Impact of climate change on wheat production in China

Abstract

Against the background of rising international disputes, numerous countries have placed great importance on ensuring self-sufficiency of crop production. Weather, as a notably variable factor than others, has a considerable influence on agricultural productivity, production variability and, in turn, on food security. Our primary objectives were to: (1) evaluate the relative importance of climate, soil, and field management factors on wheat production across major wheat-producing regions in China, (2) explore the direct and indirect ways of the effect of climate on wheat production at different phenological stages, and (3) forecast future trends in wheat production levels and stability based on historical insights. Initially, we analyzed the spatiotemporal variations in production and phenology across six subregions using linear regression. This analysis was based on data from 124 agro-meteorological stations, spanning the period from 1999 to 2013. Subsequently, we used the Random Forest algorithm to discern the relative importance of climate, soil, and field management on wheat production. Moreover, we utilized a structural equation model to elucidate the direct and indirect pathways through which climatic factors affected production during different phenological stages, incorporating the first difference method. Finally, with a Support Vector Machine algorithm, the production level and stability under RCP4.5 and RCP8.5 were predicted using 33 Global Climate Models. Over the 1999–2013 period, among 124 wheat stations, 33 stations showed a significant (P < 0.05) increase in wheat production, while 53 exhibited an insignificant (P > 0.05) increase. Conversely, 4 stations exhibited a significant (P < 0.05) decrease, and 34 showed an insignificant (P > 0.05) decrease in wheat production. Climate, soil, and field management all played significant roles in wheat production in each of the six subregions, with relative importance ranging from 19.0% to 44.2%, 30.4% to 35.9%, and 25.4% to 45.1%, respectively. Climate factors, predominantly temperature-related, influenced wheat production by altering key growth period lengths, while other factors directly impacted production. Finally, our findings suggested that the wheat production level in China is expected to increase in the future, while its production stability could decrease. These findings hold the potential to guide policymakers in different regions towards ensuring food security and enhancing agricultural system resilience in the context of climate change.