Central Rice Research Institute Annual report...2011-12

Natural Resource Management
and Input Use Efficiency for
Improved Crop Production
Enhancement of the Resource Use
Efficiency
Development of management strategies for
sustainable crop and soil productivity in
irrigated and favourable rainfed lowland
ecosystems
A field experiment was conducted during 2011 with
the objective to develop improve N management practice
for enhancing N use efficiency under irrigated
condition.Three improved methods of N management,
viz., LCC based, USG based and Sabant’s Improved Rice
Agro-technology (SIRA) were compared with recommended
practice of N management (N:P:K: @120:60:60
kg ha -1 ) along with controls (no N, no NPK ) using the
variety ‘Swarna’. Nitrogen was applied @ 120 kg ha -1 in
USG based and SIRA treatments, where as 90 kg
ha -1 was applied in LCC based management, in these
three treatments P and K was applied at recommended
dose of 60 kg ha -1 . Among all the three methods of N
management, no significant difference in grain yield
was observed; however, NUE was highest in LCC based
N management (41.1 kg grain -1 kg N) followed by SIRA
(29.58 kg grain kg -1 N).
In another experiment, feasibility of zero tillage visà-vis
incorporation of residuary organic matter of pre-
ceding legume crop was studied under rainfed lowland
rice system. The treatments included tillage practices
(conventional tillage and zero tillage), residue incorporation
(no residues and with residues) and two
doses of NPK (100% RFD and 50% of RFD) which were
replicated thrice in split-split plot design. Application
of 50% NPK along with crop residues resulted higher
yield over 100% NPK treated plots.
Simulation approach for optimization of
nutrient use
A field experiment was conducted with mediumlong
duration rice varieties viz., Pooja and Pratiksha in
wet season during 2011 under varying nitrogen dose
and application schedule. The result revealed that
across the treatments, the mean leaf area index (LAI) of
Pooja ranged from 2.8 at active tillering (AT) stage to
4.5 at flowering stage. Effect of treatment on LAI was
non-significant. Across the treatments and variety the
cumulative N uptake upto AT stage ranged from 15.1-
22.7 kg ha -1 which is about 20-40% of total uptake; 53-
70% of total uptake took place between AT and flowering
stage. Among all the treatment combinations, yield,
AE N
and RE N
ranged from 3.2-4.8 t ha -1 , 6.7-16.7 kg kg -1 ,
and 30.5-40.7%, respectively (Table 25). Reduction of
basal dose of N from 50 to 33% enhanced both N use
efficiency and yield.
Table 25. Effect of N application strategy on Yield, AE N
and RE N
Yield (t ha -1 ) AE N
(kg kg -1 ) RE N
(%)
Treatments Pooja Pratiksha Mean Pooja Pratiksha Mean Pooja Pratiksha Mean
T1 3.3 3.2 3.2 - - - -
T2 3.9 4.0 4.0 6.7 9.0 7.8 32.5 32.3 32.4
T3 4.3 4.2 4.3 11.1 11.2 11.2 40.7 38.4 39.6
T4 4.8 4.6 4.7 16.7 14.6 15.6 32.6 30.5 31.6
Mean 4.0 4.0 4.0 11.5 11.6 11.5 35.3 33.7 34.5
C.D.(5%)Variety (V) 0.24 3.5 5.6
Treatment(T) 0.45 5.3 7.4
VXT 0.7 7.5 14.6
T1: N 0; T2: N 90 kg ha -1 (50%. 25% and 25% at transplanting, maximum tillering (MT) and panicle initiation (PI);
T3: N 90 kg ha -1 (33%, 33% and 33% at 15 days after transplanting, MT and PI); T4: 120 kg ha -1 (50%, 25% and 25%
at transplanting, MT and PI)
60 CRRI ANNUAL REPORT 2011-12