Irrigation mitigates wheat yield loss by pests and diseases under global change across China

Ensuring future food security represents a significant challenge for humanity. Wheat pests and diseases are emerging threats to global food security. However, the key factors contributing to the uneven distribution of pests and diseases remain largely unknown due to insufficient observational data from major crop-producing regions. Here, on the basis of a unique historical dataset with more than 600 statistical records, we found an increased occurrence of wheat pests and diseases in China during 2000–2018. Various pests and diseases have largely different responses to climate change, crop simplification, agricultural activities and economic development. Rising temperatures expanded the distribution range of wheat mites while reducing the prevalence of underground pests. Increased precipitation decreased the incidence of aphids, wheat mites, wheat midge, and underground pests, while promoting the spread of wheat scab. Effective irrigation suppressed wheat mites, underground pests, and wheat rust, whereas fertilizer application reduced aphids, wheat midge, and wheat scab but significantly increased wheat mites and wheat rust. Gross domestic product (GDP) increased incidence of wheat midge; aging population increased percentage of occurrence area of aphids, wheat scab and wheat powdery mildew. Crop simplification significantly increased the occurrence of underground pests and wheat powdery mildew, and was strongly correlated with increased pesticide use, which in turn was associated with higher pest and disease incidence. Furthermore, rising temperatures and the overall increase in pest and disease occurrence exacerbated wheat yield losses, whereas effective irrigation mitigated these losses by suppressing pests and diseases. These observational findings emphasize the critical role of appropriate irrigation strategies in mitigating the increasing risks of pests and diseases under climate change, thereby supporting global food security.