AzoPat: a quantified description of yearly nitrogen flows on a pasture grazed by dairy cows. II. Flows of the soil-plant system.

摘要

The AzoPat model simulates the quantification of nitrogen flows in the soil-plant-animal system on an annual basis. It calculates the losses through volatilization, denitrification and leaching as well as the annual variation in the organic nitrogenfraction in the soil, and shows the annual N balance at the plot scale. Being built on the basis of very numerous references from literature, it is suitable for a large diversity of situations relative to pedoclimate, grassland species (pure grasses, grass-legume swards) or grassland utilization (grazing, mowing). Hypotheses and equations used for the calculation are detailed. The validation of AzoPat by actual experimental data confirms the consistency of its results for the prediction of losses by volatilization, denitrification and risk of leaching in a grazed system. Simulation of an alternative management by cutting + grazing are developed. Limitations and intended improvements are presented.