Selection of the best nitrogen fertilizer management scenario in wheat based on Palmer drought severity index with an environmental perspective

In arid and semi-arid regions, where winter wheat relies partially on precipitation for its water requirements, the timing and amount of precipitation play a pivotal role in nitrogen (N) losses. Given the extensive cultivation of wheat in these areas, farmers' oversight of N rates, N splitting, and the impact of precipitation patterns on N losses have led to water resources contamination. Therefore, tailoring N management to drought condition fluctuations can reduce N losses. The goal was to boost wheat yield while minimizing N losses. The CERES-Wheat model was meticulously calibrated and evaluated over three years, involving an experimental field and five farmer fields. The calibrated model simulated twenty-five N fertilizer scenarios, spanning various N levels (50–250 kg ha−1) and split patterns. This conesidered soil textures and meteorological data from 1992 to 2020. The model's outcomes, encompassing various yield indices and performance metrics such as water productivity (WP), irrigation water productivity (IWP), N residual in soil (NR), N leaching (NL), available N use efficiency (ANUE), N absorption efficiency (NAE), and N utilization efficiency (NUE), were categorized into four distinct groups based on the Palmer's Drought Severity Index (PDSI): Group A: Positive PDSI all season, Group B: Negative PDSI all season, Group C: Positive early, negative later, and Group D: Negative early, positive later. Indices underwent thorough Principal Component Analysis (PCA) to identify the optimal scenario. Model evaluation represented key parameters comprehensively. Simulated total biomass matched real-world conditions (NRMSE 12.44–26.08%, d-index 0.86–0.97). Soil moisture and N fell within specific ranges (NRMSE 18.79–25.60%, RMSE 1.98–4.95 mg kg−1). Comparing different drought and soil conditions, significant performance metric differences emerged. Specifically, in Groups A and D, WP, IWP, ANUE, and NAE increased by 3.38%, 11.53%, 5.86%, and 5.76% compared to C and B. Group B had an 8.55-fold NL increase over A, while Group A saw a substantial 50.64% NR surge compared to B. In overall assessment, the study has identified that the optimal N application rate for the study area is 150 kg ha−1. However, determining the most appropriate N split pattern hinges on the dynamic interplay between PDSI and soil available water content (AWC). [Display omitted] •25 nitrogen scenarios were tested, spanning various N levels and split patterns.•The simulation of N scenarios