Optimizing deficit irrigation for climate resilience in the wheat–maize rotation of North China Plain

Climate change significantly impacts agricultural production and water resources management, given crop growth’s dynamic response to weather changes and climate variables’ influence on irrigation supply and demand. Consequently, clarifying the effects of climate change on agricultural productivity and identifying adaptation strategies to support sustainable agriculture and livelihood security is essential. In this study, we assessed the effects of climate change on crop rotation management and water balance by simulating crop growth using the AquaCrop model under historical and projected climate scenarios (SSP2-4.5 and SSP5-8.5). Focusing on the winter wheat–summer maize rotation, the predominant cropping system in the North China Plain, we developed a computational framework to optimize irrigation practices and quantify the relationship between irrigation and yield across one year (i.e., corresponding to a complete hydrological cycle). Simulation results indicate that maize yields are projected to decline by approximately 10%, while wheat yields may increase slightly more than 20% due to the CO 2 fertilization effect. Although increased precipitation under climate change scenarios can reduce irrigation requirements, it may also lead to decreased yield stability, i.e., significantly lower yields in unfavorable years. Looking ahead, effective water demand management strategies, such as implementing water quotas, will be critical for sustainable agricultural water use. Considering constraints on irrigation water supply, total yield, and yield stability, deficit irrigation proved to be the most reliable scheduling strategy for this crop rotation system. • AquaCrop simulations spanned historical baselines and future climates. • Deficit irrigation proved most reliable for yield stability under water constraints. • CO 2 fertilization may increase wheat yield by slightly more than 20%. • Maize yield is projected to decline by about 10%. • Increased precipitation may reduce irrigation requirements by 100 mm per year.