Climatic Zoning and Suitability for Potato Cultivation in China by Integrating Climatic Suitability Index and Crop Models

As the world’s largest potato producer, China plays a crucial role in global food security. However, the impacts of climate change on both the potential planting regions and climatic suitability of potato cultivation in China remain poorly quantified. In this study, potato planting zones were delineated based on the thermal requirements of potato, utilizing the temperature data from 2177 meteorological sites during 1961‒ 2020. A comprehensive climatic suitability index (CCSI) was developed by integrating temperature, light, and precipitation suitability indices, weighted through APSIM-Potato model simulation. Compared to 1961‒1990, the unsuitable and single-season planting regions decreased by 18% and 8% respectively during 1991‒2020, while multi-season and winter planting regions expanded by 93% and 6%. During 1961‒2020, the CCSI was highest in single-season planting regions (e.g., Northeast China and the north agro-pastoral ecotone), followed by multi-season and winter planting regions. Compared to 1961‒1990, the CCSI of potato planting in single-season planting region showed a slight decrease during 1991‒2020, but increased by 1%‒2% in multi-season and winter planting regions. These findings demonstrate that the increase in potato climate suitability supports the expansion of potato planting area and the implementation of "Potato as Staple Food" policy. Increased precipitation and temperature identify the Northwest and Southwest China as the potential expansion regions for potato planting.