Abstract
Water scarcity and excessive nitrogen application have become major constraints to the sustainable development of modern agriculture. As an efficient water-saving irrigation technique, drip irrigation offers substantial potential for the precise management of water and nitrogen in crop production. To clarify how water-nitrogen coordination under drip irrigation influences winter wheat performance, a field experiment was conducted in the North China Plain. A randomized block design with varying nitrogen application rates and irrigation levels was used to systematically assess their effects on grain yield formation, photosynthetic characteristics, soil nitrogen dynamics, and water and nitrogen use efficiency. The results demonstrated that appropriate combinations of water and nitrogen significantly enhanced the net photosynthetic rate and grain yield of winter wheat. Optimal treatments not only improved water and nitrogen use efficiency but also reduced residual soil nitrogen and the risk of nitrogen leaching, promoting synergistic and efficient utilization of resources. This study elucidated the regulatory mechanisms of water-nitrogen interactions on key physiological processes during critical growth stages of winter wheat under drip irrigation, and established an optimized water-nitrogen management model aimed at improving yield and resource efficiency. The findings provide scientific guidance for water and nitrogen regulation in winter wheat drip irrigation in similar ecological regions, offering theoretical support and practical strategies to address water scarcity and nitrogen overuse.
