Fig. 4: Impact of climatic factors on different crops and different sizes of farms.

a, b Represent the effects of climate factors on cash and grain crops, respectively. c, d Represent the impacts of climate factors on large-scale and small-scale farms, respectively. Grain crops include wheat, rice, corn, soybeans, and potatoes, while cash crops include cotton, oilseeds, sugar, hemp, tobacco, sericulture, vegetables, and fruits. We use very strict classification criteria. If a farmer only grows cash crops and not grain crops, we classify them as a cash crop farmer. Conversely, if a farmer only grows grain crops and not cash crops, we classify the theme as a cash crop farmer. As of 2021, smallholder farmers account for over 98% of the total number of agricultural operators in China. Approximately 210 million smallholder farmers operate on less than 10 acres of cultivated land, where 1 mu is equal to 666.67 m². The definition of a smallholder farmer varies by region, and no clear standard exists for how many acres of operating area constitute a smallholder. For example, smallholder farmers in Hebei Province, China, typically operate on 600–1200 m² of land, whereas in Heilongjiang Province, the per capita arable land area is 8571 m². We primarily report our results using a delineation criterion of 10 mu (6670 m²). However, we also conducted robustness analyses using different criteria, including 5, 20, and 30 mu. The results can be found in supplementary materials.