Optimizing Irrigation and Nitrogen Management for Yield, Water Productivity and Greenhouse Gas Mitigation in Spring Maize of Northwest China
摘要
Purpose: Optimizing irrigation and nitrogen application is critical for balancing agricultural productivity and ecological sustainability in arid regions. Methods: A two-year field study (2023–2024) in the northwest arid region of China to explore the effects of irrigation(W1, low irrigation level; W2, medium irrigation level; W3, high irrigation level) and nitrogen fertilizer levels (F1, 40 kg N ha− 1; F2, 80 kg N ha− 1; F3, 120 kg N ha− 1; F4, 160 kg N ha− 1) on drip-irrigated spring maize growth and yield, water and fertilizer use efficiency, and greenhouse gas emissions. A multi-objective optimization approach was used to determine the optimal combination of irrigation and nitrogen fertilization levels. Results: The plant height, stem diameter, dry matter accumulation, yield, and water use efficiency of spring maize increased and then decreased with increasing irrigation and nitrogen fertilization levels. The highest values were observed with W2F3 treatment in both years. Under the same irrigation level, nitrogen partial factor productivity decreased with increasing nitrogen fertilization levels. Additionally, the W1 treatment group exhibited the lowest cumulative N2O and CO2 emission fluxes and the lowest cumulative CH4 absorption flux. By contrast, the F1 treatment group exhibited the lowest cumulative N2O and CO2 emission fluxes and the highest cumulative CH4 absorption flux. Conclusions: Multi-objective regression models determined optimal water use (423–438 mm) and nitrogen application (206–241 kg ha− 1) to synergize yield, resource efficiency, and environmental benefits. Overall, this study provides valuable insights for optimizing the irrigation and fertilization of spring maize in arid regions.