Tillage and Crop Establishment Affects Sustainability of South Asian Rice–Wheat System
- Mahesh K. Gathalaa,
- J. K. Ladha *a,
- Vivak Kumarab,
- Yashpal S. Saharawata,
- Virender Kumarab,
- Paradeep Kumar Sharmac,
- Sheetal Sharmaa and
- Himanshu Pathakd
- a International Rice Research Institute– National Agriculture Science Center, New Delhi, India
b Sardar Vallabbhai Patel University of Agriculture and Technology, Modipuram, Meerut, India
c Chaudhary Sarvan Kumar Himachal Pradesh Agriculture University, Palampur, Palampur, India
d Indian Agriculture Research Institute, Pusa, New Delhi, India
Rice (Oryza sativa L.)–wheat (Triticum aestivum L.) is the major cropping system occupying 13.5 million ha in the Indo-Gangetic Plains of South Asia. Conventional-tillage practices are resource and cost intensive. A 7-yr study evaluated six treatments (T) involving three tillage methods and two rice establishment methods on crop yield, water productivity, and economic profitability in a rice–wheat rotation. Average rice yields in the conventional practice of puddling and transplanting without (T1) and with (T2) mid-season alternate wetting-drying were highest (7.81–8.10 Mg ha−1) and increased with time (0.26 Mg ha−1 yr−1) in T2. Compared to T1, rice yields in direct drill-seeding with zero-tillage averaged 16% lower on flat (T5) and 43% lower in raised beds (T3). Rice yield in raised beds (T3 and T4) decreased with time (0.14–0.45 Mg ha−1 yr−1). Conversely, wheat yielded 18% higher after zero compared to conventional-tillage. Treatment 2, despite low soil matric potential during vegetative development, had higher water productivity with 25% less water use compared with T1 and 19% less compared with other treatments. Conventional-tillage and crop establishment practices had higher net cash return in rice but in wheat it was higher with zero-tillage. Overall, T2 and T5 had the highest net returns (∼1225US$) and T3 and T4 had the lowest (747–846 US$) in the rice–wheat system. Zero-tillage on flat beds (T5), however, would conceivably be more sustainable than the conventional T2 in the long-run. Yields of zero-tillage with direct-seeding of rice on flat beds (T5) must improve before adoption occurs.Please view the pdf by using the Full Text (PDF) link under 'View' to the left.
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