Sustainable water and nitrogen optimization to adapt to different temperature variations and rainfall patterns for a trade-off between winter wheat yield and N2O emissions

Optimizing irrigation and nitrogen (N) fertilizer applications is essential to ensure crop yields and lower environmental risks under climate change. The DeNitrification-DeComposition (DNDC) model was employed to investigate the impacts of irrigation regime (RF, rainfed; MI, minimum irrigation; CI, critical irrigation; FI, full irrigation) and N fertilizer rate (N60, N90, N120, N150, N180, N210, N240, N270, and N300 kg ha⁻¹) on yield and nitrous oxide (N₂O) emissions from winter wheat growing season under different temperature rise levels (+0, +0.5, +1.0, +1.5, and +2.0 °C scenarios) and precipitation year types (wet, normal, and dry seasons) in the North China Plain. Model evaluations demonstrated that simulated soil temperature, soil moisture, daily N₂O flux, yield, and cumulative N₂O emissions were generally in close agreement with measurements from field experiment over three growing seasons. By adopting simulation scenarios analysis, the model was then used to explore the effects of irrigation and N fertilizer inputs to balance yield and N₂O emissions from winter wheat growing season. Based on reduced water and fertilizer inputs and N₂O emissions with little yield penalty, recommended management practices included application of MI-N150 in wet season, CI-N120 in both normal and dry seasons, and CI-N150 for +0 to +2.0 °C scenarios. Recommended practices in different precipitation year types reduced irrigation amount by 75–150 mm, N rate by 75–105 kg N ha⁻¹, yield by 0.16–0.86 t ha⁻¹, cumulative N₂O emissions by 0.13–0.64 kg ha⁻¹, and yield-scaled N₂O emissions by 15.5–85.0 mg kg⁻¹ compared with current practices. The corresponding metrics for different elevated temperature levels decreased by 75 mm, 75 kg N ha⁻¹, 0.09–0.50 t ha⁻¹, 0.12–0.52 kg ha⁻¹, and 13.7–72.3 mg kg⁻¹, respectively. The proposed management practices can help to maintain high agronomic productivity and alleviate environmental pollution from agricultural ecosystems, thereby providing an important basis for mitigation strategies to adapt to climate change.