Rice Yield Gap Minimization in Central Bangladesh: Using and Adapting Existing Technologies

摘要

Rice ( Oryza sativa L.) in the dry season (Boro) followed by rice in the wet season (Aman) is the major cereal cropping system in Bangladesh. The average productivity (7 Mg·ha ~( ﹣1 ) ) of this system is far below attainable yields (14 Mg·ha ~( ﹣1 ) ) in farmers’ fields, resulting in a large yield gap mainly due to farmers’ traditional management practices. Narrowing yield gap is a vital complementary strategy in improving rice yield and consequently enhancing food security. We evaluated BRRI recommended management practices, BRRI recommended management practices along with two N management options (leaf color chart and Urea Super Granule) and farmers’ crop management practices integrated with quality seed, leaf color chart (LCC) and Urea Super Granule (USG) in farmers’ fields of Kapasia, Gazipur over 6 contiguous seasons during 2009-2012. Across years, all the management options increased grain yields compared with the farmers’ practice (FP) by 1.12 Mg·ha ~( ﹣1 ) in Aman and 0.84 Mg·ha ~( ﹣1 ) in Boro season. The higher yield response (43%) occurred with BRRI recommended management practices followed by BRRI recommended management practices in combination with Urea Super Granule (42%) as N source (BRRI-USG). Yield advantage of 41% could be attained by BRRI recommended management practices with leaf color chart (LCC) aided N management (BRRI-LCC) while this was 22%, 13% and 13% higher than FP (farmer’s practice) when only quality seeds, USG and LCC were used with farmers’ management practice. BRRI Rec., BRRI-LCC and BRRI-USG·management options reduce the yield gap of FP by 41%, with an average of 2.87 Mg·ha ~( ﹣1 ) . When farmers adopted FP-QS, FP-USG and FP-LCC management options, they reduced the yield gap of FP by 21%, 13% and 12%, with an average of 1.49, 0.88 and 0.81 Mg·ha ~( ﹣1 ) , respectively. The average added net returns with BRRI Rec., BRRI-LCC and BRRI-USG·management options were US$175 to US$362 ha ~( ﹣1 ) in the wet season and US $158 to US $263 ha ~( ﹣1 ) in the dry season. BRRI management practices and BRRI management practices integrated with two N management options, either LCC or USG has the potential to boost rice yield and consequently total rice production in Bangladesh.