Effects of climate change on maize productivity in China during 2015 to 2100 based on APSIM model

Abstract: Global climate change has posed direct challenges to crop production. Among them, maize can be one of the most widely cultivated crops in China. It was important to systematically explore the impacts of future climate change on the potential yield, in order to ensure a high and stable yield and food security. In this research, a systematic investigation was implemented to explore the effects of future climate change on maize productivity using the daily meteorological data of two climate scenarios (Shared Socioeconomic Pathways, SSP1-2.6 and SSP5-8.5) output from MPI-ESM1.2-HR model under the Inter Statistical Impact Model Intercomparison Project from 1981 to 2100, the maize phenology data, and the soil data of the agrometeorological stations of the China Meteorological Administration. Firstly, the changes in agricultural resources were analyzed during the maize growth period in five subregions of the potential maize planting areas. Then, the Agricultural Production Systems sIMulator (APSIM-Maize) was validated to simulate the length of the whole growth period, vegetative period, reproductive period, potential yield, and rainfed potential yield of maize from 1981 to 2100. And the average value and coefficient of variation were selected to quantify the impact of future climate change on the yield of maize in China. The result showed that: 1) Under both SSP1-2.6 and SSP5-8.5 scenarios, there was a rising trend in the temperature and ≥10oC effective accumulated temperature (EAT) during the whole growth period of maize. The rising amplitude was higher under SSP5-8.5 than that under SSP1-2.6. There was a large interannual fluctuation of precipitation, indicating an insignificant overall change trend. There was a slight increase under SSP1-2.6, but a decrease under SSP5-8.5. The total solar radiation increased first and then decreased. 2) Without adaptation measures, the whole growth period, vegetative period and reproductive period of maize were shortened under climate change. The shortening trend under the SSP5-8.5 scenario was greater than that under the SSP1-2.6 scenario. The shortening trend increased significantly, as time went on. 3) Without adaptation measures, future climate change reduced the potential yield and rain-fed potential yield of maize. The yield reduction rates under the SSP5-8.5 scenario were greater than that under the SSP1-2.6 scenario. The average yield reduction rates of potential yield under SSP5-8.5 and SSP1-2.6 scenarios were 13.8% and 11.9%, respectively, while the average yield reduction rates of rain-fed potential yield were 17.5% and 14.0%, respectively. Future climate change slightly improved the stability of the potential yield and the rain-fed potential yield of maize, but there were differences between subregions. Therefore, future climate change can be expected to decrease the productivity of maize, but slightly improve its stability.