TY - JOUR AU - Wendland, F. AU - Behrendt, H. AU - Gömann, H. AU - Hirt, U. AU - Kreins, P. AU - Kuhn, U. AU - Kunkel, R. AU - Tetzlaff, B. TI - Determination of nitrogen reduction levels necessary to reach groundwater quality targets in large river basins: The Weser basin case study, Germany Nutrient Cycling in Agroecosystems JO - Nutrient cycling in agroecosystems VL - 85 SN - 1385-1314 CY - Dordrecht [u.a.] PB - Springer Science + Business Media B.V M1 - PreJuSER-5097 SP - 63 - 78 PY - 2009 N1 - This project was commissioned by Germany's Federal Ministry of Food, Agriculture and Consumer protection (BMELV), the River Basin Commission Weser (RBC Weser) and the Federal States Bremen, Hessen, Niedersachsen, Nordrhein-Westfalen, Sachsen-Anhalt and Thuringen. AB - We used the interdisciplinary model network REGFLUD to predict the actual mean nitrate concentration in percolation water at the scale of the Weser river basin (Germany) using an area-differentiated (100 m x 100 m) approach. REGFLUD combines the agro-economic model RAUMIS for estimating nitrogen surpluses and the hydrological models GROWA/DENUZ for assessing the nitrate leaching from the soil. The areas showing predicted nitrate concentrations in percolation water above the EU groundwater quality standard of 50 mg NO3/l, have been identified as priority areas for implementing nitrogen reduction measures. For these "hot spot'' areas a backward modelling approach was used to quantify the maximal permissible nitrogen surplus levels in agriculture to guarantee a mean long-term nitrate concentration in percolation water below 50 mg NO3/l. Research work will directly support the implementation of the EU-Water Framework Directive in the Weser basin, e.g. by using the maximal permissible nitrogen surplus levels as a framework for the derivation of regionally adapted and hence effective nitrogen reduction measures. KW - J (WoSType) LB - PUB:(DE-HGF)16 UR - <Go to ISI:>//WOS:000269686900005 DO - DOI:10.1007/s10705-009-9248-9 UR - https://juser.fz-juelich.de/record/5097 ER -