Improvement of cereal-based cropping systems following the principles of conservation agriculture under changing agricultural scenarios in Bangladesh

In the Eastern Gangetic Plains of Bangladesh, the cropping systems are predominantly rice based, having large yield gaps in farmers' fields because of poor management practices adopted by farmers. The increasing scarcity of resources (water, labor and energy) and production costs further make the rice-based cropping system less sustainable and less profitable. We hypothesized that integrating the best compatible cropping patterns accompanied by best management practices into the portfolio of farmers' own technologies would improve system productivity, resource use efficiency and economic profitability. To test this hypothesis, we evaluated four cropping system scenarios (S1-S4) designed to be adapted to current and future drivers of agricultural changes and varying from each other in best management practices (BMPs) and conservation agriculture (CA) principles (tillage and crop establishment, residue management, and crop rotation). Four cropping system scenarios were (i) current farmers' practice (S1), (ii) BMPs with conventional tillage and farmers' crop rotation (S2), (iii) BMPs with reduced tillage and farmers' crop rotation (S3), and (iv) BMPs with reduce or zero tillage and crop diversification (S4). Scenario 2 alone compared with S1 increased system productivity (24-33%), total water productivity (16-50%) and net economic returns (85-169%), and decreased specific energy (11-17%). The combination of BMPs in S2 with reduced tillage and manual or mechanical transplanting (S3) did not further increase yield and save water. Crop diversification with potato in place of Boro rice and intensification with maize or mungbean in between Boro and Aman rice (S4) yielded 1.9-3.7 times higher net economic returns than S1. Results of a three-year study indicated that farmers' productivity and economic returns can be improved by BMPs, which not only increase crop yields but also improve the efficiencies of resources such as water and energy.