Spatiotemporal rice yield variations and potential agro-adaptation strategies in Bangladesh: A biophysical modeling approach

Abstract

Rice (Oryza sativa) is the major cereal crop in the Southeast Asian region, and its yield variations are highly sensitive to climate change. Climate change will not only threaten regional food security but also affect the global economy. Considering the fact, this study intends to assess the spatiotemporal variations of rice yield and to evaluate the effectiveness of agro-adaptive measures under future climate change in the five rice-growing regions of Bangladesh. We simulated rice yield of the 21st century by driving the rice crop model (ORYZA2000) with downscaling climate data from the outputs of two General Circulation Models (GCMs) using the A1B scenario. The simulation results indicated the substantial rice yield reduction in the two future periods ignoring the carbon dioxide (CO2) effect, while the CO2 fertilization effect was considered, it could mitigate but still not fully compensate for the rice yield reduction. The significant reductions in yields were spatially greater in the northwest region than the southeast region but marginally from central to northeast regions of Bangladesh. Four global agro-adaptation strategies, e.g., shifting transplanting dates, introducing supplemental irrigation, transplanting date delaying, and extra irrigation would decrease rice yield losses significantly by the future periods of various extents. Based on the findings, it is found that a combination of transplanting dates delaying and supplementary irrigation has proved a more effective strategy for increasing rice yield than other adaptive measures. These agro-adaptation measures can be beneficial for sustainable future rice production in Bangladesh and other parts of the world.