Quantifying yield gap for rice cropping systems in Lower Gangetic Plains

Abstract

Rice crop production needs to be increased to meet the food demand of the growing global population by utilizing the limited available resources. Reducing yield gap between potential and actual farmers’ yields could be one of the promising options for increasing rice production. In order to quantify the yield gap of rice, field experiments were conducted at two different locations in the Lower Gangetic Plains. Decision Support System for Agro-technology Transfer model was used to quantify potential yield for analyzing the attainable yield gaps with respect to water limitation, agronomic managements, difference in transplanting dates and soil variability. The results showed that an attainable average yield gap of 0.33 t/ha in rainfed condition existed in farmers’ fields due to rice transplantation after 30th July, whereas the use of supplementary irrigations produced an average attainable yield gap of 0.86 t/ha in irrigated condition. Poor agronomic practices adopted by farmers may be causing the reduction in average yield of 0.29 t/ha. The yield gap due to different transplanting dates and agronomic managements suggested to identify yield optimum transplanting date of a cultivar and appropriate agronomic management strategy to reduce the yield gap. The soil variability contributed very less attainable yield gap (0.02–0.16 and 0.02–0.19 t/ha for rainfed and rainfed with subsequent irrigation, respectively), than other factors because of similar type of soil at the study sites. Results also suggested that farmers should emphasize more on management strategies such as quantity of N-fertilizers, timing of fertilizer applications, supplementary irrigation and transplanting date that might reduce the yield gap.