Tillage and residue management effects on productivity and nitrogen-use efficiency in maize (Zea mays)─wheat (Triticum aestivum) cropping system
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Date
2011
Authors
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Publisher
IVISION OF AGRONOMY INDIAN AGRICULTURAL RESEARCH INSTITUTE
Abstract
A field study entitled “Tillage and residue management effects on productivity and
nitrogen-use efficiency in maize (Zea mays L.)–wheat (Triticum aestivum L. emend Fiori
Paol) cropping system” was conducted during 2009-10 and 2010-11 at the research farm
of Indian Agricultural Research Institute, New Delhi with the objectives: (i) to study the
effect of tillage and crop establishment techniques on agronomic productivity of maize
and wheat crops grown in sequence; (ii) to work out nitrogen, energy and water-use
efficiency under different tillage systems; and (iii) to study the effect of tillage and
residue management practices on physical, chemical and biological properties of the soil.
Two field experiments involving continuous tillage and crop establishment techniques,
viz. conventional tillage-flat planting (CT-flat); zero tillage-flat (ZT-flat); CT-bed
planting (CT-bed); ZT-bed; ZT-flat with residue (ZT-flat+R); ZT-bed+R for both in
kharif as well as rabi season and sequential tillage practices, viz. CT-flat in kharif
followed by CT-flat in rabi (CT─CT); CT─ZT; ZT─CT; ZT─ZT were accommodated in
main plot while the common treatments for both the experiments involving four levels of
N, viz. 0, 60, 120 and 180 kg/ha were accommodated in sub plot. Experiments were
conducted in split plot design with three replications in a fixed layout. The results
revealed that growth parameters, yield attributes and yields of maize were influenced
significantly, while for wheat these parameters were similar due to different continuous
as well as sequential tillage treatments. Bed planting resulted significantly higher grain
and stover yields than flat planting of maize. The maize grain yield was 4.07–6.51 %
higher under CT than ZT. However, residue application under ZT resulted similar or
better yields than CT, but significantly higher than no-residue applied treatments under
ZT. The mean system productivity of maize–wheat crops grown in sequence was
recorded maximum under ZT-bed+R (7.602 t/ha) and under CT-ZT (7.168 t/ha) with
continuous and sequential tillage treatments, respectively. Although, both the crops
responded significantly up to 120 kg N/ha, but maximum yields were obtained at
180 kg N/ha. The N uptake for both crops were similar ranging from 85.42 to 95.33
kg/ha in maize; and 83.52 to 91.82 kg/ha in wheat, but P uptake was more in maize,
while, K uptake was more in wheat. All the continuous and sequential tillage treatments
resulted positive balance of N and P, and negative balance of K. In maize–wheat
cropping system significantly more net returns (66.94 x 103 /ha) and B:C ratio were
recorded with ZT-bed continuous tillage, while among the sequential tillage treatments
CT-ZT resulted maximum net profit (65.39 x 103 /ha ) and ZT-ZT resulted maximum
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B:C ratio. The highest net returns and B:C ratio were recorded at 180 and 120 kg N/ha,
respectively, but these were statistically similar with 120 and 180 kg N/ha, respectively
in both the crops and system as a whole in both the experiments. ZT brought an average
saving of energy in the system by 3090 MJ/ha and 3600 MJ/ha with flat and bed planting
than the corresponding CT planting techniques. The maximum energy-use efficiency was
recorded with ZT-bed (14.75) ZT-ZT (13.78) under continuous and sequential tillage
experiments, respectively. Irrigation water-use efficiency was around 38 % higher in bed
than flat planting. There was saving of 28.57 % of irrigation water by adopting FIRB
over flat in wheat. NUE (ANUE, PNUE and ANR) were relatively higher under bed
planting in maize, and flat planting in wheat. Each successive higher N levels from 0 to
180 kg N/ha reduced the N and energy-use efficiency but increased the IWUE. The
maximum BD was recorded with ZT-flat (1.625 g/cm3), which was significantly higher
than the bed planting and residue applied treatments in 0-15 cm soil depth. However,
hydraulic conductivity and infiltration rate were higher with CT, bed planting and with
residue than ZT, flat planting and without residue application, respectively. Soil
aggregation was better in ZT with and without residue than CT either in flat or bed; with
higher mean weight diameter. The soil organic matter/carbon sequestration (SOC) was
7.79 and 7.69 % higher under ZT-flat+R and ZT-bed+R than CT-flat and CT-bed,
respectively. Microbial and enzymatic activities (MBC, DH activity and FDA
hydrolysis) were significantly higher under bed planting, ZT and residue application than
flat planting, CT and without residue application, respectively. Lower dose of N
improved the microbial and enzymatic activities in soil, while higher doses of N exert
weaker and toxic effects. Adoption of ZT with crop residue along with 20-25 kg/ha of
extra N dose in addition to NPK to the system is essential for improving resource-use
efficiency, productivity, profitability, soil health and sustainability of maize–wheat
cropping system.
Description
T-8567