Risk Assessment of Shifting Rice Planting Dates Under Climate Change in East Asia

Abstract

Climate change is a serious threat to crop production of northern latitude regions as well as tropic and temperate regions. The objective of this study was to assess the potential risk of climate change and impact of shifting planting date as an adaptation option in East Asia. We focused on climatic conditions during before and after heading in East Asia. Climate data set generated from outputs of global circulation models under RCP 8.5 scenario were used to assess climate conditions during late vegetative stage and reproductive stage of rice for a given planting date. Our results indicated that optimum heading periods, which is maximum period expected to be able to obtain the production of current levels, would decrease in the future. Unless the adaptation measures were implemented, occurrence of sterility would increase due to elevated temperature during reproductive stage and ripening stage. Even when the adaptation measures were used, it would be challenging to maintain the current level of yield because of high temperature during reproductive stage and reduction of solar radiation during ripening stage. These results suggested that a need for additional adaptation strategies in East Asia rice agriculture including development of varieties with high temperature tolerance and higher radiation use efficiency. It would be also recommended to provide public support for development of such varieties in order to facilitate wide adoption of new varieties by local farmers who would have limited resources for implementing adaptation strategy.