Optimal management practices of nitrogen and irrigation for the trade-off between economy and environment for maize in China

CONTEXT The growing demand for maize in China, coupled with intensive agricultural practices, has led to excessive nitrogen fertilization and inefficient irrigation aimed at boosting yields. These practices contribute to reactive nitrogen emissions and nitrate leaching, posing threats to ecosystems, human health, and climate stability. OBJECTIVE This study develops develop an integrated optimization framework for nitrogen and irrigation management in maize production across China, with the goal of balancing agricultural productivity, economic returns, and environmental sustainability. METHODS We employed the process-based model APSIM to simulate maize growth under diverse climatic, soil, and management conditions. A range of nitrogen application rates (0–270 kg N ha −1 ) and irrigation regimes (from rainfed to automatic irrigation) were evaluated. Environmental economic benefit (EEB) was calculated by integrating yield revenue, production costs, and environmental externalities such as N₂O emissions and nitrate leaching. RESULTS AND CONCLUSIONS Our results indicate that moderate nitrogen inputs (90–180 kg N ha −1 ) combined with rainfed or limited supplementary irrigation can maximize EEB while minimizing environmental losses. Spatially explicit optimization revealed regional variations: Northeast China benefits from relatively higher nitrogen inputs, while Northwest China requires more frequent irrigation to sustain yield. The North China Plain achieves optimal performance with moderate nitrogen and targeted irrigation, whereas Southern China performs better under lower nitrogen and rainfed conditions. Optimized practices significantly enhance yield stability and reduce nitrogen loss hotspots. SIGNIFICANCE This study provides a spatially explicit, evidence-based framework for precision nitrogen and irrigation management in Chinese maize production. The findings support the development of sustainable agricultural policies, contribute to national food security goals, and offer practical strategies for reducing environmental impacts while maintaining economic viability.