Evaluation of the DNDC model for simulating greenhouse gas emissions from mediterranean croplands

Abstract

One of the biggest challenges facing Mediterranean agriculture is quantifying greenhouse gas (GHG) emissions at field scale with enough accuracy to guide mitigation policy [6]. This research evaluated the DeNitrification-DeComposition (DNDC) model for simulating CO₂ and N₂O emissions from irrigated and rainfed croplands near Córdoba, Spain, over three cropping years (2019–2022). DNDC was parameterized with local soil, weather, and management data and validated against automated chamber measurements at 15 monitoring plots. For N₂O, the model achieved R² = 0.89 and RMSE = 0.34 kg N/ha/yr. For soil CO₂, R² was 0.82 with RMSE = 0.47 t C/ha/yr. Irrigated plots emitted 2.3-fold more N₂O than rainfed plots, driven by denitrification under saturated conditions. DNDC captured the seasonal emission peaks within 15% of observed values. The model is suitable for regional GHG inventories in Mediterranean cropping systems with appropriate local calibration.