Effects of Climate Warming on the Potential Northern Planting Boundaries of Three Main Grain Crops in China

The production of wheat, maize and rice accounts for more than 90% of the total grain production of China. Assessing the impact of climate warming on suitable planting regions, especially the potential northern planting boundaries of these crops, is therefore critical to help guide agricultural policymaking and further maintain food security. In this study, we analyzed the effect of climate warming on the potential northern planting boundaries of three specific crops (winter wheat, spring maize, double and triple rice cropping systems) during two time periods (1961-1990 and 1991-2020) using meteorological data from 2437 national weather stations. Results show that the potential planting boundaries of these crops present a northward movement and a westward expansion during the time period of 1991-2020 under the background of temperature increase compared with the time period of 1961-1990. Moreover, the boundaries of winter wheat and spring maize also show a trend of expansion to high-altitude areas (e.g., the Qinghai-Tibet Plateau). The average moving distance of these crops ranged from 20 km to 300 km. In general, the potential planting boundaries of winter wheat, spring maize, double and triple rice cropping systems changed significantly due to climate warming, and the suitable planting area was increased. Our study aims to provide a more recent and accurate result than those of previous studies, which is expected to strengthen our understanding of the effect of climate change on the potential northern planting boundaries of the three main grain crops in China.