and Satyanarayana (1990b) found that water soluble sulphur was positively correlated with pH, EC, CaCO3, clay and non-sulphate sulphur content of soils of North Karnataka.

Tiwari and Pandey (1990) studied the inter-correlation between different forms of sulphur with each other in some soils of Varanasi region of Uttar Pradesh. Results of the study revealed a significant positive correlation between water soluble sulphur and all other forms of sulphur except non-sulphate sulphur.

Kher and Singh (1993) showed that water soluble sulphur was found to be negatively correlated with pH and CaCO3 content whereas, it was significantly and positively correlated with organic carbon and clay content in some mustard growing soils of North Kashmir.

Hari Ram et al. (1993) noticed that water soluble sulphur significantly correlated with organic carbon, silt and clay contents in rice growing soils of Uttar Pradesh. Similar observations were also made by Dwivedi et al. (1983).

2.2.2 Sulphate sulphur with some soil properties

Rajendra Prasad et al. (1983) investigated the sulphur status of some intensively cultivated grape garden soils and observed that sulphate sulphur content showed significant correlation with total sulphur. No association was evident between sulphur forms and soil properties due to the fact that soil properties mostly affect the distribution of native forms rather than applied sulphur, except in case of trials conducted for a long period. Sulphate sulphur was found to have no consistent relation with organic carbon, pH and clay content in some soils of West Bengal (Dolui and Saha, 1983).

Cheema and Arora (1984) observed that available sulphate in some soils under groundnut-wheat cropping system was positively and significantly related with organic carbon but negatively with pH of soils. The increase in pH caused a decrease in anion exchange sites on the exchange complex and there was negligible adsorption of sulphate sulphur on the clay when the pH values were above 6.5. A negative correlation between sulphate sulphur with pH and a positive correlation between the former with organic carbon was also observed by Kher and Singh (1993).

A positive and significant correlation was observed between soluble sulphate sulphur and clay content of soil samples of Orissa (Misra et al. (1990). Arora and Takkar (1988) observed that, among the soil factors, salt content, organic carbon, silt and clay contents were significantly and positively related with available sulphur in some Inceptisols and Entisols.

Pandey et al. (1989) stated that organic carbon, EC, silt + clay contents showed significant positive correlation with sulphate sulphur whereas latter was significantly and negatively correlated with soil pH, CaCO3 and sand content.

Balanagoudar and Satyanarayana (1990b) reported a positive and significant correlation between sulphate sulphur and pH, EC, CaCO3 and clay contents in soils of North Karnataka. It was stated that sulphur supplying power of soil depended on relevant soil properties and an appreciable amount of sulphate sulphur was occluded to CaCO3 and adsorbed on clay fraction.

In some soils of Varanasi region of Eastern Uttar Pradesh, Tiwari and Pandey (1990) noticed positive correalation between organic carbon status and sulphate sulphur, which was attributed to the fact that (1) organic matter of soil holds the soluble forms complexed with water soluble fractions present in them and (2) most of sulphur present in soils was in organic matter. But, the amount of sulphate sulphur in these soils was negatively related with pH of soils which was due to the degree of H

+ and OH

- ions present on soil micelle where the

former being positively charged which attract SO42-

ions and the negatively charged OH- ions

repel SO42-

ions. An inter correlation study between different forms of sulphur with each other in these soils revealed that sulphate sulphur was significantly and positively related with all other forms of sulphur except non-sulphate sulphur.

Mohinder Singh et al. (1990) reported that 0.15 per cent CaCl2 extractable sulphate sulphur was positively related with total sulphur (r = 0.32**) in some soils of Haryana.

Mahto et al. (1992) observed a positive and significant correlation between 0.15 per cent CaCl2 extractable available sulphur and salt content.

Tripathi and Karan Singh (1992) noticed that sulphate sulphur and organic carbon were significantly and positively correlated (r = 0.68**) in some representative soil groups of Himachal Pradesh. However, this form of sulphur was negatively correlated with clay content of soils thereby indicating greater retention of sulphate sulphur by clay fraction in the soils. An inter-relationship study among different fractions of sulphur in these soils indicated that the relationship between sulphate sulphur and non-sulphate sulphur were rather marginal.

Ghosh and Sarkar (1994) stated that available sulphur content of some soils of Chotanagpur region was found to be negatively correlated with organic carbon content and cation exchange capacity.

The sulphate sulphur extracted by CaCl2 significantly correlated with total sulphur, pH and organic carbon contents in some soils of Andaman and Nicobar islands. It was likely that plant available sulphur might have derived from soil organic sulphur which evidenced by significant correlation between organic sulphur and CaCl2 extractable sulphur (Ganeshmurthy et al., 1995).

Jha et al. (1995) observed significant positive correlation of available sulphur with organic carbon, clay, and silt contents and negative correlation with the sand content. Electrolyte conductivity was significantly and positively correlated with sulphate sulphur in some calciorthents of North Bihar. This form of sulphur significantly correlated with all the other forms of sulphur (Bhogal et al. (1996).

Correlation studies conducted by Biju Joseph et al. (1999) in rice growing Alfisols and Inceptisols of the high rainfall zone of Tamil Nadu revealed that 0.15 CaCl2 extractable sulphur had negative and significant correlation with pH (r = -0.428**), EC (r = - 0.946**), available P (r = - 0.685**), available K (r = - 0.559**) exchangeable Ca (r = - 0.905**), exchangeable Mg (r = - 0.969**) and silt (r = - 0.433).

Singh et al. (2000) observed that sulphate (0.15 % CaCl2 extractable) sulphur content in soils from thirty six soil series under varying physiographies and representing four soil orders viz., Entisols, Inceptisols, Alfisols and Mollisols, had a high significant positive correlation (r = 0.637) with organic carbon content and negative one with pH (r = - 0.359) indicating organic carbon and pH regulate markedly the content of sulphate sulphur.

In a study on vertical distribution of sulphur fractions in two soils series belonging to Alfisols and Entisols of Jharkhand, Rakesh Kumar et al. (2002) noticed 0.15 per cent CaCl2 extractable sulphur content of Entisols showed positive and significant correlation with organic carbon (r = 0.759*), CEC (r = 0.749*), total nitrogen (r = 0.778*) and clay content (r = 0.633*). A significant and negative correlations were found with pH (r = - 0.802*) and silt (r = - 0.745*) while in Alfisols, available sulphur was positively and significantly correlated with total nitrogen (r = 0.711**) only.

Jat and Yadav (2006) indicated that sulphate sulphur in mustard growing Entisols of Jaipur district in Rajasthan showed a significant positive correlation with organic carbon (r = 0.502**), clay (r = 0.43**) and silt (r = 0.289**) but pH and EC showed non-significant positive relation with it.

2.2.3 Organic sulphur with some soil properties

As reported by Singh et al. (1976) and Bhan and Tripathi (1973), organic sulphur was positively and significantly correlated with organic carbon.

Lande et al. (1977) reported a significant and positive correlation of organic sulphur with clay content (r = 0.64**), organic carbon content (r = 0.70**) and pH (r = 0.63**) of some Marathwada soils.

Dolui and Saha (1983) concluded that organic sulphur was found to be significantly correlated with organic carbon (r = 0.69**) and sulphate sulphur (0.88**) but not with pH, clay content and non-sulphate sulphur.

Badiger et al. (1985) observed a close relationship (r = 0.69**) between organic sulphur and total sulphur in some soils of Karnataka.

In some benchmark soils of Punjab, Arora et al. (1988) showed that organic sulphur was positively correlated with EC, organic matter and silt + clay but negatively with pH of soil.

Pandey et al. (1989) noticed that organic sulphur had significant positive correlation with organic carbon, electrical conductivity and silt + clay contents whereas its content was negatively correlated with soil pH, CaCO3 and sand contents.

Balanagoudar and Satyanarayana (1990b) observed that organic sulphur content was significantly correlated with organic carbon (r = 0.79*) in some soils of North Karnataka.

Mohinder Singh et al. (1990) stated that organic sulphur content in soils under different agro-climatic regions of Haryana correlated positively with clay (r = 0.33*) and silt (r = 0.37*) and negatively with sand (r = 0.38*) and pH (r = 0.55**) of soils.

Similarly, Tiwari and Pandey (1990) observed a significant but negative correlation between pH and organic sulphur content on some soils of Varanasi region of Eastern Uttar Pradesh.

Tripathi and Karan Singh (1992) showed that there was significant and positive relationship between organic sulphur and organic carbon (r = 0.78**) in some representative soils of Arunachal Pradesh. Since organic carbon and total nitrogen are intimately related, the rates of mineralization and accumulation of nitrogen and sulphur in soils occur in fairly constant ratio. Organic sulphur content showed positive significant correlation with sulphate sulphur and a negative but non-significant relation with non-sulphate sulphur.

In mustard growing soils of North Kashmir, Kher and Singh, (1993) indicated that the correlations of organic sulphur with soil clay and organic carbon were significant and positive whereas its relationship with pH and CaCO3 contents were negative .

Organic sulphur had significant and positive correlation with silt + clay content and organic carbon contents in some calciorthents of North Bihar. This form of sulphur was significantly and positively correlated with all the other forms indicating the existence of dynamic equilibrium among them (Bhogal et al., 1996).

Singh et al. (2000) observed that organic sulphur content in soils from thirty six soil series under varying physiographies and representing four soil orders viz., Entisols, Inceptisols, Alfisols and Mollisols, had a high significant positive correlation (r = 0.956) with organic carbon content, which might be due to its intimate relation with organic carbon.

In a study on vertical distribution of sulphur fractions in two soils series belonging to Alfisols and Entisols of Jharkhand, Rakesh Kumar et al. (2002) showed highly significant positive correlation between organic sulphur and organic carbon (r = 0.833** in Entisols and r = 0.698* in Alfisols).

Jat and Yadav (2006) indicated that organic sulphur in mustard growing Entisols of Jaipur district in Rajasthan showed a significant positive correlation with organic carbon (r = 0.795**), clay (r = 0.485**) and silt (r = 0.312**). The combined effect of pH, EC, OC, sand, silt and clay content of soil accounted for 66.64 per cent variation.

2.2.4 Non-sulphate sulphur with some soil properties

Dolui and Saha (1983) observed that non-sulphate sulphur had no consistant relation with organic carbon, pH and clay content in some soils of West Bengal.

In some soils of Varanasi region of Eastern Uttar Pradesh, Tiwari and Pandey (1990) noticed that non-sulphate sulphur was not affected by ionic concentration of soil hence showed non-significant relation with pH.

Tripathi and Karan Singh (1992) showed that the non-sulphate sulphur content in some representative soils of Himachal Pradesh had a non-significant relation with organic carbon and clay fraction, thereby indicating little influence of these soil characters on the amount and distribution of the form of sulphur. This form of sulphur was positively and significantly related with pH which was attributed to the presence of insoluble sulphur compounds accumulated under the influence of high pH and CaCO3 contents.

Kher and Singh (1993) reported that non-sulphate sulphur showed significant positive correlation with organic carbon in some mustard growing soils of North Kashmir.

Singh et al. (2000) observed that non-sulphate sulphur content in soils from thirty six soil series under varying physiographies and representing four soil orders viz., Entisols, Inceptisols, Alfisols and Mollisols, had a highly positive and significant correlation with organic carbon (r = 0.805), indicating the influence of organic matter on the amount of this form of sulphur. The high content of non-sulphate sulphur in all these soils might be due to the dominance of insoluble sulphur compounds of iron and alminium formed under prevailing high rainfall conditions.

Jat and Yadav (2006) reported that non-sulphate sulphur in mustard growing Entisols of Jaipur district in Rajasthan showed a significant positive correlation with organic carbon (r = 0.708**), clay (r = 0.463**) and silt (r = 0.224*).

2.2.5 Total sulphur with some soil properties

Lande et al. (1977) reported that there was a significant and positive correlation of total sulphur with clay content (r = 0.70**), organic carbon (r = 0.80**) and pH (r = 0.60**) in some Marathwada soils.

Total sulphur had positive and significant correlation with organic carbon, organic sulphur and non-sulphate sulphur. Soil pH did not significantly correlate with total sulphur (Dolui and Saha, 1983).

Dolui and Das (1988) found that the total sulphur content in selected soil series of terai and teesta alluvial regions of West Bengal had positive and significant correlation with organic sulphur ( r = 0.84**) which was due to the fact that most of the sulphur occurred in organic form.

Arora et al. (1988) showed that total sulphur in some benchmark soils of Punjab was positively correlated with EC, organic matter and clay + silt.

Total sulphur had significant positive relationship with all other forms of sulphur in some alluvial soils as observed by Pandey et al. (1989). Among the relationships worked out between different forms of sulphur and soil properties, soil reaction, CaCO3, electrical conductivity and sand contents showed significant negative correlation with total sulphur whereas, significant positive correlations were recorded by organic carbon and silt + clay with total sulphur.

Misra et al. (1990) indicated that the total sulphur content in some soils of Orissa, had significant and positive correlations with clay content and organic carbon content of the soils. The correlation of total sulphur with clay was significant only in the red and laterite group, that with organic carbon was significant with all the soil groups viz., red, laterite, alluvial, black and coastal saline soils.

Mohinder Singh et al. (1990) observed significant positive correlations of total sulphur with organic carbon (r = 0.52**), silt (0.41**) and clay (r = 0.50**) in some soils of Haryana. In saline soil, total sulphur showed highly significant correlation (r = 0.88**) with electrical conductivity of soils which was expected since sulphate is one of the major constituents of soluble salts.

Tiwari and Pandey (1990) reported that there was a positive and significant correlation with all other forms of sulphur barring non-sulphate sulphur in some soils of Varanasi region of Eastern Uttar Pradesh. The values of inter-correlation between different forms of sulphur with each other in these soils revealed that total sulphur showed positive correlation with all other forms of sulphur except non-sulphate sulphur.

Tripathi and Karan Singh (1992) showed that total sulphur content of some representative soil groups of Himachal Pradesh had significant correlation with organic carbon (r = 0.87**) but it was non significantly related to clay and pH. An interrelationship among different forms of sulphur in these soils indicated that total sulphur had significant correlation with organic sulphur and sulphate sulphur.

A positive and significant correlation was observed between total sulphur, salt content and silt whereas its content was negatively correlated with sand in some soils of Chotanagpur area of Bihar (Mahto et al., 1992). A decrease in total sulphur with increase in sand particle was attributed to less organic carbon accumulation and high leaching.

In a study conducted on the status and distribution of sulphur in some pedons of Vertisols, Padmaja et al. (1993) found that none of the forms of sulphur had any significant correlations with pH, EC, CaCO3, clay and organic carbon contents of the soils.

Singh et al. (1993) observed a significant correlation of total sulphur and organic carbon contents in soils of Chotanagpur.

Kher and Singh (1993) indicated that total sulphur content of some mustard growing soils of Kashmir had significant and positive correlation with organic carbon and clay content whereas its content was negatively correlated with pH and CaCO3. These results suggested that total sulphur increases with the increase in organic carbon and clay whereas increase in pH and CaCO3 would result in a decrease of total sulphur. Similarly, Tiwari and Pandey (1990) also observed a significant but negative correlation between total sulphur and pH in some soils of Varanasi region of Eastern Uttar Pradesh.

Surendra Singh et al. (1993) observed that total sulphur had significant positive relationship with organic carbon (r = 0.683**) and clay (r = 0.521**) in some Ranchi soils of Chotanagpur area. Similar results were also reported by Singh and Sharma (1983) in some citrus growing soils of Agra region.

Bhogal et al. (1996) observed that total sulphur was significantly and positively correlated with electrical conductivity, organic carbon and silt + clay contents in some calciorthents of North Bihar. All the forms of sulphur were positively and significantly correlated indicating the existence of dynamic equilibrium among them. They concluded that organic carbon and electrical conductivity were the dominant soil properties which explained maximum per cent variation in different forms of sulphur.

Singh et al. (2000) observed that total sulphur content in soils from thirty six soil series under varying physiographies and representing four soil orders viz., Entisols, Inceptisols, Alfisols and Mollisols, had significant positive correlation (r = 0.847) with organic carbon and significant negative correlation (r = - 0.308) with pH, indicating that total sulphur increases with an increase in organic carbon content whereas an increase in pH would result in a decrease of total sulphur. Pandey et al. (1989) also reported that total sulphur to be a function of soil organic matter and acidity.

In a study on vertical distribution of sulphur fractions in two soils series belonging to Alfisols and Entisols of Jharkhand, Rakesh Kumar et al. (2002) noticed that total sulphur content of Entisols showed negative and significant correlation with silt content (r = 0.675*). It showed positive and significant correlation with organic carbon (r = 0.821**), total nitrogen (r = 0.840**) and Bray P (r = 0.915**). Total sulphur content of Alfisols showed positive and significant correlation with organic carbon (r = 0.695*), total nitrogen (r = 0.921**) and Bray P (r = 0.636*).

2.3 ROLE OF SULPHUR IN PLANTS

Sulphur performs many important functions in the plant. It is best known for its role in the synthesis of proteins, oils and vitamins. It is a constituent of three amino acids which are methionine (21% S), cysteine (26% S) and cystine (27% S). Cystine is formed by the oxidation of two molecules of cysteine (Naresh Prasad and Jangra (2007). Sulphur is also a constituent of S-glycosides, co-enzyme A, vitamins biotine and thiamine and also of iron-sulphur proteins called ferrodoxines. Volatile S-compounds, mainly di or poly sulphides are the source of pungency in onions. Sulphur is also known to promote nodulation in legumes thereby promoting N-fixation. Sulphur is associated with the production of crops of superior nutritional and market quality.

2.3.1 Effect of sulphur on growth and growth parameters

Ahmed et al. (1989) conducted a greenhouse experiment to investigate the effect of nitrogen and residual sulphur on growth and yield of rice. The highest values of plant height and number of tillers per pot were observed with the treatment receiving 120 ppm N with 60 ppm S applied as gypsum at previous monsoon season.

Mandhata Singh et al. (1993) observed that the highest plant height of rice (cv. Mahsuri) was recorded with the application of 60 kg of sulphur per ha as elemental sulphur at Varanasi. The plant height was found to be 24.6, 25.2 and 26.1 per cent higher over control treatment at tillering, panicle initiation and at harvesting stages respectively. Application of sulphur through pyrite showed the similar results.

Ram et al. (1999) reported that application of sulphur at 90 kg per ha in rice, grown under reclaimed salt affected soil in Kanpur, gave the highest grain and straw yields of 3.95 and 7.26 t per ha, respectively. The yields were 37.63 and 50 per cent higher over control for grain and straw respectively. These doses of sulphur applied through pyrite and gypsum produced significantly higher yield than 30 kg S per ha. Sulphur use efficiency was greater with gypsum than pyrites irrespective of their level of application.

Sumathy et al. (1999) conducted an experiment in Tamil Nadu using three sources of sulphur (ammonium sulphate, gypsum and iron pyrite) and three levels (0, 20 and 40 kg S per ha) with and without green manure to study the effect of integrated use of green manure and sulphur sources on yield of rice. The results revealed that significant increase in plant height, number of tillers per hill and leaf area index with sulphur levels and the effect was maximum at 40 kg S per ha. Among the sulphur sources, iron pyrite recorded the higher growth of rice. The effect of sulphur sources and levels was more pronounced in the presence of green manure than in its absence.

Chandel et al. (2002) conducted an experiment to study the effect of sulphur applied to rice and mustard grown in sequence, on growth and yield of rice in Varanasi. Increasing sulphur levels in rice, applied as single superphosphate significantly improved growth attributes of tiller number, leaf number and dry matter production up to 45 kg per ha. However 45 and 30 kg sulphur was at par.

Bhuvaneswari et al. (2007) conducted a field experiment in wetland at Annamalai University to study the effect of farmyard manure (FYM) and four levels of sulphur applied through gypsum on the growth and yield of rice var. ADT 43. Results of the experiment revealed that application of 40 kg sulphur per ha in combination with FYM (12.5 tonnes per ha) significantly increased physiological characters of crop growth rate (CGR), relative growth rate (RGR), net assimilation rate (NAR), leaf area index (LAI) over the control. CGR, RGR, NAR and LAI were least which did not receive sulphur and FYM.

2.3.2 Effect of sulphur on yield and yield components

A series of experiments were conducted in lowland (flooded) rice throughout South Sulawesi, Indonesia using a range of sulphur sources and rates. In these experiments sulphur was applied as ammonium sulphate, potassium sulfate and gypsum and yields were measured from unfertilized, NP and NPS treatments at each of 28 sites. The magnitude of the responses ranged up to 278 per cent with an average grain yield response of 18.6 per cent over the 28 sites. The wide-spread nature of the response in soils derived from varying parent material and in different river basins suggested that some 60 to 70 per cent of agricultural areas of the province were deficient in sulphur. (Graeme et al. 1979a).

Graeme et al. (1979b) conducted field experiments at three sites in South Sulawesi, Indonesia to study the effect of sulphur source (gypsum, ammonium sulphate, elemental sulphur) and rate (0 to 80 kg sulphur per ha ) on grain production in flooded rice. Yield response to sulphur was recorded at all three sites and gypsum, ammonium sulphate and elemental sulphur were equally effective in increasing yield when applied at transplanting. Elemental sulphur applied 20 days before transplanting was less effective than elemental sulphur applied at transplanting.

Tiwari et al. (1983) conducted a green house experiment to study the effect of sulphur fertilization on rice in 24 soils of district Kanpur, widely varying in their available sulphur contents. In 12 of 24 soils, the increase in grain yield of rice by sulphur application was more than 10 per cent, the highest being 30 per cent. The grain yield increased from 42.8 g per pot to 47.6 g per pot with sulphur application.

Solo Samosir and Blair, (1983) conducted a pot experiment on a low fertility Paleudult soil in Australia to test the S-supplying capacity of ammonium sulphate, gypsum, elemental sulphur and sulphur coated urea applied 30 kg S per ha to flooded rice. At maturity, yield was not significantly different between the gypsum, elemental sulphur (100 per cent <60 mesh), and ammonium sulphate sources. The results confirmed the suitability of fine (100 per cent < 60 mesh) elemental sulphur as a sulphur source for rice, and showed that S from sulphur coated urea is not available to flooded rice at least in the first crop after application.

Chien et al. (1987) revealed that prilled urea-S melt was found to be less effective than powdered urea-S melt in terms of increasing rice grain yield at a rate of 20 mg per kg. Further, they found that prilled urea-S melt was approximately 61 per cent as effective as gypsum in increasing rice grain when incorporated into the soil at 20 mg S per kg.

Altaf Hossain et al. (1987) reported that application of Zn and S alone or in combination significantly increased the grain yield of ‘BR 4’ rice under both moist and submerged conditions in Bangladesh. Under the moist condition, an application of Zn by dipping the seedling roots in a 2% ZnO solution was found to be the most effective in increasing the yield. However, under submerged condition, combined application of ZnSO4 and gypsum gave the highest grain yield.

Ahmed et al. (1989) conducted a greenhouse experiment to investigate the effect of nitrogen and residual sulphur on growth and yield of rice. The highest values of filled grain per panicle, filled grain percentage, 1000 grain weight, grain yield, straw yield and grain: straw ratio were observed with the treatment receiving 120 ppm N with 60 ppm S applied as gypsum at previous monsoon season.

Arora et al. (1990) conducted a pot experiment using 35

S labeled gypsum at the rate of 25 and 50 mg S per kg in 22 soils of Ludhiana district. Maximum response of oat was obtained in Badowal sandy soil with application of 25 mg S per kg soil.

Raju et al. (1994) reported that sulphur application had marked beneficial effect on panicle production and rice yield on coastal alluvial soils of Andhra Pradesh. Addition of sulphur at the rate of 25 and kg per ha increased the grain yield of rice by 23.8 and 26.4 per cent respectively compared with no sulphur. The magnitude of response was higher at lower dose and each kg of sulphur applied to rice resulted in 28.6 kg rough rice at 25 kg sulphur per ha.

Clarson and Ramaswami (1992) reported that the highest grain yields and 1000 grain weight of rice (IR 50 and IR 62) were recorded when sulphur was applied at the rate of 37.5 kg per ha through ammonium sulphate on wetland of Tamil Nadu Agricultural University, Coimbatore.

Mandhata Singh et al. (1993) observed that application of 60 kg of sulphur per ha as elemental sulphur recorded the highest grain yield of 50 q per ha. The yield was 23.09 per cent higher over control. This was followed by treatment in which 60 kg of sulphur applied through pyrites (49.37 q ha

-1). The yield was 21.54 per cent higher over control. Similar to

grain, straw yield was also increased significantly with increase of sulphur dose from both sources. The straw yield increased by 28.71 and 24.69 per cent over control due to elemental sulphur and pyrites respectively.

Tripathi and Sharma (1994) reported that application of sulphur at 40 kg per ha gave significant higher seed yield (2.10 tonnes ha

-1) and oil yields (0.80 tonnes ha

-1) of Indian

mustard in Indian mustard-rice cropping sequence at Lakhaoti, Uttar Pradesh. The residual effect of sulphur at 80 kg per ha reflected in maximum grain yield (3.22 tonnes ha

-1) of

succeeding rice. Both the sources of sulphur (gypsum and pyrite) were equally effective in increasing the yield and yield and yield components of by Indian mustard and succeeding rice.

Made Dana et al. (1994) evaluated sulphur availability of rice in Indonesia from a range of P-S, N-S and S sources (gypsum, elemental sulphur, urea-S melt, sulfur coated urea, sulfur coated triple superphosphate, S-bentonite, and three sulfur coated triple superphosphate products with three different adhesives UNE1, UNE2 and UNE3) with two pot experiments (flooded and non-flooded). Highest grain yields in first crop obtained with gypsum, UNE1 and UNE3 under flooded conditions and gypsum, UNE1, UNE3, sulfur coated urea and elemental sulfur under non-flooded conditions. Yield in the second crop was generally inversely related to those in first crop. The fertilized treatment which resulted in the highest grain yield in the first crop produced the lowest grain yield in the second crop. The lower yield from gypsum treatment in second crop was most likely due to a higher oxidation rate of elemental sulfur from triple superphosphate-S products which lead to a higher S uptake in the first crop.

Patra et al. (1998) investigated the effect of sulphur application and five water management practices on rice yield in six different S-deficient wetland rice soils under green house condition. Under continuously flooded condition, rice plants showed characteristics S-

deficiency symptoms and produced lowest grain yield and dry matter. Application of fertilizer or soil drying for two weeks during active tillering or panicle initiation stage and reflooding increased crop yield by eliminating S-deficiency.

Sarkunan et al. (1998) conducted a pot experiment on rice under flooded condition on P and S deficient sandy loam soil (Typic Haplaquept) at Central Rice Research Institute, Cuttack, Orissa. Although sulphur addition at 25 mg per kg resulted in 9 per cent increase in grain yield, it was not significant. A marked increase in sulphur uptake by grain was observed at 25 mg S per kg in the absence of added P, while the combined application of 100 mg P and 50 mg S per kg depressed S uptake by grain. The results suggested a positive interaction between P and S up to 100 mg P and 25 mg S per kg rates and an adverse effect at higher levels for rice.

In a field experiment conducted in Tamil Nadu, Sumathy et al. (1999) revealed that significant increase in number of panicles per m

2, number of filled grains per panicle and grain

and straw yield with increasing S levels and the effect was maximum at 40 kg S per ha. Among the sulphur sources, iron pyrite recorded the higher yield of rice. Grain and straw yields were maximum when Sesbania aculeata was applied along with iron pyrite at 20 kg sulphur per ha and were comparable with those obtained with the application of 40 kg sulphur per ha as iron pyrite in the absence of green manure.

Khare et al. (1999) noticed that oil yield and dry matter production rainfed linseed significantly increased up to 20 kg sulphur per ha and further increase beyond that level had no significant increase in first year and even significant reduction was noted in the second year. Linseed dry matter production per m

2, capsules per plant, seeds per capsule and seed

yield per ha correspondently increased with sulphur application up to the highest tested level of 30 kg sulphur per ha.

Vishwakarma et al. (1999) evaluated the efficiency of sulphur sources viz., elemental sulphur, gypsum, and oxalic acid industry waste under different sulphur levels (0, 10, 20 and 40 kg sulphur ha

-1) in soybean. Results revealed that application of 10 kg sulphur per ha

significantly improved yield attributing characters viz., branches and pods per plant, seed index and seed yield per ha. The efficiency of all three sulphur sources was almost equal for soybean yield, but oxalic acid industry waste proved to be more economical.

Chandel et al. (2002) conducted an experiment to study the effect of sulphur applied to rice and mustard grown in sequence on growth and yield of rice in Varanasi. Increasing sulphur levels, as applied single superphosphate, in rice significantly improved yield and yield attributes of panicle length, grains per panicle and test weight up to 30 kg of sulphur per ha and it was statistically on par with 45 kg of sulphur per ha. Sulphur application at 45 and 30 kg per ha significantly increased rice yield over 15 kg sulphur per ha as well as control. However, sulphur levels 45 and 30 kg per ha were statistically at par.

Subbaiah et al. (2001) conducted muti-locational trials using different sulphur sources (single superphosphate, pyrite, gypsum, elemental sulphur and ammonium sulphate) on rice at Pusa and Patana (Bihar); Kharagpur (WB); and Balagarh (MP). Results of the experiments clearly indicated that continuous application of diammonium phosphate in conjunction with sulphur containing fertilizers improved grain yield in lowland ecosystem. On the basis of mean of two years data, maximum grain yield of 4.17 t per ha was recorded by the treatment receiving recommended NPK + 20 kg S per ha as pyrite, which was followed by the treatment receiving NPK + 20 kg S per ha as elemental sulphur.

Sengupta et al. (2001) studied the effect of sulphur-containing fertilizers on productivity of rainfed greengram on a sandy-loam Gangatic alluvial soil of West Bengal. Application of sulphur through different sources (single superphosphate, potassium sulphate, elemental sulphur) increased the grain yield by 6.1 to 18.0 per cent over the fertilized control treatment (without sulphur). The grain yield was maximum in the treatment receiving N, P and K (P through single superphosphate) indicating that the best yield was obtained in the treatment where single superphosphate was applied.

Jagvir Singh and Kairon (2001) found that seed yields of irrigated cotton and sunflower grown in two year rotation in a sandy loam Inceptisol at Sirsa, Haryana, increased by 23.5 and 16.5 per cent respectively with 30 kg sulphur per ha over the control.

Pratima Sinha et al. (2001) found that low sulphur affected the maize reproductive yield more pronouncedly than the vegetative yield which was obvious in latent deficiency of sulphur where the reduction in economic yield was 36 per cent of that obtained at supra-normal sulphur supply and the depression in total biomass was only 17 per cent suggesting that the involvement of sulphur is more in the formation of economic yield.

Abraham (2001) concluded that application of 20 kg sulphur per ha in 3 splits (10 kg as basal, 5 kg 30 days after sowing and 5 kg 42 days after sowing) could enhance the yield characteristics, seed and oil yields of Indian mustard.

Sharma et al. (2002) found that onion bulb yield increased significantly with each successive increase in dose of sulphur through gypsum up to 30 kg per ha in heavy and 45 kg per ha in light textured soil in soils of Jammu districts. The increase in bulb yield with the application of 15 and 30 kg sulphur per ha were 8.44 and 14.66 over control in heavy textured soil whereas in light textured soil the values were 8.30 and 15.20 per cent with the application of sulphur at the rate of 15 and 30 kg of sulphur per ha respectively.

Reddi Ramu and Maheswara Reddy (2003) revealed that application of sulphur at the rate of 20, 30, and 40 kg per ha along with 100 kg N resulted in 20.5, 21.9 and 23.6 per cent higher seed yield of sunflower over 100 kg N alone.

Misra (2003) stated that the seed yield and stover yield of mustard grown on Udic Haplustepts at Fertilizer Research Station, Kanpur, increased in the linear order up to 40 kg sulphur per ha.

Thomas et al. (2003) conducted field experiments in UK to investigate the effect of sulphur application on yield of sugar beet. Application of sulphur at the rate of 25 kg per ha resulted in a 25 per cent increase in root yield together with significant increase in root and shoot dry matter accumulation.

Kubsad and Mallapur (2003) mentioned that safflower responded significantly up to 30 kg S per ha. Among the sulphur sources, single superphosphate was found superior to ammonium sulphate and gypsum but comparable to elemental sulphur. The interaction effect of source and level of sulphur indicated the highest yield of safflower at 30 kg S per ha applied through single super phosphate.

Dewal and Pareek (2004) reported that successive increase in sulphur levels up to 40 kg per ha significantly improved effective tillers, grains per spike, spike length and seed, straw and biological yields of wheat.

Sankaran et al. (2005) noticed that the effect of sulphur application through single superphosphate at 45 kg per ha resulted a significant increase of 9.6 per cent onion yield over control in a field trial at Coimbatore and it was at par with 30 kg per ha level. The application of sulphur at 45 kg per ha registered a maximum yield of 12.5 tonnes per ha whereas the control plot recorded the lowest yield of 11.4 tonnes per ha.

Results emanated of three year study conducted in Bangladesh revealed that onion crops receiving 45 kg of sulphur along with blanket dose of 120 kg N, 90 kg P2O5, 90 kg K2O and 5 kg Zn per ha significantly produced highest yield (Shamima Nasreen and Imamul Huq, 2005).

Jena et al. (2006) stated that application of gypsum at the rate of 60 kg S per ha to groundnut-rice cropping system recorded highest cumulative grain yield. lowest pod yield of 9.0 q per ha was recorded in control whereas highest pod yield of 18.5 q per ha was obtained with the application of gypsum at the rate of 60 kg S per ha which was significantly different from all other treatments but was at par with the application of S-95 at the rate of 60 kg S per ha. Residual effect S application was evident up to 60 kg S per ha with S-95 and gypsum on

rice. The maximum rice grain yield was 39.0 q per ha with S-95 at the rate of 60 kg S per ha which was at par with gypsum at the rate of 60 kg S per ha over the control.

Sreedevi et al. (2006) conducted field experiments in Hyderabad during wet and dry seasons of 1997-98 to find out the effect of different rates of sulfur on yield with 6 different rice cultivars. Pooled analysis of data showed that application sulfur at the rate of 20 kg per ha for hybrids produced better yield, while for conventional high yielding varieties 40 kg per ha found to be superior.

Issa Piri and Sharma (2006) conducted a field experiment at the Indian Agricultural Research Institute, New Delhi, to study the effect of sulphur on yield attributes and yield of Indian mustard. Yield attributes, seed and straw yields, oil content and oil yield increased significantly with increasing level of sulphur up to highest level of 45 kg S per ha.

Vyas et al. (2006) conducted a field experiment at National Research Centre for Soybean, Indore under rain-fed conditions to investigate the productivity of soybean genotypes as influenced by nitrogen and sulphur nutrition. Results revealed that basal application of sulphur at the rate of 40 kg per ha increased the yield by 21.8 per cent over basal application of N at the rate of 20 kg per ha. Application of 20 kg N +40 kg S per ha as basal produced the maximum seed yield.

Aziz Qureshi and Lawande (2006) observed the response of onion to sulphur application for yield in S-deficient soils at Rajgurunagar in Maharashtra. Significantly improved total bulb yield due to sulphur application at the rate of 15-75 kg per ha along with recommended dose of NPK was observed.

Tiwari (2006) conducted a field experiment to study the direct effect of sulphur on plant cane and residual effect of sulphur (obtained from the plant cane) on ratoon canes at Sehore. The results indicated that the sugarcane responded significantly to cane yield and sugar yield up to 40 kg sulphur per ha.

Patel et al. (2007) studied effect of sulphur and micronutrients with and without farmyard manure on yield of kharif groundnut and their residual effect on succeeding wheat crop. Groundnut crop fertilized with 20 kg S per ha increased pod and haulm yields. Pooled data showed that application of sulphur at the rate of 20 kg per ha recorded 11.2 per cent higher pod and 8.1 per cent haulm yields of groundnut over control.

Bhuvaneswari et al. (2007) conducted a field experiment in wetland farms in Annamalai University to study the effect of farmyard manure (FYM) and four levels of sulphur applied through gypsum on the growth and yield of rice var. ADT 43. Results of the experiment revealed that the yield characters viz., number of panicles per m

2, number of filled

grains per panicle, 1000 grain weight, grain and straw yield increased with S levels and highest grain (5750 kg per ha) and straw (7300 kg per ha) yield was noticed with 40 kg S per ha plus FYM at the rate of 12.5 t per ha and decreased thereafter with further increase in sulphur level. The per cent increase over the control was 14.5 and 15.4 for grain and straw yield respectively.

Naw Mar Lar Oo et al. (2007) reported that the grain and straw yields of rice grown in a field experiment at IARI, Delhi, increased significantly with increasing S levels. The percentage increase in the grain yield of rice at application of 20, 40 and 60 kg S per ha over control was in the order of 6.5, 7.3 and 8.8 per cent, respectively. Application of 20 kg S per ha increased significantly the biological yield of rice over control but remained statistically on par with 40 kg S per ha. The maximum biological yield of rice (19.17 t per ha) was recorded with 60 kg S per ha and it was significantly superior to rest of the S treatments.

2.3.3 Effect of sulphur on quality parameters

Sulphur is an important constituent of proteins, the building material. This also helps synthesis of carbohydrates and utilization of other nutrients particularly N and P to develop the plant parts. In several plant species sulphur deficiency is known to decrease chlorophyll content of leaves and as a result indirectly affects photosynthesis. In cereals the quality of the

produce is lowered by sulphur deficiency as the major storage sulphur rich proteins, such as glutelin, are reduced and the proportion of zein protein (a low sulphur protein) increases in maize. The sulphur content of proteins influences nutritional quality of grains e.g. methionine, one of the sulphur containing amino acids in human nutrition and often a limiting factor, in diet is lowered and also a decrease in cysteine content in low sulphur cereal grains reduces the baking quality of flour.

Zhao et al. (1997) showed that sulphur fertilization significantly improved bread making quality of field grown wheat in U.K. with the loaf volumes of the same variety grown at different sites correlating better with the concentrations of grain sulphur than grain N. Sulphur also increased gel protein content of flour, but decreased its elastic strength. In contrast, application of sulphur fertilizers to oilseed rape led to increased glucosinolate concentrations in the seed which exceeded the limit for the meal to be used in animal feeds. The addition of sulphur fertilizer increased the glucosinolate concentration much more under sulphur deficient than under sulphur sufficient conditions.

Misra et al. (2002) found that sulphur addition increased the contents of the total protein and S-containing amino acids (methionine, cysteine and cystine) in mustard seeds. Among the fatty acids in mustard oil, oleic and linoleic acid contents increased while erucic acid decreased with increasing doses of sulphur indicating improvement in the quality of sulphur by reducing harmful effects of erucic acid mainly in the heart of human body.

Thomas et al. (2003) observed that application of sulphur to a low-sulphur site significantly increased the quality of the sugarbeet in terms of a reduction in the α-amino nitrogen concentration.

Tiwari (2006) conducted an experiment to study the response of sugarcane to direct and residual effect of sulphur in medium black soils of Madhya Pradesh. Application of 60 kg sulphur per ha gave significant higher quality of juice and N and K content in juice.

2.3.4 Effect of sulphur on nutrient uptake

Mandhata Singh et al. (1993) observed that the highest uptake of sulphur in rice (cv. Mahsuri) was recorded with the application of 60 kg of sulphur per ha through elemental sulphur at harvesting in Varanasi. The plant height was found to be 24.6, 25.2 and 26.1 per cent higher over control treatment at tillering, panicle initiation and at harvesting stages respectively. Application of sulphur through pyrite showed the similar results. Significant positive correlations between sulphur uptake and dry weight at tillering (r = 0.970), at panicle initiation (r = 0.973) and grain yield (r = 0.774) confirmed the view that sulphur uptake has significant and positively influenced on growth attributes as well as on yield.

Tripathi and Sharma (1994) reported that application of sulphur at 40 kg per ha gave significant higher uptake of nutrients (N, P, K, S, and Fe) maximum being (115.3, 17.16, 87.82, 35.48 and 1.16 kg per ha) N, P, K, S and Fe respectively under Indian mustard-rice cropping sequence at Lakhaoti, Uttar Pradesh. Both the sources of sulphur (gypsum and pyrite) were equally effective in increasing the uptake by Indian mustard and succeeding rice.

Sarkunan et al. (1998) conducted a pot experiment in rice under flooded condition on P and S deficient sandy loam soil (Typic Haplaquept) in Orissa. A marked increase in sulphur uptake by grain was observed at 25 mg S per kg in the absence of added P, while the combined application of 100 mg P and 50 mg S per kg depressed S uptake by grain suggesting a positive interaction between P and S up to 100mg P and 25 mg S per kg rates and adverse effect at higher levels for rice.

Ram et al. (1999) conducted experiment to study the effect of sulphur application to rice grown under reclaimed salt affected soil in Kanpur. The sulphur content as well as uptake of rice plant was found to increase significantly over control due to increasing levels of sulphur application at tillering, panicle initiation and at harvest. Maximum sulphur content and uptake were obtained at 90 kg S per ha.

Naw Mar Lar Oo et al. (2007) reported that a significant effect of sulphur application on N, P, K and S uptake in rice grown in a field experiment at IARI, Delhi.

2.4 TRANSFORMATION OF SULPHUR IN SOILS

Sulphur in soils undergoes biological and chemical processes, which drives the complicated transformation of different forms of sulphur in soil (mainly S°, SO4

2—S, microbial

biomass-S and organic-S) in the atmosphere, soil and plants. A great diversity of reactions is possible because sulphur occurs in various status of oxidation. This is indicated by the following oxidation numbers of sulphur in representative states: sulphate, +6; sulphite, +4; thiosulphate, +6 and -2; elemental S, 0; disulphide, -1; and sulphide, -2 (Robert, 1966).

Mineralization of sulphur is the conversion of organic sulphur to inorganic Sulphate. Under aerobic conditions, mineralized inorganic sulphur presents predominantly as sulphate-sulphur. However, under reduced or flooded conditions, mineralized sulphate-sulphur may be transformed into sulphide-sulphur and other inorganic sulphur forms such as elemental sulphur, thiosulphates, sulphites, etc. It can be expected that the behaviour of organic sulphur mineralization in flooded paddy soils might be greatly different from that in upland soils. However, little information is available on sulphur mineralization in flooded paddy soils.

Haque and Walmsley (1972) carried out an incubation study to examine the release of sulphur in West Indian soils and observed that sulphate sulphur was released constantly up to 20 days, after which some sulphate was immobilized and then the content became almost constant. Assimilation of sulphate sulphur by microorganisms was reported to be the reason for immobilization. The rate of mineralization decreased with time and sulphur was released up to 50 days in clay loam and sandy loam soils. An inconsistent pattern of sulphur mineralization was noticed which was probably due to variations in soil properties viz., pH, texture and organic matter.

In an incubation study, Haldar and Barthakur (1976) investigated the effect of different rates of lime, ammonium sulphate and single super phosphate on eleven representative soils collected from waterlogged rice fields of different agro-climatic regions of Assam. Lime significantly increased all the sulphide fractions except the acid soluble one. Superphosphate significantly increased water soluble and total sulphide fractions only. The ammonium sulphate significantly increased all the sulphide fractions in soils and the combined effect of lime, ammonium sulphate and superphosphate resulted in highest H2S and water soluble sulphide production in soils.

Mukhopadhyay and Mukhopadhyay (1980) investigated the effect of two moisture sequences with a short period of drying between them. Drying resulted in release of available sulphate sulphur in the soil previously incubated at 50 per cent of water holding capacity and the effect was more striking when starch was added, whereas, drying caused a decrease in the amount in the soil kept under waterlogged condition. A short period of drying did release sulphate sulphur in available form.

Yahya (1981) conducted studies to determine the comparative sulphur mineralizing capacity of selected Malaysian and Iowan soils. Results of the mineralization study indicated that more sulphur mineralized from Malaysian soils although their average contents of total sulphur were lower compared to Iowan soils. Results of the experiment further revealed that phosphate solution consistently extracted higher quantities of sulphate in comparison to chloride solution in Malaysian surface soils implying that a portion of the sulphate existed in adsorption form and adsorption of the sulphate in soils was found to be dependent on concentration of sulphate added and followed Langmuir adsorption isotherm.

A conceptual model proposed by McGill and Cole (1981) indicated that C and N are stabilized together and mineralized through biological mineralization whereas organic P and sulphate esters are stabilized independently of the main organic moiety and are mineralized through biochemical mineralization. Biological mineralization, defined as release of inorganic forms of N and S from organic materials during oxidation of C by soil organisms to provide energy, is driven by the search for energy. Biochemical mineralization, defined as release of inorganic ions of P and S from organic form through enzymatic catalysis external to cell

membrane, is strongly controlled by the supply of and need for the element released rather than the need for energy.

Sorption of sulphate by soils is reported to be influenced mostly by pH, clay minerals, hydrous oxides, organic matter, soil solution sulphate concentration, competing anions, soil depth and moisture.

Dev and Kumar (1982) indicated that a major part of added elemental sulphur was oxidized in 20 to 60 days, as compared to the sulphate forms in calcareous soils. In an incubation study undertaken to asses the sulphate sulphur production in some groundnut growing soils, Rajendra Prasad et al. (1984) showed that there was a greater release of sulphate by mineralization in the first week and sulphate was immobilized in the second week. Sulphate was again released in the third week and subsequently immobilized in the following week. In the absence of crop, the presence of high amount of readily available sulphate sulphur favoured its immobilization by microorganisms.

McLaren et al. (1985) investigated the mineralization and immobilization of sulphur in two soils by means of incubation experiments involving the labeling of soil with radioactive 35

S. The results obtained were consistent with the concept of a continuous, concurrent mineralization and immobilization cycle taking place involving relatively small proportions (3 - 6%) of the organic pool. HI-reducible forms of S appeared to be the predominant forms of organic sulphur involved in sulphur transformations.

In an incubation study using 35

S, Maynard et al. (1985) noticed that net mineralization was significantly greater in cropped soils compared with uncropped soils. The distribution of 35

S was significantly influenced by the addition of sulfate or cellulose or a combination of both and the presence of plants.

Reddy and Raju (1986) studied the effect of period of incubation on sulphur availability in red sandy loam soil and observed that the content of available sulphur increased with increasing sulphur levels. It was greater at 110 days than at 30 days, presumably because of mineralization of organic sulphur by micro organisms.

Harmesh Singh and Mishra (1986) studied the pattern of pyrite oxidation in a Mollisol and reported that oxidation rate decreased after one week and it progressed slowly during later period. After 70

th day, the rate of pyrite oxidation was around 1 ppm per day only. This

was conceivable in view of chemical oxidation of pyrite initially and inaccessibility of pyrite surfaces for microbial attack during later period due to deposition of ferric hydroxide formed by oxidation.

Soil pH is often positively correlated with sulphur oxidation rate. Furthermore, addition of CaCO3 has also been found to be stimulatory (Janzen and Bettany, 1987). The positive effect of high pH on sulphur oxidation rate may be related to the capacity of soil to buffer against inhibitory concentrations of sulfuric acid (Barrow, 1971).

Janzen and Bettany (1987) reported that reduced aeration is much more like to limit sulphur oxidation in fine textured soils than in coarse-textured soils. The fraction of pore space occupied by water at any potential is higher in fine textured soils than a coarse textured soil because of which oxygen will become limiting at a much lower water potential in a coarse soil.

In an incubation study carried out to understand the mineralization pattern of both native and added sulphur in black, red and acid soils, Clarson and Ramaswami (1990) observed an increase in mineralization of sulphur after two weeks interval, which was reduced after four weeks and then it attained a plateau. The increase of sulphate in the first stage was due to the presence of high moisture and organic carbon contents.

Shukla and Singh (1992) carried an incubation study to evaluate the effect of soil type on the oxidation of pyrites and observed that the oxidation of sulphur in different soils was in the sequence: Vertisol > Entisol > Alfisol. The higher oxidation in Vertisol was due to its higher fine particles, indicative of higher specific surface area, and in turn, greater chemical reaction.

Ghani et al. (1992) studied the sulphur mineralization and transformations in soils as influenced by addition of sulphur and reported that the addition of sulphur on its own reduced the amount of sulphur mineralization in two Inceptisols of New Zealand.

In a laboratory experiment, Bharat Singh and Srivastava (1994) studied the effect of organic matter and gypsum on electro-chemical changes in sodic soil under submerged condition. In saline sodic soil, waterlogged for 28 days, Eh reduced from +138 mv to -195 mv. Application of gypsum reduced Eh to -305 mv and it was further reduced to -370 mv due to incorporation of dhaincha (Sesbania acueata) alongwith gypsum. Simultaneously, soil pH declined from 10.1 to 9.7 due to waterlogging and further reduced to 9.3 with the application of gypsum alone or dhaincha and gypsum together.

Blair et al. (1994) studied transformation of sulphur in some Inceptisols wherein they observed that within two weeks of incubation, at least 40 per cent of the applied sulphate had been incorporated into hydroiodic acid reducible fraction. Subsequently, the sulphur in the newly formed hydroiodic acid reducible fraction was recycled with mean net release rates of 35

S being 26 per cent over the next 21 and 28 day periods, respectively.

Jagtap and Mohite (1994) conducted an incubation experiment to study the effects of levels of moisture, organic matter, CaCO3 and particle size on the release of sulphur from iron-pyrites in saline-sodic calcareous soil. The release of available sulphur form iron-pyrites treated saline sodic calcareous soil increased up to 30 days of incubation and thereafter decreased gradually. The soil pH decreased initially in 7 days of incubation in pyrite-treated soil and thereafter increased slightly.

Tan et al. (1994) reported that the pattern of sulphur mineralization during an open incubation study was a rapid release of sulphur in the first two weeks followed by a slightly slower almost linear rate of release for the remainder of incubation.

Wu et al. (1995) monitored the sulphur immobilization and microbial transformations in a clay loam soil using

35S labeled sulphate sulphur, glucose, N and plant residues (rape

leaves and straw). Over 102 day incubation, the immobilization of SO42-

-35

S, presented as percentage of that added, was inversely related to its addition rate. Addition of glucose and plant residues increased the immobilization of SO4

2--35

S. The extent to which SO42-

-35

S was immobilized was positively correlated with the C to S ratio of the amendment, irrespective of their origins (glucose and plant residues).

In an incubation study conducted using four soil types from Kerala, Palaniswami et al. (2000) reported that in three soils of kari (Tropic Fluvaquents), sandy (Oxic Quartzipsamments) and laterite (Oxic Haplustults), the cumulative SO4

2--S mineralization

increased up to 40 days after incubation, then reached a plateau after 60 days and subsequently, increased after 80 days of incubation. In case of red sandy loam (Arenic Paleustults), increase in SO4

2--S mineralization was noticed up to 40 days after incubation

followed by slight decline and subsequent, increase after 80 days of incubation.

Sulphate adsorption is an important property of soil that affects both sulphate availability and its leaching from soil. Organic matter is considered as one of the major factors of sulphate adsorption in soil. It has both positive and negative effects on sulphate adsorption. Das et al. (2002) observed an increase in sulphate adsorption, equilibrium buffering capacity (EBC), maximum buffering capacity (MBC) and decrease in supply parameter (SP) due to removal of organic matter.

Rakesh Kumar et al. (2003) reported that the sulphate adsorption-desorption by Alfisols of Dumka district (Jharkand) followed Langmuir and Freundlich isotherms. Adsorption maxima (b), bonding energy constant (K) and maximum buffering capacity (MBC) of the soils decreased with the increase in sulphur levels varying from 282 to 338 mg per kg, 0.0218 to 0.015 L per mg and 4.31 to 5.17 L per kg, respectively. The Freundlich constants (k and 1/n) also decreased with the increase in sulphur levels. Results further revealed high value of MBC in control as well as low sulphur levels. Desorption of sulphur varied from 82 to 86 per cent of the sorbed sulphur.

The availability of applied fertilizer sulphur is a function of its adsorption/desorption by the soil colloids, which exert a strong influence on fertilizer sulphur use efficiency (Rakesh Kumar et al., 2003).

In a field experiment, Bandyopadhyay et al. (2003) estimated 16 to 49 cm3 of H2S gas

per m2 escaped to the atmosphere from waterlogged saline rice field, the extent of which

depended on the level of soil salinity (EC 5-9 dS m-1

) and the dose of organic manure (Sesbania aculata) applied (0-5 Mg ha

-1). It was further estimated that under different field

treatments an amount of 229 to 429 ppm of water insoluble metallic sulphides accumulated in the rhizozphere soil of rice during a period of 54 days after transplanting. With the increase in the period of submergence the content of insoluble metallic sulphides in soil increased.

Sammi Reddy et al. (2003) studied the relation of sulphate sorption and desorption characteristics of four acid soils with soil properties. The sorption capacity of soils varied widely among the soils and differences in the sulphate sorption capacity of the soils were attributed to differences in their soil pH and concentrations of amorphous and crystalline Fe and Al, organic carbon and phosphate extractable sulphate pools.

Alves and Lavorenti (2004) reported that the composition of the clay fraction was more important than the absolute clay content for sulphate adsorption. Although correlation analyses showed that dithionite and ammonium oxalate extractable iron and aluminium were similarly related to sulphate adsorption, regression analyses indicated that the retention of sulphate as dependent mainly on Feº and Alº. Soil pH in 1 M NaF (pH NaF) was strongly related to sulphate adsorption and was influenced by soil properties very similar to sulphate adsorption. Thus, it can be used as an estimator of the sulphate adsorption capacity of weathered subsoils.

In order to identify sulphur supplying potential in paddy soils, Wei Zhou et al. (2005) conducted an incubation study to measure sulphur mineralization in four paddy soils under flooded conditions. For all of the four soils tested, the release of sulphate-sulphur and total inorganic sulphur mineralized was curvilinear with time, while those of other inorganic sulphur forms were linear with time. Examination of soils after incubation revealed that the bulk of the mineralized sulphur was mainly derived from the C-bonded sulphur and non-reducible organic sulphur pool, while the majority of mineralized sulphur under soil sulphur exhaustion by rice was derived from C-O-S (ester sulphate) pool.

Setia et al. (2005b) concluded that adsorption of sulphur was affected by NPK addition and continuous cultivation of soil without sulphur addition might result in the depletion of native sulphur.

Shahsavani et al. (2006) examined the effect of gypsum on the adsorption of sulphate in irrigated and non-irrigated soils. Almost all of the indigenous sulphate in a range of Golesthan and North Khorasan soils with moderate pH values (>6) was found to be present in the soil solution and as a consequence, susceptible to leaching. The adsorption of sulphate to the soils receiving no gypsum was greater with correlation coefficient of r = 0.91 at 0 kg sulphur per ha as compared to the soils received 40 kg per ha gypsum as fertilizer with the value of r = 0.88.

A sulphur mineralization study conducted using three soil groups (A-low, B-medium and C-high available S) collected from Pantnagar, Uttarakhand, by Navneet Pareek (2007) reported that the highest mineralizable S content was obtained at the 8

th week in all the three

groups of soils. Order of sulphur mineralization was found as group C > group B > group > A. The maximum cumulative S-mineralization was noticed in group B soil. Group C soil did not show a consistent pattern.

3. MATERIAL AND METHODS

The particulars regarding survey and characterization, incubation study and field experiments conducted, collection and preparation of soil and plant samples and analytical methods employed are presented in this chapter.

3.1 SURVEY AND CHARACTERIZATION

A survey was conducted to study the status and distribution of different forms of sulphur in intensive rice cropping areas of zone 3.

Survey and characterization of rice growing soils was carried out with respect to eight soil pedons representing intensive rice growing areas in Gangavati taluk of Tungabhadra Project (TBP) area coming under agro-climatic zone-3 of Karnataka. The details of soils and locations are presented in Table 1 and 2. The soil samples were collected depth-wise (0-15, 15-30 and 30-45cm) and analyzed for pH, EC, OC, CEC, clay content and sulphur fractions (sulphate-S, water soluble-S, organic-S, non-sulphate-S and total-S). Correlations between sulphur status and soil properties were worked out.

3.2 INCUBATION STUDY

An incubation study was conducted to study the transformation of different sources and levels of applied sulphur.

Surface soil (0-20cm) was collected from the same location of field experiment at Agricultural Research Station, Gangavati. Seven hundred grams of soil was placed in plastic containers and incubated (Plate 1). The bottom and sides were covered by polythene sheets and recommended dose of (150:75:75) N: P2O5: K2O kg per ha, FYM (10 t per ha), ZnSO4 (20 kg ha

-1) and sulphur with different sources (Factomphos and gypsum) and levels (25.0, 37.5

and 50 kg S ha-1

) were applied and mixed according to treatments. Soils were kept under submerged condition uniformly with one cm water level above the soil surface. Soil samples were drawn at different intervals (32, 54, 75 and 109 days after incubation) and analyzed for sulphur fractions (sulphate-S, water soluble-S, organic-S, non-sulphate-S and total-S).

3.3 FIELD EXPERIMENT

Field experiments were conducted at Agricultural Research Station, Gangavati, University of Agricultural Sciences, Dharwad during rabi/summer and kharif seasons in 2007 to investigate the changes in growth, yield, quality and nutrient uptake by rice and soil fertility as influenced by sulphur application under irrigated rice-rice cropping sequence. The details of materials used and methodology adopted during the course of investigation are presented as under.

3.3.1 Location of field experiment

The research station comes under Tungabhadra command area representing the irrigated transplanted rice belt and is situated in the Northern Dry Zone of Karnataka between 15° 15’ 40” North latitude and 76° 31’ 40” East longitude at an altitude of 419 m above mean sea level.

3.3.2 Climatic condition

The meteorological data recorded during the period of experimentation at ARS, Gangavati presented in Table 3. The mean rainfall varied from 3.5 to 405.75 mm throughout

Plate.1 Random assignment of treatments in incubation study

Table 1. Locations of soils collected for survey and characterization in farmers’ fields

Sl. No. Location (village)

1. Sangapur

2. Bandibasappa

3. Hosali

4. Ayodhya

5. Voddarahatti

6. Basavapatna

7. Doctor camp

8. Herur village

Table 2. Physico-chemical properties of soils of rice fields of different locations in rice growing

areas of North Karnataka


Depth (cm)

pHw (1:2.5)

EC (dSm

-1)

OC (g kg

-1))

Clay (%)

CEC [cmol (p

+)

kg-1

]

1.

Sangapur

0-15

15-30

30-45

6.33

7.62

8.01

0.11

0.12

0.16

5.32

5.04

3.82

44.7

52.3

54.6

37.97

39.94

43.19

2.

Bandibasappa

0-15

15-30

30-45

7.17

8.12

8.27

0.48

0.33

0.20

14.25

9.15

5.85

42.9

47.8

49.7

34.32

38.71

40.75

3.

Hosali

0-15

15-30

30-45

6.56

7.26

8.03

0.11

0.10

0.12

12.45

10.35

4.05

43.1

46.9

50.1

38.32

39.43

42.27

4.

Ayodhya

0-15

15-30

30-45

8.22

8.34

8.39

0.53

0.84

0.90

9.15

4.95

4.05

47.8

52.8

55.2

37.28

42.87

43.73

5.

Voddarahatti

0-15

15-30

30-45

8.01

8.32

8.47

0.51

0.17

0.19

9.45

6.45

4.05

44.6

49.9

50.9

40.14

42.42

43.01

6.

Basavapatna

0-15

15-30

30-45

7.91

8.00

8.12

0.20

0.16

0.12

14.55

9.75

7.35

41.1

49.4

51.6

39.18

41.33

43.19

7.

Doctor camp

0-15

15-30

30-45

8.56

9.42

9.65

0.29

0.29

0.13

13.95

9.75

4.65

40.1

45.3

47.3

30.55

37.38

38.53

8.

Herur

0-15

15-30

30-45

8.31

8.64

9.02

0.29

0.17

0.19

9.15

5.55

3.15

48.7

50.4

52.9

40.90

39.26

40.73

Table 3. Weather data of Agricultural Research Station, Gangavati, 2007

Rainfall (mm) Temperature ( ºC) Relative Humidity (%)

2007 8 a.m. 2 p.m. Month

Average (1979-2006)

2007 Average

(1990-2006) Maximum Minimum

Average (1990-2006)

2007 Average

(1990-2006) 2007

January 0.87 - 30.54 31.32 16.11 77.38 81.45 54.72 72.19

February 0.80 - 32.68 32.25 16.98 74.39 73.57 55.83 62.57

March 0.69 - 34.87 36.06 20.45 74.61 80.74 50.49 64.39

April 14.53 3.5 38.85 39.00 22.30 78.18 77.90 46.68 56.10

May 29.30 97.7 38.79 39.20 24.30 79.50 85.00 48.43 48.20

June 66.71 164.0 35.70 33.30 23.70 80.14 87.50 55.68 70.40

July 64.87 19.5 32.69 31.90 23.70 82.89 86.80 60.08 71.60

August 87.58 74.75 29.67 30.50 22.70 84.51 88.30 65.92 72.10

September 122.25 405.75 30.77 30.10 22.30 84.07 89.40 61.67 72.30

October 120.21 56.25 29.65 31.80 24.30 86.13 86.30 67.77 77.70

November 26.71 - 30.27 31.40 16.80 78.30 78.20 64.30 79.00

Total 534.52 821.45

Table 4. Physico-chemical properties of the soil used for incubation study and field

experiment

Sl. No. Particulars Value

I Particle size distribution (%)

Coarse sand

Fine sand

Silt

Clay

Textural class

19.19

7.28

5.45

68.07

clay

II Chemical properties

1.

2.

3.

4.

5.

6.

7.

8.

9.

10.

11.

12.

13.

14.

15.

16.

Soil pHw (1:2.5 soil water suspension)

Soil EC (1:2.5 soil water extract) (dSm-1

)

Organic carbon (g kg-1

)

Cation exchange capacity (cmol (p+) kg-1

)

Available nitrogen (kg ha-1

)

Available phosphorus (kg ha-1

)

Available potassium (kg ha-1

)

Sulphate sulphur (mg kg-1

)

Water soluble sulphur (mg kg-1

)

Organic sulphur (mg kg-1

)

Non-sulphate sulphur (mg kg-1

)

Total sulphur (mg kg-1

)

DTPA – extractable zinc (mg kg-1

)

DTPA – extractable copper (mg kg-1

)

DTPA – extractable iron (mg kg-1

)

DTPA – extractable manganese (mg kg-1

)

8.12

0.18

4.78

66.66

172.31

14.91

312.78

11.22

22.96

105.57

800.76

940.51

0.58

2.68

7.67

9.85

Table 5. Details of field experiment

Sl. No.

Particular Details

1. Title Studies on forms and transformation of sulphur and response of rice to sulphur application in rice-rice cropping sequence

2. Design Randomized Block Design

3. Treatments T1: RDF T2: RDF + FYM+ ZnSO4 T3: T2 + 25.0 kg sulphur/ha (Factomphos) T4: T2 + 37.5 kg sulphur/ha (Factomphos) T5: T2 + 50.0 kg sulphur/ha (Factomphos) T6: T2 + 25.0 kg sulphur/ha (Gypsum) T7: T2 + 37.5 kg sulphur/ha (Gypsum) T8: T2 + 50.0 kg sulphur/ha (Gypsum)

Recommended Dose of Fertilizers (150:75:75 kg N, P2O5 and K2O ha-

1) through DAP, MOP was common to all the treatments. FYM and

ZnSO4 were applied @ 10 tonnes per ha and 20 kg per ha, respectively. Half of N and full dose of P2O5 and K2O were applied as basal. The rest of the N amount was applied in two splits at active tillering and panicle initiation stages. The required N dose was adjusted using urea after consideration of the treatments where necessary. In the second season, RDF and FYM were applied according to treatments.

4. Replications Three

5. Plot size 6 m x 5 m (net plot 4 m x 5m and destructive sample plot 2 x 5m )

6. Spacing 20 cm x 10 cm

7. Variety IR 64 (one month old seedlings raised on nursery were transplanted in 1

st and 2

nd season)

8. Date of planting

1st Season 13 January 2007

2nd

Season 07 August 2007

9.

Date of harvest

1st Season 04 May 2007

2nd

Season 21 November 2007

Table 6. Methods of analysis of soil and plant samples

Sl No.

Particulars Author/s Remarks

A Soil sample

I. Physical properties

1. Particle size analysis Piper (2002) International pipette method

II. Chemical properties

1. Soil reaction Sparks (1996) pH meter (Systronic 331)

2. Electrical conductivity Sparks (1996) EC meter (Systronic 304)

3. Organic carbon Sparks (1996)

Walkely and Black’s wet oxidation method

4. Cation exchange capacity Jackson (1973) Sodium saturation method

III. Available micronutrients

1. DTPA extractable Fe, Mn, Zn and Cu

Lindsay and Norvell (1978)

Atomic absorption spectrophotometer

B. Plant sample

1. Nitrogen Black (1965) Micro Kjeldahl mrthod

2. Phosphorus Vanadomolybdate yellow colour method

Jackson (1973)

3. Potassium Flame photometric method

Jackson (1973)

4. Sulphur Turbidimetric method Jackson (1973)

5. Micronutrients AAS method Jackson (1973)

Table 7. Estimation of different soil sulphur fractions

Sl No.

Soil sulphur fraction Procedure followed

1. Sulphate sulphur Sulphate sulphur content was estimated by extracting the soil with 0.15 per cent CaCl2.2H2O solution as described by Williams and Steinbergs (1959). Ten g of soil was shaken with 25 ml of 0.15 per cent of CaCl2.2H2O solution for 30 minutes. Sulphur in the filtered extract was determined turbidimetrically (Chesnin and Yien, 1951).

2. Water soluble-sulphur Water soluble-sulphur content was estimated according to Williams and Steinbergs (1959). Five g soil was extracted with 33 ml of one per cent sodium chloride solution and 25 ml aliquot was evaporated to dryness with two ml of three per cent H2O2. It was then kept in hot air oven at 102 ºC for one hour to remove excess peroxide. After cooling, 25 ml distilled water was added to the residue and filtered to remove suspended matter. Sulphur in the extract was estimated turbidimetrically (Chesnin and Yien, 1951).

3. Organic sulphur Organic sulphur content in soils was estimated as described by Bardsley and Lancaster (1965). Ten g of soil was shaken with 50 ml of 1N HCl for 30 minutes and the suspension was filtered by washing with 1N Ca(OAc)2 followed by distilled water using suction. The oven dried 2.5 g of soil was mixed with 0.5 g of NaHCO3 and the mixture was ignited at 500 ºC in an electric furnace for three hours. After this, the soil was shaken for 30 minutes with 25 ml of NaHPO4 + 2 N Acetic acid extracting solution. Sulphur in the filtered extract was estimated turbidimetrically.

4. Total sulphur Total sulphur content was estimated by acid digestion method as per procedure given by Tabatabai (1982). Two g of finely ground soil was mixed with 3 ml of 69 per cent HNO3 and heated on steam bath. Then, 3 ml of 60 per cent HClO4 and 7 ml of H3PO4 were added and heated on sand bath at 190 - 210 ºC until white fumes were visible. Two ml of 37 per cent HCl was added after cooing and heated again until white fumes were visible. The digest was transferred quantitatively and volume was adjusted to 100 ml using 1N HCl. Sulphur in the filtered extract was estimated turbidimetrically.

5. Non-sulphate sulphur Non-sulphate sulphur content in soil was obtained by subtracting sulphate sulphur, water soluble-sulphur and organic sulphur from total sulphur.

the crop growth period. The mean maximum temperature varied from 30.1 to 39.20 °C and mean minimum temperature ranged from 16.11 to 24.3 °C.

3.3.3 Soil characters of the experimental site

The soil of the experimental site was medium black clay. Composite soil sample from 0-20 cm depth was collected from experimental site before start of the experiment and analyzed for physical and chemical characteristics by employing standard methods. The values obtained are presented in Table 4.

3.3.4 Experimental details

Details of the field experiment, methods of analysis of soil and plant samples, estimation of different sulphur fractions and plan of lay out are presented in Table 5 - 7 and Fig. 1.

3.3.5 Cultural operations

3.3.5.1 Field preparation

Seedlings of IR 64 rice variety were raised in the nursery bed. Experimental field was ploughed and puddled to bring the soil in to fine tilth. Bunds demarcating experimental plots were constructed according to plan of layout. The same rice variety of IR 64 was used as the succeeding crop.

3.3.5.2 Fertilizer application and transplanting

Farmyard manure, half of the dose of nitrogen and full dose of phosphorus and potassium were applied in the form of urea, diammonium phosphate and muriate of potash, respectively. Sulphur in the form of factomphos (20:20:0:15), gypsum and zinc sulphate were applied to the respective plots as per the treatments. One month old seedlings were transplanted in rows according to recommended spacing. Remaining half dose of nitrogen in the form of urea was given in two split applications at active tillering and panicle initiation stages. In the second season, only RDF and farmyard manure were applied according to treatments to study the residual effect of sulphur on succeeding crop.

3.3.6 Observations on growth, yield and quality parameters

Observations with respect to growth, yield and quality parameters were recorded as per the methods presented in Table 8.

3.3.5.4 Statistical analysis

The data collected in the course of investigation at different crop growth stages were subjected to statistical analysis as described by Gomez and Gomez (1984). The level of significance used in ‘F’ test was P = 0.05. Critical differences were calculated wherever ‘F’ test was found significant.

Table 8. Methods of recording observations of different growth, yield and quality parameters Sl

No. Parameter Procedure followed

Growth parameters Each plot (6 m x 5 m) was subdivided into two sub plots as net plot (4 x 5 m) for harvesting and the other (2 x 5m) for destructive sampling. Five hills per plot were uprooted randomly and observations at active tillering (AT, 32 days after transplanting), panicle initiation (PI, 54 days after transplanting), grain filling (GF, 75 days after transplanting) and at harvest were recorded.

1.1 Plant height (cm) Plant height was measured from the base to tip of the top most leaf at AT, PI, and GF stages and up to the tip of main panicle at maturity.

1.2 Number of tillers per hill

The number of tillers from five hills was counted and the average was worked out.

1.

1.3 Dry matter production

Plant samples were dried in shade for 24 hours. Then the samples were oven dried at 70°C to a constant weight and the oven dry weight was recorded and expressed in quintals per ha.

2. Yield and yield parameters

2.1 No. of panicles per m

2

The number of panicles were counted with the help of quadrat

2.2 Panicle length Panicle length from base to tip of the panicle collected from randomly selected plants in each plot was recorded. The mean value was calculated and expressed in centimeters

2.2 Number of grains per panicle

Ten panicles were selected randomly from five hills and then grains were separated and counted. The mean value was worked out and recorded as number of grains per panicle

2.3 1000 grain weight

One thousand grains were counted from randomly selected five hills from each treatment and their weight was recorded in grams.

2.4 Grain yield

The grains were separated by threshing separately from each net plot and dried under sunlight for three days. Later, winnowed and cleaned and then weight of the grains per net plot was recorded. From the net plot values, the grain yield per ha was computed and expressed in quintals per ha.

2.5 Straw yield Straw from each net plot was dried under sunlight for ten days and weight was recorded after complete drying and expressed in q per ha.

2.6 Harvest index The harvest index was worked out from grain and straw yields using the formula (Donald, 1962).

Economic yield

H I = ——————— × 100

Biological yield.

3. Quality parameters 3.1 Protein content (%)

The nitrogen content in rice kernel was estimated by modified micro kjeldahl’s method (Black, 1965). The protein content was calculated by multiplying the per cent nitrogen with a factor 6.25 (Tai and Young, 1974).

4. Biochemical parameters

4.1 Methionine content (mg/g)

Methionine content in rice kernel was determined by the procedure given by Sadasivam and Manickam (1992).

5. Economic analysis

The prices of the inputs that were prevailing at the time of their use were considered for working out the cost of cultivation.

5.1 Net returns

Net return per hectare was calculated by deducting cost of cultivation per hectare from gross income per hectare.

5.2 Benefit cost ratio

Gross returns (Rs. ha-1

)

—————————————— Benefit: Cost =

Total cost of cultivation (Rs. ha-1

)

Fig.1 Plan of layout of the field experiment

4. EXPERIMENTAL RESULTS

The results pertaining to the investigations are presented under the following heads.

4.1 Status and distribution of different forms of sulphur in intensive rice grown areas


4.3 Direct and residual effects of sulphur fertilization in rice-rice cropping sequence

4.1 STATUS AND DISTRIBUTION OF DIFFERENT FORMS OF SULPHUR IN INTENSIVE RICE GROWN AREAS

Eight locations from rice growing areas of North Karnataka representing rice-rice cropping sequence were taken up. Soil samples were collected depth-wise (0-15, 15-30 and 30-45cm) and analyzed for pH, EC, OC, CEC, clay content and sulphur fractions (sulphate-S, water soluble-S, organic-S, non-sulphate-S and total-S). Correlation coefficients were worked out between soil properties and sulphur status.

4.1.1 Soil reaction (pH)

pH of the soil varied from 6.33 to 9.65 in the surface soil of Sangapur and subsurface soil of Doctor Camp. An increase in pH with increase in depth was noticed in all soils studied.

4.1.2 Electrical conductivity (dSm-1)

The highest electrical conductivity value (0.90 dS m-1

) was recorded in case of subsurface layer of Ayodhya and the lowest was in surface soils of Sangapur and Hosali (0.11 dS m

-1). With the increase in depth, Sangapur and Ayodhya soils recorded an increase

in electrical conductivity value. A decrease was observed in Bandibasappa soil. There was no consistent trend in other soils.

4.1.3 Organic carbon (g kg-1)

The organic carbon content of the soils varied between 3.15 g per kg in subsurface soil of Herur to 14.55 g per kg in surface soil of Basavapatna. With increase in depth, decrease in organic carbon content was noticed in all the soils.

4.1.4 Clay content (%)

The clay fraction of the soils was in the range of 40.1 to 55.2 per cent and highest was in the subsurface soil of Ayodhya (55.2 %) and the lowest was in surface soil of Doctor camp (40.1 %).

4.1.5 Cation exchange capacity [cmol (p+) kg-1]

The maximum cation exchange capacity was recorded in the subsurface soil of Ayodhya (43.73 cmol (p

+) kg

-1) while the lowest (30.55 cmol (p

+) kg

-1) was noticed in surface

soil of Doctor Camp.

4.1.6 Distribution of different sulphur fractions in soils

Results on fractionation of soil sulphur and its distribution throughout different soil depths are presented in Table 9.

4.1.6.1 Sulphate sulphur (mg kg-1

)

The results indicate that the sulphate sulphur in soils varied from 12.05 to 49.51 mg per kg. The lowest value of sulphate sulphur was observed in subsurface layer of Sangapur

Table 9. Distribution of different sulphur fractions (mg kg

-1) in soils of rice fields of different

locations in rice growing areas of North Karnataka


Depth (cm)

SO4-S Water

soluble-S

Organic-S

Non-SO4-S

Total-S

1.

Sangapur

0-15

15-30

30-45

17.03

12.05

15.90

27.72

22.11

41.08

123.25

79.91

77.17

983.92

819.91

1305.82

1151.92

933.98

1439.98

2.

Bandibasappa

0-15

15-30

30-45

25.94

18.23

16.20

54.07

36.10

33.06

188.79

108.85

88.40

1642.53

1426.13

1914.35

1911.32

1589.30

2052.02

3.

Hosali

0-15

15-30

30-45

15.38

18.75

12.21

24.58

19.13

34.09

10 1.11

88.97

68.56

420.19

712.65

1066.40

561.27

839.50

1181.27

4.

Ayodhya

0-15

15-30

30-45

48.71

49.51

29.73

54.14

52.96

52.56

232.20

127.91

119.65

1595.27

2002.49

2170.58

1930.32

2232.87

2372.52

5.

Voddarahatti

0-15

15-30

30-45

24.31

19.03

15.79

47.34

31.34

33.63

228.02

158.21

111.30

1533.24

1448.51

1376.92

1832.91

1657.10

1537.65

6.

Basavapatna

0-15

15-30

30-45

25.58

13.69

16.67

55.01

21.48

38.58

253.54

168.05

117.28

1595.35

1699.87

2036.50

1929.48

1903.09

2209.03

7.

Doctor camp

0-15

15-30

30-45

22.34

29.24

35.26

46.83

51.44

56.60

269.27

219.08

121.43

1282.37

1534.73

1750.21

1620.80

1834.49

1963.50

8.

Herur

0-15

15-30

30-45

27.69

20.06

12.19

44.47

49.85

21.33

158.65

145.58

108.44

936.92

1354.96

1319.66

1167.73

1570.45

1461.62

whereas the highest was noticed in subsurface layer of Ayodhya. In general, a decrease in sulphate sulphur with increase in depth of the soil body was observed.

4.1.6.2 Water soluble sulphur (mg kg-1

)

Water soluble sulphur in soils ranged from 19.13 to 56.60 mg per kg. The highest value of water soluble sulphate was recorded in subsurface layer of Doctor Camp while the lowest was noticed in subsurface soil of Hosali. No definite trend was observed with respect to increase in soil depth.

4.1.6.3 Organic sulphur (mg kg-1

)

The results indicated that organic sulphur content clearly decreased with increase in soil depth. The highest organic sulphur content of 269.27 mg per kg was observed in surface soil of Doctor Camp whereas the lowest of 68.56 mg per kg was recorded in subsurface soil of Hosali.

4.1.6.4 Non-sulphate sulphur (mg kg-1

)

The highest non-sulphate sulphur content was recorded in subsurface layer of Ayodhya (2170.58 mg kg

-1) and the lowest value was registered in surface layer of Hosali

(420.19 mg kg-1

). In general, non-sulphate sulphur content increased with consequent increase in soil depth.

4.1.6.5 Total sulphur (mg kg-1

)

The highest total sulphur content was recorded in subsurface layer of Ayodhya (2372.52 mg kg

-1) and the lowest value was registered in surface layer of Hosali (561.27 mg

kg-1

). No definite pattern in total sulphur content with respect to soil depth was observed.

4.1.6.6 Percentage contribution of soil sulphur fractions to total sulphur

The data on percentage contribution of different sulphur fractions to total sulphur are presented in Table 10.

Regarding the percentage contribution of different sulphur fractions to total sulphur, the percentage contribution of sulphate sulphur in different soil bodies varied from 0.72 to 2.74 per cent. The subsoil of Basavapatna showed the lowest value of sulphate sulphur whereas surface soil of Hosali indicated the highest.

The lowest contribution of water soluble sulphur was observed in subsurface soil of Basavapatna (1.13%) and the highest was recorded in surface soil of Hosali (4.38 %).

The highest organic sulphur contribution of 18.01 per cent was observed in surface soil of Hosali whereas the lowest value of 4.31 per cent was recorded in subsurface soil of Bandibasappa. There was distinct decrease in content of organic sulphur with increase in soil depth in all the soil bodies studied.

In non-sulphate sulphur fraction, the per cent contribution varied from 74.87 to 93.29 per cent. The highest content was recorded in subsurface soil of Bandibasappa whereas lowest was observed in surface soil of Hosali.

4.1.6.7 Correlation study

The data on correlation coefficients between different forms of sulphur and soil properties are presented in Table 11.

The results of the study with respect to soil properties revealed that EC and clay content significantly and positively correlated with CEC (0.570** and 0.484*, respectively).

Correlation coefficients between soil properties and sulphur fractions showed significant correlations. Highly significant correlation was found between sulphate sulphur and EC. Sulphate sulphur significantly correlated with CEC (0.702** and 0.469*). Water soluble

Table 10. Percentage contribution of sulphur fractions to total sulphur in soils selected from

rice fields of different locations in rice growing areas of North Karnataka


Depth (cm)

SO4-S Water

soluble-S Organic-S

Non-SO4-S

1.

Sangapur

0-15

15-30

30-45

1.48

1.29

1.10

2.41

2.37

2.85

10.70

8.56

5.36

85.42

87.79

90.68

2.

Bandibasappa

0-15

15-30

30-45

1.36

1.15

0.79

2.83

2.27

1.61

9.88

6.85

4.31

85.94

89.73

93.29

3.

Hosali

0-15

15-30

30-45

2.74

2.23

1.03

4.38

2.28

2.89

18.01

10.60

5.80

74.87

84.89

90.28

4.

Ayodhya

0-15

15-30

30-45

2.52

2.22

1.25

2.80

2.37

2.22

12.03

5.73

5.04

82.64

89.68

91.49

5.

Voddarahatti

0-15

15-30

30-45

1.33

1.15

1.03

2.58

1.89

2.19

12.44

9.55

7.24

83.65

87.41

89.55

6.

Basavapatna

0-15

15-30

30-45

1.33

0.72

0.75

2.85

1.13

1.75

13.14

8.83

5.31

82.68

89.32

92.19

7.

Doctor camp

0-15

15-30

30-45

1.38

1.59

1.80

2.89

2.80

2.88

16.61

11.94

6.18

79.12

83.66

89.14

8.

Herur

0-15

15-30

30-45

2.37

1.28

0.83

3.81

3.17

1.46

13.59

9.27

7.42

80.23

86.28

90.29

sulphate was significantly and positively correlated with pH and EC (0.437* and 0.573**). Organic sulphur was positively and significantly correlated with EC and OC (0.439* and 0.593**). Both Non-sulphate sulphur (0.524** and 0.504*) and total sulphur (0.535** and 0.557**) indicated significant and positive correlation with pH and EC.

Sulphate sulphur was positively and significantly correlated with water soluble sulphur (0.743**), organic sulphur (0.475*) and total sulphur (0.475*). The correlation coefficients between water soluble sulphur and organic sulphur (0.613**), non-sulphate sulphur (0.563**) and total sulphur (0.648**) were highly and positively significant. Organic sulphur (0.415*) and non-sulphate (0.988**) sulphur showed positive and significant correlation with total sulphur.

4.2 INCUBATION STUDY ON THE TRANSFORMATION OF DIFFERENT SOURCES AND LEVELS OF SULPHUR IN SOIL

Incubation study was conducted in the laboratory to study the periodical changes of different sulphur fractions in submerged soil applied with different sources and levels of sulphur. Physico-chemical properties of the soil used for incubation study are presented in Table 4.

The data on the effect of different sulphur sources and levels on the periodical changes in sulphur fractions at 32, 54, and 75 and 109 days after incubation (DAI) are presented hereunder.

4.2.1 Sulphate sulphur (mg kg-1)

The data pertaining to effect of different sources and levels of sulphur on sulphate sulphur content under incubation are presented Table 12.

As the period of incubation advanced, an increase in sulphate sulphur content of soils was noticed up to 32 days after incubation (DAI) and gradual decrease was continued up to 109 DAI. The data on sulphate sulphur content indicated significant difference between treatments.

At 32 DAI, the highest sulphate sulphur content of 31.39 mg per kg was noticed in the treatment of RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 50 kg sulphur/ha (Factomphos) (T5). It was on par with the treatment received RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 37.5 kg sulphur/ha (Factomphos) (T4) (28.64 mg kg

-1). The treatment received RDF alone (T1)

registered the lowest sulphate sulphur content (15.90 mg kg-1

) and all treatments registered significantly higher sulphate sulphur over RDF (T1).

At 54 DAI, treatment receiving RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 50 kg sulphur/ha (Factomphos) (T5) recorded the highest sulphate sulphur content of 28.13 mg per kg and it was on par with the treatment receiving RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 37.5 kg sulphur/ha (Factomphos) (T4) (26.65 mg kg

-1). The lowest sulphate sulphur content of

14.02 mg per kg was observed in the treatment of RDF (T1) and it showed significant difference over all treatments.

The highest sulphate sulphur content of 26.57 mg per kg at 75 DAI was noticed in the treatment of RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 50 kg sulphur/ha (Factomphos) (T5) and it was on par with treatments receiving RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 37.5 kg sulphur/ha (Factomphos) (T4) (23.77 mg kg

-1). The treatment that received RDF alone (T1)

registered the lowest sulphur content of 12.91 mg per kg and it was on par with the treatment receiving RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) (T2) (15.30 mg kg

-1).

At 109 DAI, the treatment received RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 50 kg sulphur/ha (Factomphos) (T5) recorded the highest sulphate sulphur content of 24.07 mg per kg. It was on par with the treatment receiving RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 37.5 kg sulphur/ha (Factomphos) (T4) (22.92 mg kg

-1). The lowest sulphate sulphur content of

Table 11. Correlation coefficients between different forms of sulphur and soil properties

Sl. No.

Soil properties pH EC Clay OC CEC SO4-S Water

soluble-S Organic-S Non-SO4-S

1. EC 0.155 - - - - - - - -

2. Clay - 0.332 0.321 - - - - - - -

3. OC - 0.254 0.008 0.173 - - - - - -

4. CEC - 0.038 0.570** 0.484* 0.024 - - - - -

5. SO4-S 0.324 0.702** 0.270 0.114 0.469* - - - -

6. Water soluble-S 0.437* 0.573** - 0.039 0.219 0.262 0.743** - - -

7. Organic-S 0.221 0.439* 0.253 0.593** 0.109 0.475* 0.613** - -

8. Non-SO4-S 0.524** 0.504* - 0.343 - 0.194 -0.045 0.398 0.563** 0.276 -

9. Total-S 0.535** 0.557** - 0.279 - 0.093 -0.009 0.475* 0.648** 0.415* 0.988**

Table 12. Effect of different levels and sources of sulphur on sulphate sulphur (mg kg

-1) at

different days after incubation

Days after incubation

Treatments

32 54 75 109

T1: RDF (control) 15.90 14.02 12.91 11.42

T2: RDF + FYM (10 t/ha)+ ZnSO4 (20 kg/ha) 21.52 18.72 15.30 14.40

T3: T2 + 25 kg Sulphur/ha (Factomphos) 26.60 23.52 21.12 19.41

T4: T2 + 37.5 kg Sulphur/ha (Factomphos) 28.64 26.65 23.77 22.92


T6: T2 + 25 kg Sulphur/ha (Gypsum) 24.72 22.12 20.82 18.25

T7: T2 + 37.5 kg Sulphur/ha (Gypsum) 25.69 23.37 21.38 19.78


S.Em+ 0.972 0.774 0.852 0.673

CD (P=0.01) 4.01 3.20 3.52 2.78

Initial sulphate sulphur content – 11.2 (mg kg-1

)

RDF – Recommended dose of fertilizer (150:75:75 kg N, P2O5 and K2O ha-1

) common for all treatments

FYM – Farmyard manure, FYM (10 t/ha) + ZnSO4 (20 kg/ha) common for T2, T3, T4, T5, T6, T7 and

T8

NS – Non significant

11.42 mg per kg sulphur was observed in treatment of RDF alone (T1). T1 treatment differed significantly with all other treatments.

4.2.2 Water soluble sulphur (mg kg-1)

The data pertaining to effect of different sources and levels of sulphur on water soluble sulphur content under incubation are presented Table 13.

As the period of incubation increased, an increase in water soluble sulphur was noticed up to 32 DAI and thereafter decreased gradually up to 109 DAI.

Among the treatments, the highest water soluble sulphur content of 46.38 mg per kg at 32 DAI was noticed in the treatment that received RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 50 kg sulphur/ha (Factomphos) (T5) and it was on par with the treatments of RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 37.5 kg sulphur/ha (Factomphos) (T4) (41.50 mg kg

-1). The

lowest water soluble sulphate of 21.94 mg per kg was recorded in treatment of RDF alone (T1). It was on par with the treatment that received RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) (T2) (24.47 mg kg

-1).

At 54 DAI, the same trend as of 32 DAI was noticed. The highest water soluble sulphur content of 43.85 mg per kg was noticed in the treatment received RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 50 kg sulphur/ha (Factomphos) (T5) and it was on par with the treatments of RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 37.5 kg sulphur/ha (Factomphos) (T4) (38.88 mg kg

-1). The lowest water soluble sulphate of 18.62 mg per kg was recorded in

treatment of RDF alone (T1). The treatment T1 was on par with the treatment T2 (22.14 mg kg-

1).

At 75 DAI, the highest water soluble sulphur content of 36.02 mg per kg was observed with the treatment of RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 50 kg sulphur/ha (Factomphos) (T5) and it was on par with the treatment of RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 37.5 kg sulphur/ha (Factomphos) (T4) (32.12 mg kg

-1). The lowest of 16.82 mg per

kg was recorded in treatment of RDF alone (T1). The treatment T1 was on par with the treatment T2 (18.62 mg kg

-1).

Water soluble sulphur content significantly differed at 109 DAI. The highest water soluble content (32.07 mg kg

-1) was recorded with the treatments of RDF + FYM (10 t/ha) +

ZnSO4 (20 kg/ha) + 50 kg sulphur/ha (Factomphos) (T5) and it was on par with the treatment receiving RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 37.5 kg sulphur/ha (gypsum) (T4) (28.54 mg kg

-1). The treatment T1 recorded the lowest water soluble sulphur content of 15.20 mg kg

-1

and it was on par with T2 (16.97 mg kg-1

).

4.2.3 Organic sulphur (mg kg-1)

Results of the periodical changes in organic sulphur content of soils due to different treatments at 32, 54, 75 and 109 days after incubation are presented Table 14.

As the period of incubation increased, a gradual increase in organic sulphur content of soils was noticed up to 109 days after incubation. The sulphur treatments significantly increased organic sulphur content.

At 32 DAI, the highest organic sulphur content (142.58 mg kg-1

) was recorded in the treatment that received RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 50 kg sulphur/ha (Factomphos) (T5) and it was on par with all treatments except treatments receiving RDF alone (T1) (113.04 mg kg

-1) and RDF + FYM (10 t/ha) + ZnSO4 (T2) (122.21 mg kg

-1).

The lowest organic sulphur content (113.04 mg kg-1

) recorded in the treatment received RDF alone (T1). All sulphur treatments indicated significant increase in organic sulphur over the treatment receiving RDF alone (T1).

Table 13. Effect of different levels and sources of sulphur on water soluble sulphur (mg kg

-1)

at different days after incubation


Treatments

32 54 75 109

T1: RDF (control) 21.94 18.62 16.82 15.20








S.Em+ 1.181 1.252 1.003 0.894

CD (P=0.01) 4.88 5.17 4.14 3.69

Initial water soluble sulphur content – 22.96 (mg kg-1

)




T8

Table 14. Effect of different levels and sources of sulphur on organic sulphur (mg kg

-1) at



Treatments

32 54 75 109

T1: RDF (control) 113.04 117.16 121.35 122.59








S.Em+ 3.880 4.717 4.394 4.378

CD (P=0.01) 16.03 19.49 18.15 18.08

Initial organic sulphur content – 105.57 (mg kg-1

)




T8

The highest organic sulphur content (159.13 mg kg-1

) at 54 DAI was recorded in the treatment of RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 50 kg sulphur/ha (Factomphos) (T5) and it was on par with all treatments except treatments receiving RDF alone (T1) (117.16 mg kg


-1). The lowest organic sulphur

content (117.16 mg kg-1

) recorded in the treatment received RDF alone (T1). All sulphur treatments showed significantly higher organic sulphur over the treatment T1.

At 75 DAI, the treatment receiving RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 50 kg sulphur/ha (Factomphos) (T5) recorded the highest organic sulphur contents of 169.43 mg per kg. It was on par with all treatments except treatments receiving RDF alone (T1) (121.35 mg kg


-1). The lowest organic sulphur

content (121.35 mg kg-1

) recorded in the treatment received RDF alone (T1). All sulphur treatments showed significantly higher organic sulphur over the treatment T1.

At 109 DAI, the treatment receiving RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 50 kg sulphur/ha (Factomphos) (T5) recorded the highest organic sulphur contents of 186.22 mg per kg. It was on par with treatments receiving RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 25 kg sulphur/ha (Factomphos) (T3) (169.12 mg kg

-1), RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) +

37.5 kg sulphur/ha (Factomphos) (T4) (178.87 mg kg-1

), RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 37.5 kg sulphur/ha (gypsum) (T7) (171.13 mg kg

-1) and RDF + FYM (10 t/ha) +

ZnSO4 (20 kg/ha) + 50 kg sulphur/ha (gypsum) (T8) (176.26 mg kg-1

). The lowest organic sulphur content (122.59 mg kg

-1) recorded in the treatment received RDF alone (T1). All

sulphur treatments showed significantly higher organic sulphur over the treatment receiving RDF alone (T1) (122.59 mg kg

-1), RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) (T2) (149.13 mg

kg-1

) and RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 25 kg sulphur/ha (gypsum) (T6) (166.57 mg kg

-1).

4.2.4 Non-sulphate sulphur (mg kg-1)

The data pertaining to effect of different sources and levels of sulphur on non-sulphate sulphur content under incubation are presented Table 15.

A perusal of data indicated that the difference between treatments with respect to non-sulphate sulphur content was found non-significant.

4.2.5 Total sulphur (mg kg-1)

The data pertaining to effect of different sources and levels of sulphur on total sulphur content under incubation are presented Table 16.

The results of the study revealed that the difference among treatments with respect to total sulphur content was found to be significant. Total sulphur did not show marked difference between initial and final stage of the investigation.

Irrespective of the levels and sources, application of sulphur increased total sulphur at all stages of the study period. At 32, 54, 75 and 109 DAI, the highest total sulphur was observed in the treatment that received RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 50 kg sulphur/ha (gypsum) (T8) (1068.6, 1066.3, 1063.9 and 1060.1 mg kg

-1).

4.3 DIRECT AND RESIDUAL EFFECTS OF SULPHUR FERTILIZATION IN RICE-RICE CROPPING SEQUENCE

Field experiments were conducted during rabi/summer and kharif seasons of 2007 to study the direct and residual effect of different sulphur sources and levels on changes in yield and soil fertility status on rice-rice cropping sequence at Agriculture Research Station, Gangavati.

The results of the field experiments recorded during the course of the experiment are presented in this chapter.

Table 15. Effect of different levels and sources of sulphur on non-sulphate sulphur (mg kg

-1)

at different days after incubation


Treatments

32 54 75 109

T1: RDF (control) 791.7 791.1 788.1 786.6








S.Em+ 19.753 16.908 24.987 24.634

CD (P=0.01) NS NS NS NS

Initial non-sulphate sulphur content – 800.76 (mg kg-1

)




T8


Table 16. Effect of different levels and sources of sulphur on total sulphur (mg kg

-1) at



Treatments

32 54 75 109

T1: RDF (control) 942.6 940.9 939.2 935.8








S.Em+ 16.933 16.512 22.114 23.788

CD (P=0.01) 69.94 68.20 91.34 98.26

Initial total sulphur content – 940.51 (mg kg-1

)




T8

4.3.1 Initial properties of soil

Physico-chemical properties, available nutrient status of the soil and sulphur fractions of the experimental field are presented in Table 4.

The experimental site soil was clayey in texture, alkaline in reaction (pH 8.12), low in electrical conductivity (0.18 dS m

-1) and medium in organic carbon (4.78 g kg

-1). The CEC of

the soil was 66.66 cmol (p+) kg

-1. The available N content was low (172.31 kg ha

-1), available

P content of the soil was medium (14.91 kg ha-1

) and available K content was high (312.78 kg ha

-1). The DTPA extractable Fe (7.67 mg kg

-1), Mn (9.85 mg kg

-1) and Cu (2.68 mg kg

-1) were

found to be high, whereas Zn (0.58 mg kg-1

) was low.

4.3.2 Growth parameters of first rice crop

4.3.2.1 Plant height (cm)

The data pertaining to the direct effect of different sources (Factomphos and gypsum) and levels (25.0, 37.5 and 50 kg ha

-1) of sulphur on plant height at different stages of rice are

presented in Table 17.

Plant height linearly increased with the advancement in age up to harvest.

The results of the investigation indicate that the different sources and levels of sulphur had significant influence on plant height at all the growth stage of rice.

At active tillering stage, application of RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 50 kg sulphur/ha (Factomphos) (T5) registered significantly higher plant height of 54.4 cm and it was at par with the treatment that received RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 37.5 kg sulphur/ha (Factomphos) (T4) (53.5 cm). The lowest plant height was recorded with the application of RDF alone (T1) (46.7 cm). It was the least when compared to rest of the treatments. However, treatment receiving RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) (T2) (49.9 cm) showed significant increase over T1.

At panicle initiation stage, the highest plant height of 71.8 cm was recorded with the application of RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 50 kg sulphur/ha (Factomphos) (T5) and it was on par with the application of RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 25 kg sulphur/ha (Factomphos) (T3) (69.1 cm) and RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 37.5 kg sulphur/ha (Factomphos) (T4) (70.8 cm). The lowest plant height (63.9 cm) was recorded with the application of RDF alone (T1). It was on par with the treatment receiving RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) (T2) (66.4 cm).

At grain filling stage, the treatment receiving RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 50 kg sulphur/ha (Factomphos) (T5) registered the highest plant height (78.5 cm) and it was on par with the application of RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 25 kg sulphur/ha (Factomphos) (T3) (75.4 cm) and RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 37.5 kg sulphur/ha (Factomphos) (T4) (77.9 cm). The lowest plant height (71.2 cm) was recorded with the application of RDF alone (T1). It was on par with the treatments that received RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) (T2) (74.1 cm), RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 25 kg sulphur/ha (gypsum) (T6) (74.1 cm), RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 37.5 kg sulphur/ha (gypsum) (T7) (74.5 cm) and RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 50 kg sulphur/ha (gypsum) (T8) (74.7 cm).

At harvest, the highest plant height of 87.8 cm was recorded by the treatment receiving RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 50 kg sulphur/ha (Factomphos) (T5) and it was also on par with application of RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 25 kg sulphur/ha (Factomphos) (T3) (84.6 cm) and RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 37.5 kg sulphur/ha (Factomphos) (T4) (86.2 cm). The lowest plant height of 78.6 cm was recorded in the treatment received RDF alone (T1). It was on par with the treatments that received RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) (T2) (81.4 cm), RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 25 kg sulphur/ha (gypsum) (T6) (82.0 cm), RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 37.5 kg sulphur/ha (gypsum) (T7) (82.3 cm).

Table 17. Effect of different sources and levels of sulphur on plant height (cm) at different

growth stages of rice

Treatments AT PI GF Harvest

T1: RDF (control) 46.7 63.9 71.2 78.6


T3: T2 + 25.0 kg sulphur/ha (Factomphos) 51.3 69.1 75.4 84.6



T6: T2 + 25.0 kg sulphur/ha (Gypsum) 51.0 66.8 74.1 82.0



S.Em+ 0.919 0.947 1.228 1.302

CD (P=0.05) 2.79 2.87 3.73 3.95

AT – Active tillering, PI – Panicle initiation, GF – Grain filling




T8

4.3.2.2 Number of tillers per hill

The data pertaining to the direct effect of different sources and levels of sulphur on number of tillers per hill at different stages of rice are presented in Table 18.

Number of tillers per hill was significantly influenced by different sources and levels of sulphur.

At active tillering stage, the highest number of tillers per hill of 19.67 was recorded with the application of RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 50 kg sulphur/ha (Factomphos) (T5) and it was on par with the treatments receiving RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 37.5 kg sulphur/ha (Factomphos) (T4) (18.20 cm) and superior over the rest of treatments. The lowest number of tillers of 13.23 was recorded in the treatment that received RDF alone (T1). The treatment T2 (RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) recorded significantly greater number of tillers per hill (15.83) over RDF alone (T1).

At panicle initiation and grain filling stages, the highest numbers of tillers of 24.03 and 21.63 were recorded in the treatment receiving RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 50 kg sulphur/ha (Factomphos) (T5) respectively and it was on par with application of RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 37.5 kg sulphur/ha (Factomphos) (T4) (22.23 and 20.10) at respective stages. The lowest number of tillers per hill at panicle initiation and grain filling stages (17.73 and 15.97) was registered by the treatment receiving RDF alone (T1) at respective stages. At grain filling stage, slight reduction in tiller number was recorded and it was improved at harvest.

At harvest, the highest number of tillers per hill (24.83) was recorded in the treatment RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 50 kg sulphur/ha (Factomphos) (T5). It was on par with application of RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 37.5 kg sulphur/ha (Factomphos) (T4) (23.03). Treatment that received RDF alone (T1) significantly registered the lowest number of tillers of 17.13.

4.3.2.3 Dry matter production (q ha-1

)

The data pertaining to the direct effect of different sources and levels of sulphur on dry matter production at different stages of rice are presented in Table 19.

At active tillering stage, the results of the experiment indicated that the highest dry matter production of 41.57 q per ha was registered with the application of RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 50 kg sulphur/ha (Factomphos) (T5) and it was on par with the treatment receiving RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 37.5 kg sulphur/ha (Factomphos) (T4) (39.62 q ha

-1). The lowest dry matter production of 29.19 q per ha was

recorded by the treatment receiving RDF alone (T1) and it was on par with the treatment that received RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) (T2) (33.70 q ha

-1).

At panicle initiation and grain filling stages, application of RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 50 kg sulphur/ha (Factomphos) (T5) recorded the highest dry matter production of 52.39 q per ha and 74.14 q per ha at respective stages and it was on par with the treatments receiving RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 25 kg sulphur/ha (Factomphos) (T3) (48.39 q ha

-1 and 70.81 q ha

-1) and RDF + FYM (10 t/ha) + ZnSO4 (20

kg/ha) + 37.5 kg sulphur/ha (Factomphos) (T4) (50.62 q ha-1

and 72.63 q ha-1

). The treatment receiving RDF alone (T1) registered the lowest dry matter production of 39.62 and 56.85 q per ha at panicle initiation and grain filling stages respectively. At panicle initiation stage, T1 was on par with the treatment receiving RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) (T2) (45.73 q ha

-

1) but at grain filling stage T1 differed significantly with all treatments.

At harvest, the highest dry matter production in straw and grain (54.72 and 49.09 q ha

-1) was recorded in the treatment received RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 50

kg sulphur/ha (Factomphos) (T5) respectively. It was on par with application of RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 37.5 kg sulphur/ha (Factomphos) (T4) (53.00 and 47.47 q ha

-

1). The lowest straw and grain dry matter (42.93 and 38.38 q ha

-1) contents were observed in

Table 18. Effect of different sources and levels of sulphur on number of tillers per hill at

different growth stages of rice


T1: RDF (control) 13.23 17.73 15.97 17.13








S.Em+ 0.713 0.781 0.702 0.723

CD (P=0.05) 2.16 2.37 2.13 2.19





T8

Table 19. Effect of different sources and levels of sulphur on dry matter production (q ha

-1) of rice

Harvest

Treatments AT PI GF

Straw Grain

T1: RDF (control) 29.19 39.62 56.85 42.93 38.38

T2: RDF + FYM (10 t/ha)+ ZnSO4 (20 kg/ha) 33.70 45.73 62.40 46.73 42.12

T3: T2 + 25.0 kg sulphur/ha (Factomphos) 37.52 48.39 70.81 50.53 45.78



T6: T2 + 25.0 kg sulphur/ha (Gypsum) 35.90 45.95 64.48 48.15 43.04



S.Em+ 1.280 1.910 1.700 1.223 0.849

CD (P=0.05) 3.88 5.79 5.16 3.71 2.58





T8

treatment of RDF alone (T1). The straw and grain dry matter recorded by the treatment T1 was significantly lowest over the rest of treatments.

4.3.3 Yield parameters of first rice crop

The data pertaining to the direct effect of different sources and levels of sulphur on productive tillers per hill and number of panicles per m

2, panicle length, number of grains per

panicle, 1000 seed weight, grain yield, straw yield and harvest index of first rice crop are presented hereunder.

4.3.3.1 Number of panicles per m2

The data pertaining to the effect of different sources and levels of sulphur on productive tillers per hill and number of panicles per m

2 of first rice crop are presented in

Table 20.

Significant differences were found between the treatments with respect to number of panicles per m

2.

The highest number of panicles per m2 (499.7) was registered with the application of

RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 50 kg sulphur/ha (Factomphos) (T5) and it was on par with RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 37.5 kg sulphur/ha (Factomphos) (T4) (484.3). The lowest number of panicles per m

2 (371.3) was recorded with the application of

RDF alone (T1). All treatments significantly increased number of panicles per m2 over RDF

alone (T1) treatment.

4.3.3.2 Panicle length (cm)

Due to sulphur nutrition, there was no significant difference existed among the treatments with respect to panicle length (Table 21).

4.3.3.3 Number of grains per panicle

Significant differences were noticed among different treatments with respect to number of grains per panicle (Table 21).

The treatment receiving RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 50 kg sulphur/ha (Factomphos) (T5) registered the highest number of grains per panicle of 98.68 and it was on par with RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 37.5 kg sulphur/ha (Factomphos) (T4) (94.89). The lowest number of grains per panicle (79.96) was recorded with the application of RDF alone (T1) and it was on par with the treatment receiving RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) (T2) (83.64), RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 25 kg sulphur/ha (gypsum) (T6) (84.58) and RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 37.5 kg sulphur/ha (gypsum) (T7) (86.47).

4.3.3.4 1000-seed weight (g)

Significant differences were noticed among different treatments with respect to 1000 seed weight of first rice crop (Table 21).

The treatment receiving RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 50 kg sulphur/ha (Factomphos) (T5) registered the highest 1000 seed weight of 23.76 g and it was on par with the application of RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 37.5 kg sulphur/ha (Factomphos) (T4) (23.65). The lowest 1000 seed weight was recorded with the application of RDF alone (T1) (22.43) and it was on par with all the treatments except (T4) and (T5).

4.3.3.5 Grain yield (q ha-1

)

The results of the experiment revealed that the sources and levels of sulphur markedly influenced the grain yield of first rice crop (Table 22).

Table 20. Effect of different sources and levels of sulphur on number of panicles per m

2

Treatments No. of panicles per m2

T1: RDF (control) 371.3

T2: RDF + FYM (10 t/ha)+ ZnSO4 (20 kg/ha) 418.7

T3: T2 + 25.0 kg sulphur/ha (Factomphos) 455.7



T6: T2 + 25.0 kg sulphur/ha (Gypsum) 419.3



S.Em+ 11.988

CD (P=0.05) 36.36



FYM – Farmyard manure, FYM (10 t/ha) + ZnSO4 (20 kg/ha) common for T2, T3, T4, T5, T6, T7 and T8

Table 21. Effect of different sources and levels of sulphur on panicle length, number of grains

per panicle and 1000 grain weight of rice

Treatments Panicle

length (cm) No. of grains per panicle

1000 grain weight (g)

T1: RDF (control) 20.27 79.96 22.43

T2: RDF + FYM (10 t/ha)+ ZnSO4 (20 kg/ha) 20.33 83.64 22.58

T3: T2 + 25.0 kg sulphur/ha (Factomphos) 21.03 89.83 22.62



T6: T2 + 25.0 kg sulphur/ha (Gypsum) 20.37 84.58 22.60



S.Em+ 0.722 2.668 0.250

CD (P=0.05) NS 8.09 0.76




T8


The highest grain yield of 57.09 q per ha was recorded with the application of RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 50 kg sulphur/ha (Factomphos) (T5) and it was at par with the treatment receiving RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 37.5 kg sulphur/ha (Factomphos) (T4) (55.20 q ha

-1). The lowest grain yield of 44.63 q per ha was registered with

the application of RDF alone (T1) treatment. All treatments recorded significantly higher grain yield over the treatment receiving RDF alone (T1).

4.3.3.6 Straw yield (q ha-1

)

Variations in straw yield due to different sources and levels of sulphur differed significantly (Table 22).

The highest straw yield of 63.63 q per ha was recorded in the treatment receiving RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 50 kg sulphur/ha (Factomphos) (T5) and it was on par with the application of RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 37.5 kg sulphur/ha (Factomphos) (T4) (61.63 q ha

-1). All treatments registered marked increase in straw yield due

to application of sulphur over the treatment receiving RDF alone (T1) (49.92 q ha-1

).

4.3.3.7 Harvest index

The data pertaining to the effect of different sources and levels of sulphur on harvest index of first rice crop were not statistically significant (Table 22).

4.3.4. Quality parameters of first rice crop

The data pertaining to the direct effect of different sources and levels of sulphur on grain protein and methionine content of first rice crop are presented in Table 23.

4.3.4.1 Grain protein content (%)

Perusal of the data indicates that application of sulphur increased protein content in rice grain.

Application of RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 50 kg sulphur/ha (Factomphos) (T5) registered the highest grain protein content of 10.20 per cent and it was on par with the treatments receiving RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 37.5 kg sulphur/ha (Factomphos) (T4) (9.63 %). All the treatments recorded marked increase in grain protein content over RDF (T1) (7.93 %).

4.3.4.2 Grain methionine content (mg g-1

)

The highest grain methionine content of 2.51 mg per g was recorded in the treatment receiving RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 50 kg sulphur/ha (Factomphos) (T5) and was at par with the treatment that received RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 37.5 kg sulphur/ha (Factomphos) (T4) (2.36 mg g

-1). The lowest methionine content of 1.80 mg per

g was recorded by the treatment T1. It was on par with the treatment that received RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) (T2) (1.82 mg g

-1), RDF + FYM (10 t/ha) + ZnSO4 (20

kg/ha) + 25 kg sulphur/ha (Factomphos) (T3) (1.98 mg g-1

) and RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 25 kg sulphur/ha (gypsum) (T6) (1.93 mg g

-1).

4.3.5 Major nutrient content and uptake by first rice crop

4.3.5.1 Nitrogen content (%)

The data pertaining to the effect of different sources and levels of sulphur on nitrogen content of first rice crop are presented in Table 24.

The perusal of the data revealed that application sulphur remarkably influenced nitrogen content in first rice crop.

Table 22. Effect of different sources and levels of sulphur on grain yield, straw yield and harvest

index of rice

Treatments Grain yield (q

ha-1

) Straw yield (q

ha-1

) Harvest index

T1: RDF (control) 44.63 49.92 0.472








S.Em+ 0.987 1.422 0.010

CD (P=0.05) 2.99 4.31 NS




T8


Table 23. Effect of different sources and levels of sulphur on grain protein (%) and methionine

content (mg g-1

)

Treatments Grain protein

(%) Methionine

(mg g-1

)

T1: RDF (control) 7.93 1.80

T2: RDF + FYM (10 t/ha)+ ZnSO4 (20 kg/ha) 8.92 1.82

T3: T2 + 25.0 kg sulphur/ha (Factomphos) 9.22 1.98



T6: T2 + 25.0 kg sulphur/ha (Gypsum) 8.94 1.93



S.Em+ 0.314 0.074

CD (P=0.05) 0.95 0.22




T8

At active tillering stage, application of RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 50 kg sulphur/ha (Factomphos) (T5) recorded the highest nitrogen content of 1.93 per cent and it was on par with the treatment receiving RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 37.5 kg sulphur/ha (Factomphos) (T4) (1.86 %). All treatments showed significant increase in nitrogen content over the treatment receiving RDF alone (T1) (1.56 %).

At panicle initiation stage, the treatment that received RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 50 kg sulphur/ha (Factomphos) (T5) showed the highest nitrogen content of 1.70 per cent and it was on par with the treatment receiving RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 37.5 kg sulphur/ha (Factomphos) (T4) (1.65 %). The lowest nitrogen content of 1.38 per cent was registered in the treatment receiving RDF alone (T1) and it was on par with the treatment supplied with RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) (T2) (1.45 %).

At grain filling stage, the treatment RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 50 kg sulphur/ha (Factomphos) (T5) recorded the highest nitrogen content of 1.39 per cent and it was on par with the treatment that received RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 37.5 kg sulphur/ha (Factomphos) (T4) (1.36 %). The treatment receiving RDF alone (T1) recorded the lowest nitrogen content of 1.13 per cent and it was on par with the treatment that received RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) (T2) (1.18 %).

In straw at harvest, the highest straw nitrogen content of 0.97 per cent was recorded in the treatment receiving RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 50 kg sulphur/ha (Factomphos) (T5). It was on par with the treatment receiving RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 37.5 kg sulphur/ha (Factomphos) (T4) (0.92 %). The lowest nitrogen content of 0.76 per cent was registered in the treatment receiving RDF alone (T1). It was on par with the treatments that received RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) (T2) (0.79 %), RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 25 kg sulphur/ha (Factomphos) (T3) (0.85 %), RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 25 kg sulphur/ha (gypsum) (T6) (0.79 %) and RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 37.5 kg sulphur/ha (gypsum) (T7) (0.83 %).

In grain at harvest, the highest nitrogen content of 1.33 per cent was recorded in the treatment receiving RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 50 kg sulphur/ha (Factomphos) (T5). It was on par with the treatments receiving RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 37.5 kg sulphur/ha (Factomphos) (T4) (1.28 %). The lowest nitrogen content of 1.11 per cent was registered in the treatment receiving RDF alone (T1) and it was on par with the treatment receiving RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) (T2) (1.16 %) and RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 25 kg sulphur/ha (Factomphos) (T3) (1.19 %), RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 25 kg sulphur/ha (gypsum) (T6) (1.17 %), RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 37.5 kg sulphur/ha (gypsum) (T7) (1.18 %) and RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 50 kg sulphur/ha (gypsum) (T8) (1.19 %).

4.3.5.2 Nitrogen uptake (kg ha-1

)

The data pertaining to the direct effect of different sources and levels of sulphur on nitrogen uptake of first rice crop are presented in Table 24.

Nitrogen uptake in first rice crop differed significantly due to the different sulphur sources and levels.

At active tillering stage, the highest nitrogen uptake of 80.23 kg per ha was registered with the treatment receiving RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 50 kg sulphur/ha (Factomphos) (T5). It was on par with the application of RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 37.5 kg sulphur/ha (Factomphos) (T4) (73.69 kg ha

-1) but, significantly superior over

the rest of treatments. The treatment that received RDF alone (T1) recorded the lowest nitrogen uptake of 45.54 kg per ha. The value differed significantly with all other treatments.

The highest nitrogen uptake of 89.06 kg per ha at panicle initiation stage was registered with the treatment receiving RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 50 kg sulphur/ha (Factomphos) (T5). It was on par with the application of RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 37.5 kg sulphur/ha (Factomphos) (T4) (83.52 kg ha

-1) but significantly

superior over the rest of treatments. However, the lowest nitrogen uptake of 54.68 kg per ha

Table 24. Effect of different sources and levels of sulphur on plant nitrogen (N) content (%) and uptake (kg

ha-1

) by rice

Harvest Treatments AT PI GF

Straw Grain

T1: RDF (control) (1.56) 45.54

(1.38) 54.68

(1.13) 64.24

(0.76) 32.63

(1.11) 42.60

T2: RDF + FYM (10 t/ha)+ ZnSO4 (20 kg/ha) (1.63) 54.93

(1.45) 66.31

(1.18) 73.63

(0.79) 36.92

(1.16) 48.86

T3: T2 + 25.0 kg sulphur/ha (Factomphos) (1.75) 65.66

(1.55) 75.00

(1.26) 89.22

(0.85) 42.95

(1.19) 54.48


(1.65) 83.52

(1.36) 98.78

(0.92) 48.76

(1.28) 60.76


(1.70) 89.06

(1.39) 103.05

(0.97) 53.08

(1.33) 65.29

T6: T2 + 25.0 kg sulphur/ha (Gypsum) (1.66) 59.59

(1.47) 67.55

(1.18) 76.09

(0.79) 38.04

(1.17) 50.36


(1.52) 70.45

(1.25) 83.36

(0.83) 41.48

(1.18) 52.92


(1.56) 72.54

(1.28) 86.46

(0.86) 43.81

(1.19) 54.29

S.Em+ (0.029) 2.239

(0.027) 3.068

(0.023) 1.583

(0.031) 1.998

(0.042) 1.672

CD (P=0.05) (0.088)

6.79 (0.082)

9.30 (0.070)

4.80 (0.094)

6.06 (0.129)

5.07

Values in parentheses indicate N concentration (%)





was noticed with the treatment supplied with RDF alone (T1). It significantly differed with all the treatments tested.

At grain filling stage, the highest nitrogen uptake of 103.05 kg per ha was registered with the treatment receiving RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 50 kg sulphur/ha (Factomphos) (T5). It was on par with the treatment that received RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 37.5 kg Sulphur/ha (Factomphos) (T4) (98.78 kg ha

-1) and significantly

superior over the rest of treatments. The lowest nitrogen uptake of 64.24 kg per ha was recorded with the treatment supplied with RDF alone (T1). All treatments registered significantly higher nitrogen uptake over RDF alone (T1).

At harvest, the highest nitrogen uptake of 53.08 and 65.29 kg per ha were obtained in straw and grain respectively in the treatment receiving RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 50 kg sulphur/ha (Factomphos) (T5). They were on par with the treatment of RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 37.5 kg Sulphur/ha (Factomphos) (T4) (48.76 and 60.76 kg ha

-1), but significantly superior over the rest of the treatments at respective stages. The

lowest nitrogen uptake of 32.63 and 42.60 kg per ha were recorded in straw and grain

respectively in the treatment receiving RDF alone (T1). In straw, the lowest straw nitrogen uptake was on par with the treatment that received RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) (T2) (36.92 kg ha

-1) and RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 25 kg sulphur/ha

(gypsum) (T6) (38.04 kg ha-1

). However, the lowest grain nitrogen uptake differed significantly with the rest of treatments.

4.3.5.3 Phosphorus content (%)

The data pertaining to the effect of different sources and levels of sulphur on phosphorus content of first rice crop are presented in Table 25.

The results of the experiment revealed that application sulphur remarkably influenced phosphorus content in first rice crop.

At active tillering stage, the highest phosphorus content of 0.307 per cent was recorded with the application of RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 50 kg sulphur/ha (Factomphos) (T5) and it was superior over the rest of treatments. The lowest phosphorus content of 0.244 per cent was registered in the treatment receiving RDF alone (T1). All treatments significantly enhanced the phosphorus content over the treatment that received RDF alone (T1).

At panicle initiation stage, the highest phosphorus content of 0.265 per cent was registered in treatment receiving RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 50 kg sulphur/ha (Factomphos) (T5). It was on par with application of RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 37.5 kg sulphur/ha (Factomphos) (T4) (0.261 %) but significantly superior over the rest of treatments. The lowest phosphorus content of 0.232 per cent was registered in the treatment receiving RDF alone (T1). It was on par with the treatments that received RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) (T2) (0.238 %), RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 25 kg sulphur/ha (gypsum) (T6) (0.239 %) and RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 37.5 kg sulphur/ha (gypsum) (T7) (0.245 %).

At grain filling stage, the treatment receiving RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 50 kg sulphur/ha (Factomphos) (T5) registered the highest phosphorus content (0.260 %). It was on par with the application of RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 37.5 kg Sulphur/ha (Factomphos) (T4) (0.252 %) but, significantly superior over the rest of treatments. The lowest phosphorus content of 0.227 per cent was registered in the treatment receiving RDF alone (T1) and it was on par with all treatments tested except (T5) and (T4).

The treatment receiving RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 50 kg sulphur/ha (Factomphos) (T5) recorded the highest straw phosphorus content of 0.144 per cent at harvest and it was significantly superior over the rest of treatments. The treatment of RDF alone (T1) registered the lowest straw phosphorus content of 0.102 per cent. It differed significantly with all treatments.

Table 25. Effect of different sources and levels of sulphur on plant phosphorus (P) content (%) and uptake (kg

ha-1

) by rice

Harvest Treatments

AT

PI

GF

Straw Grain

T1: RDF (control) (0.244)

7.12 (0.232)

9.19 (0.227)

9.19 (0.102)

4.38 (0.240)

9.21

T2: RDF + FYM (10 t/ha)+ ZnSO4 (20 kg/ha) (0.277)

9.33 (0.238) 10.88

(0.233) 14.54

(0.125) 5.84

(0.258) 10.87


(0.250) 12.10

(0.242) 17.14

(0.129) 6.52

(0.268) 12.27


(0.261) 13.21

(0.252) 18.30

(0.130) 6.89

(0.287) 13.62


(0.265) 13.88

(0.260) 19.28

(0.144) 7.88

(0.294) 14.43

T6: T2 + 25.0 kg sulphur/ha (Gypsum) (0.277)

9.94 (0.239) 10.98

(0.235) 15.15

(0.127) 6.12

(0.259) 11.15


(0.245) 11.36

(0.238) 15.87

(0.128) 6.40

(0.260) 11.66


(0.247) 11.49

(0.239) 16.14

(0.129) 6.57

(0.261) 11.91

S.Em+ (0.004) 0.344

(0.005) 0.509

(0.005) 0.488

(0.004) 0.239

(0.008) 0.460

CD (P=0.05) (0.013)

1.04 (0.014)

1.54 (0.015)

1.48 (0.013)

0.73 (0.024)

1.40

Values in parentheses indicate P concentration (%)



) common for all

treatments


In the case of grain phosphorus, the highest phosphorus content (0.294 %) was recorded with the application of RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 50 kg sulphur/ha (Factomphos) (T5). It was on par with the treatment receiving RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 37.5 kg sulphur/ha (Factomphos) (T4) (0.287 %). The lowest grain phosphorus content (0.240%) was registered by the treatment of RDF alone (T1). It was on par RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + (T2) (0.258 %), RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 25 kg sulphur/ha (gypsum) (T6) (0.259 %) and RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 37.5 kg sulphur/ha (gypsum) (T7) (0.260 %).

4.3.5.4 Phosphorus uptake (kg ha-1

)

The data pertaining to the effect of different sources and levels of sulphur on potassium uptake of first rice crop are presented in Table 25.

The results of the experiment clearly showed that there was striking effect of sulphur sources and levels on phosphorus uptake.

At active tillering stage, the highest phosphorus uptake of 12.76 kg per ha registered with the treatment receiving RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 50 kg sulphur/ha (Factomphos) (T5). It was superior over the rest of treatments. The treatment of RDF alone (T1) recorded significantly the lowest phosphorus uptake of 7.12 kg per ha. It differed significantly with the rest of treatments.

At panicle initiation stage, the highest phosphorus uptake of 13.88 kg per ha was recorded in the treatment receiving RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 50 kg sulphur/ha (Factomphos) (T5). It was on par with RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 37.5 kg sulphur/ha (Factomphos) (T4) (13.21 kg ha

-1) but significantly superior over the rest of

treatments. The treatment receiving RDF alone (T1) indicated the lowest phosphorus uptake of 9.19 kg per ha

and it differed significantly with rest of the treatments.

At grain filling stage, the highest phosphorus uptake of 19.28 kg per ha was registered in the treatment receiving RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 50 kg sulphur/ha (Factomphos) (T5). It was on par with the treatment of RDF that received + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 37.5 kg sulphur/ha (Factomphos) (T4) (18.30 kg ha

-1) but

significantly superior over the rest of treatments. The treatment receiving RDF alone (T1) recorded the lowest phosphorus uptake of 12.90 kg per ha. All treatments registered significantly higher phosphorus uptake over RDF alone (T1).

In straw at harvest, the treatment that received RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 50 kg sulphur/ha (Factomphos) (T5) registered the highest phosphorus uptake of 7.88 kg per ha. It was significantly superior over the rest of treatments. The treatment receiving RDF alone (T1) registered the lowest phosphorus uptake of 4.38 kg per ha and it differed significantly with all treatments.

In grain at harvest, the treatment that received RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 50 kg sulphur/ha (Factomphos) (T5) recorded the highest phosphorus uptake of 14.43 kg per ha. It was on par with the treatment that received RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 37.5 kg sulphur/ha (Factomphos) (T4) (13.62 kg ha

-1) but, significantly superior

over the rest of treatments. The lowest grain phosphorus uptake of 9.21 kg per ha was registered with the treatment received RDF alone (T1). It differed significantly with all treatments.

4.3.5.5 Potassium content (%)

The data pertaining to the effect of different sources and levels of sulphur on potassium content of first rice crop are presented in Table 26.

A perusal of data revealed that the sulphur nutrition did not influence significantly with respect to potassium content.

4.3.5.6 Potassium uptake (kg ha-1

)

The data pertaining to the effect of different sources and levels of sulphur on potassium uptake of first rice crop are presented in Table 26.

Potassium uptake was significantly influenced by sulphur sources and levels.

At active tillering stage, the highest potassium uptake of 76.07 kg per ha was registered with the application of RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 50 kg sulphur/ha (Factomphos) (T5). It was on par with the treatment receiving RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 37.5 kg sulphur/ha (Factomphos) (T4) (66.17 kg ha

-1) but significantly superior

over the rest of treatments. The lowest potassium uptake of 41.45 kg per ha was recoded in the treatment received RDF alone (T1). It was on par with treatment that received RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) (T2) (50.21 kg ha

-1).

At panicle initiation stage, the treatment that received RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 50 kg sulphur/ha (Factomphos) (T5) recorded the highest potassium uptake of 81.73 kg per ha. It was on par with the treatment that received RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 37.5 kg sulphur/ha (Factomphos) (T4) (74.92 kg ha


over the rest of treatments. The treatment that received RDF alone (T1) indicated significantly the lowest potassium uptake of 51.90 kg per ha.

At grain filling stage, the treatment supplied with RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 50 kg sulphur/ha (Factomphos) (T5) recorded the highest potassium uptake of 92.68 kg per ha. It was on par with the treatment that received RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 37.5 kg sulphur/ha (Factomphos) (T4) (89.33 kg ha

-1) but significantly superior over

rest of treatments. The treatment that received RDF alone (T1) recorded the lowest potassium uptake of 68.22 kg per ha and it differed significantly with all treatments.

In straw at harvest, the highest potassium uptake of 87.00 kg per ha was registered with the treatment that received RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 50 kg sulphur/ha (Factomphos) (T5). It was on par with the treatment receiving RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 37.5 kg sulphur/ha (Factomphos) (T4) (82.68 kg ha

-1). The lowest straw

potassium uptake of 60.53 kg per ha was recorded in the treatment of RDF alone (T1). All treatments registered significantly higher potassium uptake over the treatment receiving RDF alone (T1).

In grain, the highest potassium uptake of 23.56 kg per ha was registered in the treatment that received RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 50 kg sulphur/ha (Factomphos) (T5). It was on par with the application of RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 37.5 kg sulphur/ha (Factomphos) (T4) (21.89 kg ha

-1). The treatment that received

RDF alone (T1) showed the lowest grain potassium uptake of 14.58 kg per ha and it significantly differed with all treatments.

4.3.6 Sulphur content and uptake by first rice crop

The data pertaining to the direct effect of different sources and levels of sulphur on sulphur content and uptake by first rice crop are presented in Table 27.

4.3.6.1 Sulphur content (%)

The results of the experiment indicate that the sulphur nutrition significantly enhanced sulphur content in first rice crop (Table 27).

At active tillering stage, the highest sulphur content of 0.287 per cent registered with the application of RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 50 kg sulphur/ha (Factomphos) (T5) and it was on par with the treatment receiving RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 37.5 kg sulphur/ha (Factomphos) (T4) (0.256 %). The lowest sulphur content of 0.156 per cent was noticed in the treatment receiving RDF alone (T1). It was on par with the treatment that received RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) (T2) (0.185 %) and RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) 25 kg sulphur/ha (gypsum) (T6) (0.190 %).

Table 26. Effect of different sources and levels of sulphur on plant potassium (K) content (%) and uptake

(kg ha-1

) by rice


Straw Grain

T1: RDF (control) (1.42) 41.45

(1.31) 51.90

(1.20) 68.22

(1.41) 60.53

(0.38) 14.58


(1.35) 61.74

(1.21) 75.50

(1.46) 68.23

(0.41) 17.27


(1.41) 68.23

(1.22) 86.39

(1.52) 76.81

(0.42) 19.23


(1.48) 74.92

(1.23) 89.33

(1.56) 82.68

(0.44) 21.89


(1.56) 81.73

(1.25) 92.68

(1.59) 87.00

(0.48) 23.56


(1.39) 63.87

(1.21) 78.02

(1.49) 71.74

(0.43) 18.51


(1.41) 65.35

(1.23) 82.03

(1.53) 76.45

(0.44) 19.73


(1.43) 66.50

(1.24) 83.76

(1.56) 79.47

(0.46) 20.99

S.Em+ (0.090)

3.27 (0.057)

2.83 (0.028)

2.00 (0.056)

2.17 (0.024)

0.81

CD (P=0.05) (NS) 9.93 (NS) 8.57 (NS) 6.07 (NS) 6.58 (NS) 2.47

Values in parentheses indicate K concentration (%)



) common for all

treatments



At panicle initiation stage, the treatment receiving RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 50 kg sulphur/ha (Factomphos) (T5) recorded the highest sulphur content of 0.268 per cent. It was on par with the treatment receiving RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 37.5 kg sulphur/ha (Factomphos) (T4) (0.245 %) but, significantly superior over the rest of treatments. The lowest sulphur content 0.148 per cent was observed in the treatment receiving RDF alone (T1) and it was on par with RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) (T2) (0.171 %), RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) 25 kg sulphur/ha (gypsum) (T6) (0.173%), RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) 37.5 kg sulphur/ha (gypsum) (T7) (0.197 %) and RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) 50 kg sulphur/ha (gypsum) (T8) (0.201 %).

At grain filling stage, application of RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 50 kg sulphur/ha (Factomphos) (T5) recorded the highest sulphur content of 0.257 per cent and it was on par with the treatment receiving RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 37.5 kg sulphur/ha (Factomphos) (T4) (0.230 %) but superior over the rest of treatments. The lowest sulphur content 0.127 per cent was observed in the treatment receiving RDF (T1) and it was on par with the treatments RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) (T2) (0.155 %) and RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) 25 kg sulphur/ha (gypsum) (T6) (0.168 %).

The highest sulphur content in straw of 0.207 per cent was observed in the treatment receiving RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 50 kg sulphur/ha (Factomphos) (T5) and followed by the application of RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 37.5 kg sulphur/ha (Factomphos) (T4) (0.194 %). In straw, the lowest sulphur content of 0.123 per cent was observed in the treatment receiving RDF alone (T1). It was on par with the treatment receiving RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) (T2) (0.142 %).

In grain, the treatment that received RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 50 kg sulphur/ha (Factomphos) (T5) registered the highest sulphur content of 0.235 per cent and it was on par with the application of RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 37.5 kg sulphur/ha (Factomphos) (T4) (0.223 %) but superior over the rest of treatments. The lowest grain sulphur content of 0.131 per cent was registered in the treatment receiving RDF (T1) and it was on par with the treatments RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) (T2) (159 %) and RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) 25 kg sulphur/ha (gypsum) (T6) (0.161 %).

4.3.6.2 Sulphur uptake (kg ha-1

)

The results of the experiment indicate that the sulphur nutrition significantly increased sulphur uptake by first rice crop (Table 27).

At active tillering stage, the treatment that received RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 50 kg sulphur/ha (Factomphos) (T5) recorded the highest sulphur uptake of 11.93 kg per ha and it was significantly superior over the rest of treatments. The lowest sulphur uptake of 4.55 kg per ha was recorded in the treatment that received RDF alone (T1). All treatments registered significantly higher sulphur uptake over RDF alone (T1) at active tillering stage.

At panicle initiation stage, the highest sulphur uptake of 14.04 kg per ha was noticed in the treatment of RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 50 kg sulphur/ha (Factomphos) (T5). It was on par with the treatment receiving RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 37.5 kg sulphur/ha (Factomphos) (T4) (12.40 kg ha


treatments. The lowest sulphur uptake of 5.86 kg per ha was registered in the treatment receiving RDF alone (T1). It was on par with the treatments that received RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) (T2) (7.82 kg ha

-1), and RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) 25

kg sulphur/ha (gypsum) (T6) (7.95 kg ha-1

) and RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) 37.5 kg sulphur/ha (gypsum) (T7) (9.13 kg ha

-1).

At grain filling stage, the treatment receiving RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 50 kg sulphur/ha (Factomphos) (T5) recorded the highest sulphur uptake of 19.05 kg per ha and it was on par with treatment received RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 37.5 kg sulphur/ha (Factomphos) (T4) (16.70 kg ha


treatments. The lowest sulphur uptake of 7.22 kg per ha was observed in the treatment receiving RDF alone (T1) and the value was on par with the application of RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) (T2) (9.67 kg ha

-1).

Table 27. Effect of different sources and levels of sulphur on plant sulphur (S) content (%) and uptake (kg

ha-1

) by rice


Straw Grain


4.55 (0.148)

5.86 (0.127)

7.22 (0.123)

5.28 (0.131)

5.03


6.23 (0.171)

7.82 (0.155)

9.67 (0.142)

6.64 (0.159)

6.70

T3: T2 + 25.0 kg sulphur/ha (Factomphos) (0.224)

8.40 (0.209) 10.11

(0.195) 13.81

(0.167) 8.44

(0.176) 8.06


(0.245) 12.40

(0.230) 16.70

(0.194) 10.28

(0.223) 10.59


(0.268) 14.04

(0.257) 19.05

(0.207) 11.33

(0.235) 11.54


6.82 (0.173)

7.95 (0.168) 10.83

(0.153) 7.37

(0.161) 6.93


8.45 (0.197)

9.13 (0.183) 12.20

(0.166) 8.30

(0.178) 7.98


9.01 (0.201)

9.35 (0.191) 12.90

(0.172) 8.76

(0.181) 8.26

S.Em+ (0.014) 0.530

(0.018) 1.094

(0.014) 1.015

(0.010) 0.495

(0.013) 0.609

CD (P=0.05) (0.041)

1.61 (0.054)

3.32 (0.043)

3.08 (0.029)

1.50 (0.040)

1.85

Values in parentheses indicate S concentration (%)





At harvest, the highest straw sulphur uptake of 11.33 kg per ha registered by the treatment receiving RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 50 kg sulphur/ha (Factomphos) (T5) and it was on par with application of RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 37.5 kg sulphur/ha (Factomphos) (T4) (10.28 kg ha

-1) and significantly superior over

the rest of treatments. The lowest sulphur uptake of 5.28 kg per ha was observed in the treatment receiving RDF alone (T1) followed by (T2) (6.64 kg ha

-1).

In grain, the treatment receiving RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 50 kg sulphur/ha (Factomphos) (T5) recorded the highest sulphur uptake of 11.54 kg per ha and it was on par with treatments that received RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 37.5 kg sulphur/ha (Factomphos) (T4) (10.59 kg ha

-1) and superior over rest of treatments. The lowest

grain sulphur uptake of 5.03 kg per ha was noticed in the treatment receiving RDF alone (T1) and it was on par with the treatments receiving RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) (T2) (6.70 kg ha

-1).

4.3.7 Micronutrient content and uptake by first rice crop

4.3.7.1 Zn content (mg kg-1

)

The data pertaining to the direct effect of different sources and levels of sulphur on Zn content of first rice crop are presented in Table 28.

At active tillering, the treatment that received RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 50 kg sulphur/ha (Factomphos) (T5) recorded the highest Zn content of 30.56 mg kg

-

1 and it was on par with treatments that received RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) +

37.5 kg sulphur/ha (Factomphos) (T4) (29.22 mg kg-1

) but superior over the rest of treatments. The lowest Zn content of 19.88 mg kg

-1 was noticed in the treatment receiving RDF alone (T1)

and it was on par with the treatment receiving RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) (T2) (23.10 mg kg

-1).

At panicle initiation and grain filling stages same trend as of at active tillering was observed. The highest Zn content of 28.21 and 26.22 mg kg

-1 was noticed in the treatment

received RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 50 kg sulphur/ha (Factomphos) (T5) at respective stages. It was on par with the treatment receiving RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 37.5 kg sulphur/ha (Factomphos) (T4) (27.01 and 25.02 mg kg

-1) and superior

over rest of treatments at respective stages. The lowest Zn content of 18.34 and 16.97 mg kg-

1 were noticed in the treatment that received RDF alone (T1) and it was on par with the

treatment that received RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) (T2) respectively (21.12 and 19.14 mg kg

-1) respectively.

In straw, the highest Zn content of 23.56 mg kg-1

was registered in the treatment receiving RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 50 kg Sulphur/ha (Factomphos) (T5) and it was on par with the treatment receiving RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 37.5 kg sulphur/ha (Factomphos) (T4) (22.38 mg kg-1) but it was significantly superior over the rest of treatments. The treatment receiving RDF alone (T1) recorded the lowest Zn content of 14.42 mg kg-1. All treatments registered significantly higher Zn content over the treatment that received RDF alone (T1).

Similarly, in grain, the highest Zn content of 22.58 mg kg-1

was recorded in the treatment receiving RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 50 kg sulphur/ha (Factomphos) (T5) and it was on par with the treatment receiving RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 37.5 kg sulphur/ha (Factomphos) (T4) (21.46 mg kg

-1). The treatment that

received RDF alone (T1) recorded the lowest Zn content (13.82 mg kg-1) and differed significantly from all other treatments.

4.3.7.2 Zn uptake (g ha-1

)

The data pertaining to the direct effect of different sources and levels of sulphur on Zn uptake of first rice crop are presented in Table 28.

Table 28. Effect of different sources and levels of sulphur on plant Zn content (mg kg


-

1) by rice


Straw Grain

T1: RDF (control) (19.88) 58.03

(18.34) 72.66

(16.97) 96.47

(14.42) 61.91

(13.82) 53.04


(21.12) 96.58

(19.14)119.63

(16.45) 76.87

(15.77) 66.42


(24.22) 117.20

(22.42) 158.76

(20.53) 103.74

(19.70) 90.19


(27.01) 136.72

(25.02) 181.72

(22.38) 118.61

(21.46) 101.87


(28.21) 147.79

(26.22) 194.40

(23.56) 128.92

(22.58) 110.85


(22.76) 104.58

(21.02) 135.54

(18.80) 90.52

(18.02) 77.56


(23.59) 109.34

(21.82) 145.52

(19.42) 97.04

(18.64) 83.60


(24.04) 111.79

(22.23) 150.16

(19.90) 101.37

(19.08) 87.04

S.Em+ (1.272)

6.01 (1.103)

7.42 (0.744)

7.60 (0.615)

4.25 (0.628)

3.28

CD (P=0.05) (3.86) 18.24

(3.34) 22.51

(2.26) 23.05

(1.86) 12.90

(1.91) 9.95

Values in parentheses indicate Zn concentration (mg kg-1

)





The experimental data on Zn uptake due to sulphur application was significantly differed. At all the stages, application of sulphur increased Zn uptake.

At active tillering and panicle initiation stages, the highest Zn uptake of 127.04 and 147.79 g per ha was observed with the treatment that received RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 50 kg Sulphur/ha (Factomphos) (T5). It was on par with the treatment receiving RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 37.5 kg sulphur/ha (Factomphos) (T4) (115.77 and 136.72 g ha

-1) and superior over rest of treatments respectively. The lowest Zn uptake of

58.03 and 72.66 g per ha was noticed with the treatment that received RDF alone (T1) and it differed significantly with all treatments at respective stages.

At grain filling stage, the highest Zn uptake (194.40 g ha-1

) was registered in the treatment that received RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 50 kg Sulphur/ha (Factomphos) (T5) and it was on par with the treatment receiving RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 37.5 kg sulphur/ha (Factomphos) (T4) (181.72 g ha

-1) and superior over

the rest of treatments. The lowest Zn uptake of 96.47 g ha-1

was observed in the treatment that received RDF alone (T1) and it differed significantly with other treatments.

In straw at harvest, the highest Zn uptake of 128.92 g per ha was recorded in the treatment receiving RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 50 kg sulphur/ha (Factomphos) (T5). It was on par with the treatment that received RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 37.5 kg sulphur/ha (Factomphos) (T4) (118.61 g ha

-1) and superior over

the rest of treatments. The lowest Zn uptake of 61.91 g per ha was registered in the treatment that received RDF alone (T1). All treatments registered significantly higher Zn uptake over RDF alone (T1).

In grain, the treatment receiving RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 50 kg sulphur/ha (Factomphos) (T5) registered the highest Zn uptake of 110.85 g per ha and it was on par with the treatment receiving RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 37.5 kg sulphur/ha (Factomphos) (T4) (101.87 g ha

-1). The treatment receiving RDF (T1) recorded the

lowest Zn uptake of 53.04 g per ha and it differed significantly with all treatments.

4.3.7.3 Cu content (mg kg-1

)

The data pertaining to the direct effect of different sources and levels of sulphur on Cu content of first rice crop are presented in Table 29.

A perusal of data revealed that the effect of different treatments was found to be non-significant with respect to Cu content.

4.3.7.4 Cu uptake (g ha-1

)

The data pertaining to the direct effect of different sources and levels of sulphur on Cu uptake by first rice crop are presented in Table 29.

The results of the experiment indicated that the treatments increased the Cu uptake at all stages due to sulphur treatments.

At active tillering stage, the highest Cu uptake of 41.57 g ha-1

was observed with the treatment that received RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 50 kg Sulphur/ha (Factomphos) (T5). It was on par with the treatment receiving RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 25 kg sulphur/ha (Factomphos) (T3) (34.03 g ha

-1), RDF + FYM (10 t/ha) +

ZnSO4 (20 kg/ha) + 37.5 kg sulphur/ha (Factomphos) (T4) (38.23 g ha-1

) and RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 50 kg sulphur/ha (gypsum) (T8) (34.47 g ha

-1). The lowest Cu

uptake of 23.59 g per ha was observed in the treatment that received RDF alone (T1). It was on par with the treatments receiving RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) (T2) (28.46 g ha

-1) and RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 25 kg sulphur/ha (gypsum) (T6) (30.93 g

ha-1

).

At panicle initiation stage, the treatment that received RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 50 kg sulphur/ha (Factomphos) (T5) registered the highest Cu uptake of 46.81 g per ha and it was on par with the treatments receiving RDF + FYM (10 t/ha) + ZnSO4 (20

Table 29. Effect of different sources and levels of sulphur on plant Cu content (mg kg


-

1) by rice


Straw Grain

T1: RDF (control) (8.08) 23.59

(7.23) 28.63

(6.18) 35.13

(5.60) 24.04

(4.03) 15.45


(7.62) 34.82

(6.45) 40.22

(5.82) 27.20

(4.18) 17.61


(8.13) 39.34

(6.96) 49.25

(6.28) 31.71

(5.40) 24.70


(8.63) 43.66

(7.38) 53.56

(6.67) 35.32

(5.72) 27.15


(8.94) 46.81

(7.67) 56.87

(6.92) 37.87

(5.91) 28.99


(7.67) 35.22

(6.56) 42.27

(5.94) 28.58

(5.13) 22.08


(7.97) 36.92

(6.82) 45.45

(6.15) 30.71

(5.31) 23.79


(8.13) 37.78

(7.02) 47.39

(6.33) 32.22

(5.48) 24.98

S.Em+ (0.672)

2.89 (0.523)

3.27 (0.418)

3.16 (0.445)

2.21 (0.452)

2.06

CD (P=0.05) (NS) 8.78

(NS) 9.91 (NS) 9.59

(NS) 6.70

(NS) 6.24

Values in parentheses indicate Cu concentration (mg kg-1

)






kg/ha) + 25 kg sulphur/ha (Factomphos) (T3) (39.34 g ha-1

), RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 37.5 kg sulphur/ha (Factomphos) (T4) (43.66 g ha

-1), RDF + FYM (10

t/ha) + ZnSO4 (20 kg/ha) + 37.5 kg sulphur/ha (gypsum) (T7) (36.92 g ha-1


-1). The lowest Cu


-1), RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 25 kg sulphur/ha (gypsum) (T6) (35.22 g ha

-

1), RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 37.5 kg sulphur/ha (gypsum) (T7) (36.92 g ha

-

1). RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 50 kg sulphur/ha (gypsum) (T8) (37.78 g ha

-1).

At grain filling stage, the highest Cu uptake of 56.87 g per ha was noticed in the treatment that received RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 50 kg sulphur/ha (Factomphos) (T5) and it was on par with the treatments receiving RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 25 kg sulphur/ha (Factomphos) (T3) (49.25 g ha

-1), RDF + FYM (10 t/ha)

+ ZnSO4 (20 kg/ha) + 37.5 kg sulphur/ha (Factomphos) (T4) (53.56 g ha-1


-1). The lowest Cu


-1) and RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 25 kg sulphur/ha (gypsum) (T6) (42.27 g

ha-1

).

In straw at harvest, the treatment receiving RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 50 kg sulphur/ha (Factomphos) (T5) registered the highest Cu uptake of 37.87 g per ha. The value was on par with the treatments receiving RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 25 kg sulphur/ha (Factomphos) (T3) (31.71 g ha


37.5 kg sulphur/ha (Factomphos) (T4) (35.32 g ha-1


-1). The treatment receiving RDF alone

(T1) registered the lowest Cu uptake of 24.04 g per ha and it was on par with the treatments receiving RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) (T2) (27.20 g ha

-1), RDF + FYM (10 t/ha) +

ZnSO4 (20 kg/ha) + 25 kg sulphur/ha (gypsum) (T6) (28.58 g ha-1

) and RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 37.5 kg sulphur/ha (gypsum) (T7) (30.71 g ha

-1).

In grain, the treatment receiving RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 50 kg sulphur/ha (Factomphos) (T5) showed the highest Cu uptake of 28.99 g per ha and it was on par with the treatments receiving RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha (T3) (24.70 g ha

-1),

RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 37.5 kg sulphur/ha (Factomphos) (T4) (27.15 g ha-

1), RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 37.5 kg sulphur/ha (gypsum) (T7) (23.79 g ha

-1)

and RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 50 kg sulphur/ha (gypsum) (T8) (24.98 g ha-

1). The lowest Cu uptake of 15.45 g per ha was observed with the treatment that receiving

RDF alone (T1). It was on par with the application of RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) (T2) (17.61 g ha

-1).

4.3.7.5 Fe content (mg kg-1

)

The data pertaining to the direct effect of different sources and levels of sulphur on Fe content of first rice crop are presented in Table 30.

It was observed that the effect of sulphur nutrition did not influence significantly with respect to Fe content.

4.3.7.6 Fe uptake (g ha-1

)

The data pertaining to the direct effect of different sources and levels of sulphur on Fe uptake by first rice crop are presented in Table 30.

The results of the experiment indicated that the treatments significantly increased the Fe uptake at all stages of the crop growth.

At active tillering stage, the highest Fe uptake of 1870.2 g per ha was noticed in the treatment that received RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 50 kg sulphur/ha (Factomphos) (T5). It was on par with the treatment receiving RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 37.5 kg sulphur/ha (Factomphos) (T4) (1679.5 g ha


over the other treatments. The lowest Fe uptake of 1008.7 g per ha was observed with the treatment that receiving RDF alone (T1). It was on par with the application of RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) (T2) (1213.4 g ha

-1) and RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) +

25 kg sulphur/ha (gypsum) (T6) (1304.7 g ha-1

).

At panicle initiation stage, the highest Fe uptake of 2143.2 g per ha was noticed in the treatment that received RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 50 kg sulphur/ha (Factomphos) (T5). It was on par with the treatment receiving RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 37.5 kg sulphur/ha (Factomphos) (T4) (1959.8 g ha


over the rest of treatments. The lowest Fe uptake of 1257.4 g per ha was observed with the treatment that receiving RDF alone (T1). It was on par with the application of RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) (T2) (1507.8 g ha

-1), RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 25

kg sulphur/ha (gypsum) (T6) (1525.1 g ha-1


-1).

At grain filling stage the highest Fe uptake of 2509.0 g per ha was noticed in the treatment that received RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 50 kg sulphur/ha (Factomphos) (T5). It was on par with the treatment receiving RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 37.5 kg sulphur/ha (Factomphos) (T4) (2325.5 g ha


over the rest of treatments. The lowest Fe uptake of 1499.6 g per ha was observed with the treatment that receiving RDF alone (T1). It was on par with the application of RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) (T2) (1700.0 g ha


25 kg sulphur/ha (gypsum) (T6) (1773.5 g ha-1

).

In straw at harvest, the highest Fe uptake of 1740.9 g per ha was registered with the treatment receiving RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 50 kg sulphur/ha (Factomphos) (T5). It was on par with the treatment receiving RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 37.5 kg sulphur/ha (Factomphos) (T4) (1599.2 g ha


over the rest of treatments. The treatment receiving RDF alone (T1) recorded the lowest Fe uptake of 1070.1 g per ha. It was on par with the treatments receiving RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) (T2) (1178.0 g ha

-1), RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 25 kg

sulphur/ha (gypsum) (T6) (1247.6 g ha-1


-1).

In grain, the highest Fe uptake of 1213.6 g per ha which was recorded with the

application of RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 50 kg sulphur/ha (Factomphos) (T5). It was on par with the treatments of RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 37.5 kg sulphur/ha (Factomphos) (T4) (1113.3 g ha

-1). The treatment receiving RDF alone (T1)

recorded significantly the lowest Fe uptake of 736.6 g per ha. It was on par with the treatments that receiving RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) (T2) (848.8 g ha

-1) and

RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 25 kg sulphur/ha (gypsum) (T6) (876.0 g ha-1

).

4.3.7.7 Mn content (mg kg-1

)

The data pertaining to the direct effect of different sources and levels of sulphur on Mn content of first rice crop are presented in Table 31.

The results of the experiment revealed that sulphur application did not influence Mn content throughout the growing period.

4.3.7.8 Mn uptake (g ha-1

)

The data pertaining to the direct effect of different sources and levels of sulphur on Mn uptake by first rice crop are presented in Table 31.

The results of the experiment indicated that sulphur nutrition significantly increased the Mn uptake at all stages of crop growth.

At active tillering stage, panicle initiation and grain filling stages, the highest Mn uptake of 1358.3, 1417.3 and 1545.7 g per ha was noticed in the treatment that received RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 50 kg sulphur/ha (Factomphos) (T5). It was on par with the treatment receiving RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 37.5 kg sulphur/ha

Table 30. Effect of different sources and levels of sulphur on plant Fe content (mg kg


-1)

by rice


Straw Grain

T1: RDF (control) (345.56) 1008.7

(317.36) 1257.4

(263.78) 1499.6

(249.26) 1070.1

(191.91) 736.6


(329.72) 1507.8

(272.44) 1700.0

(252.09) 1178.0

(201.53) 848.8


(357.93) 1732.0

(295.89) 2095.2

(278.78) 1408.7

(216.75) 992.3


(387.16) 1959.8

(320.18) 2325.5

(301.73) 1599.2

(234.52) 1113.3


(409.09) 2143.2

(338.41) 2509.0

(318.14) 1740.9

(247.21) 1213.6


(331.90) 1525.1

(275.05) 1773.5

(259.10) 1247.6

(203.52) 876.0


(345.62) 1601.9

(288.06) 1921.1

(272.21) 1360.2

(210.68) 944.9


(361.05) 1678.9

(298.47) 2016.2

(282.05) 1436.8

(218.30) 995.9

S.Em+ (23.30) 108.03

(20.49) 124.47

(17.65) 121.48

(17.04) 99.28

(12.59) 59.91

CD (P=0.05) (NS)

327.68 (NS)

377.53 (NS)

368.48 (NS)

301.12 (NS)

181.72

Values in parentheses indicate Fe concentration (mg kg-1

)






(Factomphos) (T4) (1235.9, 1318.5 and 1415.7 g ha-1

) but significantly superior over the other treatments. The lowest Mn uptake of 744.1, 840.2 and 913.4 g per ha was registered with the treatment that receiving RDF alone (T1). It was on par with the application of RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) (T2) (889.7, 971.1 and 1092.1 g ha


ZnSO4 (20 kg/ha) + 25 kg sulphur/ha (gypsum) (T6) (955.5, 992.1 and 1101.6 g ha-1

).

In straw, the highest Mn uptake of 1698.6 g per ha was registered in the treatment of RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 50 kg sulphur/ha (Factomphos) (T5). It was on par with the treatments receiving RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 37.5 kg sulphur/ha (Factomphos) (T4) (1560.3 g ha

-1) but significantly higher over the rest of treatments. The

treatment receiving RDF alone (T1) registered the lowest Mn uptake of 1044.1 g per ha. It was on par with the treatment that received RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) (T2) (1176.8 g ha

-1) and RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 25 kg sulphur/ha (gypsum) (T6)

(1217.2 g ha-1

).

In grain, the highest Mn uptake of 162.4 g per ha was recorded with the application of RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 50 kg sulphur/ha (Factomphos) (T5) and it was on par with the treatments receiving RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 37.5 kg sulphur/ha (Factomphos) (T4) (147.9 g ha


treatments. The treatment receiving RDF alone (T1) recorded the lowest Mn uptake of 82.0 g per ha. It differed significantly with all treatments.

4.3.8. Soil pH and EC at different stages of rice (first crop)

The data pertaining to the direct effect of different sources and levels of sulphur on soil pH and EC of first rice crop are presented in Table 32 and 33.

The results of the experiment revealed that the treatments did not significantly influence soil pH and EC at different stages of rice.

4.3.9 Sulphur fractions in first rice crop soil


)

The data pertaining to the direct effect of different sources and levels of sulphur on sulphate sulphur content of first rice crop are presented in Table 34.

The results of the investigation revealed that sulphur nutrition remarkably influenced the sulphate sulphur content in soil.

At active tillering, panicle initiation, grain filling stages and at harvest the highest sulphate sulphur content of 23.14, 19.92, 17.83 and 16.67 mg per kg was registered in the treatment that received RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 50 kg sulphur/ha (Factomphos) (T5). It was on par with the application of RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 37.5 kg sulphur/ha (Factomphos) (T4) (21.05, 17.83, 16.92 and 15.26 mg kg

-1) at

respective growth stages but significantly superior over the rest of treatments. The treatment which received RDF alone (T1) registered the lowest sulphate sulphur contents of 12.75, 11.25, 11.0 and 10.81 mg per kg throughout growing period. At active tillering, panicle initiation and grain filling stages, T1 (RDF alone) treatment was on par with T2 which recorded 14.43, 13.75 and 13.36 mg per kg respectively. At harvest, treatment T1 registered lowest sulphate sulphur (10.81 mg kg

-1) and it was on par with the treatments receiving RDF + FYM

(10 t/ha) + ZnSO4 (20 kg/ha) (T2) (12.32 mg kg-1

), RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 25 kg sulphur/ha (Factomphos) (T3) (13.18 mg kg


kg/ha) + 25 kg sulphur/ha (gypsum) (T6) (12.92 mg kg-1

).


)

The data pertaining to the effect of different sources and levels of sulphur on water soluble sulphur content of first rice crop are presented in Table 35.

Table 31. Effect of different sources and levels of sulphur on plant Mn content (mg kg


-1) by

rice


Straw Grain


744.1 (212.07)

840.2 (160.66)

913.4 (243.21) 1044.1

(21.36) 82.0


889.7 (212.35)

971.1 (175.01) 1092.1

(251.82) 1176.8

(26.03) 109.6


(244.96) 1185.4

(176.43) 1249.3

(272.01) 1374.5

(28.46) 130.3


(260.47) 1318.5

(194.92) 1415.7

(294.40) 1560.3

(31.15) 147.9


(270.53) 1417.3

(208.49) 1545.7

(310.41) 1698.6

(33.08) 162.4


955.5 (215.90)

992.1 (170.85) 1101.6

(252.80) 1217.2

(26.15) 112.5


(234.36) 1086.3

(175.17) 1168.2

(265.59) 1327.2

(27.69) 124.2


(246.11) 1144.4

(179.84) 1214.8

(275.20) 1401.9

(28.84) 131.6

S.Em+ (17.84) 78.75

(13.73) 57.28

(10.08) 69.69

(15.35) 79.39

(2.14) 8.51

CD (P=0.05) (NS)

237.64 (NS)

173.75 (NS)

211.39 (NS)

240.81 (NS) 25.80

Values in parentheses indicate Mn concentration (mg kg-1

)






Table 32. Effect of different sources and levels of sulphur on pH at different growth stages of

rice


T1: RDF (control) 8.43 8.45 8.30 8.20








S.Em+ 0.160 0.051 0.089 0.045







Table 33. Effect of different sources and levels of sulphur on EC (dS m

-1) at different growth

stages of rice


T1: RDF (control) 0.21 0.20 0.19 0.24








S.Em+ 0.044 0.030 0.014 0.029







Table 34. Effect of different sources and levels of sulphur on sulphate sulphur (mg kg-1

) in soil


T1: RDF (control) 12.75 11.25 11.00 10.81








S.Em+ 0.771 0.976 0.784 0.883

CD (P=0.05) 2.34 2.96 2.38 2.68





Data presented in the Table 35 indicated that, at all stages, the highest water soluble sulphur contents of 36.58, 34.41, 32.46 and 30.82 mg per kg were registered in the treatment receiving RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 50 kg sulphur/ha (Factomphos) (T5). It was on par with the treatment receiving RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 37.5 kg sulphur/ha (Factomphos) (T4) (33.22, 30.83, 29.11 and 28.27 mg kg

-1) but siginificantly

superior over the rest of treatments. The treatment which received RDF alone (T1) registered the lowest water soluble sulphate contents of 20.37, 18.21, 17.14 and 16.09 mg per kg. The treatment which received RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) (T2) was on par with T1 and resulted 22.65, 19.12, 18.49 and 17.03 mg per kg with respect to water soluble sulphur at active tillering, panicle initiation, grain filling stages and harvest, respectively.


)

The data pertaining to the direct effect of different sources and levels of sulphur on organic sulphur content of first rice crop are presented in Table 36.

Organic sulphur content in soil differed significantly due to sulphur nutrition at grain filling stage and harvest.

The treatment receiving RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 50 kg sulphur/ha (Factomphos) (T5) registered the highest organic sulphur contents of 137.31 and 129.29 mg per kg

at grain filling and harvest stages. It was on par with application of RDF + FYM (10

t/ha) + ZnSO4 (20 kg/ha) + 37.5 kg sulphur/ha (Factomphos) (T4) (129.61 and 122.30 mg kg-1

) but significantly superior over the rest of treatments. At grain filling stage, the lowest organic sulphur contents of 108.69 mg per kg

was noticed in the treatment that received RDF alone

(T1) and it was on par with the treatments receiving RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) (T2) (113.18 mg kg

-1), RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 25 kg sulphur/ha

(Factomphos) (T3) (120.14 mg kg-1

), RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 25 kg sulphur/ha (gypsum) (T6) (114.22 mg kg


37.5 kg sulphur/ha (gypsum) (T7) (118.48 mg kg-1

). At harvest, the lowest organic sulphur content of 100.48 mg per kg was recorded in the treatment that received RDF alone (T1) and it was on par with the treatments receiving RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) (T2) (108.32 mg kg

-1), RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 25 kg sulphur/ha (gypsum) (T6)

(109.13 mg kg-1

).


)

The data pertaining to the effect of different sources and levels of sulphur on non-sulphate sulphur content of first rice crop are presented in Table 37.

The perusal of the data revealed that non-sulphate sulphur content in soil did not differ significantly due to sulphur nutrition.


)

The data pertaining to the effect of different sources and levels of sulphur on total sulphur content of first rice crop are presented in Table 38.

The results of the experiment indicated that the differences due to sulphur nutrition on total sulphur content in soil were not significant throughout the cropping period. However, the treatment receiving RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 50 kg sulphur/ha (gypsum) (T8) registered the highest total sulphur contents of 1070.0, 1060.7, 1056.1 and 1052.8 mg per kg

at active tillering, panicle initiation, grain filling stages and at harvest respectively. The

lowest total sulphur contents of 956.5, 946.6, 941.7 and 936.5 mg per kg were noticed with

the treatment received RDF alone (T1) at respective growth stages.

4.3.10 DTPA-extractable micronutrients in soil (first rice crop)

4.3.10.1 DTPA-extractable Zn (mg kg-1

)

The data pertaining to the direct effect of different sources and levels of sulphur on DTPA-extractable Zn content of first rice crop are presented in Table 39.

Table 35. Effect of different sources and levels of sulphur on water soluble sulphur (mg kg

-1) in

soil


T1: RDF (control) 20.37 18.21 17.14 16.09








S.Em+ 1.255 1.273 1.203 1.174

CD (P=0.05) 3.81 3.86 3.65 3.56





Table 36. Effect of different sources and levels of sulphur on organic sulphur (mg kg

-1) in soil


T1: RDF (control) 90.52 96.47 108.69 100.48








S.Em+ 4.421 5.656 4.046 3.556

CD (P=0.05) NS NS 12.27 10.78






Table 37. Effect of different sources and levels of sulphur on non-sulphate sulphur

(mg kg-1

) in soil


T1: RDF (control) 833.0 820.7 804.9 809.1








S.Em+ 32.32 29.09 31.38 30.27







Table 38. Effect of different sources and levels of sulphur on total sulphur (mg kg

-1) in soil


T1: RDF (control) 956.6 946.6 941.7 936.5








S.Em+ 31.17 29.53 32.24 29.99






T8


At active tillering, panicle initiation and grain filling stages, the difference in DTPA-extractable Zn content due to treatments was significant. The treatment received RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) (T2) registered the highest DTPA extractable Zn (0.99, 0.96 and o.96 mg kg

-1) at respective growth stages. It was on par with the treatments that received

RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 25 kg sulphur/ha (Factomphos) (T3) (0.82, 0.81, and 0.80 mg kg


(0.89, 0.88 and 0.87 mg kg-1

) and RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 37.5 kg sulphur/ha (gypsum) (T7) (0.84, 0.82 and 0.81 mg kg

-1). The lowest DTPA extractable Zn was

recorded with the treatment receiving RDF alone (T1) (0.58, 0.57 and 0.56 mg kg-1

) at respective growth stages. It was on par with the treatments receiving differed RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 50 kg sulphur/ha (Factomphos) (T5) (0.70, 0.68, and 0.68 mg kg

-1).

At harvest, treatment that received RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) (T2) recorded the highest DTPA-extractable Zn content of 0.94 mg per kg. It was on par with the treatment supplied with RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 25 kg sulphur/ha (Factomphos) (T3) (0.79 mg kg


sulphur/ha (gypsum) (T6) (0.85 mg kg-1


-1). The treatment receiving RDF alone (T1) showed the

lowest DTPA-extractable Zn content of 0.55 mg per kg and It was on par with the treatments that received RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 37.5 kg sulphur/ha (Factomphos) (T4) (0.72 mg kg


(Factomphos) (T5) (0.66 mg kg-1

).

4.3.10.2 DTPA-extractable Cu (mg kg-1

)

The data pertaining to the residual effect of different sources and levels of sulphur on DTPA-extractable Cu content of first rice crop are presented in Table 40.

Non-significant difference was observed between treatments with respect to DTPA-extractable Cu content in soil at all stages of first rice crop.

4.3.10.3 DTPA-extractable Fe (mg kg-1

)

The data pertaining to the residual effect of different sources and levels of sulphur on DTPA-extractable Fe content of first rice crop are presented in Table 41.

The results of the investigation revealed that the differences due to sulphur nutrition were not significant.

4.3.10.4 DTPA-extractable Mn (mg kg-1

)

The data pertaining to the residual effect of different sources and levels of sulphur on DTPA-extractable Mn content of first rice crop are presented in Table 42.

A perusal of data of the investigation revealed that DTPA-extractable Mn content did not differ as influenced by sulphur nutrition.

4.3.11 Growth parameters of succeeding rice crop

4.3.11.1 Plant height (cm)

The data pertaining to the residual effect of different sources and levels of sulphur on plant height of succeeding rice crop at different stages of growth are presented in Table 43.

Plant height linearly increased with the advancement in age up to harvest.

The results of the investigation indicate that the different sources and levels of sulphur had significant influence on plant height at active tillering, panicle initiation, grain filling stages and at harvest.

At active tillering stage, application of RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 50 kg sulphur/ha (Factomphos) (T5) registered significantly higher plant height of 53.0 cm and it

Table 39. Effect of different sources and levels of sulphur on DTPA-extractable Zn (mg kg

-1)

in soil


T1: RDF (control) 0.58 0.57 0.56 0.55








S.Em+ 0.060 0.053 0.052 0.057

CD (P=0.05) 0.182 0.161 0.158 0.174





T8

Table 40. Effect of different sources and levels of sulphur on DTPA-extractable Cu (mg kg

-1)

in soil


T1: RDF (control) 3.08 3.00 2.97 2.93








S.Em+ 0.175 0.153 0.140 0.135






T8


Table 41. Effect of different sources and levels of sulphur on DTPA-extractable Fe (mg kg

-1)

in soil


T1: RDF (control) 9.78 9.96 13.66 10.03








S.Em+ 0.539 0.481 0.657 0.497






T8


Table 42. Effect of different sources and levels of sulphur on DTPA-extractable Mn (mg kg-1

) in soil


T1: RDF (control) 12.70 15.75 13.11 10.86








S.Em+ 0.730 0.873 0.698 0.774






T8


was on par with treatments receiving RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 37.5 kg sulphur/ha (Factomphos) (T4) (50.6 cm) and RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 50 kg sulphur/ha (gypsum) (T8) (50.9 cm). The lowest plant height of 44.6 cm was recorded with the application of RDF alone (T1). It differed significantly with all treatments.

The highest plant height of 69.5 cm at panicle initiation stage was recorded with the application of RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 50 kg sulphur/ha (Factomphos) (T5) and it was on par with the application of RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 37.5 kg sulphur/ha (Factomphos) (T4) (67.7 cm), RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 37.5 kg sulphur/ha (gypsum) (T7) (67.3 cm) and RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 50 kg sulphur/ha (gypsum) (T8) (68.3 cm). The lowest plant height of 60.6 cm was recorded with the application of RDF alone (T1) and it differed significantly with rest of treatments.

At grain filling stage, the treatment receiving RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 50 kg sulphur/ha (Factomphos) (T5) registered the highest plant height of 77.9 cm and it was on par with the application of RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 37.5 kg sulphur/ha (Factomphos) (T4) (76.8 cm), RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 37.5 kg sulphur/ha (gypsum) (T7) (76.0 cm) and RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 50 kg sulphur/ha (gypsum) (T8) (77.1 cm). The lowest plant height of 70.8 cm was recorded with the application of RDF alone (T1) and it differed significantly with all treatments.

Among the treatments, the highest plant height of 86.5 cm at harvest was recorded by the treatment receiving RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 50 kg sulphur/ha (Factomphos) (T5) and it was on par with application of RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 37.5 kg sulphur/ha (Factomphos) (T4) (85.5 cm), RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 37.5 kg sulphur/ha (gypsum) (T7) (84.3 cm) and RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 50 kg sulphur/ha (gypsum) (T8) (86.1 cm). The lowest plant height of 77.5 cm was recorded with the application of RDF alone (T1). All treatments registered significantly greater plant height over the treatment receiving RDF alone (T1).

4.3.11.2 Number of tillers per hill

The data pertaining to the residual effect of different sources and levels of sulphur on number of tillers per hill of succeeding rice crop at different stages of growth are presented in Table 44.

Number of tillers per hill differed significantly as influenced by different sources and levels of sulphur.

At active tillering stage, the highest number of tillers of 16.47 was recorded with the application of RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 50 kg sulphur/ha (Factomphos) (T5) and it was on par with the treatments receiving RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 37.5 kg sulphur/ha (Factomphos) (T4) (14.93) and RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 50 kg sulphur/ha (gypsum) (T8) (15.87) but superior over the rest of treatments. The lowest number of tillers of 11.17 was registered by the treatment receiving RDF alone (T1). It differed significantly with rest of the treatments.

At panicle initiation stage, the highest number of tillers of 20.08 was recorded with the application of RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 50 kg sulphur/ha (Factomphos) (T5) and it was on par with the treatments receiving RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 37.5 kg sulphur/ha (Factomphos) (T4) (19.36) and RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 50 kg sulphur/ha (gypsum) (T8) (19.48). The lowest number of tillers of 14.95 was registered by the treatment receiving RDF alone (T1) and it was on par with the treatments receiving RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) (T2) (16.65) and RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 25 kg sulphur/ha (gypsum) (T6) (16.76).

At grain filling stage, the highest number of tillers of 19.70 was recorded with the treatment receiving RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 50 kg sulphur/ha (Factomphos) (T5) and it was on par with application of RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 37.5 kg sulphur/ha (Factomphos) (T4) (18.80) and RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 50 kg sulphur/ha (gypsum) (T8) (18.13). The lowest number of tillers of 12.67 at grain

Table 43. Residual effect of different sources and levels of sulphur on plant height (cm) at

different growth stages of rice


T1: RDF (control) 44.6 60.6 70.8 77.5








S.Em+ 0.901 0.964 0.970 1.108

CD (P=0.05) 2.73 2.92 2.94 3.36





T8

Table 44. Residual effect of different sources and levels of sulphur on number of tillers per

hill at different growth stages of rice


T1: RDF (control) 11.17 14.95 12.67 14.83








S.Em+ 0.682 0.695 0.668 0.788

CD (P=0.05) 2.07 2.11 2.02 2.39





T8

filling stage was registered by the treatment receiving RDF alone (T1). The value differed significantly with rest of the treatments. At grain filling stage, slight reduction in tiller number was recorded and it was improved at harvest.

At harvest, the highest number of tillers of 21.77 was recorded with the treatment receiving RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 50 kg sulphur/ha (Factomphos) (T5) and it was on par with application of RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 37.5 kg sulphur/ha (Factomphos) (T4) (19.47) and RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 50 kg sulphur/ha (gypsum) (T8) (20.88) and the lowest number of tillers of 14.83 at harvest was registered by the treatment receiving RDF alone (T1). It was significantly different with rest of the treatments.

4.3.11.3 Dry matter production (q ha-1

)

The data pertaining to the residual effect of different sources and levels of sulphur on dry matter production of succeeding rice crop at different stages of growth are presented in Table 45.

The results of the experiment at active tillering stage indicated that the highest dry matter production of 40.39 q per ha was registered with the application of RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 50 kg sulphur/ha (Factomphos) (T5) and it was on par with the treatments receiving RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 37.5 kg sulphur/ha (Factomphos) (T4) (38.14 q ha

-1), RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 37.5 kg

sulphur/ha (gypsum) (T7) (36.78 q ha-1

) and RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 50 kg sulphur/ha (gypsum) (T8) (38.65 q ha

-1). The lowest dry matter production of 27.32 q per ha

was recorded by the treatment receiving RDF alone (T1) and the value was on par with the treatment received RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) (T2) (31.31 q ha

-1).

At panicle initiation stage, application of RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 50 kg sulphur/ha (Factomphos) (T5) recorded the highest dry matter production of 49.40 q per ha and it was on par with the treatments receiving RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 37.5 kg sulphur/ha (Factomphos) (T4) (47.13 q ha

-1), RDF + FYM (10 t/ha) + ZnSO4 (20

kg/ha) + 37.5 kg sulphur/ha (gypsum) (T7) (45.77 q ha-1

) and RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 50 kg sulphur/ha (gypsum) (T8) (47.63 q ha

-1). The treatment receiving RDF

alone (T1) registered the lowest dry matter production of 35.33 q per ha. It was found significantly different with rest of treatments.

At grain filling stage, the highest dry matter content of 66.99 q per ha was recorded in

the treatment of RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 50 kg sulphur/ha (Factomphos) (T5) and it was on par with application of RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 37.5 kg sulphur/ha (Factomphos) (T4) (64.31 q ha


50 kg sulphur/ha (gypsum) (T8) (64.95 q ha-1

). The treatment receiving RDF alone (T1) registered significantly the lowest dry matter production of 52.36 q per ha. It differed significantly with rest of treatments.

At harvest, treatment that received RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 50 kg sulphur/ha (Factomphos) (T5) registered the highest straw dry matter (49.90 q ha

-1). It was on

par with the treatments that receiving RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 37.5 kg sulphur/ha (Factomphos) (T4) (48.16 q ha


50 kg sulphur/ha (gypsum) (T8) (48.90 q ha-1

). In the treatment that received RDF alone (T1) registered the lowest dry matter production of 39.61 q per ha. All treatment registered significantly higher straw dry matter production over RDF alone (T1).

The highest grain dry matter production of 44.64 q per ha was registered in the treatment that received RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 50 kg sulphur/ha (Factomphos) (T5) and it was on par with application of RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 37.5 kg sulphur/ha (Factomphos) (T4) (43.00 q ha

-1), and RDF + FYM (10 t/ha) +

ZnSO4 (20 kg/ha) + 50 kg Sulphur/ha (gypsum) (T8) (43.02 q ha-1

). The lowest straw dry matter production of 34.42 q per ha was noticed in the treatments that received RDF alone (T1) and it differed significantly with all treatments.

Table 45. Residual effect of different sources and levels of sulphur on dry matter production (q ha-1

) of rice

Harvest

Treatments AT PI GF

Straw Grain

T1: RDF (control) 27.32 35.33 52.36 39.61 34.42

T2: RDF + FYM (10 t/ha)+ ZnSO4 (20 kg/ha) 31.31 40.30 57.29 42.88 38.19







S.Em+ 1.586 1.609 1.246 0.788 0.943

CD (P=0.05) 4.81 4.88 3.78 2.39 2.86





4.3.12 Yield parameters of succeeding rice crop

4.3.12.1 Number of panicles per m2

The data pertaining to the effect of different sources and levels of sulphur on number of panicles per m

2 of succeeding rice crop are presented in Table 46.

Significant differences were found among the treatments with respect to number of panicles per m

2.

The highest number of panicles per m2 of 442.6 was registered with the application of

RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 50 kg sulphur/ha (Factomphos) (T5) and it was on par with RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 37.5 kg sulphur/ha (Factomphos) (T4) (429.0) and RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 50 kg sulphur/ha (gypsum) (T8) (428.6). The lowest number of panicles per m

2 of 352.3 was noticed in the treatment which

received RDF alone (T1). All treatments recorded significantly higher number of panicles per m

2 over RDF alone (T1) treatment.

4.3.12.2 Panicle length (cm)

The data pertaining to the residual effect of different sources and levels of sulphur on panicle length of succeeding rice crop are presented in Table 47.

Due to sulphur nutrition, there was no significant difference existed among the treatments with respect to panicle length.

4.3.12.3 Number of grains per panicle

Significant differences were noticed among different treatments with respect to number of grains per panicle (Table 47).

The treatment receiving RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 50 kg sulphur/ha (Factomphos) (T5) registered the highest number of grains per panicle of 97.53 and it was on par with the application of RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 37.5 kg sulphur/ha (Factomphos) (T4) (90.41), RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 37.5 kg sulphur/ha (gypsum) (T7) (90.05) and RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 50 kg sulphur/ha (gypsum) (T8) (96.93). The lowest number of grains per panicle (71.72) was recorded with the application of RDF alone (T1) and it was on par with the treatment T2 (RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) (75.72), RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 25 kg sulphur/ha (Factomphos) (T3) (79.46) and RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 25 kg sulphur/ha (gypsum) (T6) (78.48).

4.3.12.4 1000-seed weight (g)

Significant differences were noticed among different treatments with respect to 1000 seed weight of succeeding rice crop (Table 47).

The treatment receiving RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 50 kg sulphur/ha (Factomphos) (T5) registered the highest 1000 seed weight of 23.43 g and it was on par with the RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 37.5 kg sulphur/ha (Factomphos) (T4) (23.32 g), RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 37.5 kg sulphur/ha (gypsum) (T7) (23.27 g) and RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 50 kg sulphur/ha (gypsum) (T8) (23.40 g). Application of RDF alone (T1) showed the lowest 1000 seed weight (21.77 g). It was on par with the treatments that received (RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) (T2) (22.28 g), RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 25 kg sulphur/ha (Factomphos) (T3) (22.32 g) and RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 25 kg sulphur/ha (gypsum) (T6) (22.39 g).

4.3.12.5 Grain yield (q ha-1

)

The results of the experiment revealed that the sources and levels of sulphur markedly influenced the grain yield of succeeding rice crop (Table 48).

Table 46. Residual effect of different sources and levels of sulphur on number of panicles per

m2

Treatments No. of panicles per m2

T1: RDF (control) 352.3

T2: RDF + FYM (10 t/ha)+ ZnSO4 (20 kg/ha) 389.6







S.Em+ 8.32

CD (P=0.05) 25.23




T8

Table 47. Residual effect of different sources and levels of sulphur on panicle length, number

of grains per panicle and 1000 grain weight of rice

Treatments Panicle

length (cm) No. of grains per panicle

1000 grain weight (g)

T1: RDF (control) 19.23 71.72 21.77








S.Em+ 0.526 2.893 0.284

CD (P=0.05) NS 8.77 0.86




T8


Application of sulphur had striking effect on grain yield. The highest grain yield of 51.90 q per ha was recorded with the application of RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 50 kg sulphur/ha (Factomphos) (T5) and it was on par with the treatments receiving RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 37.5 kg sulphur/ha (Factomphos) (T4)( 50.00 q ha

-1) and

RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 50 kg Sulphur/ha (gypsum) (T8) (50.02 q ha-1

). The lowest grain yield of 40.02 q per ha was registered with the application of RDF alone (T1) treatment. All treatments recorded significantly higher grain yield over the treatment receiving RDF alone (T1).

4.3.12.6 Straw yield (q ha-1

)

Straw yields differed significantly due to different sources and levels of sulphur (Table 48).

The highest straw yield of 58.02 q per ha was recorded in the treatment receiving RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 50 kg sulphur/ha (Factomphos) (T5) and it was on par with the application of RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 37.5 kg sulphur/ha (Factomphos) (T4) (56.00 q ha

-1) and RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 50 kg

sulphur/ha (gypsum) (T8) (56.86 q ha-1

). All treatments registered marked increase in straw yield due to application of sulphur over the treatment receiving RDF alone (T1) (46.06 q ha

-1).

4.3.12.7 Harvest index

The data pertaining to the effect of different sources and levels of sulphur on harvest index of succeeding rice crop was not statistically significant (Table 48).

4.3.13 Quality parameters of succeeding rice crop

The data pertaining to effect of different sources and levels of sulphur on grain protein and methionine content of succeeding rice crop are presented in Table 49.

4.3.13.1 Grain protein content (%)

Application of RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 50 kg sulphur/ha (Factomphos) (T5) registered the highest grain protein content of 9.78 per cent and it was on par with the treatments receiving RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 37.5 kg sulphur/ha (Factomphos) (T4) (9.39 %) and RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 50 kg sulphur/ha (gypsum) (T8) (9.64 %). All treatments significantly increased grain protein content over the treatment supplied with RDF (T1) (7.49 %) (Table 49).

4.3.13.2 Grain methionine content (mg g-1

)

The highest grain methionine content of 2.18 mg per g recorded in the treatment receiving RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 50 kg sulphur/ha (Factomphos) (T5) and it was on par with the treatment receiving RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 37.5 kg sulphur/ha (Factomphos) (T4) (1.99 mg g


50 kg sulphur/ha (gypsum) (T8) (2.00 mg g-1

). The lowest grain methionine content of 1.35 mg per g was observed in the treatment RDF alone (T1) and it was on par with the treatments received RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) (T2) (1.43 mg g

-1), RDF + FYM (10 t/ha) +

ZnSO4 (20 kg/ha) + 25 kg sulphur/ha (Factomphos) (T3) (1.56 mg g-1

) and RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 25 kg sulphur/ha (gypsum) (T6) (1.54 mg g

-1) (Table 49).

4.3.14 Major nutrient content and uptake of succeeding rice crop

4.3.14.1 Nitrogen content (%)

The data pertaining to the residual effect of different sources and levels of sulphur on nitrogen content of succeeding rice crop are presented in Table 50.

The perusal of the data revealed that sulphur nutrition remarkably influenced nitrogen content in succeeding rice crop.

Table 48. Residual effect of different sources and levels of sulphur on grain yield, straw yield

and harvest index of rice

Treatments Grain yield (q ha

-1)

Straw yield (q ha

-1)

Harvest index

T1: RDF (control) 40.02 46.06 0.465








S.Em+ 1.097 0.916 0.008

CD (P=0.05) 3.33 2.78 NS




T8


Table 49. Residual effect of different sources and levels of sulphur on grain protein (%) and

methionine content (mg g-1

)

Treatments Grain protein (%) Methionine (mg

g-1

)

T1: RDF (control) 7.49 1.35

T2: RDF + FYM (10 t/ha)+ ZnSO4 (20 kg/ha) 8.59 1.43







S.Em+ 0.180 0.068

CD (P=0.05) 0.54 0.21





T8

At active tillering stage, application of RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 50 kg sulphur/ha (Factomphos) (T5) recorded the highest nitrogen content of 1.88 per cent and it was on par with the treatments receiving RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 37.5 kg sulphur/ha (Factomphos) (T4) (1.74 %) and RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 50 kg sulphur/ha (gypsum) (T8) (1.81 %). The treatment that received RDF alone (T1) registered the lowest nitrogen content of 1.51 per cent. The value was on par with the treatments receiving RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) (T2) (1.57 %), RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 25 kg sulphur/ha (gypsum) (T6) (1.61) and RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 25 kg sulphur/ha (gypsum) (T7) (1.67).

At panicle initiation stage, the highest nitrogen content of 1.64 per cent was noticed with the treatment receiving of RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 50 kg sulphur/ha (Factomphos) (T5). It was on par with the treatments receiving RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 37.5 kg sulphur/ha (Factomphos) (T4) (1.53 %) and RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 50 kg sulphur/ha (gypsum) (T8) (1.58 %). The treatment that received RDF alone (T1) registered the lowest nitrogen content of 1.29 per cent. It was on par with the treatment receiving RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) (T2) (1.32 %).

At grain filling stage, treatment that received RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 50 kg sulphur/ha (Factomphos) (T5) recorded the highest nitrogen content of 1.42 per cent and it was on par with the treatments that receiving of RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 37.5 kg sulphur/ha (Factomphos) (T4) (1.28 %) and RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 50 kg sulphur/ha (gypsum) (T8) (1.34 %). The treatment that received RDF alone (T1) recorded the lowest nitrogen content of 1.11 per cent. It was on par with the treatments receiving RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) (T2) (1.14 %), RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 25 kg sulphur/ha (Factomphos) (T3) (1.22 %), RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 25 kg sulphur/ha (gypsum) (T6) (1.17) and RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 25 kg sulphur/ha (gypsum) (T7) (1.23).

The highest straw nitrogen content of 0.96 per cent was registered with treatment received RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 50 kg sulphur/ha (Factomphos) (T5) at harvest and it was on par with the application of RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 37.5 kg sulphur/ha (Factomphos) (T4) (0.90 %) and RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 50 kg sulphur/ha (gypsum) (T8) (0.93 %). The treatment receiving RDF alone (T1) registered the lowest nitrogen content (0.75 %) and it was on par with the treatment receiving RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) (T2) (0.79 %) and RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 25 kg sulphur/ha (gypsum) (T6) (0.80 %).

In grain at harvest, the highest nitrogen content of 1.32 per cent was recorded in the treatment receiving RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 50 kg sulphur/ha (Factomphos) (T5) and it was on par with the treatments receiving RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 37.5 kg sulphur/ha (Factomphos) (T4) (1.27 %) and RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 50 kg sulphur/ha (gypsum) (T8) (1.31 %). The lowest grain nitrogen content of 1.09 per cent was registered in the treatment receiving RDF alone (T1). It was on par with the treatments receiving RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) (T2) (1.16 %) and RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 25 kg sulphur/ha (gypsum) (T6) (1.18 %).

4.3.14.2 Nitrogen uptake (kg ha-1

)

The data pertaining to the residual effect of different sources and levels of sulphur on nitrogen uptake of succeeding rice crop are presented in Table 50.

The results of the experiment indicate that sulphur nutrition strikingly influenced nitrogen uptake of succeeding rice crop.

At active tillering stage, the highest nitrogen uptake of 75.93 kg per ha was recorded with the application of RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 50 kg sulphur/ha (Factomphos) (T5) and it was on par with the treatment receiving RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 37.5 kg sulphur/ha (Factomphos) (T4) (66.36 kg ha

-1) and RDF + FYM (10

t/ha) + ZnSO4 (20 kg/ha) + 50 kg sulphur/ha (gypsum) (T8) (69.96 kg ha-1

). The treatment receiving RDF alone (T1) registered the lowest nitrogen uptake of 41.25 kg per ha and it was

Table 50. Residual effect of different sources and levels of sulphur on plant nitrogen (N) content (%)

uptake (kg ha-1

) by rice


Straw Grain

T1: RDF (control) (1.51) 41.25

(1.29) 45.58

(1.11) 58.12

(0.75) 29.71

(1.09) 37.52


(1.32) 53.20

(1.14) 65.31

(0.79) 33.48

(1.16) 44.30


(1.48) 63.89

(1.22) 75.42

(0.85) 39.27

(1.20) 49.56


(1.53) 72.11

(1.28 ) 82.32

(0.90) 43.34

(1.27) 54.61


(1.64) 81.02

(1.42) 95.13

(0.96) 47.90

(1.32) 58.92


(1.44) 61.30

(1.17) 69.44

(0.80) 35.60

(1.18) 46.70


(1.47) 67.28

(1.23) 76.32

(0.85) 39.68

(1.20) 49.84


(1.58) 75.26

(1.34) 87.03

(0.93) 45.48

(1.31) 56.36

S.Em+ (0.055) 3.406

(0.048) 3.055

(0.051) 2.477

(0.024) 1.413

(0.035) 1.447

CD (P=0.05) (0.167) 10.33

(0.146) 9.27

(0.155) 7.51

(0.074) 4.29

(0.108) 4.39

Values in parentheses indicate N concentration (%)





on par with the treatment receiving RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) (T2) (49.16 kg ha

-1).

At panicle initiation stage, the highest nitrogen uptake of 81.02 kg per ha was registered with the application of RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 50 kg sulphur/ha (Factomphos) (T5) and it was on par with the treatments receiving RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 37.5 kg sulphur/ha (Factomphos) (T4) (72.11 kg ha



). The lowest nitrogen uptake of 45.58 kg per ha was registered in the treatment receiving RDF alone (T1) and it was on par with the treatment receiving RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) (T2) (53.20 kg ha

-1).

At grain filling stage, the highest nitrogen uptake of 95.13 kg per ha was recorded with the application of RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 50 kg sulphur/ha (Factomphos) (T5) and it was significantly superior over the rest of treatments. The lowest nitrogen uptake of 58.12 kg per ha was observed in the treatment receiving RDF alone (T1) and it was on par with the treatment receiving RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) (T2) (65.31 kg ha

-1).

At harvest, the highest straw nitrogen uptake of 47.90 kg per ha was registered with the application of RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 50 kg sulphur/ha (Factomphos) (T5) and it was on par with the treatment receiving RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 50 kg sulphur/ha (gypsum) (T8) (45.48 kg ha

-1). The lowest straw nitrogen uptake of 29.71 kg

per ha was registered in the treatment receiving RDF alone (T1) and it was on par with the treatment receiving RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) (T2) (33.48 kg ha

-1).

In grain, the treatment receiving RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 50 kg sulphur/ha (Factomphos) (T5) recorded the highest nitrogen uptake of 58.92 kg per ha. It was on par with the treatment receiving RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 37.5 kg sulphur/ha (Factomphos) (T4) (54.61 kg ha


50 kg sulphur/ha (gypsum) (T8) (56.36 kg ha-1

). The treatment receiving RDF alone (T1) registered the lowest nitrogen uptake of 37.52 kg per ha and it differed significantly with all treatments.

4.3.14.3 Phosphorus content (%)

The data pertaining to the residual effect of different sources and levels of sulphur on phosphorus content of succeeding rice crop are presented in Table 51.

The results of the experiment indicate that sulphur nutrition remarkably influenced phosphorus content of succeeding rice crop.

At active tillering stage, the highest phosphorus content of 0.298 per cent was registered with treatment received RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 50 kg sulphur/ha (Factomphos) (T5) and it was on par with the application of RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 37.5 kg sulphur/ha (Factomphos) (T4) (0.285 %) and RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 50 kg Sulphur/ha (gypsum) (T8) (0.284 %). The lowest phosphorus content of 0.238 per cent was registered in the treatment receiving RDF alone (T1) and it s differed significantly with rest of treatments.

The highest phosphorus content of 0.275 per cent at panicle initiation was observed with the application of RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 50 kg sulphur/ha (Factomphos) (T5) and it was on par with the treatments of RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 37.5 kg sulphur/ha (Factomphos) (T4) (0.261 %) and RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 50 kg sulphur/ha (gypsum) (T8) (0.265 %). The lowest phosphorus content of 0.216 per cent registered in the treatment receiving RDF alone (T1) and it differed significantly with the rest of treatments.

At grain filling stage, the highest phosphorus content of 0.269 per cent was noticed in the treatment receiving RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 50 kg sulphur/ha (Factomphos) (T5) and it was on par with the application of RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 37.5 kg sulphur/ha (Factomphos) (T4) (0.256 %) and RDF + FYM (10 t/ha) + ZnSO4

Table 51. Residual effect of different sources and levels of sulphur on plant phosphorus (P) content (%)

and uptake (kg ha-1

) by rice

Harvest

Treatments

AT

PI GF

Straw Grain


6.51 (0.216)

7.63 (0.209) 10.94

(0.101) 4.00

(0.232) 7.99


8.60 (0.248)

9.99 (0.240) 13.75

(0.116) 4.97

(0.254) 9.70


9.50 (0.252) 10.88

(0.244) 15.08

(0.117) 5.41

(0.263) 10.86


(0.261) 12.30

(0.256) 16.46

(0.124) 5.97

(0.276) 11.87


(0.275) 13.59

(0.269) 18.02

(0.130) 6.49

(0.285) 12.72


9.25 (0.251) 10.69

(0.241) 14.30

(0.116) 5.16

(0.258) 10.21


(0.258) 11.81

(0.249) 15.45

(0.121) 5.60

(0.273) 11.34


(0.265) 12.62

(0.259) 16.82

(0.126) 6.16

(0.280) 12.05

S.Em+ (0.005) 0.429

(0.005) 0.507

(0.004) 0.397

(0.003) 0.224

(0.004) 0.313

CD (P=0.05) (0.015)

1.30 (0.014)

1.54 (0.013)

1.20 (0.009)

0.68 (0.012)

0.95

Values in parentheses indicate P concentration (%)





(20 kg/ha) + 50 kg Sulphur/ha (gypsum) (T8) (0.259 %). The lowest phosphorus content of 0.209 per cent registered in the treatment receiving RDF alone (T1) which significantly differed with all treatments.

At harvest, the highest straw and grain phosphorus contents of 0.130 and 0.285 per cent were registered with the application of RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 50 kg sulphur/ha (Factomphos) (T5) respectively and they were on par with the treatment receiving RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 37.5 kg sulphur/ha (Factomphos) (T4) (0.124 and 0.276 %), RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 37.5 kg sulphur/ha (gypsum) (T7) (0.121 and 0.273 %) and RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 50 kg sulphur/ha (gypsum) (T8) (0.126 and 0.280 %) respectively. The lowest straw and grain phosphorus contents of 0.101 and 0.232 per cent were registered in the treatment receiving RDF alone (T1) in straw and grain respectively. The values significantly differed with all treatments.

4.3.14.4 Phosphorus uptake (kg ha-1

)

The data pertaining to the residual effect of different sources and levels of sulphur on phosphorus uptake by succeeding rice crop are presented in Table 51.

The results of the experiment indicate that sulphur nutrition significantly influenced phosphorus uptake by succeeding rice crop.

At active tillering stage, the highest phosphorus uptake of 12.02 kg per ha registered in the treatment receiving RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 50 kg sulphur/ha (Factomphos) (T5) and it was on par with treatments receiving RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 37.5 kg sulphur/ha (Factomphos) (T4) (10.86 kg ha


ZnSO4 (20 kg/ha) + 50 kg sulphur/ha (gypsum) (T8) (10.99 kg ha-1

). The lowest phosphorus uptake of 6.51 kg per ha was noticed in the treatment receiving RDF alone (T1). All treatments significantly increased the phosphorus content over the treatment supplied with RDF alone (T1).

At panicle initiation stage, the highest phosphorus uptake of 13.59 kg per ha was observed with the treatment receiving RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 50 kg sulphur/ha (Factomphos) (T5) and it was on par with the application of RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 37.5 kg sulphur/ha (Factomphos) (T4) (12.30 kg ha



). The lowest phosphorus uptake of 7.63 kg per ha was noticed in the treatment receiving RDF alone (T1). All treatments increased the phosphorus uptake significantly over RDF alone (T1).

At grain filling stage, the treatment receiving RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 50 kg sulphur/ha (Factomphos) (T5) registered the highest phosphorus uptake of 18.02 kg per ha and it was on par with the treatment that received RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 50 kg sulphur/ha (gypsum) (T8) (16.82 kg ha

-1) but significantly superior over the rest

of treatments. The treatment receiving RDF alone (T1) registered the lowest phosphorus uptake of 10.94 kg per ha. All treatments recorded significantly higher phosphorus uptake over RDF alone (T1).

The treatment receiving RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 50 kg sulphur/ha (Factomphos) (T5) registered the highest phosphorus uptakes of 6.49 and 12.72 kg per ha in straw and grain respectively and they were on par with the application of RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 37.5 kg sulphur/ha (Factomphos) (T4) (5.97 and 11.87 kg ha

-1) and

RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 50 kg sulphur/ha (gypsum) (T8) (6.16 and 12.05 kg ha

-1) respectively. The lowest phosphorus uptakes of 4.00 and 7.99 kg per ha were noticed

in the treatment receiving RDF alone (T1) in straw and grain and both values significantly differed from all treatments respectively.

4.3.14.5 Potassium content (%)

The data pertaining to effect of different sources and levels of sulphur on potassium content of succeeding rice crop are presented in Table 52.

A perusal of the data in the Table 52 revealed that the effect of sulphur nutrition proved non-significant with respect to the potassium content throughout the growing period of succeeding rice crop.

4.3.14.6 Potassium uptake (kg ha-1

)

The data pertaining to the effect of different sources and levels of sulphur on phosphorus uptake by succeeding rice crop are presented in Table 52.

The results of the experiment revealed that the sulphur nutrition significantly enhanced potassium uptake in succeeding rice crop.

At active tillering stage, the highest potassium uptake of 68.26 kg per ha was observed with the treatment receiving RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 50 kg sulphur/ha (Factomphos) (T5) and it was on par with the application of RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 37.5 kg sulphur/ha (Factomphos) (T4) (59.88 kg ha



). The lowest potassium uptake of 37.16 kg per ha was noticed in the treatment receiving RDF alone (T1). It was on par with (T2) RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) (44.15 kg ha

-1).

At panicle initiation stage, the treatment receiving RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 50 kg sulphur/ha (Factomphos) (T5) registered the highest potassium uptake of 78.55 kg per ha and it was on par with application of RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 37.5 kg sulphur/ha (Factomphos) (T4) (69.28 kg ha



). The lowest potassium uptake of 45.22 kg per ha was noticed in the treatment receiving RDF alone (T1). It was on par with (T2) RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) (53.60 kg ha

-1).

At grain filling stage, the highest potassium uptake of 81.06 kg per ha was registered with application of RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 50 kg sulphur/ha (Factomphos) (T5). It was on par with the treatments of RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 25 kg sulphur/ha (Factomphos) (T3) (71.71 kg ha


37.5 kg sulphur/ha (Factomphos) (T4) (75.89 kg ha-1

), RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 37.5 kg sulphur/ha (gypsum) (T7) (72.60 kg ha

-1) and RDF + FYM (10 t/ha) + ZnSO4

(20 kg/ha) + 50 kg sulphur/ha (gypsum) (T8) (77.29 kg ha-1

). The lowest potassium uptake of 57.60 kg per ha was recorded in the treatment receiving RDF alone (T1). It was on par with RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) (T2) (64.74 kg ha



).

With respect to potassium uptake in straw, the highest potassium uptake of 83.33 kg per ha was recoded in the treatment receiving RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 50 kg sulphur/ha (Factomphos) (T5) and it was on par with the treatments of RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 37.5 kg sulphur/ha (Factomphos) (T4) (74.17 kg ha

-1), RDF + FYM

(10 t/ha) + ZnSO4 (20 kg/ha) + 37.5 kg sulphur/ha (gypsum) (T7) (70.95 kg ha-1

) and RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 50 kg sulphur/ha (gypsum) (T8) (76.77 kg ha

-1). The

lowest straw potassium uptake of 53.08 kg per ha was noticed in the treatment receiving RDF alone (T1). It was on par with the treatment which received RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) (T2) (60.03 kg ha


(gypsum) (T6) (64.97 kg ha-1

).

Among the treatments, the highest potassium uptake of 18.30 kg per ha in grain was noticed with the treatment of RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 50 kg sulphur/ha (Factomphos) (T5) and it was on par with the treatments that received RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 37.5 kg sulphur/ha (Factomphos) (T4) (17.20 kg ha

-1), RDF + FYM (10

t/ha) + ZnSO4 (20 kg/ha) + 37.5 kg sulphur/ha (gypsum) (T7) (16.61 kg ha-1

) and RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 50 kg sulphur/ha (gypsum) (T8) (17.64 kg ha

-1). The lowest

grain potassium uptake of 12.74 kg per ha was noticed in the treatment receiving RDF alone (T1). It was on par with RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) (T2) (14.51 kg ha

-1).

Table 52. Residual effect of different sources and levels of sulphur on plant potassium (K) content (%)

uptake (kg ha-1

) by rice


Straw Grain

T1: RDF (control) (1.36) 37.16

(1.28) 45.22

(1.10) 57.60

(1.34) 53.08

(0.37) 12.74


(1.33) 53.60

(1.13) 64.74

(1.40) 60.03

(0.38) 14.51


(1.41) 60.87

(1.16) 71.71

(1.48) 68.38

(0.39) 16.11


(1.47) 69.28

(1.18) 75.89

(1.54) 74.17

(0.40) 17.20


(1.59) 78.55

(1.21) 81.06

(1.67) 83.33

(0.41) 18.30


(1.39) 59.17

(1.14) 67.66

(1.46) 64.97

(0.39) 15.44


(1.44) 65.91

(1.17) 72.60

(1.52) 70.95

(0.40) 16.61


(1.49) 70.97

(1.19) 77.29

(1.57) 76.77

(0.41) 17.64

S.Em+ (0.066)

2.99 (0.061)

3.30 (0.028)

2.16 (0.077)

4.19 (0.019)

0.65

CD (P=0.05) (NS) 9.07

(NS) 10.01

(NS) 12.81

(NS) 12.70 (NS) 1.98

Values in parentheses indicate K concentration (%)






4.3.15 Sulphur content and uptake of succeeding rice crop

The data pertaining effect of different sources and levels of sulphur on sulphur content and uptake by succeeding rice crop are presented in Table 53.

4.3.15.1 Sulphur content (%)

The results of the experiment revealed that the sulphur nutrition significantly enhanced sulphur content in succeeding rice crop.

At active tillering stage, the highest sulphur content of 0.280 per cent registered with the application of RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 50 kg sulphur/ha (Factomphos) (T5). It was on par with the treatments of RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 37.5 kg sulphur/ha (Factomphos) (T4) (0.253 %) and RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 50 kg sulphur/ha (gypsum) (T8) (0.262 %) but significantly superior over the rest of treatments. The lowest sulphur content of 0.145 per cent was noticed in the treatment receiving RDF alone (T1) and it was on par with the treatment (T2) RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) (0.172 %).

At panicle initiation and grain filling stages, the treatment receiving RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 50 kg sulphur/ha (Factomphos) (T5) recorded the highest sulphur contents of 0.265 and 0.234 per cent respectively and they were on par with the treatments receiving RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 37.5 kg sulphur/ha (Factomphos) (T4) (0.240 and 0.212 %) and RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 50 kg sulphur/ha (gypsum) (T8) (0.251 and 0.221 %) at respective stages. The lowest sulphur contents of 0.136 and 0.122 per cent were observed in the treatment receiving RDF alone (T1) at panicle initiation and grain filling stages and on par with RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) (T2) (0.162 and 0.144 %).

The highest straw sulphur content of 0.214 per cent was observed in the treatment received RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 50 kg sulphur/ha (Factomphos) (T5). It was on par with the application of RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 37.5 kg sulphur/ha (Factomphos) (T4) (0.195 %) and RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 50 kg sulphur/ha (gypsum) (T8) (0.201 %) but significantly superior over the rest of treatments. The treatment receiving RDF alone (T1) showed the lowest sulphur content of 0.110 per cent and it was on par with the treatment receiving RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) (T2) (0.130 %).

In grain, the treatment that received RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 50 kg sulphur/ha (Factomphos) (T5) registered the highest sulphur content of 0.240 per cent. It was on par with the application of RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 37.5 kg sulphur/ha (Factomphos) (T4) (0.219 %) and RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 50 kg sulphur/ha (gypsum) (T8) (0.224 %) but significantly superior over rest of treatments. The lowest grain sulphur content of 0.122 per cent was registered in the treatment receiving RDF alone (T1) and it was on par with RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) (T2) (0.144 %).

4.3.15.2 Sulphur uptake (kg ha-1

)

The results of the experiment indicate that sulphur uptake in succeeding rice crop remarkably differed due to sulphur nutrition (Table 53).

At active tillering stage, the treatment that received RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 50 kg sulphur/ha (Factomphos) (T5) recorded the highest sulphur uptake of 11.31 kg per ha and it was on par with the treatment that received RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 50 kg sulphur/ha (gypsum) (T8) (10.13 kg ha


of treatments. The lowest sulphur uptake 3.96 kg per ha was recorded in the treatment receiving RDF alone (T1). All treatments registered significantly higher sulphur uptake over RDF alone (T1).

At panicle initiation stage, the highest sulphur uptake of 13.09 kg per ha was recorded in the treatment receiving RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 50 kg

Table 53. Residual effect of different sources and levels of sulphur on plant sulphur (S) content (%) and

uptake (kg ha-1

) by rice


Straw Grain


3.96 (0.136)

4.81 (0.122)

6.39 (0.110)

4.27 (0.122)

4.55


5.39 (0.162)

6.53 (0.144)

8.25 (0.130)

5.51 (0.144)

5.70


7.52 (0.205)

8.85 (0.178) 11.00

(0.161) 7.17

(0.181) 7.51


9.65 (0.240) 11.31

(0.212) 13.63

(0.195) 9.07

(0.219) 9.55


(0.265) 13.09

(0.234) 15.68

(0.214) 10.22

(0.240) 10.76


6.61 (0.184)

7.83 (0.161)

9.56 (0.145)

6.29 (0.161)

6.56


8.50 (0.215)

9.84 (0.188) 11.67

(0.172) 7.77

(0.194) 8.34


(0.251) 11.96

(0.221) 14.36

(0.201) 9.51

(0.224) 9.88

S.Em+ (0.013) 0.447

(0.014) 0.567

(0.012) 0.760

(0.007) 0.345

(0.012) 0.628

CD (P=0.05) (0.038)

1.36 (0.041)

1.72 (0.037)

2.30 (0.021)

1.05 (0.036)

1.91

Values in parentheses indicate S concentration (%)





sulphur/ha (Factomphos) (T5). It was on par with the treatment receiving RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 37.5 kg sulphur/ha (Factomphos) (T4) (11.31 kg ha

-1) and RDF

+ FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 50 kg sulphur/ha (gypsum) (T8) (11.96 kg ha-1

) but significantly superior over the rest of treatments. The treatment receiving RDF alone (T1) registered the lowest sulphur uptake of 4.81 kg per ha and it was on par with the treatment supplied with RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) (T2) (6.53 kg ha

-1).

At grain filling stage, the treatment receiving RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 50 kg sulphur/ha (Factomphos) (T5) recorded the highest sulphur uptake of 15.68 kg per ha and it was on par with treatment receiving RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 37.5 kg sulphur/ha (Factomphos) (T4) (13.63 kg ha


37.5 kg sulphur/ha (gypsum) (T7) (11.67 kg ha-1

) RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 50 kg sulphur/ha (gypsum) (T8) (14.36 kg ha

-1). The lowest sulphur uptake of 6.39 kg per ha

was observed in the treatment receiving RDF alone (T1) and it was on par with the treatment supplied with RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) (T2) (8.25 kg ha

-1).

At harvest, the treatment receiving RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 50 kg sulphur/ha (Factomphos) (T5) registered the highest straw sulphur uptake of 10.22 kg per ha which was on par with the treatment receiving RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 50 kg sulphur/ha (gypsum) (T8) (9.51 kg ha

-1). The lowest sulphur uptake of 4.27 kg per ha was

noticed in the treatment receiving RDF alone (T1). It differed significantly with all treatments.

In grain, the treatment receiving RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 50 kg sulphur/ha (Factomphos) (T5) recorded the highest sulphur uptake of 10.76 kg per ha. It was on par with treatment receiving RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 37.5 kg sulphur/ha (Factomphos) (T4) (9.55 kg ha


sulphur/ha (gypsum) (T8) (9.88 kg ha-1

) but significantly superior over the rest of treatments. The lowest grain sulphur uptake of 4.55 kg per ha was registered in the treatment receiving RDF alone (T1) and it was on par with the treatment that received RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) (T2) (5.70 kg ha

-1).

4.3.16 Micronutrient content and uptake of succeeding rice crop

4.3.16.1 Zn content (mg kg-1

)

The data pertaining to the residual effect of different sources and levels of sulphur on Zn content of succeeding rice crop are presented in Table 54.

The results of the experiment indicated that the treatments significantly influenced Zn content at all stages of the crop growth.

At active tillering stage, the highest Zn content of 26.18 mg kg-1

registered with the application of RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 50 kg sulphur/ha (Factomphos) (T5). It was on par with the treatments of RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 37.5 kg sulphur/ha (Factomphos) (T4) (23.47 mg kg


50 kg sulphur/ha (gypsum) (T8) (25.02 mg kg-1

) but significantly superior over the rest of treatments. The lowest Zn content of 15.90 mg kg

-1 was noticed in the treatment receiving

RDF alone (T1) and it differed significantly with all treatments.

At panicle initiation and grain filling stage, the treatment receiving RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 50 kg sulphur/ha (Factomphos) (T5) recorded the highest Zn contents of 24.20 and 22.39 mg kg

-1 respectively and they were on par with the treatments

receiving RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 37.5 kg sulphur/ha (Factomphos) (T4) (21.67 and 20.01 mg kg


(gypsum) (T8) (23.36 and 21.58 mg kg-1) at respective stages. The lowest Zn contents of 14.65 and 13.49 mg kg-1 were registered in the treatment receiving RDF alone (T1) and the values differed significantly with the rest of treatments.

The highest straw and grain Zn contents of 19.95 and 19.02 mg kg-1

was noticed in the treatment received RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 50 kg sulphur/ha (Factomphos) (T5). It was on par with the application of RDF + FYM (10 t/ha) + ZnSO4 (20

Table 54. Residual effect of different sources and levels of sulphur on plant Zn content (mg kg

-1)

uptake (g ha-1

) by rice


Straw Grain

T1: RDF (control) (15.90) 43.45

(14.65) 51.69

(13.49) 70.57

(12.11) 47.97

(11.44) 39.33


(18.14) 73.17

(16.75) 95.98

(15.00) 64.30

(14.31) 54.59


(20.22) 87.26

(18.67) 115.41

(16.61) 76.71

(15.86) 65.44


(21.67) 102.30

(20.01) 128.55

(17.79) 85.66

(16.98) 72.95


(24.20) 119.11

(22.39) 149.48

(19.95) 99.52

(19.02) 84.92


(18.54) 79.08

(17.11) 101.85

(15.31) 68.13

(14.54) 57.36


(20.57) 93.74

(18.99) 117.80

(16.98) 79.25

(16.22) 67.36


(23.36) 111.16

(21.58) 140.15

(19.38) 94.74

(18.59) 79.98

S.Em+ (0.966) 5.809

(0.950) 4.695

(0.963) 6.235

(0.940) 1.254

(0.762) 3.074

CD (P=0.05) (2.93) 17.62

(2.88) 14.24

(2.92) 18.91

(2.85) 3.80

(2.31) 9.32

Values in parentheses indicate Zn concentration (mg kg-1

)





kg/ha) + 37.5 kg sulphur/ha (Factomphos) (T4) (17.79 and 16.98 mg kg-1

) and RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 50 kg sulphur/ha (gypsum) (T8) (19.38 and 18.59 mg kg

-

1) but significantly superior over the rest of treatments. The treatment receiving RDF alone

(T1) recorded the lowest Zn contents of 12.11 and 11.44 mg kg-1

and they differed significantly with rest of the treatments.

4.3.16.2 Zn uptake (g ha-1

)

The data pertaining to the residual effect of different sources and levels of sulphur on Zn uptake of succeeding rice crop are presented in Table 54.

At active tillering stage, the highest Zn uptake of 105.76 g per ha was observed with the treatment receiving RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 50 kg sulphur/ha (Factomphos) (T5). It was on par with the treatments of RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 37.5 kg sulphur/ha (Factomphos) (T4) (89.54 g ha

-1)) and RDF + FYM (10 t/ha) +


) but significantly superior over the rest of treatments. The lowest Zn uptake of 43.45 g per ha was noticed in the treatment receiving RDF alone (T1) and it differed significantly with all treatments.

At panicle initiation and grain filling stage, the treatment receiving RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 50 kg sulphur/ha (Factomphos) (T5) recorded the highest Zn uptake of 119.11 and 149.48 g per ha respectively and they were on par with the treatments receiving RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 50 kg sulphur/ha (gypsum) (T8) (111.16 and 140.15 g ha

-1) and superior over rest of treatments at respective stages. The lowest Zn

uptake of 51.69 and 70.57 g per ha were registered in the treatment receiving RDF alone (T1) and the values differed significantly with the rest of treatments.

The highest Zn uptake of 99.52 g per ha in straw at harvest was noticed with the application of RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 50 kg sulphur/ha (Factomphos) (T5). It was on par with the treatment receiving RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 50 kg sulphur/ha (gypsum) (T8) (94.74 g ha


treatments. The treatment receiving RDF alone (T1) registered the lowest Zn uptake of 47.97 g per ha. It differed significantly with all treatments.

In grain, the treatment with application of RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 50 kg sulphur/ha (Factomphos) (T5) registered the highest Zn uptake of 84.92 g per ha. It was significantly superior over the rest of treatments. (T1). The treatment receiving RDF alone (T1) registered the lowest grain Zn uptake of 39.33 g per ha. All treatments indicated higher Zn uptake over the treatment receiving RDF alone (T1)

4.3.16.3 Cu content (mg kg-1

)

The data pertaining to the effect of different sources and levels of sulphur on Cu content of succeeding rice crop are presented in Table 55.

A perusal of data revealed that the effect of sulphur nutrition was found to be non-significant with respect to Cu content.

4.3.16.4 Cu uptake (g ha-1

)

The data pertaining to the effect of different sources and levels of sulphur on Cu uptake of succeeding rice crop are presented in Table 55.

At active tillering stage, the treatment receiving RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 50 kg sulphur/ha (Factomphos) (T5) showed the highest Cu uptake of 37.95 g per ha. It was on par with the application of RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 37.5 kg sulphur/ha (Factomphos) (T4) (32.95 g ha

-1), RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 37.5



-1). The lowest Cu uptake of 21.00 g per ha was

registered with the application of RDF alone (T1). It was on par with the application of RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) (T2) (24.89 g ha


kg/ha) + 25 kg sulphur/ha (gypsum) (T6) (27.26 g ha-1

).

At panicle initiation stage, the treatment receiving RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 50 kg sulphur/ha (Factomphos) (T5) showed the highest Cu uptake of 41.59 g per ha. It was on par with the treatments that received RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 37.5 kg sulphur/ha (Factomphos) (T4) (36.36 g ha

-1), RDF + FYM (10 t/ha) + ZnSO4 (20

kg/ha) + 37.5 kg sulphur/ha (gypsum) (T7) (34.21 g ha-1


-1). The lowest Cu uptake of 23.69 g

per ha was registered with the application of RDF alone (T1). It was on par with the treatment that received RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) (T2) (28.53 g ha

-1) and RDF + FYM

(10 t/ha) + ZnSO4 (20 kg/ha) + 25 kg sulphur/ha (gypsum) (T6) (30.76 g ha-1

).

At grain filling stage, the treatment receiving RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 50 kg sulphur/ha (Factomphos) (T5) showed the highest Cu uptake of 48.80 g per ha. It was on par with the treatments received RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 25 kg sulphur/ha (Factomphos) (T3) (40.12 g ha

-1), RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 37.5

kg sulphur/ha (Factomphos) (T4) (42.96 g ha-1

), RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 37.5 kg sulphur/ha (gypsum) (T7) (41.05 g ha

-1) and RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha)

+ 50 kg sulphur/ha (gypsum) (T8) (45.50 g ha-1

. The lowest Cu uptake of 31.10 g per ha was recorded with the application of RDF alone (T1). It was on par with application of RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) (T2) (35.35 g ha


25 kg sulphur/ha (Factomphos) (T3) (40.12 g ha-1


-1).

In straw at harvest, the highest Cu uptake of 32.88 g per ha in straw was observed in the treatment receiving RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 50 kg sulphur/ha (Factomphos) (T5). It was on par with the application of RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 37.5 kg sulphur/ha (Factomphos) (T4) (29.06 g ha

-1), RDF + FYM (10 t/ha) + ZnSO4

(20 kg/ha) + 37.5 kg sulphur/ha (gypsum) (T7) (27.89 g ha-1


-1). The treatment receiving

RDF alone (T1) registered the lowest Cu uptake of 21.21 g per ha and it was on par with the treatments that received RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) (T2) (23.95 g ha

-1) and


).

In grain, the highest Cu uptake of 24.62 g per ha was registered with the application of RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 50 kg sulphur/ha (Factomphos) (T5) and it was on par with the application of RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 25 kg sulphur/ha (Factomphos) (T3) (20.34 g ha

-1), RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 37.5 kg

sulphur/ha (Factomphos) (T4) (21.82 g ha-1

), RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 37.5 kg sulphur/ha (gypsum) (T7) (20.85 g ha

-1) and RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 50


). The treatment receiving RDF alone (T1) registered the lowest Cu uptake of 13.66 g per ha. It was on par with the treatment receiving RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) (T2) (17.95 g ha

-1).

4.3.16.5 Fe content (mg kg-1

)

The data pertaining to the residual effect of different sources and levels of sulphur on Fe content of succeeding rice crop are presented in Table 56.

At all growth stages, different sulphur treatments did not influence significantly on Fe content.

4.3.16.6 Fe uptake (g ha-1

)

The data pertaining to the effect of different sources and levels of sulphur on Fe uptake of succeeding rice crop are presented in Table 56.

The perusal of data of the experiment indicated that the treatments increased the Fe uptake throughout the growing period.

At active tillering stage, the highest Fe uptake of 1748.81 g per ha was noticed with the application of RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 50 kg sulphur/ha (Factomphos) (T5) and it was on par with the treatment receiving RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 50 kg sulphur/ha (gypsum) (T8) (1572.48 g ha


Table 55. Residual effect of different sources and levels of sulphur on plant Cu content (mg kg

-1)

and uptake (g ha-1

) by rice


Straw Grain

T1: RDF (control) (7.69) 21.00

(6.71) 23.69

(5.94) 31.10

(5.36) 21.21

(3.97) 13.66


(7.08) 28.53

(6.17) 35.35

(5.59) 23.95

(4.70) 17.95


(7.52) 32.46

(6.49) 40.12

(5.87) 27.10

(4.93) 20.34


(7.72) 36.36

(6.68) 42.96

(6.04) 29.06

(5.08) 21.82


(8.42) 41.59

(7.29) 48.80

(6.59) 32.88

(5.52) 24.62


(7.23) 30.76

(6.26) 37.15

(5.65) 25.12

(4.74) 18.76


(7.48) 34.21

(6.62) 41.05

(5.98) 27.89

(5.02) 20.85


(8.10) 38.56

(7.01) 45.50

(6.33) 30.93

(5.35) 23.02

S.Em+ (0.516)

2.28 (0.498)

2.44 (0.419)

3.15 (0.398)

1.71 (0.327)

1.47

CD (P=0.05) (NS) 6.90

(NS) 7.39

(NS) 9.55

(NS) 5.19

(NS) 4.46

Values in parentheses indicate Cu concentration (mg kg-1

)






treatments. The treatment receiving RDF alone (T1) registered the lowest Fe uptake of 902.82 g per ha and it was on par with application of RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) (T2) (1078.22 g ha

-1).

At panicle initiation stage, the treatment that received RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 50 kg sulphur/ha (Factomphos) (T5) recorded the highest Fe uptake of 1976.49 g per ha and it was on par with the treatments receiving RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 37.5 kg sulphur/ha (Factomphos) (T4) (1659.40 g ha



) but significantly superior over the rest of treatments. The lowest Fe uptake of 1069.05 g per ha was observed with the application of RDF alone (T1) and it was on par with the treatment that received RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) (T2) (1283.27 g ha



).

At grain filling stage, the highest Fe uptake of 2233.58 was registered with the application of RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 50 kg sulphur/ha (Factomphos) (T5). It was on par with the treatments receiving RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 37.5 kg sulphur/ha (Factomphos) (T4) (1888.40 g ha



). The lowest Fe uptake of 1322.88 g per ha was observed with the application of RDF alone (T1) and it was on par with the treatment that received RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) (T2) (1522.54 g ha

-1) and


).

In straw and grain at harvest, the highest Fe uptake of 1570.35 and 1093.06 g per ha was observed in the treatment receiving RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 50 kg sulphur/ha (Factomphos) (T5) and it was on par with the application of RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 37.5 kg sulphur/ha (Factomphos) (T4) (1330.56 and 941.57 g ha

-1) and

RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 50 kg sulphur/ha (gypsum) (T8) (1443.23 and 987.95 g ha

-1) but significantly superior over the rest of treatments respectively. The treatment

receiving RDF alone (T1) registered the lowest Fe uptake of 933.61 and 620.94 g per ha and it was on par with the treatment that received RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) (T2) (1067.88 and 743.86 g ha


(gypsum) (T6) (1130.34 and 782.30 g ha-1

).

4.3.16.7 Mn content (mg kg-1)

The data pertaining to the effect of different sources and levels of sulphur on Mn content of succeeding rice crop are presented in Table 57.

At all stages, different sulphur treatments did not affect significantly on Mn content.

4.3.16.8 Mn uptake (g ha-1

)

The data pertaining to the effect of different sources and levels of sulphur on Mn uptake of succeeding rice crop are presented in Table 57.

The results of the experiment revealed that the treatments significantly influenced the Mn uptake throughout the growing period.

Among the treatments, the treatment received RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 50 kg Sulphur/ha (Factomphos) (T5) registered the highest Mn uptake of 1292.6 g per at active tillering stage. It was on par with the treatments of RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 37.5 kg sulphur/ha (Factomphos) (T4) (1074.1 g ha



) but significantly superior over rest of treatments. The treatment receiving RDF alone (T1) registered the lowest Mn uptake of 657.9 g per ha. It was on par with the treatment that received RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) (T2) (799.3 g ha



).

At panicle initiation stage, the treatment that received RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 50 kg sulphur/ha (Factomphos) (T5) recorded the highest Mn uptake of 1381.0 g per ha and it was on par with the treatments receiving RDF + FYM (10 t/ha) + ZnSO4 (20

Table 56. Residual effect of different sources and levels of sulphur on plant Fe content (mg kg


-1) by rice


Straw Grain

T1: RDF (control) (330.46) 902.82

(302.59) 1069.05

(252.65) 1322.88

(235.70) 933.61

(180.40) 620.94


(318.43) 1283.27

(265.76) 1522.54

(249.04) 1067.88

(194.78) 743.86


(335.78) 1449.56

(280.14) 1731.83

(263.57) 1217.69

(205.08) 846.98


(352.09) 1659.40

(293.64) 1888.40

(276.28) 1330.56

(218.97) 941.57


(400.10) 1976.49

(333.42) 2233.58

(314.70) 1570.35

(244.86) 1093.06


(323.52) 1377.22

(269.97) 1602.27

(254.01) 1130.34

(197.65) 782.30


(346.71) 1586.89

(289.19) 1794.42

(272.08) 1270.07

(211.71) 879.23


(375.02) 1786.60

(312.63) 2030.53

(295.14) 1443.23

(229.65) 987.95

S.Em+ (22.12) 80.44

(21.29) 120.44

(16.81) 118.81

(17.00) 81.60

(13.21) 58.35

CD (P=0.05) (NS)

243.99 (NS)

365.33 (NS)

360.38 (NS)

247.50 (NS)

176.98

Values in parentheses indicate Fe concentration (mg kg-1

)






Table 57. Residual effect of different sources and levels of sulphur on plant Mn content (mg kg-1

) and uptake (g ha

-1) by rice


Straw Grain

T1: RDF (control) (240.81) 657.9

(213.23) 753.3

(147.68) 773.3

(227.97) 903.0

(21.24) 73.1


(216.21) 871.3

(163.26) 935.3

(241.79) 1036.8

(25.22) 96.3


(229.80) 992.0

(170.97) 1056.9

(255.07) 1178.4

(26.61) 109.9


(230.95) 1088.5

(188.16) 1210.1

(269.79) 1299.3

(28.66) 123.2


(259.55) 1381.0

(215.24) 1441.9

(304.06) 1517.3

(31.72) 141.6


(217.25) 924.8

(169.51) 1006.0

(247.70) 1102.3

(25.84) 102.3


(221.73) 1106.4

(188.33) 1168.6

(259.47) 1211.2

(27.91) 115.9


(248.55) 1183.8

(202.80) 1317.2

(289.61) 1416.2

(30.21) 130.0

S.Em+ (17.26) 76.24

(11.69) 72.66

(13.40) 91.18

(16.20) 68.85

(2.12) 9.38

CD (P=0.05) (NS) 231.25

(NS) 220.38

(NS) 276.56

(NS) 208.85

(NS) 28.45

Values in parentheses indicate Mn concentration (mg kg-1

)







) but significantly superior over the rest of treatments. The lowest Mn uptake of 753.3 g per ha was observed with the application of RDF alone (T1) and it was on par with the treatment that received RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) (T2) (871.3 g ha



).

At grain filling stage, the highest Fe uptake of 1441.9 was registered with the application of RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 50 kg sulphur/ha (Factomphos) (T5). It was on par with the treatments receiving RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 37.5 kg sulphur/ha (Factomphos) (T4) (1210.1 g ha

-1), RDF + FYM (10 t/ha) + ZnSO4 (20

kg/ha) + 37.5 kg sulphur/ha (gypsum) (T7) (1168.6 g ha-1


-1). The lowest Mn uptake of 773.3 g

per ha was observed with the application of RDF alone (T1) and it was on par with the treatment that received RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) (T2) (935.3 g ha

-1) and RDF

+ FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 25 kg sulphur/ha (gypsum) (T6) (1006.0 g ha-1

).

In straw at harvest, the highest Mn uptake of 1517.3 g per ha was observed in the treatment receiving RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 50 kg sulphur/ha (Factomphos) (T5) and it was on par with the application of RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 50 kg sulphur/ha (gypsum) (T8) (1416.2 g ha


of treatments. The treatment receiving RDF alone (T1) registered the lowest Mn uptake of 903.0 g per ha and it was on par with the treatment that received RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) (T2) (1036.8 g ha



).

In grain at harvest, the highest Mn uptake of 141.6 g per ha was observed in the treatment receiving RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 50 kg sulphur/ha (Factomphos) (T5) and it was on par with the application of RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 37.5 kg sulphur/ha (Factomphos) (T4) (123.2 g ha

-1), RDF + FYM (10 t/ha) + ZnSO4

(20 kg/ha) + 37.5 kg sulphur/ha (gypsum) (T7) (115.9 g ha-1



over the rest of treatments. The treatment receiving RDF alone (T1) registered the lowest Fe uptake of 73.1 g per ha and it was on par with the treatment that received RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) (T2) (96.3 g ha

-1).

4.3.17. Soil pH and EC at different stages of rice (succeeding crop)

The data pertaining to the direct effect of different sources and levels of sulphur on soil pH and EC of succeeding rice are presented in Table 58 and 59.

Soil pH and EC of succeeding rice were found to be non-significant due to residual effect of the treatments applied in previous season.

4.3.18 Sulphur fractions in succeeding rice crop soil


)

The data pertaining to the residual effect of different sources and levels of sulphur on sulphate sulphur content of succeeding rice crop are presented in Table 60.

The perusal of data on sulphate sulphur content of soil registered marked influence due to sulphur nutrition.

The results of the investigation indicate that the highest sulphate sulphur contents of 17.65, 15.46, 14.46 and 13.60 mg per kg were recorded with the treatment receiving RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 50 kg sulphur/ha (Factomphos) (T5) at active tillering, panicle initiation and grain filling stages and at harvest. It was on par with the treatment received RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 37.5 kg sulphur/ha (Factomphos) (T4) (15.83, 14.05, 13.26 and 12.88 mg kg

-1) and RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 50

kg sulphur/ha (gypsum) (T8) (16.94, 14.31, 13.76 and 12.95 mg kg-1

) but significantly superior over the treatments that received RDF alone (T1) (11.50, 10.08, 9.02 and 8.29 mg kg

-1), RDF

Table 58. Residual effect of different sources and levels of sulphur on pH at different growth stages

of rice


T1: RDF (control) 8.23 8.34 8.47 8.48








S.Em+ 0.068 0.077 0.063 0.058






T8


Table 59. Residual effect of different sources and levels of sulphur on EC (dS m

-1) at different

growth stages of rice


T1: RDF (control) 0.20 0.19 0.20 0.20








S.Em+ 0.031 0.035 0.037 0.011







Table 60. Residual effect of different sources and levels of sulphur on sulphate sulphur (mg

kg-1

) in soil


T1: RDF (control) 11.50 10.08 9.02 8.29








S.Em+ 0.847 0.699 0.763 0.508

CD (P=0.05) 2.57 2.12 2.31 1.54





T8

+ FYM (10 t/ha) + ZnSO4 (20 kg/ha) (T2) ( 12.36, 11.83, 10.29 and 9.26 mg kg-1

), RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 25 kg sulphur/ha (Factomphos) (T3) (13.94, 12.67, 11.70 and 10.91 mg kg


(13.28, 12.60, 11.42 and 10.22 mg kg-1

) and RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 37.5 kg sulphur/ha (gypsum) (T7) (14.30, 13.29, 12.04 and 11.18 mg kg

-1). The treatment that

received RDF alone (T1) registered the lowest sulphate sulphur contents of 11.50, 10.08, 9.02 and 8.29 mg per kg.


)

The data pertaining to the effect of different sources and levels of sulphur on water soluble sulphur content of succeeding rice crop are presented in Table 61.

Perusal of data on water soluble sulphur with respect to residual effect revealed that sulphur nutrition remarkably influenced the water soluble sulphur content in soil.

Among the treatments, the treatment received RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 50 kg sulphur/ha (Factomphos) (T5) registered the highest water soluble sulphur contents of 38.17, 32.25 and 26.49 mg per kg at active tillering, panicle initiation and grain filling stages. It was on par with the treatment receiving RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 37.5 kg sulphur/ha (Factomphos) (T4) (35.08, 28.58 and 23.49 mg kg

-1) and RDF +

FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 50 kg sulphur/ha (gypsum) (T8) (35.18, 30.87 and 25.86 mg kg

-1) but significantly superior over the treatments that received RDF + FYM (10 t/ha) +

ZnSO4 (20 kg/ha) (T2) (20.58, 18.24 and 16.75 mg kg-1

), RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 25 kg sulphur/ha (Factomphos) (T3) (30.86, 24.24 and 20.06 mg kg

-1), RDF + FYM

(10 t/ha) + ZnSO4 (20 kg/ha) + 25 kg sulphur/ha (gypsum) (T6), (29.47, 24.64 and 19.34 mg kg

-1), RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 37.5 kg sulphur/ha (gypsum) (T7) (31.43,

27.76 and 21.61 mg kg-1

) and RDF alone (T1). The treatment that received RDF alone (T1) registered the lowest sulphate sulphur content of 17.12, 15.72 and 14.21 mg per kg at respective growth stages. It was on par with the treatment received RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) (T2) (20.58, 18.24 and 16.75 mg kg

-1), respectively.

At harvest, the treatment received RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 50 kg sulphur/ha (Factomphos) (T5) registered the highest water soluble sulphur contents of 25.22 mg per kg and it was on par with the treatments that received RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 37.5 kg sulphur/ha (Factomphos) (T4) (22.22 mg kg

-1) and RDF + FYM (10 t/ha)

+ ZnSO4 (20 kg/ha) + 50 kg sulphur/ha (gypsum) (T8) (23.85 mg kg-1

). The treatment receiving RDF alone (T1) registered the lowest water soluble sulphur of 13.08 mg per kg and it was on par with the treatment that received RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) (T2) (14.15 mg kg

-1) and RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 25 kg sulphur/ha (gypsum)

(T6) (16.06 mg kg-1

).


)

The data pertaining to the effect of different sources and levels of sulphur on organic sulphur content of succeeding rice crop are presented in Table 62.

Organic sulphur content in soil differed significantly due to sulphur nutrition at grain filling stage and harvest.

At grain filling stage, the treatment receiving RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 50 kg sulphur/ha (Factomphos) (T5) registered the highest organic sulphur content of 132.07 mg per kg. It was on par with application of RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 37.5 kg sulphur/ha (Factomphos) (T4) (124.20 mg kg

-1), RDF + FYM (10 t/ha) + ZnSO4 (20

kg/ha) + 37.5 kg sulphur/ha (gypsum) (T7) (120.10 mg kg-1

) and RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 37.5 kg sulphur/ha (gypsum) (T8) (128.02 mg kg

-1) but significantly

superior over the rest of treatments. At grain filling stage, the lowest organic sulphur content of 104.79 mg per kg

was noticed in the treatment received RDF alone (T1) and it was on par

with the treatments receiving RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) (T2) (110.65 mg kg-1

), RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 25 kg sulphur/ha (gypsum) (T6) (113.01 mg kg

-1).

Table 61. Residual effect of different sources and levels of sulphur on water soluble sulphur (mg

kg-1

) in soil


T1: RDF (control) 17.12 15.72 14.21 13.08








S.Em+ 1.481 1.221 1.119 1.099

CD (P=0.05) 4.49 3.70 3.40 3.33





T8

Table 62. Residual effect of different sources and levels of sulphur on organic sulphur (mg

kg-1

) in soil


T1: RDF (control) 89.66 94.77 104.79 100.53








S.Em+ 5.407 5.234 4.010 3.133

CD (P=0.05) NS NS 12.16 9.50





T8


At harvest, the highest organic sulphur content of 123.74 mg per kg was recorded in the treatment that received RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 50 kg sulphur/ha (Factomphos) (T5) and it was on par with the treatments receiving RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 37.5 kg sulphur/ha (Factomphos) (T4) (116.33 mg kg

-1) and RDF + FYM

(10 t/ha) + ZnSO4 (20 kg/ha) + 37.5 kg sulphur/ha (gypsum) (T8) (116.90 mg kg-1

). The lowest organic sulphur content of 100.53 mg per kg

was noticed in the treatment received RDF alone

(T1) and it was on par with the treatments receiving RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) (T2) (103.28 mg kg


(gypsum) (T6) (107.58 mg kg-1

).


)

The data pertaining to the residual effect of different sources and levels of sulphur on non-sulphate sulphur content of succeeding rice crop are presented in Table 63.

A perusal of data on non-sulphate sulphur revealed that the differences due to sulphur nutrition were non-significant.


)

The data pertaining to the effect of different sources and levels of sulphur on total sulphur content of succeeding rice crop are presented in Table 64.

The results of the experiment with respect to total sulphur indicated that the differences due to sulphur application on total sulphur content in soil were not significant.

4.3.19 DTPA-extractable micronutrients in soil (succeeding rice crop)

4.3.19.1 DTPA-extractable Zn (mg kg-1

)

The data pertaining to the residual effect of different sources and levels of sulphur on DTPA-extractable Zn content of succeeding rice crop are presented in Table 65.

At active tillering and panicle initiation stages, the highest DTPA-extractable Zn contents of 0.98 and 0.96 mg per kg was noticed in the treatment of RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) (T2) and it was on par with the treatments that received FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 25 kg sulphur/ha (Factomphos) (T3) (0.87 and 0.86 mg kg

-1), FYM (10

t/ha) + ZnSO4 (20 kg/ha) + 37.5 kg sulphur/ha (Factomphos) (T4) (0.80 and 0.79 mg kg-1

), RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 25 kg sulphur/ha (gypsum) (T6) (0.94 and 0.92 mg kg

-1), RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 37.5 kg sulphur/ha (gypsum) (T7) (0.87 and

0.85 mg kg-1

) and RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 50 kg sulphur/ha (gypsum) (T8) (0.79 and 0.77 mg kg

-1). The treatment receiving RDF alone (T1) recorded the lowest DTPA

extractable Zn (0.56 and 0.55 mg kg-1

) and it was on par with the treatment received RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 50 kg sulphur/ha (Factomphos) (T5) (0.73 and 0.71 mg kg

-1).

At grain filling stage, the highest DTPA-extractable Zn content of 0.88 mg per kg was noticed in the treatment of RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) (T2) and it was on par with the treatments that received FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 25 kg sulphur/ha (Factomphos) (T3) (0.78 mg kg


sulphur/ha (gypsum) (T6) (0.84 mg kg-1


-1). The treatment receiving RDF alone (T1) recorded the

lowest DTPA extractable Zn (0.55 mg kg-1

) and it was on par with the treatment received RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 50 kg sulphur/ha (Factomphos) (T5) (0.63 mg kg

-1) and

RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 50 kg sulphur/ha (gypsum) (T8) (0.69 mg kg-1

).

At harvest, the treatment that received RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) (T2) registerd the highest DTPA-extractable Zn (0.81 mg kg

-1) and it was on par with the

treatments that received FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 25 kg sulphur/ha (Factomphos) (T3) (0.71 mg kg

-1), RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 25 kg sulphur/ha (gypsum)

Table 63. Residual effect of different sources and levels of sulphur on non-sulphate sulphur

(mg kg-1

) in soil


T1: RDF (control) 815.6 809.9 796.6 799.4








S.Em+ 40.85 35.56 30.59 31.05






T8


Table 64. Residual effect of different sources and levels of sulphur on total sulphur (mg kg-1

) in soil


T1: RDF (control) 934.2 930.5 924.6 921.3








S.Em+ 38.67 34.10 30.83 31.22






T8


Table 65. Residual effect of different sources and levels of sulphur on DTPA-extractable Zn

(mg kg-1

) in soil


T1: RDF (control) 0.56 0.55 0.55 0.54








S.Em+ 0.065 0.063 0.052 0.050

CD (P=0.05) 0.198 0.192 0.158 0.151





T8

Table 66. Residual effect of different sources and levels of sulphur on DTPA-extractable Cu

(mg kg-1

) in soil


T1: RDF (control) 3.21 3.12 3.06 2.90








S.Em+ 0.177 0.158 0.152 0.139






T8


Table 67. Residual effect of different sources and levels of sulphur on DTPA-extractable Fe (mg kg

-

1) in soil


T1: RDF (control) 8.83 8.53 13.70 9.25








S.Em+ 0.553 0.448 0.671 0.415






T8


Table 68. Residual effect of different sources and levels of sulphur on DTPA-extractable Mn (mg kg

-

1) in soil


T1: RDF (control) 10.30 12.92 11.24 9.00








S.Em+ 0.548 0.887 0.695 0.549






T8


Table 69. Effect of different sources and levels of sulphur on economics of first rice crop

Cost of cultivati

on

Gross return

Net return

Treatments

Grain yield

(q/ha)

Straw yield (q/ha)

(Rs ha-1

)

B:C ratio

T1: RDF (control) 44.63 49.92 19,592 32,239 12,647 1.65

T2: RDF + FYM (10 t/ha)+ ZnSO4

(20 kg/ha) 48.97 54.33 23,540 35,366 11,826 1.50

T3: T2 + 25.0 kg sulphur/ha (Factomphos) 53.23 58.75 23,938 38,436 14,498 1.61



T6: T2 + 25.0 kg sulphur/ha (Gypsum) 50.05 55.98 23,844 36,155 12,310 1.52






T8

Table 70. Effect of different sources and levels of sulphur on economics of succeeding rice

crop

Cost of cultivati

on

Gross return

Net return

Treatments

Grain yield

(q/ha)

Straw yield (q/ha)

(Rs ha-1

)

B:C ratio

T1: RDF (control) 40.02 46.06 19,592 28,935 9,343 1.48

T2: RDF + FYM (10 t/ha)+ ZnSO4

(20 kg/ha) 44.41 49.87 22,926 32,084 9,159 1.40


T4: T2 + 37.5 kg sulphur/ha (Factomphos) 50.00 56.00 22,926 36120 13,194 1.58





Recommended dose of fertilizer (150:75:75 kg N, P2O5 and K2O ha-1



T8

(T6) (0.77 mg kg-1


-1). The treatment receiving RDF alone (T1) recorded the lowest DTPA

extractable Zn (0.54 mg kg-1

) and it was on par with the treatment received RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 37.5 kg sulphur/ha (Factomphos) (T4) (0.64 mg kg

-1), RDF + FYM

(10 t/ha) + ZnSO4 (20 kg/ha) + 50 kg sulphur/ha (Factomphos) (T5) (0.57 mg kg-1

) and RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 50 kg sulphur/ha (gypsum) (T8) (0.63 mg kg

-1).

4.3.19.2 DTPA-extractable Cu (mg kg-1

)

The data pertaining to the residual effect of different sources and levels of sulphur on DTPA-extractable Cu content of succeeding rice crop are presented in Table 66.

The results of the study indicted that sulphur nutrition did not influence DTPA-extractable Cu content of succeeding rice crop.

4.3.19.3 DTPA-extractable Fe (mg kg-1

)

The data pertaining to the residual effect of different sources and levels of sulphur on DTPA-extractable Fe content of succeeding rice crop are presented in Table 67.

A perusal of data indicated that sulphur nutrition did not influence DTPA-extractable Fe content of succeeding rice crop.

4.3.19.4 DTPA-extractable Mn (mg kg-1

)

The data pertaining to the residual effect of different sources and levels of sulphur on DTPA-extractable Mn content of succeeding rice crop are presented in Table 68.

Non-significant difference was observed between treatments with respect to DTPA-extractable Mn content in soil at all stages.

4.3.20 Economics

The data on economic analysis of the present investigation involving rice (cv. IR 64) with respect to sulphur nutrition are presented in the Table 69 and 70.

In the present investigation, the highest gross returns of first rice crop (Rs. 41,236/-), net returns (Rs. 16847/-) and benefit:cost ratio (1.69) was obtained in the treatment receiving RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 50 kg sulphur/ha (Factomphos) (T5) compared to other treatments. The cost of cultivation was lower in the treatment that received RDF alone (Rs. 19,592/-) and highest with the application of RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 50 kg sulphur/ha (Factomphos) (T5) (Rs. 24,388/-). However, the highest net return was obtained with T5 treatment. This clearly suggests that direct sulphur fertilization to rice (RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 50 kg sulphur/ha (Factomphos) (T5) helps to obtain higher net returns of Rs. 4200/- over RDF alone (T1) and Rs. 5021/- over (RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) (T2).

With respect to residual effect, the application of RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) + 50 kg sulphur/ha (Factomphos) (T5) recorded the highest gross returns (Rs. 37,490/-), net returns (Rs. 14565/-) and benefit: cost ratio (1.64) as compared to other treatments. The treatment that received RDF alone (T1) registered the lowest cost of cultivation (Rs. 19,592/-) whereas all other treatments recorded similar cost of production (Rs. 22,926/-). Residual effect of sulphur fertilization to rice helps to obtain higher net returns of Rs. 5222/- over RDF alone (T1) and Rs. 5406/- over (RDF + FYM (10 t/ha) + ZnSO4 (20 kg/ha) (T2).

Higher gross returns, net returns and benefit:cost ratio were registered in first rice crop compared to succeeding rice crop.

5. DISCUSSION

The results obtained from the research work conducted to study the changes in yield and soil fertility as influenced by sulphur under intensive rice cropping system are discussed in this chapter under three headings.

5.1 Status and distribution of different forms of sulphur in intensive rice cropping areas


5.3 Direct and residual effects of sulphur fertilization on rice-rice cropping sequence

5.1 STATUS AND DISTRIBUTION OF DIFFERENT FORMS OF SULPHUR IN INTENSIVE RICE CROPPING AREAS

5.1.1 Distribution of different sulphur fractions in soil


)

Perusal of data in the Table 9 showed that sulphate sulphur content in soil of different locations varied from 12.05 to 49.51 mg per kg. The values of sulphate sulphur are generally higher in surface than at the lower depths. Higher amount of sulphate in surface layer than in subsurface layer might be due to recycling over the years by plants and subsequent organic matter accumulation. Above results are in conformity with the finding of Bhatnagar et al. (2003). However, higher values at lower depths in Doctor camp soil body indicate the leaching of sulphate. In Vertisols, Balanagoudar and Satyanarayana (1990a) reported leaching of sulphate to deeper layer where it precipitated as gypsum crystals. Cheema and Arora (1984) also accounted the accumulation of available sulphur in subsurface layers to the leaching of soluble sulphates. Sulphate sulphur showed positive and high relationship with water soluble sulphur (0.743**), organic sulphur (0.475**) and total sulphur (0.475*) (Table 11). Positive and significant correlations between sulphate sulphur and water soluble sulphur were recorded by Venkatesh (1997), Sharma and Jaggi (2001) and Rakesh Kumar et al. (2002).


)

Water soluble sulphur fraction mostly contains free inorganic and some organically bound SO4

2- (Williams and Steinbergs, 1959). The data from the Table 8 revealed that water

soluble sulphur was in the range of 19.13 to 56.60 mg per kg. The amount of water soluble sulphur present in soil was greater than that of sulphate sulphur. The reason might be due to the clayey nature of the soils. No definite relationship of water soluble sulphur was observed in relation to the depth of soil bodies. Water soluble sulphur was highly related to sulphate sulphur (0.743**) (Table 10). Sharma and Jaggi (2001) recorded similar type of association between water soluble sulphur and total sulphur.


)

Organic sulphur content in soils varied from 68.56 to 269.27 mg per kg. In all the soils, the surface soils contained higher amount of organic sulphur than the subsurface soils. Vertisols owing to moderately rich in organic matter, are likely to be rich in organic sulphur (Bhatnagar et al. (2003). The data further revealed that the content of organic sulphur seemed to be dependent upon organic carbon content. It may be due to its being intimately related with organic carbon content of the soil as is evidenced by highly significant correlation coefficient between them (0.593**) (Table 10). Similar observations were also reported by Tripathi and Karan Singh (1992), Misra et al. (1990), Balanagoudar and Satyanarayana (1990a), Bhan and Tripathi (1973), Lande et al. (1977) and Singh et al. (1976).


)

Perusal of data from Table 9 showed that non-sulphate sulphur content in soils was in the range of 420.19 to 2170.58 mg per kg. The values of non-sulphate sulphur in the present study are comparable with the results (771.50 to 2781.13 ppm) as reported by Venkatesh (1997). Such a wide range may be due to the variation in sulphur compounds in the soils. The high content of non sulphate sulphur in all these soils might be due to the dominance of insoluble sulphur compounds. The results indicated that total sulphur content behaved, like the content of non-sulphate sulphur. This was strongly justified by the positive correlation that was observed between non-sulphate sulphur and total sulphur (0.988**) (Table 10). A critical view on different sulphur fractions indicated that non-sulphate sulphur was higher than the organic sulphur. This might be due to the rapid oxidation of organic matter and mineralization of sulphur under prevailing high temperature in the study area. Presence of CaCO3 and alkaline condition may also be the factors leading to higher amount of non-sulphate sulphur in these soils. The results are in accordance with the findings of Ram and Diwedi (1994) and Singh et al. (2000).


)

The total sulphur content which indicate the reserves of this element in soil, ranged from 561.27 to 2372.52 mg per kg. The lowest value of total sulphur was generally recorded in surface layers than in subsurface layers. Probably most of total sulphur was constituted by insoluble sulphates or sulphates occluded in calcium carbonate. This type of pattern may occur where sulphides and carbonates get accumulated in lower depths (Takkar, 1988). Balasubramaniam and Kothandaraman (1985) opined that highest values of total sulphur in calcareous black soil of Coimbatore were due to gypsiferous nature of soils.

The total sulphur content positively and significantly correlated with pH (0.535**) and EC (0.557**) (Table 10). In the present investigation, a significant positive correlation of all the forms of sulphur (sulphate sulphur 0.475*, water soluble sulphur 0.648**, organic sulphur 0.415** and non-sulphate sulphur 0.988**) was observed suggesting that these forms of sulphur exist in a state of dynamic equilibrium. Total sulphur showed the highest significant correlation with non-sulphate sulphur which shows that total sulphur is mostly contributed by non-sulphate sulphur. The sulphides of non-sulphate sulphur fraction might have oxidized to form sulphate sulphur because of which the observed relationship may be existing as also reported by Balanagoudar and Satyanarayana (1990b) in Vertisols of North Karnataka.

5.1.2 Per cent contribution of sulphur fractions to total sulphur

Among the different sulphur fractions, the most predominant form in these soils was non-sulphate sulphur that accounted for 74.87 to 93.29 per cent of the total sulphur, thus forming a major fraction (Table 10). These values compared favourably with those reported by Balanagoudar and Satyanarayana (1990a) and Singh et al. (2000). Venkatesh (1997) reported that the non-sulphate fraction in Vertisols of north Karnataka constituted ranging from 75.48 to 97.23 per cent. The lowest sulphate sulphur percentage was observed in Basavapatna subsurface soil (0.72 %) and the highest in surface soil of Hosali (2.74 %). Water soluble sulphur ranged from 1.13 to 4.38 per cent. Percentage of water soluble fraction was lesser in subsurface soil of Basavapatna (1.13 %) whereas the maximum in the surface soil of Hosali (4.38 %) soil body. As percentage of total sulphur, organic sulphur varied from 4.38 to 18.61 per cent, its content showed a decrease with increase in soil depth which was due to the high amount of organic matter in surface horizons. The per cent contribution of organic sulphur to total sulphur was quite low compared to that reported by many workers. The low organic sulphur status may be due to high mineralization of organic matter because of high temperature in soils of present study. Dharkanath et al. (1995) reported that organic sulphur constituted about 1.1 to 5.5 per cent of total sulphur in Vertisols of Maharashtra state.

The percentage contribution of different sulphur fractions to total sulphur decreased in the following order: non-sulphate sulphur > organic sulphur > water soluble sulphur > sulphate sulphur (Fig. 2). Similar findings were reported by Venkatesh (1997) and Singh et al. (2000).

Non sulphate S

87.16%

Organic S

9.01%

Water soluble S

2.44%

Sulphate S

1.39%

Fig. 2. Average per cent contribution of different forms of sulphur to total sulphur in various soil bodies

5.2 INCUBATION STUDY ON THE TRANSFORMATION OF DIFFERENT SOURCES AND LEVELS OF SULPHUR IN SOIL

Incubation study was conducted in the laboratory to study the effect of different sources and levels of sulphur on periodical changes of different sulphur fractions on soil for the period of 109 days.

The data on the effect of sulphur nutrition on the periodical changes of sulphate sulphur, water soluble sulphur, organic sulphur, non-sulphate sulphur and total sulphur at 32, 54, 75 and 109 days after incubation are presented in this chapter.

In general, it is was observed that, there was an increase in sulphate sulphur and water soluble sulphur from the initial levels up to 32 days after incubation and thereafter both fractions decreased gradually up to 109 days (Table 12 and 13 and Fig. 3 and 4). On the contrary, organic sulphur content progressively increased from 32 to 109 days after incubation (Table 14 and Fig. 5). When sulphate is applied to the soil, it slowly gets transformed into organic constituents through a series of chemical and bio-chemical processes. Using S

35-labelled sulphate, Sachdev and Chhabra (1974) reported that under

aerobic condition 68.1 per cent and in flooded condition 12.7 per cent of added sulphur could be recovered as sulphate. Further, they noticed that in aerobic condition 28.1 per cent and in case of flooded condition 37.8 per cent of the added sulphur could be recovered as organic sulphur. This clearly indicates that the reduction of sulphate was more rapid under flooded condition.

At 32 days after incubation, the treatment T5 (50 kg S ha-1

by Factomphos) was found to be the highest with respect to sulphate sulphur. It indicated per cent increase by 97.4 over RDF alone (T1). The treatment T5 (37.5 kg S/ha by Factomphos) was on par with the treatment T4 which increased 80.1 per cent in sulphate sulphur over RDF alone (T1). The lowest sulphate sulphur content was noticed in the treatment that received RDF alone (T1).

Application of 50 kg S per ha by Factomphos (T5) showed the highest per cent increase (100.6 %) sulphate sulphur over RDF alone (T1) treatment at 54 days after incubation. It was on par with the treatment T4 (37.5 kg S ha

-1 by Factomphos) which

increased 90.1 per cent in sulphate sulphur over RDF alone (T1).

The effect of varying levels and sources of sulphur was significant with respect to sulphate sulphur at 75 days after incubation. The highest per cent increase in sulphate sulphur was noticed with the treatment receiving 50 kg sulphur per ha by Factomphos (T5) which indicated 105.7 per cent increase over RDF alone (T1). The treatment receiving 37.5 kg S per ha by Factomphos (T4) was on par with T5 and showed 84.1 per cent increase in sulphate sulphur over T1.

Increased sulphur levels in soils significantly increased sulphate sulphur at 109 days after incubation. The highest per cent increase with respect to sulphate sulphur was observed with the treatment T5 which indicated 110.6 per cent increase over the treatment receiving RDF alone (T1). The per cent increase of 100.7 indicated with the treatment T4 was on par with T5 treatment.

At 32, 54, 75 and 109 days after incubation, the highest per cent increase in water soluble sulphur was observed in the treatment receiving 50 kg S per ha by Factomphos (T5) indicating 111.4, 135.5, 114.2 and 110.9 per cent increase over the treatment receiving RDF alone (T1) at respective days after incubation. The treatment T5 was on par with the treatment T4 which recorded 89.2, 108.8, 91.0 and 87.7 per cent increase in water soluble sulphur at 32, 54, 75 and 109 days after incubation.

The decrease in sulphate sulphur and water soluble sulphur fractions of soil from 32 days onwards may be due to conversion of these forms of sulphur into organic form through immobilization process that are mediated by soil microorganisms. It was evident with the increase in organic sulphur throughout the study period. However, gypsum did not show

0

5

10

15

20

25

30

35

Su

lph

ate

su

lph

ur

(mg k

g-1

)

Initial T1 T2 T3 T4 T5 T6 T7 T8

Treatments

32 DAI 54 DAI 75 DAI 109 DAI

T1: RDF, T2: RDF + FYM (10t/ha)+ ZnSO4 (20 kg/ha), T3: T2 + 25 kg sulphur/ha (Factomphos), T4: T2 + 37.5 kg sulphur/ha (Factomphos),

T5: T2 + 50 kg sulphur/ha (Factomphos), T6: T2 + 25 kg sulphur/ha (gypsum), T7: T2 + 37.5 kg sulphur/ha (gypsum), T8: T2 + 50 kg sulphur/ha (gypsum)

Fig. 3: Effect of different levels and sources of sulphur on sulphate sulphur at different days after incubation

0

5

10

15

20

25

30

35

40

45

50

Wate

r so

lub

le s

ulp

hu

r (m

g k

g-1

)


Treatments


T1: RDF, T2: RDF + FYM (10t/ha)+ ZnSO4 (20 kg/ha), T3: T2 + 25 kg sulphur/ha (factomphos), T4: T2 + 37.5 kg sulphur/ha (factomphos),

T5: T2 + 50 kg sulphur/ha (factomphos), T6: T2 + 25 kg sulphur/ha (gypsum), T7: T2 + 37.5 kg sulphur/ha (gypsum), T8: T2 + 50 kg sulphur/ha (gypsum)

Fig. 4: Effect of different levels and sources of sulphur on water-soluble sulphur at different days after incubation

0

20

40

60

80

100

120

140

160

180

200

Org

an

ic s

ulp

hu

r (m

g k

g-1

)


Treatments




Fig. 5: Effect of different levels and sources of sulphur on organic sulphur at different days after incubation

significant influence with respect to this sulphur fraction. The reason may be due to the lesser solubility compared to Factomphos which consist of ammonium phosphate sulphate.

The highest per cent of increase in organic sulphur was noticed in the treatment receiving 50 kg S per ha by Factomphos (T5) indicating 26.1, 35.8, 39.6 and 51.9 per cent increase over the treatment receiving RDF alone (T1) at 32, 54, 75 and 109 days after incubation respectively. At 32, 54 and 75 days after incubation, the increase in organic sulphur in the treatment that received T5 was on par with the treatment T3 (17.1, 24.0 and 32.6 %), T4 (21.8, 33.9 and 36.2 %), T6 (15.3, 20.0 and 29.2 %), T7 (17.6, 23.8 and 30.3 %) and T8 (19.3, 28.7, 32.2 %) over T1. At 109 days after incubation, T5 was on par with the treatment T3 (38.0 %), T4 (45.9 %), T7 (39.6 %) and T8 (19.3, 28.7, 32.2 %) over T1. Under flooded soil conditions, two genera of sulphur reducing bacteria, Desulphovibrio and Desulphotomaculam reduce sulphate to sulphide ion through the potential inorganic intermediates (thiosulphate, tetrathionate and colloidal sulphur). Due to limitation of oxygen, the sulphide concentration increases to a relatively high amount and combined with iron in soil to form iron sulphide and is thus retained in the soil (Sachdev and Chhabra, 1974).

Regarding the effect of varying levels and sources of sulphur on non-sulphate fraction, the differences between treatments were found non-significant throughout the incubation study period (Table 15).

The results of the investigation revealed that the total sulphur content significantly increased with the application of sulphur irrespective of source and level. At 32, 54, 75 and 109 days after incubation, the highest per cent of increase in total sulphur was noticed in the treatment receiving 50 kg S per ha by gypsum (T8) indicating 13.5, 13.4, 13.3, and 13.5 per cent increase over the treatment receiving RDF alone (T1) (Table 16 and Fig. 6). Similar results were obtained by Venkatesh (1997).

5.3 DIRECT AND RESIDUAL EFFECTS OF SULPHUR FERTILIZATION ON RICE-RICE CROPPING SEQUENCE

The results obtained from the field experiments conducted on a Vertisol under irrigated condition at Agriculture Research Station, Gangavati, during Rabi/summer and Kharif seasons of 2007 to study the changes in yield and soil fertility as influenced by sulphur under rice-rice cropping system are discussed under following chapter.

5.3.1 Growth, yield and quality parameters of first rice crop

5.3.1.1 Growth parameters of first rice crop

Sulphur nutrition had distinct influence on plant height, number of tillers per hill and dry matter production of first rice (Tables 17-19).

At active tillering stage, the treatment T5 (50 kg S ha-1

by Factomphos) was found to be the highest over the rest of treatment with respect to plant height. It indicated 16.5 per cent increase over RDF alone (T1). The treatment T5 (37.5 kg S/ha by Factomphos) was on par with the treatment T4 which increased 14.4 per cent in plant height over T1. The treatment received 50 kg sulphur per ha by Factomphos (T5) indicated the highest plant height at panicle initiation, grain filling and harvest stages which showed 12.3, 10.2 and 11.8 per cent increase over (T1) at respective stages. Application of 37.5 kg sulphur per ha by Factomphos (T4) was on par with the treatment T5. It resulted 10.7, 9.4 and 9.7 per cent increase in plant height over T1 at panicle initiation, grain filling and harvest stages respectively. Treatment T3 (25 kg S ha

-1 by Factomphos) was also on par with T5 and it showed 8.1, 5.9 and 7.7 per cent

increase in plant height at panicle initiation, grain filling and harvest stages, respectively.

The increased plant height is to increased uptake of sulphur supplied through sulphur containing fertilizers. Assimilated sulphur might have played vital role in growth and development of rice plants because of their active role in plant metabolic processes. Sulphur performs many physiological functions like synthesis of sulphur containing amino acids (cysteine, cystine and methionine), synthesis of vitamins, and metabolism of carbohydrates

850

900

950

1000

1050

1100

To

tal

sulp

hu

r (

mg

kg

-1)


Treatments




Fig. 6: Effect of different levels and sources of sulphur on total sulphur at different days after incubation

and proteins. Plants deficient in sulphur are reported to be small and spindly with short and slender stalks, their growth is retarded. The results related to plant height in this study are consonance with the findings of Ram et al. (1999), Sumathy et al. (1999), Shailendra Kumar (2002), Chandel et al. (2002) and Sreedevi et al. (2006).

Similarly, number of tillers per hill and dry matter production at all growth stages increased significantly due to sulphur application (Table 18).

Application of sulphur fertilizers by Factomphos had significant influence on number of tillers at active tillering stage. Treatment T5 (50 kg S/ha by Factomphos) showed the highest number of tillers an increased by 48.7 per cent over T1. Treatment T3 and T4 which were on par with treatments T5, had recorded 32.0 and 37.6 per cent increase in number of tillers at active tillering stage respectively. At panicle initiation , grain filling and harvest stages, the treatment that received 50 kg S per ha by Factomphos (T5) exhibited the highest number of tillers which accounted to increase in number of tillers by 35.5, 35.4 and 45.0 per cent over T1 at respective stages. Similarly, application of T4 was on par with T5 and it indicated increase in number of tillers by 25.9, 25.9 and 34.4 per cent over T1 at panicle initiation, grain filling and harvest stages. Tillering is the product of expanding auxiliary buds, which is closely associated with the nutritional conditions of the mother culm during its early growth period, which gets improved by the application of sulphur (Blair et al., 1979 and Hossain et al., 1987). The results obtained in this study are in conformity with the findings of Ahmed et al. (1989), Made Dana et al. (1994), Patra et al. (1998), Sumathy et al. (1999) and Chandel et al. (2002).

The total dry matter production in first rice crop increased significantly with increased sulphur levels (Table 19). As compared to T1 (RDF alone) treatment, the dry matter production in T5 treatment (50 kg S ha

-1 by Factomphos) increased by 42.4 per cent at active

tillering stage. It was on par with T4 (37.5 kg S ha-1

by Factomphos). The treatment of T4

showed 35.7 per cent increase in dry matter compared to T1. Sriramachandrasekharan et al. (2005) studied the direct supply of available sulphur in rice-rice cropping sequence and reported an increase of 48.6 per cent dry matter with the application of sulphur at the rate of 40 kg per ha compared to no fertilizer treatment at tillering stage.

At panicle initiation, grain filling stages and at harvest, the dry matter production increased with the application of sulphur. The highest dry matter production was recorded by T5 (50 kg S ha

-1 by Factomphos) treatment over T1 (RDF alone) treatment at respective

stages. Percentage increase in dry matter production by T5 over T1 (RDF alone) at respective stages were 32.2, 30.4, 27.5 and 27.9 per cent. The treatment receiving 25 kg S per ha by Factomphos (T3) was also on par with T5 resulting increase in dry matter by 22.1, 24.6, 17.7 and 19.3 per cent over T1 at panicle initiation, grain filling stages and in straw and grain at harvest. Sriramachandrasekharan et al. (2005) reported 22.8 and 32.7 per cent increase in dry matter production in first rice crop due to application of 40 kg sulphur over no sulphur application at panicle initiation and harvest stages respectively. Increase in dry matter production due to sulphur may be because of higher rate in protein synthesis and enhanced photosynthetic activity of the plant with increased chlorophyll synthesis.

5.3.1.2 Yield parameters of first rice crop

The yield and yield parameters such as productive tillers per hill and number of panicles per m

2 number of grains per panicle, 1000 grain weight, grain yield and straw yield

were significantly influenced by sulphur nutrition (Tables 20-22 and Fig. 7).

Application of sulphur had marked influence on yield and yield components of first rice crop. The treatment T5 (50 kg S ha

-1 by Factomphos) significantly increase the number of

panicle per m2 (34.6 %), number of grains per panicle (23.4 %), 1000 grain weight (5.9 %),

grain yield (27.9 %) and straw yield (27.5 %) over T1 and followed by T4 (37.5 kg S ha-1

by Factomphos) which recorded an increase in number of panicles per m

2 (30.4 %), number of

grains per panicle (18.7 %), 1000 grain weight (5.4 %), grain yield (23.7 %) and straw yield (23.5 %). The lowest number of panicles per m

2, number of grains per panicle, 1000 grain

weight, grain yield and straw yield were recorded in the treatment receiving RDF alone (T1). Harvest index and panicle length had no significant difference due to sulphur application in

Plate.2. General view of he experiment at active tillering stage first rice crop

Plate.3. Direct effect of sulhur nutrition at active tillering stage

Plate.4. General view of the experiment at grain filling stage rice crop

Plate.5. Direct effect of sulphur nutrition at grain filling stage

Plate.6. General view of the experiment at harvest first rice crop

0

10

20

30

40

50

60

70G

rain

an

d s

traw

yie

ld (

q/h

a)

T1 T2 T3 T4 T5 T6 T7 T8

Treatments

Grain yield Straw yield



Fig. 7: Effect of different sources and levels of sulphur on grain and straw yield of rice

first rice crop. The higher soluble nature of Factomphos compared to gypsum might have resulted in high amount of sulphur release during growth in the treatment receiving Factomphos which consisted of ammonium phosphate sulphate. Favourable effect of sulphur on yield and yield attributes of rice could be due to its stimulating effect in the synthesis of chloroplast protein resulting in greater photosynthetic efficiency which in turn resulted in increased yield (Biswas and Tewatia, 1992). Beneficial effect of sulphur on rice yield was reported by Graeme et al. (1979a), Poongothai et al. (1999), Ram et al. (1999), Badrul Hasan (1998), Sumathy et al. (1999), Singh, (2000), Wani and Refique (2000), Subbaiah et al. (2001), Sreedevi et al. (2006) and Bhuvaneswari et al. (2007). Application of Zn might have contributed to increase yield of rice. Rajakumar (1994) reported that application of Zn by soil application or by dipping rice seedlings grown in Vertisol increased rice yield. Sriramachandrasekaran and Mathan (1991) reported that application of ZnSO4 @ 25 kg per ha increased the grain and straw yield over no Zn application which could be due to the favourable effect yield components and perhaps Zn influenced the uptake of plant nutrients by rice through enzymatic effect in the metabolic process which ultimately account for higher grain yield. The superiority of Factomphos as a source of sulphur to gypsum can be attributed to the readily soluble nature of the former.

5.3.1.3 Quality parameters of first rice crop

Application of sulphur to the sulphur deficient soils has been found to increase the crop yield as well as improve the quality of crop produce. The sulphur containing amino acids and protein have been found to go up with sulphur application in crops. Quality parameters of first rice crop like grain protein and methionine content increased significantly due to the effect of sulphur application (Table 23 and Fig. 8).

Application of sulphur at the rate of 50 kg sulphur per ha by Factomphos (T5) strikingly increased rice grain protein content by 28.6 per cent over the treatment T1 (RDF alone). The protein content registered by T5 was on par with T4 (37.5 kg S ha

-1 by

Factomphos) that resulted in 21.4 per cent increase over the treatment T1. The lowest protein content was recorded by the treatment T1. It significantly differed with the rest of treatments. The results of these investigations are in consonance with the findings of Clarson and Ramaswami (1992), Ali et al. (2004) and Rahman et al. (2007).

Similarly, the highest per cent increase in grain methionine content (39.4 %) was observed with the treatment receiving 50 kg sulphur per ha through Factomphos (T5) compared to T1 (RDF). The value recorded in methionine content by T5 was on par with T4 (37.5 kg S ha

-1 by Factomphos) which resulted in 31.1 per cent increase over T1. The lowest

methionine content was obtained with the treatment receiving RDF alone (T1). The treatments T2, T3 and T6 were on par with T1 which resulted in 1.1, 10.0 and 7.2 per cent increase in methionine content over T1. Clarson and Ramaswami (1992) reported that the methionine content of rice increased by 32.1 per cent due to sulphur containing fertilizers over control.

5.3.1.4 Nutrient content and uptake by first rice crop

Plant nutrients in soil, whether naturally endowed or artificially maintained are major determinants of success or failure of a crop production system. The data on nitrogen, phosphorus, potassium and sulphur content and uptake in first rice crop was found to differ significantly due to application of sulphur.

Sulphur application distinctly increased nitrogen content at active tillering, panicle initiation, grain filling stages and in grain and straw at harvest stage (Table 24 and Fig. 9).

Among the treatments, the treatment receiving 50 kg sulphur per ha by Factomphos (T5) showed 23.7, 23.2, 23.0 27.6 and 19.8 per cent increase in nitrogen over T1 (RDF) at active tillering, panicle initiation, grain filling stages and in straw and grain at harvest, respectively. At active tillering stage, the nitrogen content recorded by T5 was on par with the treatment T4 which resulted in 19.2 per cent increase compared to T1 (RDF). Similar trend was found at panicle initiation stage and T4 showed 19.6 per cent increase over T1. At grain filling stage, the highest per cent increase of 23.0 was recorded by T5 (50 kg S ha

-1 by

Factomphos) over T1 and it was on par with T4 (37.5 kg S ha-1

by Factomphos) which

0.00

2.00

4.00

6.00

8.00

10.00

12.00

Pro

tein

con

ten

t (%

) an

d m

eth

ion

ine

con

ten

t (m

g g

-1)

T1 T2 T3 T4 T5 T6 T7 T8

Treatments

Grain protein Methionine



Fig. 8:Effect of different sources and levels of sulphur on grain protein and methionine content of rice

0.00

0.20

0.40

0.60

0.80

1.00

1.20

1.40

1.60

1.80

2.00

Nit

rogen

con

ten

t (%

)

T1 T2 T3 T4 T5 T6 T7 T8

Treatments

Active tillering Panicle initiationGrain filling StrawGrain



Fig. 9: Effect of different sources and levels of sulphur on nitrogen content at different growth stages of rice

indicated 20.4 per cent increase in nitrogen content. The highest increases in nitrogen per cent recorded by T5 in straw and grain were 27.6 and 19.8 per cent over T1. The treatment T4

was on par with T5 and resulted in 21.1and 15.3 per cent increase in straw and grain nitrogen. The lowest nitrogen content was observed with the treatment T1 (RDF). Ali et al. (2004) reported that application of sulphur at the rate of 40 kg per ha significantly increased the nitrogen content by 49.5 per cent over no sulphur treatment at the maximum tillering stage of rice. This might be due to increased availability of nitrogen in soil because of sulphur application as well as the addition of farmyard manure. As nitrogen and sulphur are constituents of protein and involved in chlorophyll formation, there is a direct link between nitrogen and sulphur. Similar results of these investigations were observed by Tiwari et al. (1983), Viney Singh et al. (1986), Mandhata Singh et al. (1994) and Jena et al. (2006).

It was observed in the present study that sulphur application distinctly increased nitrogen uptake at active tillering, panicle initiation, grain filling stages and in straw and grain at harvest stage, respectively (Table 24 and Fig. 10).

The treatment T5 showed 76.2, 62.9, 60.4, 62.7 and 53.3 per cent increase in nitrogen uptake at active tillering, panicle initiation, grain filling stages and in straw and grain at harvest stage. At all stages, T5 was on par with the treatment T4 which indicated 61.8, 52.8, 53.8, 49.4 and 42.6 per cent increase over T1. The lowest nitrogen uptake was observed with the treatment T1 (RDF) at all stages of the crop. Similar findings were observed by Sachdev et al. (1982).

Sulphur application remarkably increased phosphorus content at active tillering, panicle initiation, grain filling stages and in grain and straw at harvest stage (Table 25 and Fig. 11).

Application of T5 treatment increased phosphorus content by 25.8 per cent over the treatment T1 at active tillering stage. It was superior over the rest of treatments. The lowest phosphorus content was observed in the treatment receiving T1 (RDF). At panicle initiation stage, treatment T5 showed the highest per cent increase of 14.2 followed by T4 (12.5 %). Ali et al. (2004) observed that application of sulphur at the rate of 40 kg per ha significantly increased the phosphorus content by 42.9 per cent over no sulphur treatment at the maximum tillering stage of rice. At grain filling stage, the treatment receiving 50 kg sulphur per ha by Factomphos (T5) showed the highest per cent increase (14.5 %) in phosphorus content compared to T1. It was on par with the treatment T4 which resulted 11.0 per cent increase in phosphorus content. The lowest phosphorus content was observed with the treatment T1. At harvest, the highest straw phosphorus increase of 41.2 per cent over T1 was observed with the treatment T5 and it was significantly superior over the rest of treatments. the highest grain phosphorus increase of 22.5 per cent was observed with T5 followed by T4 (19.6 %). The lowest grain sulphur was noticed in the treatment T1. Phosphorus exhibited a synergistic effect with sulphur application, which enhanced better utilization of nutrients. This confirms the findings of Naw Mar Lar Oo et al. (2007). Significant increase of phosphorus due to sulphur was reported by Mandhata Singh et al. (1994), Sarkunan et al. (1998), Viney Singh et al. (1986) and Rahman et al. (2007). The increase in phosphorus content might be due to the role of sulphur in growth, development and chlorophyll development formation, resulting in its higher utilization (Aulakh et al., 1980).

Sulphur application remarkably increased the phosphorus uptake in first rice (Table 25 and Fig. 12).

The data on plant phosphorus uptake showed that T5 treatment increased phosphorus uptake by 79.2, 51.0, 49.4, 79.9 and 56.7 per cent over the treatment T1 at active tillering, panicle initiation, panicle initiation stages and in straw and grain at harvest, respectively. At active tillering stage, T5 was superior over the rest of treatments. Phosphorus uptake observed in the treatment T4 was on par with T5 and it increased phosphorus uptake by 43.7 per cent at panicle initiation stage, 41.8 per cent at grain filling stage and 47.9 per cent in grain, respectively. The lowest phosphorus uptake was noticed in the treatment T1 throughout the growing period. The increase of phosphorus uptake due to sulphur application was reported by Jena et al. (2006) and Naw Mar Lar Oo et al. (2007).

0.00

20.00

40.00

60.00

80.00

100.00

120.00

Nit

rogen

up

tak

e (k

g h

a-1

)

T1 T2 T3 T4 T5 T6 T7 T8

Treatments

Active tillering Panicle initiation

Grain filling Straw

Grain



Fig. 10: Effect of different sources and levels of sulphur on nitrogen uptake at different growth stages of rice

0.000

0.050

0.100

0.150

0.200

0.250

0.300

0.350

Ph

osp

horu

s co

nte

nt

(%)

T1 T2 T3 T4 T5 T6 T7 T8

Treatments


Grain filling Straw

Grain



Fig. 11: Effect of different sources and levels of sulphur on phosphorus content at different growth stages of rice

Potassium content in first rice crop did not significantly differ due to application of sulphur throughout the growing period (Table 26).

Applied sulphur had profound influence on potassium uptake in first rice (Table 26 and Fig. 13).

The treatment T5 registered significantly highest per cent potassium uptake (83.5 %), (57.5 %), (35.8 %), (43.7 %) and (61.6 %) over T1 at active tillering, panicle initiation, grain filling stages and in straw and grain at harvest stage respectively. The uptake recorded by T4 was on par with T5 and it showed (59.6, 44.3, 31.0, 36.6 and 50.1 %) over T1 at active tillering, panicle initiation, grain filling stages and in straw and grain at harvest stage respectively. The lowest potassium uptake was recorded in the treatment T1 throughout the growing period. Findings of Jena et al. (2006) Naw Mar Lar Oo et al. (2007) in aromatic rice corroborate with these results.

5.3.1.5 Sulphur content and uptake by first rice crop

Crops in general require as much sulphur as they need phosphorus. Sulphur requirement of crop mainly depends on soil-crop-climate complex. Sulphur application significantly influenced the sulphur content of first rice (Table 27 and Fig. 14).

The sulphur content progressively increased with increasing levels of sulphur application. The plots receiving T5 significantly increased sulphur content by (84.0, 81.1, 102.4, 68.3 and 79.4 %) over T1 at active tillering, panicle initiation, grain filling stages and in straw and grain at harvest stage respectively. The treatment T4 was on par with T5 and resulted increase in sulphur content by (64.1, 65.5, 81.1, 57.7 and 70.2 %) over T1 at active tillering, panicle initiation, grain filling stages and in straw and grain at harvest. The treatment that received RDF (T1) registered the lowest sulphur content compared to other treatments. Similar results were noticed by Tiwari et al. (1983), Alam et al. (1985), Mandhata Singh et al. (1993) and Ram et al. (1999).

Application of sulphur significantly influenced on sulphur uptake of first rice (Table 27 and Fig. 15).

The plots receiving T5 registered markedly increased sulphur uptake by (162.0, 139.4, 163.9, 114.5 and 129.4 %) over T1 at active tillering, panicle initiation, grain filling stages and in straw and grain at harvest respectively. The treatment T5 was superior at active tillering and on par with T4 at panicle initiation, grain filling stages and in straw and grain. It resulted in increase in sulphur uptake by 111.5, 131.4, 94.7 and 110.5 per cent over T1 at respective growth stages. The lowest sulphur uptake was observed in the treatment T1. Sulphur uptake generally followed the sulphur concentration pattern and increased uptake of sulphur can be ascribed to the increased content of available sulphur in soil. The reason to increase in sulphur uptake might be due to integrated use of farmyard manure with sulphur. Integrated use of green manure and sulphur fertilizers promoted N, P, K and S availability to rice crop and increased grain yield (Sumathy et al. 1999). Sriramachandrasekharn et al. (2007) in their study reported that the increase of sulphur uptake in first rice crop (67.3% in grain and 69.7% in straw) due to direct effect of sulphur applied at the level of 60 kg per ha. The results of this investigation are consonance with the finding of Mandhata Singh et al. (1993), Sarkunan et al. (1998), Ram et al. (1999) and Sriramachandrasekharn et al. (2005).

5.3.1.6 Micronutrient content and uptake of first rice crop

Direct effect of the treatments on micronutrient content (Zn) and uptake (Zn, Cu, Fe and Mn) influenced significantly in first rice (Tables 28-31).

The favourable effect of micronutrients especially Zn may be due to beneficial effect of micronutrients on various physiological activities of the crop plants. Mahatim Singh et al. (1978) reported significant influence of Zn in improving yield, protein content and uptake of N, P and K in rice.

0.00

2.00

4.00

6.00

8.00

10.00

12.00

14.00

16.00

18.00

20.00

Ph

osp

ho

rus

up

tak

e (k

g h

a-1

)

T1 T2 T3 T4 T5 T6 T7 T8

Treatments


Grain filling Straw

Grain



Fig. 12: Effect of different sources and levels of sulphur on phosphorus uptake at different growth stages of rice

0.00

10.00

20.00

30.00

40.00

50.00

60.00

70.00

80.00

90.00

100.00

Pota

ssiu

m u

pta

ke

(k

g h

a-1

)

T1 T2 T3 T4 T5 T6 T7 T8

Treatments

Active tillering Panicle initiationGrain filling StrawGrain



Fig. 13: Effect of different sources and levels of sulphur on potassium uptake at different growth stages of rice

0.000

0.050

0.100

0.150

0.200

0.250

0.300

Su

lph

ur

con

ten

t (%

)

T1 T2 T3 T4 T5 T6 T7 T8

Treatments


Grain filling Straw

Grain



Fig. 14: Effect of different sources and levels of sulphur on sulphur content at different growth stages of rice

0.00

2.00

4.00

6.00

8.00

10.00

12.00

14.00

16.00

18.00

Su

lph

ur

up

tak

e (k

g h

a-1

)

T1 T2 T3 T4 T5 T6 T7 T8

Treatments


Grain filling Straw

Grain



Fig. 15: Effect of different sources and levels of sulphur on sulphur uptake at different growth stages of rice

Treatments increased Zn content at active tillering, panicle initiation, grain filling and in straw and grain at harvest over T1 treatment. Data with respect to the Cu, Fe and Mn contents did not differ significantly due to different treatments in first rice. The lowest content of all micronutrients was registered with the treatment of T1. With respect to Zn content, treatment T5 recorded 53.7, 53.8, 54.5 63.4 and 63.4 per cent increase in Zn content over T1 treatment at active tillering, panicle initiation, grain filling stages and in straw and grain at harvest respectively. The data revealed that treatment T4 was on par with T5 with respect to Zn content and recorded increase in Zn content by 47.0, 47.3, 47.4, 55.2 and 55.3 per cent respectively compared to T1. Zn uptake at all stages of crop growth was increased due to different treatments. Treatment T5 registered per cent increase in Zn uptake of 118.9, 103.4, 101.5 108.3 and 109.0 per cent over T1 treatment at active tillering, panicle initiation, grain filling stages and in straw and grain at harvest respectively. The data revealed that treatment T4 was on par with T5 with respect to Zn uptake and recorded increase in uptake by 99.5, 88.2, 88.4, 91.6 and 92.1 per cent respectively compared to T1.

At all growth stages, the treatment T5 registered significantly higher Cu uptake by 76.3, 63.5, 61.9, 57.5 and 87.6 per cent over T1 treatment and it was on par with T3, T4, T6

and T8. At all growth stages, treatments influenced significantly on Fe uptake. The treatment T5 registered the highest increase in Fe uptake over T1 at active tillering (85.4 %), panicle initiation (70.5 %), grain filling (67.3 %) and at harvest in straw (62.7 %) and in grain (64.8 %) over the T1. The treatment T4 was also on par with T5 and recorded per cent increase of 66.5, 55.9, 55.1, 49.4 and 51.1 per cent over T1 treatment respectively. The lowest Fe uptake was observed in the treatment T1 throughout the growing period of first rice. With respect to Mn uptake due to treatments, significant difference was recorded at all stages of the crop. The highest per cent increase in Mn uptake over T1 at active tillering (82.5 %), panicle initiation (68.7 %), grain filling (69.2 %) and in straw (62.7 %) and in grain (98.1 %) over the T1. The treatment T4 was also on par with T5 and recorded an increase of 66.1, 56.9, 55.0, 49.4 and 80.4 per cent over T1 treatment, respectively. The lowest Mn uptake was observed in the treatment T1 throughout the growing period. Results of the investigation are in consonance with the findings of Singh (1971). Rajakumar (1994) reported that application of Zn to soil or by dipping rice seedlings grown in Vertisol increased Zn uptake and rice yield. Anand Swarup (1998) reported that although gypsum markedly reduced soil pH and ESP in sodic soil, it resulted in higher yield than did farmyard manure. Sriramachandrasekhran and Mathan (1991) observed that application of Zn with NPK increased Zn uptake over NPK alone by 34.6 to 58.6 per cent in grain and 51.0 to 76.6 per cent in straw. Further, they noticed that Zn fertilization increased Mn and Cu uptake indicating synergistic effect. Chavan and Banerjee (1980) observed that uptake of Fe increased significantly with higher levels of zinc. Similar results were reported by Haldar and Mandal (1981).

5.3.1.7 Soil pH and EC of first rice crop

Submergence of a soil leads to reduction which profoundly influences the growth and nutrition of rice through its effects on pH nutrient availability and other electrochemical properties. However, application of different levels and sources of sulphur did not significantly influence soil pH and EC in first rice (Table 32 and 33).

5.3.1.8 Sulphur fractions in soil (first rice crop)

The data on sulphur fractions (sulphate sulphur, water soluble sulphur, organic sulphur) at active tillering, panicle initiation, grain filling stages and harvest stage in soil differed significantly due to the direct effect of applied treatments. However, non-sulphate sulphur fraction and total sulphur was found to be non-significant due to different treatments.

Table 34 and Fig. 16 indicated that the sulphate sulphur decreased with the advancement of crop growth of the first rice, but increased with sulphur levels at all stages of crop growth. The treatment T5 increased sulphate sulphur by 81.5, 77.1, 62.1 and 54.2 per cent as compared to T1 at active tillering, panicle initiation, grain filling and harvest stage, respectively. Similarly, the treatment T4 increased sulphate sulphur by 65.1, 58.5, 53.8 and 41.2 per cent at active tillering, panicle initiation and grain filling stages and harvest. The lowest sulphate sulphur content was observed in the treatment T1 at active tillering, panicle initiation, grain filling and harvest stages. Under flooded conditions, in addition to plant uptake

of sulphate, it is reduced by two genera of bacteria, viz, Desulfovibrio and Desulfotomaculam and converted into organic forms. The results of this investigation are in consonance with the findings of Sachdev et al. (1982), Alam et al. (1985) and Clarson and Ramaswami (1992).

At active tillering, panicle initiation, grain filling and harvest stages, the values of the per cent increase with respect to water soluble sulphur by the treatment T5 were 79.6, 89.0, 89.4 and 91.5 over T1. The treatment T4 increased water soluble sulphur by 63.1, 69.3, 69.8 and 91.5 per cent over T1 at active tillering, panicle initiation, grain filling and harvest stages. The lowest water soluble sulphur was registered by the treatment T1 throughout the growing period of succeeding crop (Table 35 and Fig. 17).

Organic sulphur increased with the advancement of crop from active tillering to grain filling stage (Table 36 and Fig. 18). There was slight decrease in organic sulphur content at harvest. However, the difference in organic sulphur was significant only at grain filling and harvest.

With respect to organic sulphur, there was no significant difference at active tillering and panicle initiation, but the treatment T5 increased organic sulphur by 26.3 and 28.7 per cent as compared to T1 at grain filling and harvest, respectively. The treatment T4 increased organic sulphur by 19.2 and 21.7 per cent over T1 at respective growth stages. The treatment T1 registered the lowest organic sulphur in first rice soil throughout the growing period. The increase of applied sulphur in the form of organic sulphur (

35S) from tillering to maturity of rice

was noticed by Sachdev et al. (1982).

Non-sulphate sulphur fraction was found to be non-significant with respect to the effect of sulphur treatments at all stages of the first crop (Table 37).

There was no significant difference in total sulphur throughout the growing season (Table 38). Shailendra Kumar (2002) observed significant increase in total, organic, water soluble and available sulphur due to application of sulphur in rice and Dhanajaya and Basavaraj (2002) in maize after harvest.

5.3.1.9 Available micronutrient content in soil (first rice crop)

At all stages, treatments influenced significantly the DTPA-extractable Zn (Table 39). At active tillering, panicle initiation, grain filling and harvest stages, the treatment T2 recorded the highest increase DTPA-extractable Zn (70.7, 68.4, 71.4 and 70.9 %) over T1. It was on par with the treatments T3 (41.4, 42.1, 42.9 and 43.6 %), T6 (53.4, 54.4, 55.4 and 54.5 %) and T7 (44.8, 43.9, 44.6 and 45.5 %). The lowest DTPA-extractable Zn was noticed in T1 treatment. The reason might be that T1 did not receive ZnSO4 while all other treatments received uniform level of ZnSO4. Similar results were reported by Bandyopadhyay et al. (2003). Akther et al. (1994) noticed that the sulphur induced Zn deficiency is less probable in wet land rice.

No significant difference was found between treatments with respect to DTPA-extractable Cu, Fe and Mn in first rice soil due to sulphur nutrition (Tables 40-42).

5.3.2 Growth, yield and quality parameters of succeeding rice crop

5.3.2.1 Growth parameters of succeeding rice

The results of the investigation indicate that residual effect of sulphur application significantly influenced the growth parameters of succeeding rice (Tables 43-44).

At active tillering stage, the highest per cent increase in plant height (18.8 %) over T1

was recorded by the treatment T5 (50 kg S ha-1

by Factomphos). It was on par with the treatments of T4, and T8 (37.5 kg S ha

-1 by Factomphos and 50 kg S ha

-1 by gypsum) which

showed increase of 13.5 and 14.1 per cent in plant height over T1.

At panicle initiation stage, the treatment T5 (50 kg S ha-1

by Factomphos) showed the highest plant height which was 14.7 per cent increase over T1 (RDF alone). It was on par with the treatments of T4, T7 and T8 (37.5 kg S ha

-1 by Factomphos, 37.5 kg S ha

-1 by gypsum and

0.00

5.00

10.00

15.00

20.00

25.00

Su

lph

ate

su

lph

ur

(mg k

g-1

)

T1 T2 T3 T4 T5 T6 T7 T8

Treatments


Grain filling Harvest



Fig. 16: Effect of different sources and levels of sulphur on sulphate sulphur content at different growth stages of rice

0.00

5.00

10.00

15.00

20.00

25.00

30.00

35.00

40.00W

ate

r-so

lub

le s

ulp

hu

r (m

g k

g-1

)

T1 T2 T3 T4 T5 T6 T7 T8

Treatments





Fig. 17: Effect of sulphur nutrition on water-soluble sulphur content at different growth stages of rice

0.00

20.00

40.00

60.00

80.00

100.00

120.00

140.00O

rga

nic

su

lph

ur

(mg k

g-1

)

T1 T2 T3 T4 T5 T6 T7 T8

Treatments





Fig. 18: Effect of different sources and levels of sulphur on organic sulphur content at different growth stages of rice

50 kg S ha-1

by gypsum). The increases in plant height associated with T4, T7 and T8 over the T1 (RDF) were 11.7, 11.1 and 12.7 per cent, respectively.

At grain filling and harvest stage, a similar trend of increase in plant height was observed. The treatment T5 (50 kg S ha

-1 by Factomphos) recorded 10.0 and 11.6 per cent

increase in plant height over T1 at grain filling and at harvest. Treatments of T4, T7 and T8 (37.5 kg S ha


-1 by gypsum and 50 kg S ha

-1 by gypsum) were

on par with T5 at respective stages. T4 showed 8.5 and 10.3 per cent increase in plant height at grain filling and harvest stages whereas T7 indicated 7.3 and 8.8 per cent increase over T1 respectively. Similarly T8 recorded 8.9 and 11.1 per cent increase in plant height, respectively. The increase in plant height might be due to the effect of residual sulphur applied in previous season. Ahmed et al. (1989) concluded that significant residual effect of sulphur can be expected if the rate of added sulphur was high in the previous season.

Table 44 indicates that at all stages of succeeding rice (active tillering, panicle initiation, grain filling and harvest), residual effect of application of 50 kg S per ha by Factomphos (T5) recorded the highest number of tillers per hill. The increases in the number of tillers per hill were 47.4, 34.3, 55.5 and 46.8 per cent compared to T1 at respective growth stages. Treatments T4 and T8 were on par with T5. T4 treatment indicated 33.7, 29.5, 48.4 and 31.3 per cent increase in number of tillers per hill whereas T8 showed 42.1, 30.3, 43.1 and 40.8 per cent increase compared to T1 at respective growth stages. Similar results were reported by Ahmed et al. (1989) with respect to residual effect of sulphur.

Residual effect of application of 50 kg sulphur per ha by Factomphos (T5) recorded the highest dry matter production at all stages of succeeding rice (Table 45). At active tillering stage, the highest dry matter production 40.39 q per ha (47.8 % increase over T1 ) recorded by treatment T5 (50 kg S ha

-1 by Factomphos) and it was on par with the treatments of T4, T7

and T8 (37.5 kg S ha-1

by Factomphos, 37.5 kg S ha-1

by gypsum and 50 kg S ha-1

by gypsum). The treatments of T4, T7 and T8 showed 39.6, 34.6 and 41.5 per cent increase in dry matter production over T1.

At panicle initiation stage, treatment T5 (50 kg S ha-1

by Factomphos) recorded 39.8 per cent increase in dry matter over the treatment T1. The value was on par with the treatments of T4, T7 and T8 (37.5 kg S ha


-1 by gypsum and 50

kg S ha-1

by gypsum) (33.4, 29.5 and 34.8 %). At grain filling stage, T5 (50 kg S ha-1

by Factomphos) treatment showed 27.9 per cent increase in dry matter over T1. Treatment T4 and T8 were on par and indicated 22.8 and 24.0 per cent increase over T1.

The dry matter production in straw increased by 26.0 per cent by the treatment receiving 50 kg sulphur per ha by Factomphos (T5) and it was on par with T4 (21.6 %) and T8

(23.5 %) over T1. In grain, the highest per cent increase in dry matter was registered by T5 (29.7 %) and it was on par with T4 (24.9 %) and T8 (25.0 %). Tripathi and Sharma (1994) concluded that sulphur application, apart from influencing the main crop of Indian mustard exerted residual effect on the succeeding rice, especially at higher rates of application under sequence in cropping. The results observed in this study corroborate the findings of Patra et al. (1998) and Singh (2000). Sriramachandrasekharn et al. (2005) reported increase in dry matter production at tillering, panicle initiation and at harvest due to residual effect of different sulphur levels applied in previous rice crop.

5.3.2.2 Yield parameters of succeeding rice crop

Sulphur application in general, benefits more than one crop in sequence and produces a significant residual response. The yield and yield parameters such as number of panicles per m

2, number of grains per panicle and 1000 grain weight were significantly

influenced by sulphur nutrition in succeeding rice (Tables 46-47).

Sulphur fertilizer level on first rice crop was found to have appreciable residual effects in terms of grain and straw yield of succeeding rice crop. Both the sources of sulphur (Factomphos and gypsum) at higher levels performed more or less same in increasing grain yield in residual rice crop (Table 48 and Fig. 19).

Plate.7. General view of the experiment at active tillering stage succeeding rice crop

Plate.8. Residual effect of sulphur nutrition at active tillering stage

Plate.9. General view of the experiment at grain filling succeeding rice crop

Plate.10. Residual effect of sulphur nutrition at grain filling stage succeeding rice crop

Plate.11. General view of the experiment at harvest succeeding rice crop

Application of sulphur had marked influence to step up the yield and yield components of succeeding rice. With respect to residual effect of applied sulphur, the highest per cent increase in number of panicles per m

2 (25.6 %), number of grains per panicle (36.0

%), 1000 grain weight (7.6 %), grain yield (29.7 %), straw yield (26.0 %) were recorded with application of 50 kg S per ha by Factomphos (T5) over T1 (RDF) and it was on par with T4

(37.5 kg S ha-1

by Factomphos) indicating increase in number of panicles per m2 (21.8 %),

number of grains per panicle (26.1 %), 1000 grain weight (7.1 %), grain yield (24.9 %) and straw yield (21.6 %). The treatment T8 (50 kg S ha

-1 by gypsum) was also on par with T5

which resulted in increase in number of panicles per m2 (21.7 %), number of grains per

panicle (35.2 %), 1000 grain weight (7.5 %), grain yield (25.0 %) and straw yield (23.4 %). Similarly, the treatment that received 37.5 kg sulphur ha by gypsum (T7) was also on par with T5 (50 kg S ha

-1 by Factomphos) with respect to yield components viz. number of grains per

panicle (25.6 %), 1000 grain weight (6.9 %). The lowest number of panicles per m2, number

of grains per panicle, 1000 grain weight, grain yield, straw yield was recorded in the treatment receiving RDF (T1). Harvest index and panicle length had no significant difference due to sulphur application in succeeding rice. The beneficial effect of sulphur on rice yield was possible because of its vital role in synthesis of proteins and vitamins. Increase in rice yield due to sulphur could be attributed to stimulating effect of applied sulphur in the synthesis of chloroplast protein resulting in greater photosynthetic efficiency which in turn resulted in increased yield (Biswas and Tewatia, 1992). Under present study, increase of yield and yield attributes was due to better assimilation of carbohydrates in panicle. Results of this investigation on residual effect of sulphur are in consonance with the findings of Aulakh et al. (1977), Addy et al. (1987), Altaf Hossain et al. (1987), Ahmed et al. (1989), Tripathi and Sharma (1994), Sriramachandrasekharn et al. (2005) and Jena et al. (2006).

Ahmed et al. (1989) studied the residual effect of sulphur that was applied during previous season in rice. They concluded that the highest yield of grain and straw were found in treatment in which the rate of added sulphur was highest (60 kg ha

-1) in the previous year.

Similar results related to residual effect of sulphur were recorded in groundnut-rice cropping system by Jena et al. (2006). Badrul Hassan (1998) reported that application of 10 kg sulphur per ha in alternate years proved remunerative for realizing sustainable crop yield in rice-

0

10

20

30

40

50

60

Gra

in a

nd

str

aw

yie

ld (

q/h

a)

T1 T2 T3 T4 T5 T6 T7 T8

Treatments

Grain yield Straw yield



Fig. 19: Residual effect of different sources and levels of sulphur on grain and straw yield of rice

rapeseed cropping system. Hanumantha Rao, (1979) noticed that grain yield of rice grown in Telgi series and coastal soils of Karnataka increased with the application of Zn.

5.3.2.3 Quality parameters of succeeding rice crop

Sulphur nutrition significantly influenced quality parameters of succeeding rice grain, viz. protein and methionine content due to residual effect (Table 49 and Fig. 20).

The highest increase in protein content of 30.6 per cent was observed with the treatment receiving 50 kg sulphur per ha by Factomphos (T5) compared to T1 (RDF). Treatment T5 was on par with T4 (37.5 kg S ha

-1 by Factomphos) and T8 (50 kg S ha

-1 by

gypsum) which resulted in 25.4 and 28.7 per cent increase in protein content over T5 respectively. The treatment T1 (RDF) recorded the lowest grain protein content.

The investigation revealed that grain methionine content recorded by T5 in succeeding rice increased by 61.5 per cent over the treatment T1 (RDF). It was on par with the treatment receiving 37.5 kg sulphur per ha by Factomphos (T4) (47.4 %) and 50 kg sulphur per ha by gypsum (T8) (48.1 %). The treatment T1 (RDF) recorded the lowest content of grain methionine content.

5.3.2.4 Nutrient content and uptake by succeeding rice crop

The residual effect due to addition of sulphur recorded marked increase in nitrogen, phosphorus and potassium content.

The highest nitrogen content showed by T5 recorded increase of (24.5, 27.1, 27.9, 28.0 and 21.1 %) in nitrogen content compared to T1 at active tillering, panicle initiation, grain filling stages in straw and grain and at harvest, respectively. The increase recorded by T4 was on par with the T5 and it showed (15.2, 18.6, 15.3, 20.0 and 16.5 %) increase in nitrogen content compared to T1 respectively. Similarly, T8 registered 19.9, 22.5, 20.7, 24.0 and 20.2 per cent increase in nitrogen content. (Table 50 and Fig. 21). Similar results were reported by Shailendra Kumar (2002).

The results of the study revealed that sulphur application distinctly increased nitrogen uptake at active tillering, panicle initiation, grain filling stages and in straw and grain at harvest stage respectively (Table 50 and Fig. 22).

The treatment T5 showed 84.1, 77.8, 63.7, 61.3 and 57.1 per cent increase in nitrogen uptake at active tillering, panicle initiation, grain filling stages and in straw and grain at harvest. At active tillering, panicle initiation stages and in straw and grain at harvest, T5 was on par with the treatment T4 and T8 which indicated (60.9 and 69.6 %), (58.2 and 65.1 %), (45.9 and 53.1 %) and (45.6 and 50.2 %) increase over T1. However, the highest nitrogen uptake increase of 63.7 per cent was recorded by T5 which was superior over the rest of treatments at grain filling. The lowest nitrogen uptake was observed with the treatment T1

(RDF) at all stages of the crop.

With respect to residual effect on phosphorus content, there was profound influence on phosphorus content (Table 51 and Fig. 23).

The highest per cent increase in phosphorus content was observed with the treatment T5 which recorded (24.9, 27.3, 28.7, 28.7 and 22.8 %) significant increase in phosphorus content compared to T1 at active tillering, panicle initiation, grain filling stages and in straw and grain, respectively. The treatment T5 was on par with the treatment of T4 and T8 at all stages of the crop growth. The treatments T4 and T8 recorded increase in phosphorus compared to T1 (19.4 and 19.3 %), (20.8 and 22.7 %), (22.5 and 23.9 %), (22.8 and 24.8 %) and (19.0 and 20.7 %) at active tillering, panicle initiation and grain filling stages and in straw and grain at harvest. Further, T7 registered significant increase in phosphorus content by 18.8 and 17.7 per cent in straw and grain over T1. The lowest phosphorus content was noticed in the treatment T1 throughout the growing period. This confirms the finding of Shailendra Kumar (2002) in studies on sulphur status and response of rainfed rice to sulphur.

0

1

2

3

4

5

6

7

8

9

10

Pro

tein

co

nte

nt

(%)

an

d m

eth

ion

ine

con

ten

t (m

g g

-1)

T1 T2 T3 T4 T5 T6 T7 T8

Treatments

Grain protein Methionine



Fig. 20: Residual effect of different sources and levels of sulphur on grain protein and methionine content of rice

0

0.5

1

1.5

2

2.5

Nit

rogen

con

ten

t (%

)

T1 T2 T3 T4 T5 T6 T7 T8

Treatments


Grain filling Straw

Grain



Fig. 21: Residual effect of different sources and levels of sulphur on nitrogen content at different growth stages of rice

0

10

20

30

40

50

60

70

80

90

100

Nit

rogen

up

tak

e (k

g h

a-1

)

T1 T2 T3 T4 T5 T6 T7 T8

Treatments


Grain filling Straw

Grain



Fig. 22: Residual effect of different sources and levels of sulphur on nitrogen uptake at different growth stages of rice

Sulphur application remarkably increased the phosphorus uptake in succeeding rice (Table 51 and Fig. 24).

The data on plant phosphorus uptake showed that T5 treatment increased phosphorus uptake by 84.6, 78.0, 64.7, 62.2 and 59.3 per cent over the treatment T1 at active tillering, panicle initiation, panicle initiation stages and in straw and grain at harvest respectively. At active tillering panicle initiation and in straw and grain, T5 was on par with T4

and T8 treatments. The treatments T4 and T8 increased phosphorus uptake by 66.7 and 68.8 per cent at active tillering stage, 61.2 and 65.4 per cent at panicle initiation stage, 49.3 and 54.0 per cent in straw and 48.6 and 50.8 per cent in grain respectively. At grain filling stage, the highest phosphorus uptake increase of 64.7 per cent recorded by T5 over T1 and it was on par only with T8 which resulted 53.7 per cent increase over T1. The lowest phosphorus uptake was noticed in the treatment T1 throughout the growing period.

The residual effect on potassium content did not show significant influence throughout the growing period of succeeding rice but potassium uptake significantly increased with sulphur treatments. However, sulphur application positively influenced potassium content at all stages of crop (Table 52).

The treatment T5 registered significantly highest per cent increase in potassium uptake (83.7, 73.7, 40.7, 57.0 and 43.7 %) over T1 at active tillering, panicle initiation, grain filling stages and in straw and grain respectively (Table 52 and Fig.25). The uptake recorded by T4 and T8 was on par with T5 and it showed increase of 61.2 and 64.4 at active tillering, 53.2 and 56.9 per cent at panicle initiation, 31.8 and 34.2 per cent at grain filling, 39.7 and 44.6 per cent in straw and 35.1 and 38.5 per cent in grain over T1. The lowest potassium uptake was recorded in the treatment T1 throughout the growing period. Jena et al. (2006) reported that potassium uptake increased by 79.3 per cent in succeeding rice crop due to application of sulphur at the rate of 60 kg per ha in previous groundnut crop. The results of the present investigation are in accordance with the report of Ali et al. (2004).

5.3.2.5 Sulphur content and uptake by succeeding rice crop

With respect to sulphur content in succeeding rice, application of sulphur resulted significantly higher sulphur content in succeeding rice crop (Table 53 and Fig. 26).

Among the treatments, residual effect of the application of T5 recorded the highest per cent increase of sulphur content by (93.1, 94.9, 91.8, 94.5 and 96.7 %) over T1 at active tillering, panicle initiation, grain filling stages and in straw and grain at harvest. Among the treatments, T4 and T8 were on par with the T5 with respect to sulphur content and indicated increase by (74.5 and 80.7 %), (76.5 and 84.6 %), (73.8 and 81.1%), (77.3 and 82.7 %) and (79.5 and 83.6 %) over T1 at respective growth stage.

The residual effect due to addition of sulphur recorded significant increase in sulphur uptake in succeeding rice crop (Table 53 and Fig. 27).

Residual effect of application of T5 registered the highest per cent increase in sulphur uptake by (185.4, 172.5, 145.4, 145.1 and 155.1 %) over T1 at active tillering, panicle initiation, grain filling stages and in straw and grain at harvest stage respectively. Addition of sulphur in previous crop and farmyard manure might cause the highest sulphur uptake over T1. The lowest sulphur uptake was obtained with the treatment T1. Sriramachandrasekharn et al. (2007) in their study reported that the increase of sulphur uptake in succeeding rice crop (202.7 % in grain and 110.4 % in straw) due to residual effect of sulphur applied at previous rice crop at the level of 60 kg per ha. Sakal et al. (2001) reported that 45 kg sulphur per ha applied to first rice crop supported two crops grown in succession. The results of the investigation are in consonance with the finding of Patnaik and Arun Sathe (1993) and Jena et al. (2006).

An increase in the level of residual sulphur in succeeding rice crop showed significant variations in the uptake of N, P, K and S. The increase in uptake might be due to residual effect of sulphur applied at higher level, which might have increased the utilization of these nutrients in various plant plants, leading to increased uptake by rice.

0

0.05

0.1

0.15

0.2

0.25

0.3

0.35P

hosp

horu

s co

nte

nt

(%)

T1 T2 T3 T4 T5 T6 T7 T8

Treatments


Grain filling Straw

Grain



Fig. 23: Residual effect of different sources and levels of sulphur on phosphorus content at different growth stages of rice

0

2

4

6

8

10

12

14

16

Ph

osp

ho

rus

up

tak

e (k

g h

a-1

)

T1 T2 T3 T4 T5 T6 T7 T8

Treatments


Grain filling Straw

Grain



Fig. 24: Residual effect of different sources and levels of sulphur on phosphorus uptake at different growth stages of rice

0

10

20

30

40

50

60

70

80

Pota

ssiu

m u

pta

ke

(kg

ha

-1)

T1 T2 T3 T4 T5 T6 T7 T8

Treatments


Grain filling Straw

Grain



Fig. 25: Residual effect of different sources and levels of sulphur on potassium uptake at different growth stages of rice

0.000

0.050

0.100

0.150

0.200

0.250

0.300S

ulp

hu

r co

nte

nt

(%)

T1 T2 T3 T4 T5 T6 T7 T8

Treatments


Grain filling Straw

Grain



Fig. 26: Residual effect of different sources and levels of sulphur on sulphur content at different growth stages of rice

5.3.2.6 Micronutrient content and uptake of succeeding rice crop

Organic manures are found to favourably alter the availability of several plant nutrients through their impact on chemical and biological properties of soils, besides the direct addition of micronutrients (Savithri et al. 1999). The changes in the oxidant reduction regimes particularly in submerged soils and chelation/complexation capacity brought about the addition of organic manures dictates the transformation of micronutrients (Takkar, 1996).

Residual effect of the treatments significantly increased micronutrient content (Zn) and uptake (Zn, Cu, Fe and Mn) of succeeding rice (Tables 54-57). The results of the investigation revealed that residual effect of the treatments had significantly influenced with respect to Zn content at active tillering, panicle initiation, grain filling stages and in straw and grain at harvest stage. The treatment T5 significantly increased Zn content by 64.7, 65.2, 66.0, 64.7 and 66.3 per cent over T1 at respective growth stages. Zn content recorded by the treatments T4 and T8 was on par with T5 and recorded (47.6, 47.9, 48.3, 46.9 and 48.4 %) and (57.4, 59.5, 60.0, 60.0 and 62.5 %) increase over T1 treatment.

Regarding the residual effect of treatments, Cu Fe and Mn contents in succeeding rice was not affected significantly. The lowest Cu, Fe and Mn contents were registered by the treatment T1.

The highest Zn uptake was noticed in plots receiving T5 at active tillering, panicle initiation, grain filling stages and in straw and grain at harvest. The per cent increased by T5 over T1 was 143.4, 130.4, 111.8, 107.5 and 115.9 at active tillering, panicle initiation, grain filling stages and in straw and grain at harvest respectively. The highest per cent increase in Cu uptake was noticed with the treatment T5 at active tillering, panicle initiation, grain filling stages and in straw and grain at harvest. The increase in Cu uptake by T5 over T1 was 80.7, 75.6, 56.9, 55.0 and 80.2 per cent at respective stages. Savithri et al. (1999) reported that irrespective of the kind of green manure, it provides evidence for the involvement in Zn transformation reactions in soils besides the direct contribution of Zn. They further indicated that Zn use efficiency was increased by two or three times by the addition of green manure with ZnSO4.

Residual effect of application of T5 registered the highest per cent increase in Fe uptake by (93.7, 84.9, 68.8, 68.2 and 76.0 per cent at active tillering and panicle initiation, grain filling stages and in straw and grain. The increase in Fe uptake recoded by T4 and T8 was on par with T5 treatment. T4 and T8 treatments registered (55.2, 42.7, 42.5 and 51.6 %) and (67.1, 53.5, 54.6 and 59.1 %) increase in Fe uptake. Residual effect of sulphur application recorded significant increase in Mn uptake in succeeding rice at harvest. Among the treatment, the treatment T5 significantly increased Mn uptake by 96.5, 83.3, 86.5, 68.0 and 93.7 per cent over T1. The lowest increase in Fe uptake was recorded by T1 treatment throughout the growing period. Sriramachandrasekaran and Mathan (1991) reported that Zn fertilization increased Fe, Mn, Cu and Zn uptake with other nutrients indicating synergestic effect in rice.

5.3.2.7 Soil pH and EC of succeeding rice crop

There was no significant residual effect on pH and EC due to application of different sources and levels of sulphur (Table 58 and 59).

5.3.2.8 Sulphur fractions in soil (succeeding rice crop)

In the present investigation, the data on the residual effect of sulphur treatments on sulphur fractions (sulphate sulphur, water soluble sulphur, organic sulphur and total sulphur) revealed that the treatments significantly influenced different sulphur fractions. However, non-sulphate fraction and total sulphur did not differ significantly due to application of sulphur with different treatments.

The sulphate sulphur fraction changed markedly by residual effect of sulphur application and decreased with time (Table 60 and Fig. 28).

0.00

2.00

4.00

6.00

8.00

10.00

12.00

14.00

16.00

18.00

20.00

Su

lph

ur

up

tak

e (k

g h

a-1

)

T1 T2 T3 T4 T5 T6 T7 T8

Treatments


Grain filling Straw

Grain



Fig. 27: Residual effect of different sources and levels of sulphur on sulphur uptake at different growth stages of rice

It was maximum at active tillering stage and least after final harvest and even fell below the initial 11.2 mg per kg in the treatment T1 where no sulphur was applied. Residual effect of application of T5 registered the highest per cent increase (53.5, 53.4, 60.3 and 64.1 %) in sulphate sulphur as compared to T1 at active tillering, panicle initiation, grain filling and harvest stages. The treatment T4 was on par with T5 resulting in 37.7, 39.4, 47.0 and 55.4 per cent increase over T1 at active tillering, panicle initiation, grain filling and harvest stages respectively. Similarly, treatment T8 was on par with T5 at active tillering, panicle initiation, grain filling and harvest stages indicating 47.3, 42.0, 52.5 and 56.2 per cent increase in sulphate sulphur over T1. T1 treatment registered the lowest sulphate sulphur content at all stages in the study period. Sriramachandrasekharn et al. (2007), in their investigation reported that the increase in available sulphur on no fertilizer treatment at tillering (101.7 %), panicle initiation (112.0 %) and harvest (152.9 %) due to residual effect of different sulphur levels applied at previous rice crop. Similar results were obtained by Clarson and Ramaswami (1992).

Water soluble sulphur gradually decreased with the advancement of the succeeding rice crop. Among the treatments, the treatment T5 increased water soluble sulphur by 123.0, 105.2, 86.4 and 92.8 per cent as compared to T1 at active tillering, panicle initiation, grain filling and harvest stages. Similarly, the treatment T4 increased water soluble sulphur indicating the increase of 104.9, 81.8, 65.3 and 69.9 per cent at active tillering, panicle initiation, grain filling and harvest stages respectively. The treatment T8 registered per cent increase of 105.5, 96.4, 86.4 and 82.3 at active tillering, panicle initiation, grain filling and harvest stages due to residual effect of applied sulphur (Table 61 and Fig. 29).

The highest organic sulphur was recorded by T5 which resulted per cent increase in organic sulphur by 26.0 and 23.1 per cent over T1 treatment at grain filling and harvest stages. The treatment T4 registered increase in organic sulphur content (18.5 and 15.7 %) at respective stages due to residual effect of applied sulphur over the treatment T1. Similarly, the treatment T8 registered increase in organic sulphur content (22.2 and 16.3 %) at grain filling and harvest stages due to residual effect of applied sulphur over the treatment T1. The lowest organic sulphur content was observed with T1 treatment (Table 62 and Fig. 30).

Among the sulphur fractions, the residual effect of treatments did not influence significantly on non-sulphate fraction and total sulphur in succeeding rice soil (Table 63 and 64).

Poongothai et al. (1999) reported that sulphur fertilization increased the available sulphur content of post harvest soil significantly the highest content being recorded for the application of sulphur as gypsum. They further noticed that application of green manure increased the available sulphur content of the soil. The results of this investigation are in consonance with the findings of Sriramachandrasekhran et al. (2007). Sreemannarayana and Sreenivasa Raju (1994) reported that due to application of gypsum, significantly greater amounts of sulphate sulphur were left behind in soils compared to that of ammonium sulphate and the succeeding crops showed response to residual sulphur from sparingly soluble sources of sulphur. Although gypsum contains sulphur in the form of sulphate, when it is applied to soils, the presence of free calcium ions in soil solution reduces its solubility as result of common ion effect.

5.3.2.9 Available micronutrient in soil (succeeding rice crop)

The highest per cent increase in DTPA-extractable Zn (75.0, 74.5, 60.0, and 50.0 %) was observed in the treatment T2 at active tillering stage, panicle initiation, grain filling and harvest stages (Table 65). However, DTPA extractable Zn in the treatments receiving T3, T6, T7 and T8 treatments was on par with T2 treatment. The reason might be that, ZnSO4 and farmyard manure were applied to all treatments except T1 treatment and the differences related to Zn uptake by different treatments. Residual effect of treatments did not significantly influence on DTPA-extractable Cu, Fe and Mn in succeeding rice soil (Tables 66-68).

0.00

2.00

4.00

6.00

8.00

10.00

12.00

14.00

16.00

18.00S

ulp

ha

te s

ulp

hu

r (m

g k

g-1

)

T1 T2 T3 T4 T5 T6 T7 T8

Treatments





Fig. 28: Residual effect of different sources and levels of sulphur on sulphate sulphur content at different growth stages of rice

0.00

5.00

10.00

15.00

20.00

25.00

30.00

35.00

40.00W

ate

r so

lub

le s

ulp

hu

r (m

g k

g-1

)

T1 T2 T3 T4 T5 T6 T7 T8

Treatments





Fig. 29: Residual effect of different sources and levels of sulphur on water-soluble sulphur content at different growth stages of rice

0.00

20.00

40.00

60.00

80.00

100.00

120.00

140.00

Org

an

ic s

ulp

hu

r (m

g k

g-1

)

T1 T2 T3 T4 T5 T6 T7 T8

Treatments





Fig. 30: Residual effect of different sources and levels of sulphur on organic sulphur content at different growth stages of rice

5.3.3 Economics

With respect to the economics of first rice, among sulphur application treatments to soil, the higher net returns (Rs. 16847/-) and Benefit: cost ratio (1.69) was obtained in the treatment receiving RDF + FYM (10t/ha) + ZnSO4 (20 kg/ha) + 50 kg sulphur/ha (Factomphos) (T5) as compared to other treatments. The lowest net returns (Rs. 11826/-) and benefit: cost ratio (1.50) was observed in the treatment receiving RDF + FYM (10t/ha) + ZnSO4 (20 kg/ha) (T2). This suggests that application of T5 treatment can help to get more net returns per ha over other treatments. This might be due to increased sulphur availability and uptake for the plants (Table 69).

Residual effect of application of sulphur gave increased net returns and benefit: cost ratio of succeeding rice. The plots receiving RDF + FYM (10t/ha) + ZnSO4 (20 kg/ha) + 50 kg sulphur/ha (Factomphos) (T5) registered the highest net returns (Rs. 14565/-) and benefit: cost ratio (1.64) as compared to other treatments. The treatment that received RDF + FYM (10t/ha) + ZnSO4 (20 kg/ha) (T2) recorded the lowest net returns (9,159/-) and benefit: cost ratio (1.40) in succeeding rice crop (Table 70). This suggests that residual effect of application of T5 treatment can help to get more net returns per ha over the other treatments. It could be due to increased sulphur availability resulted with the application of sulphur to first rice.

This clearly suggests that direct sulphur fertilization to rice (RDF + FYM (10t/ha) + ZnSO4 (20 kg/ha) + 50 kg sulphur/ha Factomphos) (T5) helps to obtain higher net returns of Rs. 4,200/- over RDF alone (T1) and Rs. 5,021/- over T2 (RDF + FYM (10t/ha) + ZnSO4 20 kg/ha). Similarly, residual effect of the application of RDF + FYM (10t/ha) + ZnSO4 (20 kg/ha) + 50 kg sulphur/ha Factomphos) (T5) increased net returns of Rs. 5,222/- over RDF alone (T1) and Rs. 5,406/- over T2 (RDF + FYM (10t/ha) + ZnSO4 20 kg/ha) indicating its economic superiority throughout the rice-rice cropping sequence.

5.3.4 Results of practical utility

Based on the results obtained from the present investigation, the following points can be listed out.

• Addition of sulphur sources changed soil sulphur status due to different sulphur transformations in the incubation study.

• Application of sulphur at the rate of 50 kg per ha through Factomphos along with recommended dose of fertilizer, farmyard manure and ZnSO4 gave highest grain yield (57.90 q ha

-1) and improved quality parameters viz., grain protein (6.17 %) and

methionine contents (2.51 mg g-1

) over no sulphur treatment in first rice crop. Similarly, the values recorded by the treatment of application of 37.5 kg sulphur per ha by Factomphos (grain yield, 55.20 q ha

-1, grain protein 5.83 % and methionine

2.36 mg g-1

) were on par with the application of 50 kg per ha by Factomphos.

• With respect to residual effect of applied sulphur, addition of sulphur at the rate of 50 kg per ha through Factomphos, 50 kg per ha through gypsum and 37.5 kg per ha through Factomphos resulted in significant difference in grain yield (51.9, 50.2 and 50.0 q ha

-1), protein content (5.92, 5.83 and 5.68 %) and methionine content (2.18,

2.00 and 1.99 mg g-1

) compared to no fertilizer treatments.

5.3.5 Future line work

� Systematic information about status, forms and distribution of sulphur for rice growing soils in different agro eco-regions and their relationship with soil properties need to be generated to develop sulphur inventory database and maps.

� Studies on changes in sulphur availability in rice rhizosphere soil, microbiological transformations of sulphur from different sources under different rice growing soils and dynamics of sulphur in different rice growing soils need to be initiated.

� Since significantly greater amounts of sulphate sulphur were left behind in soils, detailed investigations need to be conducted to assess the effect of residual sulphur on third crop in cropping sequences to ensure high economic returns.

� Detailed balance sheet of sulphur based on its accession from atmosphere, irrigation water, rainfall, fertilizer, organic residues and removal through crops, volatilization, leaching and erosion is required to develop models for predicting sulphur deficiency in rice based cropping systems.

6. SUMMARY AND CONCLUSIONS

The present study was conducted to know the changes in yield and soil fertility as influenced by sulphur under intensive rice cropping system in zone 3 of Karnataka. For characterization of soil, samples were collected from intensive rice growing areas from Sangapur, Bandibasappa, Hosali, Ayodhya, Voddarahatti, Basavapatna, Doctor Camp and Herur in Gangavati taluka. For incubation study, soil sample was collected from Agriculture Resaerch Station, Gangavati. Field experiments were conducted at Agriculture Research Station, Gangavati during rabi/summer and kharif seasons in 2007 under irrigated condition to study the direct and residual effect of applied sulphur on growth, yield, quality, nutrient uptake and different soil sulphur fractions in a rice-rice cropping sequence. The results obtained during the course of the investigations are summarized hereunder.

• Sulphate sulphur content in soils of different locations varied from 12.05 to 49.51 mg per kg and found more in surface layers than in subsurface layers. None of soil bodies was found deficient in sulphur considering critical level (10 ppm).

• Water soluble sulphur was in the range of 19.13 to 56.60 mg per kg in soil bodies and the amount present in soil was greater than sulphate sulphur.

• Organic sulphur in soils ranged from 68.56 to 269.27 mg per kg. In all soils, the surface soils contained higher amount of organic sulphur than the subsurface soils.

• Non-sulphate sulphur content in soils was in the range of 420.19 to 2170.58 mg per kg constituting the major sulphur fraction.

• The total sulphur content ranged from 561.27 to 2372.5 mg per kg and a lower value of total sulphur was generally recorded in surface layer than subsurface layer.

• The percentage contribution of soil sulphur fractions to total sulphur were in order of: non sulphate sulphur > organic sulphur > water soluble sulphur > sulphate sulphur.

• The increase in sulphate sulphur and water soluble sulphur was observed at 32nd

day of incubation period. However, these fractions started declining thereafter except organic sulphur.

• The direct effect of applied sulphur as Factomphos resulted in significant difference with respect to growth (plant height, number of tillers per hill, dry matter production) and yield parameters (number of grains per panicle, 1000 grain weight, number of productive tillers per hill and number of panicles per m

2) of first rice crop. Application

of 50.0 kg sulphur per ha through Factomphos recorded the highest growth and yield parameters and it was on par with the application of 37.5 kg sulphur per ha through Factomphos. The lowest value was recorded in the treatment receiving no sulphur.

• Grain protein and methionine content in rice increased significantly when 50 kg sulphur per ha through Factomphos was applied and it was on par with the application of 37.5 kg sulphur per ha through Factomphos. The lowest values were recoded by no sulphur treatment.

• Application of 50.0 kg sulphur per ha through Factomphos increased N, P, S and Zn content and N, P, K, S, Zn, Cu, Fe and Mn uptake by rice and it was on par with the application of 37.5 kg sulphur per ha through Factomphos.

• With respect to sulphur fractions, significant differences were noticed in sulphate sulphur, water soluble sulphur, organic sulphur and total sulphur. Application of sulphur increased the availability of sulphur in soil. The highest sulphur availability was recorded with the application of 50.0 kg sulphur per ha through Factomphos and it was on par with the addition of 37.5 kg sulphur per ha through Factomphos.

• Economic analysis of rice as influenced by sulphur application indicates that the maximum net returns can be obtained with the application of 50.0 kg sulphur per ha

by Factomphos and this practice can help to obtain higher profit over the application of recommended fertilizer.

• The residual effect of application of 50.0 kg sulphur per ha through Factomphos had profound effect on growth parameters (plant height, number of tillers per hill and dry matter production) and yield parameters (number of grains per panicle, 1000 grain weight, number of productive tillers per hill, number of panicles per m

2 and grain yield

and straw yield) of succeeding rice and it was on par with the treatment receiving 37.5 kg sulphur per ha through Factomphos and 50.0 kg sulphur per ha through gypsum.

• Application of 50.0 kg sulphur per ha by Factomphos to the first rice crop significantly increased grain protein and methionine content of succeeding rice crop and it was on par with the treatment receiving 37.5 kg sulphur per ha through Factomphos and 50.0 kg sulphur per ha through gypsum.

• Treatments which had received 50 and 37.5 kg sulphur per ha through Factomphos, and 50.0 kg sulphur per ha through gypsum recorded increase in N, P, S, and Zn content and N, P, K, S, Zn, Cu, Fe and Mn uptake in succeeding rice crop. The lowest values were recorded in the treatment that received RDF alone.

• Influenced by residual effect of sulphur application, economic analysis of succeeding rice indicates that the maximum net returns can be obtained with the application of 50.0 kg sulphur per ha through Factomphos and this practice can help to obtain higher profit over the application of recommended fertilizer to first crop.

• The highest grain and straw yields were observed in the treatment that received 50.0 kg sulphur per ha through Factomphos.

• The highest grain protein and methionine content were noticed in the treatment that received 50.0 kg sulphur per ha through Factomphos.

• Sulphur fertilization to rice crop at the rate of 50 kg per ha through Factomphos helps to obtain higher net returns of Rs. 4,200/- over application of RDF alone and Rs. 5,021/- over the application of RDF + FYM (10t/ha) + ZnSO4 20 kg per ha.

• Residual effect of the application of RDF + FYM (10t/ha) + ZnSO4 (20 kg/ha) + 50 kg sulphur per ha through Factomphos increased net returns of Rs. 5,222/- over the application of RDF alone and Rs. 5,406/- over the application of RDF + FYM (10t/ha) + ZnSO4 20 kg per ha indicating its economic superiority throughout the rice-rice cropping sequence.

• Application of 37.5 kg sulphur per ha through Factomphos can be recommended for two rice crops grown in succession.

REFERENCES

Abraham, G., 2001, Increasing productivity of Indian mustard (Brassica juncea) through split application of sulphur. Indian J. Agri. Sci., 71(10) : 674-675.

Addy, S. K., Singh, A., Singh, R. and Awasthi, C. P., 1987, Effect of pyrites and fertilizer on rice protein quality. Int. Rice Res. Newslett., 12 : 44-45.

Ahmed, I. U., Faiz, S. M. A., Rahman, S., Anwar Hussain, A. K. M., and Bhuiyan, N. I., 1989, Effect of nitrogen and residual sulphur on the growth, yield and N-S composition of rice. J. Indian. Soc. Soil Sci., 37 : 323-327.

Akhter, S., Ali, M. I., Jahiruddin, M., Ahmed, S., Rahman, L., 1994, Main and interaction effects of sulphur and zinc on rice. Crop Res., 7 (1) : 1-7.

Alam, M. L., Farrukh Ahmed and Mesbahul Karim, 1985, Effect of different sources of sulphur on rice under submerged condition. J. Indian Soc. Soil Sci., 33 : 586-590.

*Ali, M. M., Mian, M. S., Islam, A., Begum, J. A. and Ferdous, A. K. M. 2004, Interaction effects of sulphur and phosphorus on wetland rice. Asian J. Pl. Sci., 3(5) : 597-601.

Altaf Hossain, S. M., Sattar, M., Ahmad, J. U., and Islam, M. S., 1987, Effect of Zn and sulphur on the yield and yield components of rice. Indian J. Agric. Sci., 57(5) : 343-346.

Alves, M. E. and Lavorenti, A., 2004, Sulfate adsorption and its relationships with properties of representative soils of the Sao Paulo State, Brazil. Geoderma, 118 (1-2) : 89-99.

Anand Swarup, 1988, Effect of gypsum, farmyard manure and rice husk on the availability of iron and manganese to rice in submerged sodic soil. Oryza, 25 : 38-42.

Ananthanarayana, R., Reddy, M. N., Mithyantha, M. S. and Perur, N. G., 1986, Status of available secondary nutrients in acid soils of Karnataka. J. Indian. Soc. Soil Sci., 34 : 614-616.

Anonymous, 2005, Five decades of Rice Research in Karnataka, Ed. Prabhakara Setty, T. K., Purushotham, S, and Nagamani, M. K., Directorate of Research, Univ. Agric. Sci., GKVK, Bangalore, Karnataka (India).

Arora, B. R., Ghai, V. K. and Hundal, H. S., 1988, Distribution of sulphur in benchmark soils of Panjab. J. Indian. Soc. Soil Sci., 36 : 367-368.

Arora, B. R., Hundal, H. S. and Sekhon, G. S., 1990, Utilization of fertilizer sulphur by oat (Avena sativa L.) in different soils of Ludhiana. J. Nuclear. Agric. Biol., 19 : 92-96.

Arora, C. L., and Takkar, P. N., 1988, Influence of soil characteristics on the forms and availability of sulphur in some Entisols and Inceptisols. J. Indian. Soc. Soil Sci., 36 : 496-499.

Arvind Kumar, Datta, S. P., Singh, R. P., Singh, K. P. and Sarkar, A. K., 1994, Available sulphur and micronutrient status of dominant soil series of South Chotanagpur in Bihar. J. Indian Soc. Soil Sci., 42 : 649-651.

Aulakh, M. S. and Dev, G., 1976, Profile distribution of sulphur in some soil series of Sangrur district, Punjab. J. Indian Soc. Soil Sci., 24 : 308-313.

Aulakh, M. S., Pasricha, N. S. and Sahota, N. S., 1977, Nitrogen and sulphur relationship in brown sarson and Indian mustard. Indian J. Agric. Sci., 47 : 249-253.

Aulakh, M. S., Pasricha, N. S. and Sahota, N. S., 1980, Yield nutrient concentrations and quality of mustard crop as influenced by nitrogen and sulphur fertilization. J. Agic. Sci., 94 : 545.549.

Aziz Qureshi, A. and Lawande, K. E., 2006, Response of onion (Allium cepa) to sulphur application for yield, quality and its storability in S-deficient soils. Indian J. Agric. Sci., 21(9) : 499-504.

Badiger, M. K., Rosalind Michael, Jayaram, N. and Shivaraj, B., 1985, Studies on some aspects of soil sulphur and response of sunflower to sulphur application. J. Indian. Soc. Soil Sci., 33 : 73-77.

Badrul Hasan, 1998, Rice-rapeseed cropping system as influenced by levels and frequencies of sulphur and zinc application in Kashmir valley, India. Oryza, 35(4) : 382-383.

Balanagoudar, S. R. and Satyanarayana, T., 1990a, Depth distribution of different forms of sulphur in Vertisols and Alfisols. J. Indian. Soc. Soil Sci., 38 : 634-640.

Balanagoudar, S. R. and Satyanarayana, T., 1990b, Correlations of different forms of sulphur with soil properties and with organic carbon and nitrogen in some Vertisols and Alfisols. J. Indian. Soc. Soil Sci., 38 : 641-645.

Balasubramaniam, A. S. and Kothandaraman, G. V., 1985, Different forms of sulphur in major soil series of Coimbatore district. Proc. National Seminar on Sulphur in Agriculture, 95-99.

Bandyopadhyay, B. K., Sen, H. S., and Maji, B., 2003, Studies on transformation of sulphate salts under paddy cultivation in coastal saline soil and its effect on growth on rice. J. Indian Soc. Soil Sci., 51(2) : 155-160.

Bardsley, C. E. and Lancaster, J. D., 1965, Sulphur. In : Mathods of soil analysis. Part 2, Agronomy 9, Ed. Black, C. A., Amarican Society of Agronomy, Madison, Wisconsin.

Barrow, N. J., 1971, Slowly available sulphur fertilizer in South – Western Australia. Australian J. Exptl. Agric. Animal Husbandry, , 11 : 211-216.

Bhan, C. and Tripathi, B. R., 1973, Forms and its contents of sulphur in some soils of Uttar Pradesh. J. Indian Soc. Soil Sci., 21 : 499-504.

Bharat Singh and Srivastava, O. P., 1994, Effect of organic matter and gypsum on electro-chemical changes in sodic soil under submerged condition. Oryza, 31 : 240-241.

Bhardwaj, S. P. and Pathak, A. N., 1969, Fractionation of sulphur in soils of Uttar Pradesh and its relation to phosphorus. J. Indian Soc. Soil Sci., 17 : 285-289.

Bhatnagar, R. K., Bansal, K. N. and Trivedi, S. K., 2003, Distribution of sulphur in some profiles of Shivpuri district of Madhya Pradesh. J. Indian Soc. Soil Sci., 51(1) : 74-76.

Bhogal, N. S., Choudhary, K. C. and Sakal, R., 1996, Distribution of different forms of sulphur in calciorthents of North Bihar. J. Indian Soc. Soil Sci., 44(1) : 65-69.

Bhuvaneswari, R., Sriramachandrasekharan and Ravichandran, M., 2007, Integrated use of farmyard manure and sulfur for the growth and yield rice. Oryza, 44(2) : 169-171.

Biju Joseph, Savithri, P., Vennila, R. K., Poongothai, S. and Suresh, S., 1999, Available sulphur and boron status of rice growing Alfisols and Inceptisols of the high rainfall zone of Tamil Nadu. Oryza, 36(3) : 270-271.

*Biswas, B. C. and Tewatia, R. K., 1992, Role of sulfur in balanced nutrition. In : Int. Symp. on Role of S, Mg and Micronutrients in Balanced Plant Nutrition, Chengdur, China, p. 6.

Black, C. A., 1965, Methods of soil Analysis (part-2) Agronomy monograph 9, Amer. Soc. Agron. Madison, Wisconsin, USA.

Blair, G. J., Momuat, E. O. and Mamaril, C. P., 1979, Sulphur nutrition of rice. II. Effect of source and rate of S on growth and yield under flooded conditions. Agon. J., 71(3) : 477-480.

Blair, G. J., Till, A. R. and Shedley, C. D., 1994, Transformation of sulphur in soil and subsequent uptake by subterranean clover. Australian J. Soil Res., 32 : 1207-1214.

Chandel, R. S., Sudhakar, P. C., and Kalyan Singh, 2002, Effect of sulphur application on growth and yield of rice in rice-mustard cropping sequence. Crop Res., 24(2) : 261-265.

Chavan, A. S. and Banerjee, N. K., 1980, Response of rice to iron zinc interrelationships in zinc deficient soils. J. Maharashtra Agric. Univ., pp. 101-102.

Cheema, H. S. and Arora, C. L., 1984, Sulphur status of soils, tube well waters and plants in some areas of Ludhiana under groundnut-wheat cropping pattern. Fert. News, 29 : 28-31.

Chesnin, L. and Yien, C. H., 1951, Turbidimetric determination of available sulphur. Soil Sci. Soc. Amer. Proc. 15 : 149-151.

Chien, S. H., Hellums, D. T. and Henao, J., 1987, Green house evaluation of elemental sulfur and gypsum for flooded rice. Soil Sci. Soc. Am. J. 51 : 120-123.

Clarson, D. and Ramaswami, P. P., 1990, Mineralization pattern of sulphur in different soil types . Madras Agric. J., 77(2) : 70-73.

Clarson, D. and Ramaswami, P. P., 1992, Response of rice to sulphur nutrition. Fert. News, 37(6) : 31-37.

Das , P. K., Sahu, S. K. and Acharyya, N., 2002, Effect of organic matter on sulphate adsorption in some Alfisols of Orissa. J. Indian Soc. Soil Sci., 50(1) : 23-28.

Dev, G. and Kumar, V., 1982, Secondary nutrients, In : Review of soil Research in India. J. Indian Soc. Soil Sci., 1 : 342-360.

Dewal, G. S. and Pareek, R. G., 2004, Effect of phosphorus, sulphur and zinc on growth yield and nutrient uptake of wheat (Triticum arstivum). Indian J. Agron., 49 : (3) 160-162.

Dhananjaya, B. C. and Basavaraj, B., 2002, Effect of sulphur application on sulphur fractions in soil as influenced by maize rhizosphere. Karnataka J. Agric. Sci., 15 : (1) 148-150.

Dharkanath, K., Mhite, A. V. and Patil, M. D., 1995, Sulphur status of some important soil series of Vertisols of Maharashtra state. J. Indian Soc. Soil Sci., 43(3) : 364-367.

Dolui, A. K. and Bandyopadhyay, A. K., 1983, Distribution of sulphur and carbon-nitrogrn-sulphur relationships of some coniferous forest soil profiles of North Bengal. Indian Agriculturist, 27 : 167-175.

Dolui, A. K. and Das, N. V., 1988, Profile distribution of sulphur in selected soil series of Terai and Testa alluvial regions of West Bengal. Indian Forester, 114 : 891-893.

Dolui, A. K. and Guhathakurta, D., 1988, Sulphur fractions and carbon, nitrogen and sulphur relationships in some soils of West Bengal. J. Indian Soc. Soil Sci., 36 : 53-58.

Dolui, A. K. and Nayek, A. K., 1981, Distribution of different forms of sulphur in some red and lateritic soil profiles of West Bengal. Indian Agriculturist, 25 : 185-189.

Dolui, A. K. and Saha, S. G., 1983, Studies on sulphur status of some soils of West Bengal. Indian J. Agric. Res., 16 : 259-265.

Donald, C. M., 1962, In search of yield, J. Aust. Inst. Agric. Sci., 28 : 171-178.

Dwivedi, K. N., Pathak, A. N. and Shankar, H., 1983, Forms of sulphur in relation to soil properties in some central alluvial soils of Uttar Pradesh. J. Indian. Soc. Soil Sci., 31 : 308-309.

Ganeshmurthy, A. N., Ganauri Singh and Singh, N. T., 1995, Sulphur status and response of rice to sulphur on some soils of Andaman and Nicobar islands. J. Indian. Soc. Soil Sci., 43(4) : 637-641.

Ganeshmurthy, A. N., Mongia, A. D. and Singh, N. T., 1989, Forms of sulphur in soil profiles of Andaman and Nicobar Islands. J. Indian. Soc. Soil Sci., 37(4) : 825-829.

Ghani, A., McLaren, R. G. and Swift, R. S., 1992, Sulphur mineralization and transformation in soils as influenced by addition of carbon, nitrogen and sulphur. Soil Biol. Biochem., 24(4) : 331-341.

Ghosh, G. K., and Sarkar, A. K., 1994, Availability of S and some micronutrients in acid sedentary soils of Chotanagpur region. J. Indian Soc. Soil Sci., 42(3) : 464-466.

Gomez, K. A. and Gomez, A. A., 1984, Statistical Procedure for Agriculture Research, An International Rice Research Institute book, A. Wiley-interscience, John-Willey and sons Inc. New York, USA.

Graeme J. Blair, Mamaril, C. P., Pangerang Umar, A., Momuat, E. O. and Christine Momuat, 1979a, Sulfur nutrition of rice. I. A survey of soils of South Sulawesi, Indonesia. Agron. J., 71 : 473-477.

Graeme J. Blair, Momuat, E. O. and Mamaril, C. P., 1979b, Sulfur nutrition of rice. II. Effect of source and rate of S on growth and yield under flooded conditions. Agron. J., 71 : 477-480.

Haldar, B. R., and Barthakur, H. P., 1976, Sulphide production in some typical rice soils of Assam. J. Indian Soc. Soil Sci., 24(4) : 387-395.

Haldar, M. and Mandal, L. N., 1981, Effect of phosphorus and zinc on the growth and phosphorus, zinc, copper, iron and manganese nutrition of rice. Plant and Soil, 59(4) : 415-425.

Hanumantha Rao, P. S., 1979, Micronutrients in dry and irrigated Telgi soil series and response of rice to applied Zn in Telgi and coastal soils of Karnataka. M. Sc. (Agri.) Thesis, Univ. Agric. Sci. Dharwad, Karnataka (India).

Haque, I. and Walmsley, D., 1972, Incubation studies on mineralization of organic sulphur and organic nitrogen. Plant and Soil, 37 : 255-264.

Hari Ram, Dixit, V. K. and Khan, T., 1993, Distribution of different forms of sulphur in rice growing soils of Uttar Pradesh. J. Indian Soc. Soil Sci., 41(3) : 564-565.

Hariram, V. K. and Dwivedi, K. N. 1994, Delineation of sulphur deficient soil groups in the central alluvial tract of Uttar Pradesh, J. Indian Soc. Soil Sci., 42(2) : 284-286.

Harmesh Singh and Mishra, B., 1986, Effect of temperature and particle size on the oxidation of pyrite in a Mollisol. J. Indian Soc. Soil Sci., 34(2) : 407-408.

Hegde, D. M. and Sudhakara Babu, S. N., 2007, Correcting sulphur deficiencies in soils and crops. Indian J. Fert., 3(1) : 65-79.

Hossain, S. M. A., Satter, M., Ahmad, J. U. and Islam, M. S., 1987, Effect of zinc and sulphur on the yield and yield components of rice. Indian J. Agric. Sci., 57 : 343-346.

Hu, Z. Y., Zhao, F. J. and McGrath, S. P., 2005, Sulphur fractionation in calcareous soils and bioavailablity to plants, Plant and Soil, 268 : 103-109.

Issa Piri and Sharma, S. N., 2006, Effect of levels and sources of sulphur on yield attributes, yield and quality of Indian mustard (Brassica juncea). Indian J. Agron., 51(3) : 217-220.

Jackson, M. L., 1973, Soil Chemical Analysis, Prentice Hall of India Pvt. Ltd., New Delhi, p. 187.

Jagtap, P. B., and Mohite, A. V., 1994, Release of sulphur and iron pyrites in saline-sodic calcareous soil and soil reaction. J. Maharashtra Agri. Univ., 19(1) : 11-15.

Jagvir Singh and Kairon, M. S., 2001, Yield and nutrient contents of cotton (Gossypium hirsutum) and sunflower (Helianthus annuus) as influenced by applied sulphur in irrigated Inceptisol. Indian J. Agric. Sci., 71(1) : 35-37.

Janzen, H. H. and Bettany, J. R., 1987, The effect of temperature and water potential on S oxidation in soils. Soil Science, 144 (2) : 81-89.

Jat, J. R. and Yadav, B. L., 2006, Different forms of sulphur and their relationship with properties of Entisols of Jaipur district (Rajasthan) under mustard cultivation. J. Indian Soc. Soil Sci., 54 (2) : 208-212.

Jena, D., Sahoo, R., Sarangi, D. R. and Singh, M. V., 2006, Effect of different sources and levels of sulphur on yield and nutrient uptake by groundnut-rice cropping system in an Inceptisol of Orissa. J. Indian Soc. Soil Sci., 54(1) : 126-129.

Jha, S. K., Singh, K. P. and Sarkar, A. K., 1995, Sulphur availability in acid sedentary soils of Bihar. J. Res. Birsa Agric. Univ., 7(1) 25-29.

Joshi, D. C., Choudhari, J. S. and Jain, S. V., 1973, Distribution of sulphur fractions in relation to forms of phosphorus in soils of Rajasthan. J. Indian Soc. Soil Sci., 21 : 289-294.

Kanwar, J. S. and Takkar, P. N., 1964, Distribution of sulphur forms in tea soils of Punjab J. Res. Punjab Agriculture University, 1 : 1-5.

Karwasra, S. P. S., Bharti, A. and Khera, A. P., 1986, Sulphur status of some soils of Haryana. J. Indian Soc. Soil Sci., 34 : 617-618.

Karwasra, S. P. S., Mohinder Singh and Khera, A. P., 1990, Different forms of sulphur and their contents in various soils of Haryana. Crop Res., 3(1) : 27-34.

Khare, J. P., Sharma, R. S. and Soni, S. N., 1999, Influence of sulphur and antitranspirants on morpho-physiological growth and yield of rainfed linseed. J. Oilseeds Res., 16(1) : 61-64.

Kher, D. and Singh, N., 1993, Different forms of sulphur in mustard growing soils of North Kashmir. J. Indian Soc. Soil Sci., 41(1) : 164-165.

Kubsad, V. S. and Mallapur, C. P., 2003, Effect of sulphur nutrition on productivity of safflower. J. Oilseeds Res., 20(1) : 96-98.

Kumar, V. and Singh, M., 1974, Organic and available sulphur status of Nainital Tarai soils. J. Indian Soc. Soil Sci., 22 : 198-200.

Lande, M. G. Varade, S. B. and Badhe, N. N., 1977, Sulphur status and its relationship with physico-chemical properties of Marathwada soils. J. Maharashtra Agric. Univ., 2(3) : 195-201.

Lindsay, W. L. and Norvell, W. A., 1978, Development of a DTPA soil test for Zn, Fe, Mn and Cu. Soil Sci. Soc. Amer. Proc., 42 : 421-428.

Made Dana, Rod, D. B. Lefroy and Graeme J. Blair, 1994, A glass house evaluation of sulfur fertilizer sources for crops and pastures. 1. Flooded and non-flooded rice. Aust. J. Agric. Res., 45 : 1497-1515.

Mahatim Singh, Srivastrava, J. P., and Kalyan Singh, 1978, Effect of micronutrients and their methods of application on yield and nutrient uptake of drilled rice variety IR-8. Indian J. Agron., 23(1) : 31-36.

Mahto, S. N., Singh, K. P., Surendra Singh and Singh, B. P., 1992, Total and available sulphur in some soils of Chotanagpur area of Bihar in relation to soil properties. J. Indian Soc. Soil Sci., 40(4) : 846-847.

Mandhata Singh, Singh, R. P. and Gupta, M. L., 1993, Effect of sulphur on rice. Oryza, 30 : 315-317.

Mandhata Singh, Singh, R. P. and Singh, B., 1994, Influence of sulphur application on N, P and S content of plant and soil. Crop Res., 7(1) : 8-12.

Marsonia, P. J., Patel, M. S. and Koria, R. G., 1986, Status and distribution pattern of different forms of sulphur in some profiles of calcareous soils of dry farming areas of Saurashtra and adjoining tract. Gujarat Agric. Univ. Res. J., 11 : 44-51.

Maynard, D. G., Stewart, J. W. B., and Bettany, J. R., 1985, The effects of plants on soil sulphur transformations. Soil Biol. Biochem., 17(2) : 127-134.

McGill, W. B. and Cole, C. V., 1981, Comparative aspects of cycling of organic C, N, S and P through soil organic matter. Geoderma, 26 : 267-286.

McLaren, R. G., Keer, J. I., and Swift, R. S., 1985, Sulphur transformations in soils using sulphur-35 labelling. Soil Biol. Biochem., 17(1) : 73-79.

Mishra, B. 2003, Rice research in India – Major achievements and future thrusts, Winter school on advances in hybrid rice technology , Eds Viraktamath, B. C., Llyas Ahmad, M. and Mishra, B., Directorate of Rice Research, Hyderabad.

Misra, S. K., 2003, Effect of sulphur and potassium on yield, nutrient uptake and quality characteristics of mustard (Brassica juncea L.) in Udic Haplustepts of Kanpur. J. Indian Soc. Soil Sci., 51(4) : 544-548.

Misra, S. K., Singh, R. N. Tiwari, V. N. and Tiwari, K. N., 2002, Effect of sulphur fertilization on quality characteristics of mustard (Brassica juncea L.) seed in five cultivars. J. Indian Soc. Soil Sci., 50(1) : 141-143.

Misra, U. K., Das, C. P. and Mitra, G. N., 1990, Forms of sulphur in some soils of Orissa in relation to relevant soil properties. J. Indian Soc. Soil Sci., 38 : 61-69.

Mohinder Singh, S. P., Karwasra, R. and Khera, A. R., 1990, Distribution of different forms of sulphur in some soils of Haryana. Haryana Agric. Univ. J. Res., 20(2) : 125-133.

Mukhopadhyay, P. and Mukhopadhyay, A. K., 1980, Status and distribution of different forms of sulphur in some typical soil profiles of West Bengal. J. Indian Soc. Soil Sci., 28(4) : 454-459.

Naresh Prasad and Jangra, K. K., 2007, Sulphur in balanced fertilization in Rajasthan. Indian J. Fert., 3(2) : 41-47.

Navneet Pareek, 2007, Soil mineralizable sulphur : A sulphur availability index. J. Indian Soc. Soil Sci., 55(3) : 289-283.

Naw Mar Lar Oo, Shivay, Y. S., Dinesh Kumar, R. P., Pandey, R. N., 2007, Effect of nitrogen and sulphur fertilization on productivity and nutrient uptake in aromatic rice. Indian J. Fert., 2(11) : 29-33.

Padmaja, G., Raju, A. S. and Rao, K. V. S., 1993, Status and distribution of sulphur in some pedons of Vertisols. J. Indian Soc. Soil Sci., 41(3) : 560-561.

Palaniswami, C., Upadhyay, A. K. and Biddappa, C. C., 2000, Sulphur mineralization and oxidation potential of some soil types of Kerala. J. Indian Soc. Soil Sci., 48(2) : 234-237.

Pandey, D. K., Tiwari, K. N. and Tiwari, R. C., 1989, Different forms of sulphur in alluvial soils. J. Indian Soc. Soil Sci., 37(2) : 161-163.

Patel, B. T., Patel, J. J. and Patel, M. M., 2007, Response of groundnut (Arachis hypogea) to FYM, sulphur and micronutrients and their residual effect on wheat (Triticum aestivum). J. Soils Crops, 17(1) : 18-23.

Patnaik, M. C. and Arun Sathe, 1993, Influence of N, K and CaSO4 on utilization of sulphur by rice in red sandy loam soil. J. Nuclear Agric. Biol., 22(2) : 75-79.

Patra, P. K., Neue, H. U. and Goswami, N. N., 1998, Influence of sulphur application and water management practices on sulphur nutrition, growth and yield of rice in some sulphur deficient wetland rice soils. Oryza, 35(2) : 135-139.

Piper, C. S., 2002, Soil and Plant Analysis, Hans Publications, Bombay, India.

Poongothai, S., Savithri, P., Vennila, R. K. and Biju Joseph, 1999, Influence of gypsum and Greenleaf manure application on rice and on soil deficient in sulphur. J. Indian Soc. Soil Sci., 47(1) : 96-99.

Ponnamperuma, F. N., 1979, The chemistry of submerged soils. Adv. Agon., 24 : 29-96.

Pratima Sinha, D. B. K. and Chatterjee, C., 2001, Sulphur deficiency effects on metabolism and seed quality of maize (Zea mays) and recovery there from. Indian J. Agric. Sci., 71(4) : 267-270.

*Rahman, M. N., Sayem, S. M., Alam, M. K., Islam, M. S. and Mondol, A. T. M. A. I., 2007, Influence of sulphur on nutrient content and uptake by rice and its balance in old Brahmaputra floodplain soil. J. Soil Nature, 1(3) : 5-10.

Rajakumar, G. R., 1994, Studies on forms and distribution of micronutrients in paddy soils of Tungabhadra project-Karnataka. M.Sc. (Agri.) Thesis, Univ. Agric. Sci. Dharwad, Karnataka (India).

Rajendra Prasad, B., Subba Rao, A. and Subba Rao, I. V., 1983, Sulphur status of some intensively cultivated grape garden soils. J. Indian Soc. Soil Sci., 31 : 608-610.

Rajendra Prasad, B., Subba Rao, A. and Subba Rao, I. V., 1984, Mineralization and immobilization of sulphur in some groundnut growing soils. J. Indian Soc. Soil Sci., 32 : 744-745.

Raju, R.A., Reddy, K. A. and Reddy, M. N., 1994, Response of rice (Oryza sativa) to sulphur and zinc on coastal alluvials of Andhra Pradesh. Indian J. Agron., 39 (4) : 637-638.

Rakesh Kumar, Singh, K. P. and Sarkar, A. K., Wadood, A. and Surendra Singh, 2003, Sulphate sorption-desorption characteristics of Dumka district (Jharkhand). J. Indian Soc. Soil Sci., 51(4) : 512-517.

Rakesh Kumar, Singh, K. P. and Surendra Singh, 2002, Vertical distribution of sulphur fractions and their relationships among carbon, nitrogen and sulphur in acidic soil of Jharkhand. J. Indian Soc. Soil Sci., 50(3) : 502-505.

Ram, H., Singh, S., and Chaubey, C. N., 1999, Response of rice to sulphur under reclaimed salt affected soil. Oryza, 36(3) : 272-273.

Ram M. and Diwedi, K. N., 1994, Delineation of sulphur deficient soil groups in central alluvial tract of Uttar Pradesh. J. Indian Soc. Soil Sci., 42 : 284-286.

Ravi, S., 2004, Effect of sulphur zinc and iron nutrition on growth, yield and certain quality parameters of safflower (Carthamus tirtorious). M.Sc. (Agri.) Thesis, Univ. Agric. Sci. Dharwad, Karnataka (India).

Reddi Ramu, Y. and Maheswara Reddy, P., 2003, Yield, quality and economics of sunflower as influenced by nitrogen and sulphur nutrition. J. Oilseeds Res., 20(1) : 131-132.

Reddy, V. N. and Raju, A. S., 1986, Effcet of period of incubation on sulphur and molybdenum availability in red sandy loam soil. Madras Agric. J., 73(12) : 714-717.

Robert, L. S., 1966, Oxidation and reduction of sulfur compounds in soils. Soil Sci. 4 : 229-345.

Ruhal, D. S. and Paliwal, K. V., 1978, Status and distribution of sulphur in soils of Rajasthan. J. Indian Soc. Soil Sci., 26(4) : 352-358.

Ruhal, D. S. and Paliwal, K. V., 1980, Soil properties affecting the availability of sulphur in soils of Rajasthan. J. Indian Soc. Soil Sci., 28 : 529-531.

Sachdev, M. S, Mittal, R. B. and Sachdev, P., 1982, Utilization of sulphur by rice from gypsum and its balance sheet in soil using

35S. J. Nuclear Agric. Biol., 11 : 11-14.

Sachdev, M. S. and Chhabra, 1974, Transformation of S35

labelled sulphate in aerobic and flooded soil conditions. Plant and Soil, 11 : 529-531.

Sadasivam, S. and Manickam, A., 1992, Biochemical Methods for Agricultural Sciences, Wiley Eastern Ltd. New Delhi. 46-47.

Sahoo, A. K., Sah, K. D. and Gupta, S. K., 1998, Sulphur distribution in some mangrove soils of the Sunderbans. J. Indian Soc. Soil Sci., 46(1) : 138-140.

Sakal, R. Singh, A. P., Choudhary, B. C. and Shati, B., 2001, sulphur status of Ustifluvents and response of crops to sulphur application. Fert. News, 46(10) : 61-65.

Sankaran, K., Bharathi, C. and Sujatha, S., 2005, Effcet of sulphur fertilization on yield and nutrient uptake by onion in red soils (Udic Haplustalf). J. Maharashtra Agric. Univ., 30(2) : 135-136.

Sammi Reddy. K., Tripathi, A. K., Muneshwar Singh, Subba Rao, A., and Anand Swarup, 2003, Sulphate sorption-desorption characteristics in relation to properties of some acid soils. J. Indian Soc. Soil Sci., 49(1) : 74-80.

Sarkunan, V., Misra, A. K., and Mohapatra, A. R., 1998, Effcet of phosphorus and sulphur on yield and uptake of P and S by rice. J. Indian Soc. Soil Sci., 46(3) : 476-477.

Savithri, P., Poongothai, S., Biju Joshep and Vennila, R. K., 1999, Non-conventional sources of micronutrients for sustaining soil health and yield of rice-greengram cropping system. Oryza, 36(3) : 219-222.

Setia, R. K. and Sharma, K. N., 2005a, Effect of long-term differential fertilization on depth-distribution of forms of sulphur and their relationship with sulphur nutrition of wheat under maize-wheat sequence. J. Indian Soc. Soil Sci., 53(1) : 91-96.

Setia, R. K., Sharma, K. N. and Sharma, P. K., 2005b, Sulphur adsorption by soil after differential fertilization for twenty-two years with NPK under a continuous maize-wheat cropping systems. J. Indian Soc. Soil Sci., 53(3) : 417-420.

Sengupta, K., Subrata Nandi and Chakraborthy, N., 2001, Effect of sulphur-containing fertilizers on productivity of rainfed greengram (Phaseolus radiatus). Indian J. Agric. Sci., 71(6) : 408-410.

*Shahsavani, S., Ardalan, M., and Sistani, K. R., 2006, Sulphate adsorption in soils of North and Northeast Iran. Comm. Soil Sci. Plant Anal., 37(1-2) : 1587-1596.

Shailendra Kumar, 2002, Studies on sulphur status and response of rainfed rice to sulphur in Kulghatgi taluk of Dharwad district. M.Sc. (Agri.) Thesis, Univ. Agric. Sci. Dharwad, Karnataka (India).

Shamima Nasreen and Imamul Huq, S. M., 2005, Effect of sulphur fertilization on yield, sulphur content and uptake by onion. Indian J. Agric. Res., 39(2) : 122-127.

Sharma, A. K. and Gangawar, M. S. 1997, Distribution of different forms of sulphur and their relationship with some soil properties in Alfisols, Inceptisols and Mollisols of Moradabad district, Uttar Pradesh. J. Indian Soc. Soil Sci., 45(3) : 480-485.

Sharma, B. R., Kanwar, B. S. and Kanwar, B. B., 1988, Forms of sulphur and available sulphur extracted by some extractants in soils of North Western Himalaya. J. Indian Soc. Soil Sci., 36(4) : 500-509.

Sharma, B. R., Kanwar, B. S. and Kanwar, B. B., 1986, Distribution of sulphur forms in some important soil profiles of North Western Himalayas. Himachal J. Agric. Res., 12 : 119-127.

Sharma, K. R. and Dev, G., (1976) Profile distribution of sulphur in selected soil series of the pilot project area, Patiala. J. Res. Punjab Agric. Univ., 13 : 19-22.

Sharma, M. P., Singh, A. and Gupta, J. P., 2002, Sulphur status and response of onion (Allium cepa) to applied sulphur in soils of Jammu districts. Indian J. Agric. Sci., 72(1) : 26-28.

Sharma, R. K. and Jaggi, R. C., 2001, Relationships of forms and availability indices of sulphur with properties of soils of Kangra, Himachal Pradesh. J. Indian Soc. Soil Sci., 49 : 698-702.

Shukla, A. K. and Singh, R. S., 1992, Oxidation of sulphur in pyrites in relation to soil and water regime. J. Indian Soc. Soil Sci., 40 : 848-850.

Shukla, U. C. and Gheyi, A. K. 1971, Sulphur status of some Rajasthan soils. Indian J. Agric. Sci., 41 : 247-253.

Singh, H. G., 1971, Effect of sulphur on tissue composition and prevention of chlorosis in rice seedlings. Indian J. Agron., XVI : 143-148.

Singh, R., Goraya, D. S. and Brar, S. P. S., 1976, Distribution of different forms of sulphur in some soils of Himachal Pradesh. J. Res. Punjab Agricultural University, 13 : 255-260.

Singh, R. S. Gupta, M. D. and Yadav, A. D., 1981, Distribution of different forms of sulphur in the soils of Bundhelkhand region. Indian J. Agric. Res., 15 : 201-207.

Singh, S., Singh, K. P., Rana, N. K. and Sarkar, A. K., 1993, Forms of sulphur in some Ranchi soils of Chotanagpur J. Indian Soc. Soil Sci., 41(4) : 562-563.

Singh, S. K., 2000, Effect of different sources of sulphur on rice under rainfed lowlands. Oryza, 37(1) : 81-82.

Singh, S. P., Ram, J. and Singh, N., 2000, Forms of sulphur in relation to soil characteristics in some soil series of Nagaland. J. Maharashtra Agric. Univ., 25(1) : 3-8.

Singh, V. and Sharma, R. L., 1983, Forms of sulphur in citrus growing soils of Agra regions in Uttar Pradesh. J. Indian Soc. Soil Sci., 31 : 482-485.

Solo Samosir and Blair, G. J., 1983, Sulfur nutrition of rice. III. A comparison of fertilizer sources for flooded rice. Agron. J., 75 : 203-206.

Sparks, D. L., Page, A. L., Helmke, P. A., Leoppert, R. H., Soltanpour, P. N., Tabatabai, M. A., Johnston, C. T. and Sumner, M. E., 1996, Methods of soil Analysis, Part 3, Chemical methods, No. 5 in Soil Science Society of America book series, Soil Science Society of America Inc. Madison, Wisconsin, USA

Sreedevi, B., Singh, S. P. and Subbaiah, S. V., 2006, Effcet of sulfur application on conventional and hybrid rice cultivars. Oryza, 43(2) : 112-115.

Sreemannarayana, B. and Sreenivasa Raju, A, 1994, Influence of different cropping sequences on status of sulphur fractions in Vertisols and Alfisols. Ann. Agric. Res., 15(3) : 344.350.

Sridhara Adiga and Ananthanarayana, R., 1996, Vertical distribution of sulphur in base unsaturated rice fallow profiles of Karnataka. J. Indian Soc. Soil Sci., 44(4) : 652-656.

Sriramachandrasekharan, M. V. and Mathan, K. K., 1991, Effect of newer sources of Zn application on Zn, Mn, Cu and Fe uptake by rice (var IR-60) in lowland. Madras Agric. J., 78(5-8) : 261-263.

Sriramachandrasekharan, M. V., Bhuvaneswari, R. and Ravichandran, M., 2005, Direct and residual supply of available sulphur and its balance sheet in rice-rice cropping sequence. Adv. Pl. Sci., 18(2) : 699-703.

Sriramachandrasekharan, M. V., Bhuvaneswari, R. and Ravichandran, M., 2007, Direct and residual effect of sulphur and organics on yield and S nutrition in rice-rice sequence. Indian J. Crop Sci., 2(1) : 231-232.

Subbaiah, S. V., Singh, S. P., and Pillai, K. G., 2001, Effect of sulphur nutrition on grain yield of lowland rice. Oryza, 38(1-2) : 82-83.

Sumathy, N., Vaiyapuri, V., Sriramachandrasekharan, M. V., and Ravichandran, M., 1999, The effect of integrated use of green manure with S sources on the yield of rice. Oryza, 36(3) : 268-269.

Surendra Singh, Singh, K. P., Rana, N. K. and Sarkar, A. K., 1993, Forms of sulphur in some Ranchi soils of Chotanagpur. J. Indian Soc. Soil Sci., 41(3) : 562-563.

Swarnakar, K. C. and Verma, M. M., 1978, Distribution of forms of sulphur in soil profile of Bundhelkhand region. Indian J. Agric. Chem., 11 : 49-57.

Tabatabai, M. A., 1982, Sulfur, In Methods of Soil Analysis Ed. Page, A. L. et al., ASA, Madison, Wisconsin, USA.

Tabatabai, M. A., and Al-Khafaji, A. A., 1980, Comparison of nitrogen and sulphur mineralization in soils. Soil Sci. Soc. Amer. J., 44(5) : 1000-1006.

Tai, Y. P. and Young, G. P., 1974, Variation in protein percentage in properties of peanut cotyledons. Crop Sci., 14 : 222-229.

Takkar, P. N., 1988, Sulphur status of Indian soils. Proc. TSI-FAI Symp. on Sulphur in Agriculture, New Delhi, S 1/2/1-31.

Takkar, P. N. 1996, Micronutrient research and sustainable agricultural productivity in India. J. Indian Soc. Soil Sci., 44 : 562-581.

Tan, L., McLaren, R. G., and Cameron, K. C., 1994, Comparison of sulphur mineralization in open and closed incubation systems and from field. Comm. Soil Sci. Plant Anal., 25(19-20) : 3191-3198.

Tandon, H. L. S., 1991, Sulphur Research and Agricultural Production in India, 3rd

Ed, FDCO, New Delhi, 140.

Thomas, S. G., Hocking, T. J. and Bilsborrow, P. E., 2003, Effect of sulphur fertilization on the growth and metabolism of sugarbeet grown on soils of differing sulphur status. Field Crop Res., 83 : 223-235.

Tiwari, K. N., Vandana Nigam and Pathak, A. N., 1983, Effcet of sulphur fertilization on yield response and sulphur and nitrogen composition of rice grown in the soils of Kanpur district. Indian J. Agic. Sci., 53(9) : 812-819.

Tiwari, R. C. and Pandey, D. K., 1990, Status of different forms and deficiency of sulphur in some soils of Varanasi region of Eastern Uttar Pradesh. Fert. News, 35 : 35-39.

Tiwari, R. J., 2006, Response of sugarcane (Saccharum officinarum) to direct and residual effect of sulphur. Indian J. Agric. Sci., 76(2) : 117-119.

Tripathi, D. and Karan Singh, 1992, Vertical distribution of sulphur in representative soil groups of Himachal Pradesh. J. Indian Soc. Soil Sci., 40 : 447-453.

Tripathi, P. N. and Sharma, N. L., 1994, Evaluation of pyrite and gypsum as a source of sulphur in Indian mustard (Brassica juncea)-rice (Oryza sativa) cropping sequence. Indian J. Agric. Sci., 64(8) : 536-539.

Tripathi, R. K. Kuldeep Singh and Karwasra, S. P. S., 1997, Forms of sulphur and their distribution in some Aridisols of Haryana state under grape vineyards. J. Indian Soc. Soil Sci., 45 : (2) 386-388.

Vaneet Aggarwal and Nayar, V. K., 1998, Available soil sulphur status and sulphur nutrition of wheat crop. J. Indian Soc. Soil Sci., 46(1) : 71-75.

Venkateswarlu, J.., Subbiah, B. V. and Tamhane, R. V., 1969, Vertical distribution of forms of sulphur in selected rice soils of India. Indian J. Agric. Sci., 39(2) : 426-431.

Venkatesh, M. S., 1997, Studies on sulphur in Vertisols under oilseed based cropping system of North Karnataka. Ph.D. Thesis, Univ. Agric. Sci., Dharwad, Karnataka (India).

Viney Singh, Mehata, V. S., Komal Singh and Prasad, K., 1986, Effect of sulphur and Zn on yield and utilization of nutrients by wheat. Indian J. Pl. Path. 29 : 219-224.

Virmani, S. M. and Kanwar, J. S., 1971, Distribution of forms of sulphur in six soil profiles of North East India. J. Indian Soc. Soil Sci., 19 : 73-77.

Vishwakarma, S. K., Sharma, R. S. and Ayachi, A. K., 1999, Effect of sources and levels of sulphur on yield attributes, seed yield and economics of soybean. J. Oilseeds Res., 16(1) : 65-67.

Vyas, A. K., Billore, S. D., Op Joshi and Panchlania, N. 2006, Productivity of soybean (Glycine max) genotypes as influenced by nitrogen and sulphur nutrition. Indian J. Agric. Sci., 76(4) : 272-273.

Wani, M. A. and Refique, M. M, 2000, Effect of different levels of sulphur on yield and nutrient uptake of rice. Adv. Pl. Sci., 13(1) : 139-143.

Wei Zhou, Ping He, Shutian Li and Bao Lin, 2005, Mineralization of organic sulphur in paddy soils under flooded conditions and its availability to plants. Geoderma 125 : 85-93.

Williams, C. H., 1975, The chemical nature of sulphur compounds in soils. In : Sulphur in Australian Agriculture, pp. 21-30.

Williams, C. H. and Steinbergs, A., 1959, Soil sulphur fractions and chemical indices of available sulphur in some Australian soils. Australian J. Agric. Res., 10 : 340-352.

Wu, J., O’Donnel, A. G., and Syers, J. K., 1995, Influence of glucose, nitrogen and plant residues on the immobilization of sulphate-S in soil. Soil Biol. Biochem., 27(11) : 1363-1370.

Yahya M. N, 1981, Sulphur mineralization and adsorption in soils. Plant and Soil, 60(3) : 451-459

Yifter Nega, Srikanth, K., Sudhir, K. and Sharnappa, 2001, Sulphur status of an Alfisol under continuous cropping and fertilizer schedule. Indian J. Agric. Sci., 71(5) : 334-336.

*Zhao, F. J., Withers, P. J. A., Evans, E. J., Monaghan, J., Salmon, S. E., Shewry, P. R. and McGrath, S. P., 1997, Sulphur nutrition : An important factor for the quality of wheat and rapeseed. Soil Sci. Pl. Nutr., 43 : 1137-1142.

*Original not seen

APPENDIX

Appendix I: Price of inputs and returns used in calculating cost of cultivation

Sl No. Particulars Unit Price (Rs.)

1 Inputs

a Seed paddy kg 12.00

2. Fertilizers

a Urea kg 4.65

b Diamonium phosphate kg 8.95

c Muriate of potash kg 4.35

d Farmyard manure tonne 333.00

e ZnSO4 kg 30.70

f Factomphos kg 7.20

g Gypsum kg 2.00

3. Returns

a Rice grains quintal 700.00

b Rice straw tonne 200.00

Appendix II: Cost of different operations used in calculating cost of cultivation

Sl No.

Operation No. of times

Rate (Rs./ha) Amount (Rs./ha)

1 Tilling twice 750 1500

2 Puddling twice 750 1500

3 Levelling once 750 750

4 Bund scraping once 325 325

5 Seedling uprooting and transplanting

once 1625 1625

6 Line marking once 75 75

7 Weeding

a) Manual

b) Weedicide

twice

once

750

625

1500

625

8 Irrigation charges once 300 300

9 Plant protection

a) Furadan

b) Beam + bacterimycin

c) Chloropyriphos

d) Bipvin

twice

once

once

once

1160

300

250

350

2320

300

250

350

10 Harvesting, threshing, cleaning and bagging

once 3000 3000

11 Nursery cost once 1950 1950

Total 16370

STUDIES ON FORMS AND TRANSFORMATION OF

SULPHUR AND RESPONSE OF RICE TO SULPHUR

APPLICATION IN RICE-RICE CROPPING SEQUENCE

D. N. SAMARAWEERA 2009 Dr.H.T.CHANNAL Major Advisor

ABSTRACT

Soil characterization, incubation study and field experiments were conducted to study the distribution of S forms, transformation and direct and residual effect of sulphur on growth, yield and quality of rice-rice cropping system during rabi/summer and kharif seasons during 2007, respectively. In characterization study, there was lot of variations among sulphur forms in soils of eight selected locations. Correlation studies revealed that sulphate sulphur was significantly and positively correlated with EC and CEC, water soluble sulphur, organic sulphur and total sulphur. Water soluble sulphur significantly correlated with pH, EC, organic sulphur, non-sulphate sulphur and total sulphur. Results obtained from incubation study revealed that Factomphos increased sulphate sulphur and water soluble sulphur up to 32

nd

day of incubation and these fractions declined thereafter.

Field investigations on response of rice to applied two sulphur sources indicated that Facomphos was superior over gypsum and the highest grain and straw yield (57.09 and 63.63 q ha

-1), protein and methionine content (6.17% and 2.51 mg g

-1) were recorded with

Factomphos apllied @ 50 kg ha-1

, respectively. In succeeding rice, same treatment registered highest grain and straw yield (51.90 and 58.02 q ha

-1), protein and methionine content (5.92%

and 2.18 mg g-1

), respectively. Economic analysis revealed that application of Factomphos @ 50 kg ha

-1 resulted the highest benefit:cost (B:C) ratio of 1.69 in first rice with net return of Rs.

16,847/ha which was 33.2 per cent increase over control (Rs. 12647/ha). Similarly, the highest benefit:cost (B:C) ratio of 1.64 in succeeding rice with net return of Rs. 14,565.00/ha was recorded with the residual effect of the same treatment and that was 55.9 per cent increase over control (Rs. 9343/ha).

studies on forms and transformation of sulphur and response of rice to sulphur application in rice

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