Search

Rice based cropping systems are the most predominantly grown systems in India contributing a major share to India's food grain production. However, systems i.e., rice-rice and rice-wheat brought us second generation sustainability issues over long run. Cowpea being a multi-role legume crop can be considered for the intensification of rice-based system with limited resources and its residue having lower C:N ratio can easily decompose in soil and enhance soil fertility. Following experiment was conducted at Institutional Research Farm, ICAR-National Rice Research Institute, Cuttack, Odisha during kharif, rabi and summer season during 2017-18 and 2018-19. The treatments were laid out in split plot design and consisted of three replications. The main plot consisted of two rice-based cropping systems i.e., rice-maize-cowpea (R-M-C) and rice-groundnut-cowpea (R-G-C), sub-plots consisted of five nutrient and residue management practices i.e., C-C-C, R-R-R, RI+R75-R-R, RI+R75-SM+R-R and RI+R75-SM+R-R50. The pooled value for the season 2017-18 and 2018-19 revealed that, RI+R75-SM+R-R and RI+R75-SM+R-R50 resulted higher yield i.e., pod yield, seed yield, stover yield, HI, nutrient content, nutrient uptake, economic return i.e., gross return, net return and B:C ratio, higher CH4 flux and lower N2O flux than R-R-R. Between two cropping systems, R-M-C cropping system recorded highest yield and is more feasible to take over R-G-C. Among nutrient management, RI+R75-SM+R-R recorded higher growth and yield but due to consistent residue retention and incorporation, even if using 50% of recommended dose of fertilizer in cowpea i.e., RI+R75-SM+R-R50 recorded similar growth, yield, economic return, and even higher B:C ratio than RI+R75-SM+R-R and recommended. Cowpea residue incorporation and 25% reduced dose of chemical fertilizer application in rice crop, rice straw mulch in rabi maize and 50% reduction in chemical fertilizer application in summer cowpea (RI+R75-SM+R-R50) received highest cowpea yield, and economic return and this system-based nutrient management should be recommended in R-M-C cropping system. [ABSTRACT FROM AUTHOR]