Entwicklung eines Modells zur Quantifizierung landwirtschaftlicher Stickstoffbilanzen in Rheinland-Pfalz - AGRUM-RP

Background The targets for groundwater quality set out in the Nitrates Directive have not yet been achieved across the board, neither in Germany as a whole nor in Rhineland-Palatinate (RP) (BMU and BMEL, 2020). In RP, 35 of the total 117 groundwater bodies were in poor chemical condition in 2019/2020, corresponding to about 40 % of the state's area (MKUEM Rheinland-Pfalz, 2022). 31 groundwater bodies are in poor chemical condition due to nitrate. Both the Water Framework Directive and the first version of the General Administrative Regulation for the Designation of Nitrate Polluted Areas (AVV GeA), which was passed in 2021, require spatially differentiated information for the planning of mitigation measures and the delineation of polluted areas. Against this background, a tool was developed that quantifies agricultural nitrogen emissions with high spatial resolution, at the municipality level and also within the municipality. The results provide detailed nitrogen budgets for the period 2016 to 2019. This information can be used as a decision support tool for policy processes, as basis for environmental monitoring, and to inform agricultural nitrogen management. The results enable the identification of pollution hot spots as well as uncontaminated areas and allow conclusions to be drawn about the causes of agricultural nitrogen emissions. In combination with additional geohydrological information, regional discharge potentials can be estimated (nitrate leaching).