Impact of climate change and planting date shifts on growth and yields of double cropping rice in southeastern China in future

CONTEXT: It is predicted that climate change characterized by global warming will adversely affect the rice. To study the impacts of future climate change on rice growth and yields are of significance to ensure world food supply.OBJECTIVE: This study aims to explore the growth and yield changes of double cropping rice in Southeast China, determine the key meteorological factors affecting the yield of double cropping rice and analyze the impact of planting date shifts on the phenology and yield of double cropping rice.METHODS: The phenology and yield of double cropping rice in the future was simulated based on Decision Support System for Agrotechnology Transfer (DSSAT) v4.7.5. The relationship between double cropping rice yield and meteorological factors is explored by using feature importance (IF) based on Random Forests model and copula entropy (CE). The impact of planting date shifts on phenology and yield of double cropping rice was determined by changing the planting date.RESULTS AND CONCLUSIONS: The result suggested that the yield of double cropping rice increased by 2.6%, 1.8%,-2.0% and 0.1% respectively under the scenarios for SSP1-2.6, SSP2-4.5, SSP3-7.0 and SSP5-8.5 when considered the effects of CO2. With the increase of radiative forcing, the precipitation (Pre) and solar radiation (SRAD) on yield of double cropping rice would become less and less important, and the importance of tem-perature on yield of double cropping rice would be greater and greater. Early planting of early rice and late planting of late rice will increase the length of phenology and yield of double cropping rice. However, the increased phenological length for early rice is mainly due to the increase for length of planting to anthesis (P-A), and late rice is due to the increase for length of anthesis to maturation (A-M). When the optimal planting date is adopted, the rice yield will increase by 4.6%, 5.4%, 3.4% and 10.2%, respectively.SIGNIFICANCE: This study provides adaptive measures and suggestions for local decision makers on how to deal with the impact of future climate change.