Description of an application with SOILNDB at the Mellby experimental station in south-west Sweden simulating nitrate leaching between 1984 and 1998 for 10 different management practices

For an efficient abatement of diffuse N pollution from arable land, it is important to have practical and reliable tools, which 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 N in harvested products and tile-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 mostly well captured by the model, which is also indicated by high model efficiency values (average = 0.59). This application also gave promising results regarding 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).