Modelling of nitrogen turnover and leaching in Saxony

Abstract. From 2005 to 2009 we modelled the input of nitrogen and phosphorus in waters in the area of the Federal State of Saxony (Germany). The model results are an important component in elucidating the present situation of nutrient loads in groundwater and surface water as well as its future development. The present contribution focuses on the modelling of diffuse nitrogen leaching on arable land. Processes of mobilization and immobilization of nitrogen are included in the modelling. They will be estimated as induced by the respective types of fruit, management practices and local conditions. Source areas can be derived using the relationship of nitrogen sources (mobilization, deposition) and sinks (immobilization, denitrification) on the regional scale.