Effect of tillage and crop establishment practices on rainfed chickpea productivity, energy balance and greenhouse gas emission under rice fallow of North East India

Abstract

A field experiment was conducted over a 3-year period (2011 to 2013) on a clay soil after lowland kharif rice at Imphal, Manipur to study the response of post-rice (Oryza sativa L.) tillage practices on crop establishment, productivity, energy use and CO2 emission on rainfed chickpea (Cicer arietinum L.). Seven different combinations of tillage and crop establishment practices were tested in a randomized block design with three replications. Conventional tillage followed by line sowing with straw mulch (CT+L+M) was superior over all other treatments. It had 21 %, 25.4 % and 54.7-55.4% higher grain yield over those in conventional tillage followed by line sowing without straw mulch (CT+L), reduced tillage followed by line sowing with straw mulch (RT+L+M) and direct seeding in un-tilled field using zero till drill (DSZT) or plough (DSM), respectively. CT+L+M had 25 and 55 % higher gross margin over those in RT+L+M and DSZT respectively. RT+L+M had 40% higher gross margin than that in DSZT. Labour productivity of CT+L+M was however, at par with DSZT and broadcasting seed followed by reduced tillage (BS+RT). Reduced tillage followed by line sowing (RT+L) saved 13.5 % energy input, enhanced 10.3 % energy use efficiency and 9 % energy productivity as compared to CT+L. Regardless of crop establishment and mulching practices, DSZT and RT resulted in 50% lower CO2 emissions compared with CT. Although implementation of CT tended to be more promising and attractive for higher chickpea yield, the adoption of RT is strongly desirable to improve energy performance and reduce GHG emissions in chickpea production system on rainfed rice fallow land in north east India.