Simulating climate change impacts on T. aman (BR-22) rice yield: a predictive approach using PRECIS and DSSAT models

Climate change has added a new dimension to the uncertainty in rice (Oryza sativa L.) yield worldwide and Bangladesh in particular. The present study estimated the potential impacts of climate change on the yield of T. aman (Transplanted aman, BR-22) rice variety for 12 representative districts in Bangladesh using DSSAT 4.0 (Decision Support System for Agrotechnology Transfer) model. Available data on soil and typical crop management practice for T. aman rice were used in the simulations. The daily weather inputs prerequisite for this model were generated for this study using PRECIS (Predicting Regional Climate Impact Studies) model. The model predicted an average yield of T. aman cultivars for selected locations in comparison to the baseline year 2008 are +5.04, +6.06 and -32.43% for the year 2030, 2050 and 2070, respectively. Changes of monthly average temperatures were found to be primarily responsible for the reduction in rice yield. Variability in rainfall pattern over the growing period of T. aman rice also affected the yield. Furthermore, model outcomes envisaged that climate change may make rice yield more susceptible to transplanting date, forecasting a significant change in yield as transplanting date is shifted from beginning to the end of July. These outcomes may provide valuable insight into the potential impacts of climate change on rice yield and adequate adaptive measures to mitigate the adverse effect of future climate change in Bangladesh as well as other rice-growing countries.