Update of a biogeochemical model with process-based algorithms to predict ammonia volatilization from fertilized cultivated uplands and rice paddy fields

Abstract. Accurate simulation of ammonia (NH3) volatilization from fertilized croplands is crucial to enhancing fertilizer-use efficiency and alleviating environmental pollution. In this study, a process-oriented model, CNMM–DNDC (Catchment Nutrient Management Model–DeNitrification–DeComposition), was evaluated modified using NH3 observations 44 19 fertilizer application events in cultivated uplands paddy rice fields China, respectively. The major modifications for simulating were primarily derived peer-reviewed published study. jointly regulated by wind speed, soil depth, clay fraction, temperature, moisture, vegetation canopy, rainfall-induced canopy wetting. Moreover, three principle made simulate fields. First, the floodwater layer its pH added. Second, effect algal growth on diurnal fluctuation introduced. Finally, Jayaweera–Mikkelsen model introduced volatilization. results indicated that original not only performed poorly but also failed showed remarkable performances cumulative calibrated validated cases, with drastically significant zero-intercept linear regression slopes 0.94 (R2 = 0.76, n 40) 0.98 0.71, 23), simulated dose type nitrogen irrigation implementation, while sensitive pH; depth application; flooding management strategies, such as depth. acceptable compile regional or national emission inventories develop strategies alleviate