Climatic Zoning and Suitability Assessment for Potato Cultivation in China: An Integrated Climatic Suitability Index and Crop Model Approach

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 Agricultural Production Systems Simulator (APSIM)-Potato model simulation. During 1991‒2020, compared to 1961‒1990, the unsuitable and single-season planting regions decreased by 18% and 8%, while the multi-season and winter planting regions expanded by 93% and 6%, respectively. 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. During 1991‒2020, compared to 1961‒1990, CCSI of potato planting in the single-season planting region showed a slight decrease, but it increased by 1%‒2% in the multi-season and winter planting regions. These findings demonstrate that the increase in potato climate suitability supports the expansion of potato planting area and implementation of the “Potato as Staple Food” policy. Increased precipitation and temperature identify Northwest and Southwest China as the potential expansion regions for potato planting.