Analysis and modelling of seasonal nitrate concentration variations in the groundwater of the Mnasra aquifer, Morocco

A mechanistic simulation model was developed for predicting, under field conditions, the unsaturated water flow and nitrogen transfer in an area located in Mnasra. The model parameters can be calculated from easily measured physical and chemical soil properties or obtained from the literature. Comparison between observed and calculated groundwater nitrate concentrations revealed that the application rate of 120 kg N·ha-1·yr-1 should be reduced on agricultural soils, especially during winter, which coincides with heavy rainfall and the absence of vegetation cover.