Improving Resource Use Efficiency of Cereal Based Cropping Systems with Integration of Best Management with Conservation Agriculture Under Changing Agricultural Scenarios in Cauvery Delta of Tamil Nadu

Cropping systems in Cauvery Delta Zone of Tamil Nadu is intensive rice based with double or triple rice crops in a year. The rice system in the region is threatened by yield stagnation, scarcity of water and labour, increased costs of cultivation, and resource degradation. During 2009-2012, we evaluated four scenarios involving a range of best management practices (BMPs) with and without conservation agriculture (CA) components for improving the system productivity and economic returns of rice-based system. Four scenarios were (i) current farmers' practice (S1), (ii) BMPs with conventional tillage (S2), (iii) BMPs with conservation agricultural technologies (S3), and (iv) BMPs with conservation agricultural technologies along with crop diversification (S4). The Key parameters tested were crop yields, system productivity, laBour and energy use efficiency, and economics. Results indicated that compared to S1, the BMPs in S2 improved system crop productivity (22-57%), and net economic returns (67-166%) with reduced cultivation cost (10-16%), and total system energy use (4.4-8%), and higher labour productivity (18-59%). Compared to farmers practices (S1), BMPs with CA practices such as zero/reduced tillage, direct seeding of rice in dry season and mechanical transplanting of rice in wet season (S3) had lower labor (14-25%) and energy (20-37%) usages with higher economic returns (25-37%). Crop diversification with maize in place of dry season rice in S4 though saved in labor input, crop productivity and economic returns were also lower. This study concluded that there is potential of improving productivity and economic returns of rice based cropping systems with BMPs and CA in Cauvery Delta Zone of Tamil Nadu. However, more medium to long-term adaptive system research is needed to identify compatible alternative crops-management practices in rice based systems to diversify the food production and increase the system productivity while conserving the natural resources