rural waste management in a south indian village — a case study

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Bioresource Technology 53 (1995) 157-164 © 1995 Elsevier Science Limited

Printed in Great Britain. All rights reserved 0960-8524/95/$9.50

RURAL WASTE MANAGEMENT IN A SOUTH INDIAN VILLAGE A CASE STUDY

M. Chowde Gowda

Division of Agricultural Engineering, University of Agricultural Sciences, G.K.V.K., Bangalore - 560 065, India

G. S.V. Raghavan,* B. Ranganna & Suzelle Barrington Department of Agricultural Engineering, MacDonaM Campus of McGill University, Ste Anne De Bellevue, Quebec, Hgx 3V9,

Canada

(Received 1 February 1995; revised version received 10 May 1995; accepted 15 May 1995)

Abstract A micro-level study was carried out in a typical south Indian village to assess the quantity and type of wastes generated and its present mode of management. This information was used to identify the appropriate technologies which could enhance the value of the waste produced and, at the same time, improve the economic conditions of rural people. The study indicated that nearly 2364 tons of rural wastes in the form of crop residues, animal manure and human excreta are produced annually in the village with a population of 510. About 77% of the waste generated in the village was used as domestic fuel, animal fodder and organic fertilizer for crop production. The rest (23%) was left out in open fields for natural decomposition. The energy balance sheet of the village indicated that the present consumption of biomass resources was 50% less than that actually required for various domestic and agricultural applications. Anaerobic digestion of animal manure and human excreta produced in the village could yield 82% of the domestic energy required besides enriching the waste by 3-4 times as compared to conventional storage on the ground. If the traditional mud chulha (stove) were replaced by an improved chulha, each family unit could reduce their annual biomass (fire wood) consumption by about 2/3. Commercializing the utilization of coconut and paddy biomass using the village's man-power and facilities could increase the rural family income several fold.

Key words: Crop residue, animal waste, domestic refuse, coconut biomass, biogas, chulha, mushroom.

INTRODUCTION

The residential housing of Indian villages are con- centrated in one central location and are surrounded by agricultural, horticultural, pasture and forest

* Author to whom correspondence should be addressed.

157

lands. The average village family consists of 4-5 adult members and an equal number of cattle. The crop residues and domestic refuse (human excreta and kitchen waste) are the major wastes generated, most of which are piled on the ground in an open yard and left to compost just a few metres away from the dwellings. The mixed odour of decaying human excreta and the smoke from the inefficient burning of biomass fuels heralds ones approach to the villages. The proper management of crop residues and excreta from animal and human habitants in rural areas is needed. Identification and adoption of appropriate technologies suitable to the location can provide more hygienic waste-management practices and the energy required for domestic needs, the raw material for developing industries and the organic fertilizer for producing better crops.

Karnataka is one of the southern states of India whose economy is mainly dependent on agriculture. Considerable amounts of crop residues, animal wastes and domestic refuse are produced every year in the rural sectors of the state. In the absence of appropriate technologies, these surplus wastes are uneconomically utilized at present. They are either burned inefficiently as fuel or left unutilized to decompose naturally. In either case the rich carbon biomass is lost into the air, thus polluting the atmosphere (Chowde Gowda & Chowdiah, 1993). Several researchers have demonstrated the role of rural wastes as an alternate source of clean and renewable fuels for energy, which can replace, to a great extent, our future dependence on fossil fuels (Bhattacharya, 1983). Studies have been carried out on the various aspects of biogas production from animal and human excreta and also on the fertilizer value of the spent slurry (Tam & Thanh, 1983; Bhatnagar et al., 1989; Ranganna et al., 1991; Ranganna et al., 1992).

Mushroom is a potential contributor to the human food supply since it has the ability to transform wastes into highly acceptable nutritious foods. Crop

158 M. Chowde Gowda, G. S. I4. Raghaven, B. Ranganna, S. Barrington

residue, like paddy straw, has been evaluated as one of the best supporting materials for mushroom production (Shashi Dhanda, 1986; Garcha et al., 1987).

Coconut palm is a very high utility crop having numerous domestic and commercial applications. Coconut fronds, husk and shells from the coconut tree serve as raw materials for various industries. Coconut pith, a by-product of the coir (a fibre from the husk of coconut) industry, contains 77% volatile solids and can be used for biodegradation to generate methane (Menon, 1987).

In rural India, 90% of householders burn biomass fuels in traditional mud chulhas (stoves) for domestic cooking. The thermal efficiencies of these chulhas vary from 2 to 10% and pose problems such as the release of smoke and other post-combustion prod- ucts. These cause discomfort and health hazards to the users and pollution of the environment (Bakshi & Pathak, 1984; Sampath Kumar et al., 1985).

The natural composting of crop residues, animal manure and human excreta deteriorates the living conditions of the rural population who already live in poor and badly drained houses. The wastes are dumped in heaps and left to rot a few metres away from the dwellings, attracting insects, releasing unpleasant odours and draining everywhere (Chowde Gowda & Chowdiah, 1994). In view of these facts, improved waste-management techniques are the key to better sanitary conditions in rural areas. A typical south Indian village called Man- dyakoppal in the state of Karnataka was studied with the following objectives: (i) to quantify and characterize the wastes produced in the village, (ii) to identify the present waste-management practices of the villagers and (iii) to recommend the appropriate technologies which could be adopted by the villagers for better management of the wastes and to improve the living conditions.

METHODS

Mandyakoppal has 103 families fully dependent on agriculture and its allied activities for their living. The quantity of crop residues, animal manure and human excreta produced under different cropping seasons was measured for the 103 families of the village, using already established standard proce- dures (Pachauri et al., 1983). The data were averaged for the four cropping seasons over a 2 year span (between June and October (Kharif season) and November and December (Rabi season) of 1988 and 1989).

Consumption patterns of biomass and non-biomass energy sources were studied by structured interviewing of the farm men and women of the village. The consumption of energy sources was expressed by the consumers in local units, such as head loads, cart loads and measuring bottles. To

assess the agreement of the local units, 10% of the families (10 families) were randomly selected and the expression of biomass consumed in the local units was measured and converted into kilograms and litres.

The actual consumption of biomass as fuel by each of the randomly selected 10 families was recor- ded over a period of 24 h. Eight such observations were made for each selected family during the period of study and the average consumption was computed. For this computation, the householders were asked to keep aside all the biomass fuels needed near the kitchen for the subsequent 24 h and an extra quantity of biomass was also kept to ensure that there would be no shortfall during the period of observation. The fuel was segregated into three categories, namely, firewood, crop residues and dung cakes, which are commonly used in combination. All three categories of fuels were then weighed and placed in a single pile at a convenient place near the kitchen. Every householder was advised to only use the fuel from the measured pile until the investiga- tor called on the following days. They were also requested not to deviate from their normal cooking practices. The remaining biomass in the pile was again desegregated, as done earlier, and weighed. The data now gave the quantity of biomass fuel consumed by the householder during the preceding 24 h period. This procedure was repeated for seven more observations with the same household during the four cropping seasons, and the average per capita fuel consumption was estimated (Wijesinghe, 1988). The average per capita consumption of electricity was determined based on the monthly energy consumption bill issued to the householder by the Karnataka Electricity Board during the 12 month period (Reddy, 1982). The quantity of kerosene consumed per month was estimated by interviewing the household women individually (Reddy, 1982). The level of per capita domestic energy consumed was calculated and compared with an all India average per capita consumption and an estimated requirement was calculated. Further, estimation of organic manure for crop production was calculated as per the recommendations of the Package of Practices for High Yielding Crops, a joint publication of the Uni- versity of Agricultural Sciences and the Department of Agriculture, Government of Karnataka (Anon, 1989). Total energy contents of various fuels were calculated in kilocalories and the energy consumed for domestic activities was expressed in gigajoules (Maheshwari et al., 1983). The energy value of coconut biomass was estimated as 4000 kcal/kg for the fronds, 3850 kcal/kg for the husk and 5500 kcal/kg for the shells (Chowde Gowda, 1994). The prevailing market prices and local wages were taken into con- sideration while estimating the cost of biomass fuel, the cost of cultivating mushrooms and the fodder value of paddy straw.

Rural waste management: a case study 159

RESULTS AND DISCUSSION

The village Mandyakoppal has the potential of gen- erating 2364 Mg rural wastes (dry weight) annually, in the form of crop residues, tree biomass, animal manure and human excreta (Table 1). Animal manure contributed 57% of the total wastes followed by crop residues (32%), human excreta (8%) and tree biomass (3%). It is clear from the results that 77% (1822 Mg) of the waste produced in the village is being used as cooking fuel, animal fodder and organic fertilizer. The rest of the wastes (542 Mg) is either burned or left to decompose naturally in open fields. The unutilized waste includes 168 Mg of human excreta left in open fields and 374 Mg of sugercane trash, which is mostly burned in the grow- ing fields. Further, the results revealed that only 6.2% of the waste produced in the village was consumed as a domestic fuel. All the animal manure and human excreta could be used as raw materials for biogas production, which also enhances the man- urial value. The wastes are inefficiently utilized and handled in the existing systems.

The annual estimated per capita domestic energy requirement (9.23 GJ) using traditional fuel burning devices is compared against present consumption (5.78 GJ) in Table 2. Firewood made up the major

share of the estimated energy requirement (54.39%) followed by crop residues (28.60%), dung cake (9-97%), electricity (3-90%), kerosene (2"38%) and coal (0-76%). The estimated per capita energy requirement (9.23 G J) for the village's domestic needs was in agreement with the per capita domestic energy consumption (7-83-12.50 GJ) in rural India, the variation depending upon the food habits (Bo Wander et al., 1983). Further, 93% of the energy estimated for domestic needs of the village is basi- cally from biomass sources. Table 2 shows that Mandyakoppal uses less than 50% of the biomass energy requirement for domestic uses.

The balance sheet of biomass and non-biomass energy resources of the village is presented in Table 3. The data shows that the consumption of biomass energy (19910 GJ) was 50% less than the estimated biomass energy requirement (39 390 G J) for various end uses like domestic fuel, animal fodder and organic fertilizer. This was attributed to a deficit in biomass production over and above inefficient han- dling and utilization. Conversely, the consumptions of non-biomass energy resources, such as kerosene and electricity, were 74 and 56%, respectively, higher than the estimated requirement. This was due to the non-availability of a sufficient quantity of firewood and less-efficient fuel-burning devices used in

Table 1. Annual average production and consumption of rural waste in Mandyakoppal village

Biomass source Production (Mg) Consumption (Mg)

Cooking Animal Organic Total fuel fodder compost (Mg)

Untapped waste

Crop residues 745.12 11-60 359.42 - - 371.02 374.10 Tree biomass 87.34 87.34 -- - - 87.34 - - Human excreta 186.15 - - - - 18-62 18.62 167-53 Animal manure 1345-28 47-39 - - 1297.89 1345.28 - - Total 2363-89 146-33 359-42 1316.51 1822.26 541.63

Source: Directorate of Economics & Statistics, Govt of Karnataka, and data collection through village inventory survey.

Table 2. Annual average consumption and estimated requirement of various fuels for domestic use in Mandyakoppal village

Source Unit Present/capita Estimated/capita consumption requirement

Biomass Crop residue kg 23.00 210.00 Firewood kg 170.00 300.00 Dungcake kg 92.00 92.00

Energy value GJ 4.06 8"58 Non-biomass

Kerosene L 23.30 6-60 Electricity kWh 73.79 30-15 Coal kg 3.00 3.00 Energy value GJ 1.72 0.65

Total energy value (biomass + non-biomass) GJ 5-78 9.23

160 M. Chowde Gowda, G. S. V Raghaven, B. Ranganna, S. Barrington

the village. The resources balance sheet (Table 3) indicates that the energy deficit in the form of crop residues, firewood and animal manure was about 15 067 GJ/yr and the energy surplus estimated in the form of human excreta, kerosene and electricity was 3202 G J/yr. The situation demands an increased production of those biomass resources in deficit and a more efficient use of those energy sources being used beyond their estimated requirements. Thus, domestic fuel, fodder and fertilization requirements could be met while improving the quality of life of the villagers. There is also a need to more effectively

use the available biomass resources by adopting appropriate technologies suitable to the location.

Appropriate technologies identified for Mandyakoppal village

Biogas energy production Figure 1 shows how animal manure and human excreta could be processed through conventional composting and anaerobic digestion. If these wastes were conventionally composted (piled on the ground to decompose naturally) they would yield only 737

Table 3. Biomass and non-biomass resource balance sheet of Mandyakoppal village

Energy source Unit Produced/ Present Estimated Surplus Deficit imported consumption requirement

Biomass produced Crop residue Mg 745.12 371-02 929.70 - - 184-58 Firewood Mg 87.34 87.34 153" 10 - - 65.76 Animal manure Mg 1345.28 1345-28 2505.04 - - 1159-76 Human excreta Mg 186-15 18.62 - - 167-43 - - Energy value GJ 27 127 19 910 39 390 2522 15 067

Non-biomass imported Kerosene L 13 153 13 153 3366 9787 - - Electricity kWh 53 319 53 319 23 419 29 900 - - Coal Mg 2 2 2 - - - - Energy value GJ 1112 1112 432 690 15 067

Total energy value GJ 28 240 21 022 39 822 3202 15 067 (biomass + non-biomass)

L m ~ m m ~ l m

~g. 1.

JCONVENTIONALI I COMPOST ] COMPOSTING/ It 737 Mg (76.6 % m.c) [

T ANIMAL MANURE

AND HUMAN EXCRETA

1,531 Mg

I 899kg I --'---"b I NITROGEN I P-5~I

~'l PHOSPHORUS I (0.2%)

ANAEROBIC DIGESTION

I DIGESTED = COMPOST "1 2,235 MO (90 % re.c)

899 k0 POTASH (0.5%) I

3,352,,g ] NITROGEN (, 5% I

j ko I PH(:~PHORUS "1 (1.o%)

• ~ ',788 v= I POTASH (0,8%)

..--.--J 30S'10Skcal I

j o,..oo i I "IUSEFULENERGY I

Potential of biogas, compost and nutrients from the wastes produced in Mandyakoppal village.


Fig. 2.

Mud chulha I LOSS OF HEAT ENERGY AND J

SMOKY ENVlRONM ENT I t

ANNUAL REQUIREMENT J OF BIOMASS FUEL I

USING MUD CHULHA I 3.000 kg I I

i , i I I'o" I COSTOF I TRANsF,°RTA'n°N I

BIOMASS lAND PROCESS!NG | R, ~.2= ,y, loosr R.,.,,o ,y, I

t ~ TOTAL COSTOF BIOMASS L_ I FIS 3,710/farnlly/yr ] "

I ISAVING IN BIOMASS COSTI ~l ~ 2,474 / krnlly I yr J¢

Improved chulha

INCREASE IN HEAT ENERGY I UTILIZATION AND SMOKE FREE

ENVIRONMENT

"r I ANNUAL REQUIREMENT I OF BIOMASS FUEL USING I

IMPROVED CHULHA I 1,oo[ ~ I

1 * j COSTOF i" , ~ , ~ s I

BIOMASS I TRANsP°RTA'n°N I Rs 750 1 yr I AND PROCESSING I • l .COSr~4~ '~ I

I J TOTAL COST OF SIOMASS d

1 JSAVING IN BIOMASS FUEL L 'l 2.0oo ~ / k.l,y/y, r

J IMPROVED HEALTH [ "l OF RURALWOMEN 4

Comparison of the economics of using improved chulha over mud chulha in a family unit.

Table 4. Average annual biomass production of a coconut tree

Biomass Production/tree

Quantity Energy PLE a (kg) (10 3 kcal)

Production/ Total production hectare in the village (PLE) a (PLE) =

Fronds 27 107 13 1948 27 266 Husk 36 140 17 2553 35 725 Shells 20 107 13 1953 27 329 Total 83 354 43 6454 90 320

"PLE=equivalent to 1 I of petroleum.

Mg of compost at 75-6% moisture and 899 kg of nitrogen, 359 kg of phosphorus and 899 kg of potassium. In contrast, if the same wastes were anaerobically digested, enough biogas (61 240 m 3 ) could be generated to meet 82% of the domestic energy requirement of the village. Besides this biogas, 2235 Mg of digested slurry at 90% moisture could be recovered to provide the 3352 kg of nitrogen, 2235 kg of phosphorus and 1788 kg of potassium for crop production. In conventional composting, the organic wastes are aerobically decomposed at the temperature of 60-70°C and a major portion of the nitrogen is lost through volatilization; while in anaerobic digestion, the organic wastes are decomposed in a dosed chamber at a temperature between 25 and 35°C (other than win- ter months) and no ammonia volatilization occurs.

Furthermore, the anaerobic chamber retains the wastes while the uncontained compost waste is exposed to leaching. If all the available animal manure and human excreta was anaerobically digested, enough biogas could be produced to supplement 82% of the domestic energy needs of the village, besides recovering 3-4 times more nutrients for the crops.

Improved chulha The observations and discussions with householders indicate that a family of five adult members in the village needs about 3 Mg of biomass fuel annually for domestic consumption when burnt in a traditional mud chulha (stove). The performance of the traditional chulha was compared to the improved chulhas (Fig. 2). The latter burns biomass with a

162 M. Chowde Gowda, G. S. V. Raghaven, B. Ranganna, S. Barrington

L - -

1 COST OF FRONDS Rs 3,140

,.I TOTAL COSTOFCO, NVENTIONALLY ' I USED FRONDS Rs 37,720

I COST OF BROOMS I R$ 7,180 I r

r Rs 10,959 I MIDRIBS FOR I FRONDS FOR

BROOMS ~ EXTRACTING 0.72 Mg

~ FRONDSAS BUILDING L

MATERIALS

J 4 qP

COST OF MIDRIBS EXTRACTED FRONDS

AND BROOMS

MIDRIBS 8.43 Mg

ICONVENTK)NAL USE l 56.18 Mg

I COSTOFFRONDS I - AS FUEL

i R$ 31779

I MIDRIBS EXTRACTEDJ

I I FRONDSAS

DOMESTIC FUEL

42.13 Mg

COST OF FRONDS Rs 23,613

JMIDR, CTEDI $ I M'DR'BS FOR I I FRONDS AS FUEL 14-'---'1 COMMERCIAL EXTRACTION I -=I BROOMS I 51.39 Mg I / .le.o , I 4.7g Mg I

t, ,P

Rs 25,188 I USED FRONDS I Rs 47,860 I I R $ 73,048

ADDITIONAL INCOME THROUGH COMMERCIAL EXTRACTION OF

FRONDS Rs 35,328

Fig. 3. Potential of enhancing the utility of coconut fronds.

1

. - I

thermal efficiency of 22%, rather than that of 7% normally obtained with the former. The traditional chulhas have no chimney but rather are opened all around the bottom of the vessel, which results in the emission of smoke inside the house and the loss of cooking heat energy. The improved chulha has a closed chamber with no open space around the bottom of the vessel and a chimney to exhaust the smoke. This minimizes the loss of heat to the sur- rounding atmosphere and emits the smoke outside, as well as the post-combustion releases. The improved chulha could therefore save about 2/3 of the fuel requirement listed in Fig. 2 and reduce by 67% the annual expenditure in non-biomass fuel. Adoption of the improved chulha has several other advantages, like smoke-free fuel burning and improved health for rural women (Paul, 1983).

Commercial extraction of coconut biomass energy value About 2099 coconut trees were found scattered around the village's cultivated land. These trees annually produce 56.2, 76.5 and 41.0 Mg (dry weight) of fronds (branches), husk and shells, respectively. Thus, each coconut tree annually produces about 1.5 GJ of biomass energy, or an equivalent of 43 1 of petroleum (Table 4). The 2099 coconut trees scattered around the village could produce the equivalent of 90320 1 (3100 GJ) of petroleum/yr, or 8% of the village's energy need.

Coconut fronds The village's 2099 coconut trees produced about 56 Mg of coconut fronds, yielding 4.8 Mg of midribs. The midrib is the hard stick in the centre of the leaves of the frond measuring about 1 m in length and is used as a raw material for brooms and match- sticks. Coconut fronds could be used more extensively with the available manpower and existing infrastructural facilities (Fig. 3). Conventionally, a major portion of the fronds (43.13 Mg) is burned as fuel for domestic uses, while the rest is sold for its midribs (8.43 Mg) or used as a roofing material (5"62 Mg) for animal sheds. The data showed that the village can earn Rs 35 328 extra revenue/yr, besides using midrib-extracted fronds (51.39 Mg) as domestic fuel (860 G J).

Coconut husk Coconut husk is another important by-product of the coconut tree. In the village of Mandyakoppal, about 76-5 Mg of coconut husk could be harvested annually. Figure 4 shows how coconut husk is cur- rently being used in the village. About 65% of the husk is burned conventionally as a domestic fuel, while it could be used as fibre for the manufacturing of coir ropes. The pith derived from the extracted fibre of the husk is left in open fields, where it decomposes and contaminates ponds and the canal water of the village. If all the available coconut husk (76.5 Mg) was used, nearly 32.13 Mg of fibre could


io co o , o.i i I ~TH I

15.53 Mg I

t I

I ~,.RE E~'CT'OHI._____Ico~ENT'O"'~ OSd I 2~.7~ .0 I" I 76.5 .g I

t

t COCONUT HUSK PROOUCTION 7S.S Mg |

RBRE L 32.13 Mg ]"

,I, I RAWMAT~IALFOR I COIR INDUSTRIES I

I ADDITIONAL EMPLOYMENTL

DOMESTIC I USE l

I =

T .Io0.EST,C~OELI "1 4973.o I

I CO=VERC=L EXTRACT,ONL~J--R~'-- I I 7e.5 ug I

q r ! ~WMA~R,ALFOR I

~,.?=s ~.ooocTION I + I ANAEROBIC DIGESTION I

WITH CATTLE MANURE (1:1 )[

BIOGAS ENERGY 39"6°106kcal I

[ DOMESTIC USE I

I Fig. 4. Potential of enhancing the utility of coconut husk.

be sold to manufacture coir rope and 44.37 Mg of pith could be mixed with an equal quantity of cattle manure to produce 165 GJ of biogas (Chowde Gowda, 1994). In addition, the sale of husk also creates additional employment for the villagers to enhance their economic status.

Paddy straw as a raw material for mushroom cultivation The average paddy-straw production in the village was 196 Mg/yr. Most of the straw was used as animal fodder. Paddy straw is a good medium for mushroom production (Garcha et al., 1987). Enough labour is available to take up this rural cottage enterprise. If 25% (50 Mg) of the total paddy-straw (196 Mg) produced in the village is diverted as a medium, about 13 Mg of edible mushrooms could be produced at a production cost of Rs 4000 ($125)/Mg. The production of mushroom could yield an additional net revenue of Rs 248 000 ($7750) if sold at the prevailing minimum market price of Rs 25 ($0"80)/kg. In contrast, 50 Mg of paddy straw sold as fodder could yield Rs 25 000 ($781).

CONCLUSIONS

Analyses of the waste management problems asso- ciated with a typical south Indian village led to the

following conclusions.

1. The village Mandyakopal produces about 2364 Mg of rural wastes as compared to the 3588 Mg for domestic fuel and organic manure.

2. About 77% of the wastes produced was converted into useful end uses. The rest (23%) was left in open fields to decompose and leach into ponds and canals, deteriorating water quality.

3. The village mainly depends on the biomass as a source of fuel, which was still well short of the actual requirement for domestic use.

4. Animal manure and human excreta was anaerobically digested. Biogas could meet 82% of the domestic energy demand and 75-80% of the nutrients otherwise lost by leaching would be conserved.

5. The typical family unit of five adult members can reduce its biomass fuel consumption by 2/3 and its annual fuel expenditure by 67% if an improved biomass stove is used.

6. The village could make better use of the coconut biomass. Full recovery of the midribs, fibres and pith could increase the income of the farming community and generate additional employment.

7. Paddy straw could serve as a good medium for mushroom production, thus yielding nearly 10

164 M. Chowde Gowda, G. S. V. Raghaven, B. Ranganna, S. Barrington

I COSTOF FODDER Rs 25,000

FODDER J. 50 Mg i"

i

I PADDY STRAW I I so Mg I

ITOTAL INCOME

I

USED STRAW AS ORGANIC

MANURE 50 M~I

T M USHROOM

CULTIVATION 50 Mg

FRESH MUSHROOMS

13 Mg

$ COST OF

PRODUCTION Rs 52,000

INCOME FROM PRODUCE Rs 2,73,000

Fig. 5. Potential of paddy straw as a substratum for mushroom production.

times more income as compared to the sale as livestock fodder.

ACKNOWLEDGEMENTS

The authors gratefully acknowledge the financial support by the University of Agricultural Sciences, Bangalore, India; the CIDA through International Cooperation and Development Service Division; and the Natural Science and Engineering Research Council, Canada, for research support.

REFERENCES

Anon. (1989). Package of Practices for High Yielding Crops. A joint publication of the University of Agricultural Sciences, Bangalore, and the Department of Agricul- ture, Government of Karnataka, India.

Bakshi, R. & Pathak, B.S. (1984). Comparative evaluation of different types of chulhas. Agric. Engng Today, 8(6), 4-6.

Bhattacharya, K.N. (1983). The source of biomass. Inven- tion Intelligence, 18(5), 186-94.

Bhatnagar, S.S., Mathur, A.N. & Sudhirjain (1989). Bio- gas option for a rural family. Ujra, 4, 63-6.

Bo Wander, B., Ravishankar, K. & Prasad, S. (1983). Energy Implication and Social Forestry. Centre for Energy, Environment and Technology, Administrative Staff College of India, Hyderabad, India.

Chowde Gowda, M. & Chowdiah, M.P. (1993). Conserva- tion of resources by valorisation of wastes in Indian villages. J. Inst. Engrs (India), 73 (ID3), 35-7.

Chowde Gowda, M. (1994). Valorisation of rural wastes for quality life in villages. Ph.D., Thesis, Bangalore Uni- versity, Bangalore, India.

Chowde Gowda, M. & Chowdiah, M.P. (1994). Valor- isation of wastes in rural India for a better life tomorrow. Proc. 9th Indian Engineers Congress, Calcutta, India.

rural waste management in a south indian village — a case study

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