Simulation of nitrate leaching using a modelling system with automatic parameterization routines

. For an efficient abatement of diffuse N pollution from arable land, it is important to have practical and reliable tools that can quantify the effect of different management practices on leaching, and also analyse the effect of alternative management scenarios aimed at reducing leaching. We present here an application of soilndb, a management-oriented model for quantifying nitrate leaching from arable land. Simulations with soilndb were compared with measurements of pipe-drain discharge of nitrate taken in a 14-year field experiment on a sandy loam soil in south-west Sweden. Following adjustment of parameters connected to litter and faeces decomposition and mineralization, the model gave satisfactory predictions of nitrate leaching for all 10 treatments. The temporal pattern was generally well captured by the model, as was confirmed by high model efficiency values (average = 0.59). This application also supports the model's ability to simulate the long-term influence of different crops and catch crops as well as different manure strategies on leaching. However, further studies should be done to evaluate the model under additional agro-environmental conditions (e.g. soils, climates, and crops).