rice straw mulching and nitrogen requirement to improve productivity of no-till wheat following rice...
DESCRIPTION
A presentation from the WCCA 2011 event held in Brisbane, Australia.TRANSCRIPT
Wheat Research Centre Bangladesh Agricultural Research Institute
Gazipur
Dr. Md. Ataur Rahman
Rice straw mulching and nitrogen requirement to improve productivity of no-
till wheat following rice in Bangladesh
M. A. Rahman, NCD Barma, T. P. Tiwari and J. G. Lauren
Why no-tillage? To conserve national resources.
Improve productivity, soil physics and many others.
But we at Wheat Research Centre, initiated no-till what with different objectives-
1. Reduce the time interval between rice harvest to wheat sowing thus ensure the proper time of wheat sowing.
2. To utilize the residual soil moisture.
What is our experience?
Soil moisture during seeding is the key factor for establishment of no-till wheat. In most cases soil moisture either higher or lower than the requirement.
In light textured soil, rapid dry up of top soil caused Poor stand establishment, Also Weed infestation was higher with Low nitrogen use efficiency Low productivity no till wheat.
No-till Wheat following rice No-till Maize following wheat
PTPR No-till rice (DSR) following maize
Attempts to address the constraints
Farmers remained with their traditional system. Preferred well till soil for upland crops and
Well puddling for wetland rice.
Crop residue has the multiple use, as feed and fuel.Also rice straw is used in thatching the rural huts. Thus the retention of crop residue is rare in Bangladesh.
What is about crop residue retention?
Under such a condition, we initiate an alternate approach of duel use of rice straw. For a short period as mulch and after withdrawing as fuel.
To examine whether mulching for a short period have the potentials in improving no-till wheat by - Conserving initial soil moisture.
- Controlling weed growth.
- Increasing nitrogen use efficiency.
Objectives
Experimental Design and treatments
Factorial RCBD
Mulch treatments
M0 = No mulching
M1 = Straw mulch @ 4.0 t ha-1 which withdrawn at 20 DAS
M2 = Straw mulch @ 4.0 t ha-1 that was retained on soil
Nitrogen levels
N0 = No nitrogen
N1 = 80 Kg ha-1
N2 = 120 Kg ha-1
N3 = 160 Kg ha-1
WRC, Dinajpur, 2007-08 and 2008-09, post-rice harvested paddy field.
LocationMethodology
Applied as 3 equal split during sowing seeds, 20 DAS and 35 DAS.
Soil Moisture in surface soil layers (0-15 cm) was monitored gravimetrically from sowing to 40 DAS at 5 days interval.
Weed sampling and biomass were measured at 20, 35 and 45 DAS.
Growth analysis of wheat roots (RLD and RWD) was carried out at anthesis stage of the crop.
N content in straw and grain was analyzed to determine N uptake and ANR (%).
ANR%= [(A – B)/C] × 100
Where, A is N uptake by the plant under the treatment of interest (kg/ha), B is N uptake by the plant under N0 treatment (kg/ha), and C is N applied for the treatment of interest (kg/ha)
Measurements
Fig. 1: Effect of mulch and N levels on surface soil moisture in time
10
15
20
25
30
35
1 5 10 15 20 25 30 35 40
Days after sowing
So
il m
ois
ture
(%
)
M0M1M2
2000-01
10
15
20
25
30
35
0 5 10 15 20 25 30 35 40
Days after sowing
So
il m
oist
ure
(%
)
M0M1M2 2001-02
First year 2nd year
10
15
20
25
30
35
0 5 10 15 20 25 30 35 40
Days after sowing
Soil
moi
stur
e (%
)N0N80N120N160
2001-02
10
15
20
25
30
35
0 5 10 15 20 25 30 35 40
Days after sowing
Soi
l moi
stu
re (
%)
N0N80N120N160
2000-01
First year 2nd year
↑IR
↑IR
↑IR
↑IR
Fig. 2: Effect of mulch and N levels on weed growth
2nd Year
0
30
60
90
120
150
0 20 35 45
Days after sowing
Dry
mat
ter
(g m
-2)
N0N80N120N160
2nd Year
0
30
60
90
120
150
0 20 35 45
Days after sowing
Dry
mat
ter
(g m
-2)
M0
M1
M2
0
30
60
90
120
150
0 20 35 45
Days after sowing
Dry
mat
ter
(g m
-2)
N0N80N120N160
1st Year
0
30
60
90
120
150
0 20 35 45
Days after sowing
Dry
mat
ter
(g m
-2)
M0M1M2
1st Year
2nd Year
Fig. 3: Interaction effect of mulch and N levels on number of spikes/m2 of no-till wheat
100
150
200
250
300
350
N0 N80 N120 N160
Sp
ikes
/m2
M0 M1 M2
N levels
Table1: Root growth of no-till wheat at anthesis stage under different mulch and N levels
Treatment Shoot weight
(g/plant)
Root weight (g/plant)
Root weight density (mg/cc)
Root length density (cm/cc)
Mulch levels
M0 24.6 b 0.69 b 0.23 b 0.76 bM1 45.4 a 1.61 a 0.35 a 1.44 aM2 47.5 a 1.69 a 0.38 a 1.50 a
N levels
N0 19.29 d 0.82 b 0.15 b 1.05 cN80 38.45 c 1.40 a 0.31 a 1.21 bN120 46.20 b 1.44 a 0.33 a 1.49 aN160 52.54 a 1.45 a 0.36 a 1.33 ab
0
30
60
90
120
N0 N80 N120 N160
N u
pta
ke
(k
g/h
a)
M0 M1 M2
Fig. 4: Interaction effect of mulch and N levels on N uptake of no-till wheat
N levels
Treat-Treat-mentment
M0 M1 M2
N0 0.45 B d 0.72 A c 0.75 A c
N80 1.73 B c 2.58 A b 2.67 A b
N120 2.16 B b 3.72 A a 3.98 A a
N160 2.81 B a 3.81 A a 3.90 A a
Table 2: Effect of mulch and N levels on grain Table 2: Effect of mulch and N levels on grain yield of wheat (Mean of 2 years, in t hayield of wheat (Mean of 2 years, in t ha -1-1))
Capital letters to compare mulch effect under any N level and small lettering to compare N effect under any mulch level
Fig. 5: Nitrogen level Vs. grain yield relationship under different much treatments.
0
1
2
3
4
5
1 2 3 4
0
1
2
3
4
5
1 2 3 4
M2
Gra
in Y
ield
(kg
/ha)
0
1000
2000
3000
4000
0 80 120 160N (kg ha-1)
M0
0 80 120 160
0
1000
2000
3000
4000
5000
0 80 120 160
M1
N (kg ha-1)
y = 388 + 30.2x - 0.132x2
R2 = 0.898
Optimum N Dose = 115 kg ha-1
N (kg ha-1)
Gra
in Y
ield
(kg
/ha)
y = 364 + 27.1x - 0.111x2
R2 = 0.916
Optimum N Dose = 122 kg ha-1
y = 17.5x + 216
R2 = 0.965
Straw mulch conserves initial soil moisture and suppresses weed growth.
Mulch ensures plant establishment with higher spikes/m2.
Improves N-uptake and root proliferation of no-till wheat.
Mulching for a short period of 20 DAS is as effective as straw retention, in eliminating the production constraints and favoring the production factors of no-till wheat.
When the recommendation of straw retention is prohibited due to multiple need for straw, farmer’s could practice the alternate option of short term mulching.
Conclusion and Remarks Conclusion and Remarks
Acknowledgement
BARI Anthurium-1
BARI Gerbera-1
Thank you very much