On-farm Evaluation of Resource Conservation Technologies for Yield, Income, and Global Warming Potential in Rice-Wheat System.
Yash Saharawat, J.K. Ladha, Himansu Pathak, and Mahesh Kumar Gathala. International Rice Research Institute, India-Office, NASC Complex, Pusa, New Delhi, India
The rice-wheat (RW) rotation is one of the world’s largest agricultural production systems (13.5 million hectares in South Asia), occupying about 85 % of the cultivated land in Indo-Gangetic Plains (IGP) and nearly one-sixth of the total geographical area of the Indian sub-continent that supports millions of people of the region. During past two decades, due to heavy emphasis on “economic output maximization”, the system has resulted in declining factor productivity, and deteriorating natural resource base, thus looking for immediate and long-term solutions. The resource-conserving technologies (RCTs) that occupy more than 3 million hectares in IGP are able to produce more food at less cost with apparently higher input use efficiency. Although tillage practice is believed to improve soil health and reduce global warming potential (GWP), data from farmer fields are scarce. A survey of 70 farmers practicing no-till/reduced till and conventional till in RW was carried out to take stocks of all input and outputs to estimate energy balance and GWP. GWP of different tillage and crop establishment techniques was evaluated using the infoRCT model. No-till planting systems significantly improve wheat productivity as compared with conventional tillage practices. Reduced till (avoid wet tillage) in transplanted rice attained higher yields compared to conventional practices and the direct seeded rice had comparable yields. The net income of farmers was increased by 17%, 12% and 9% in direct dry seeded rice – no-till wheat, unpuddled transplanting of rice- no-till wheat and no-till transplanted rice-no-till wheat respectively. There was 29% decrease in GWP under double no-till system compared to conventional RW. This study indicates that the double no-till practice in RW will be the immediate and long-term solution to increase farm income, improve soil health and reduce global warming.