Conception and parameterization of field-scale models for simulating ammonia loss from fertilized lands: a review

Ammonia is a crucial component in the biogeochemical cycle of nitrogen, with various harmful environmental effects. The primary source of NH 3 is agriculture, particularly the application of fertilizers in crop cultivation. A significant portion of the nitrogen content from fertilizers, when applied without utilization, is released into the environment, becoming a source of loss and pollution. Emissions occur both from the soil and through stomata. However, if the compensation point concentration of the apoplast is lower than the nearby concentration of NH 3 , stomatal absorption occurs. Additionally, cuticular deposition processes and bidirectional exchange of droplets on foliage (rain, dew, guttation) contribute to the ammonia cycle within the canopy. Depending on the conditions, a considerable amount of the ammonia emitted by the soil can be recaptured by the canopy. This recapture helps reduce both nitrogen loss from fertilizers and environmental pollution. This article presents a general review of models simulating the bi-directional exchange of ammonia in the soil—plant—atmosphere system, focusing on determining ammonia loss and amounts recycled by the canopy. The review covers concepts and parameterization of various model inputs.