Kunkel Ralf, Eisele Michael, Wendland Frank
Institute of Chemistry and Dynamics of the Geosphere, Agrosphere Institute (ICG-4), Research Centre Jülich, Jülich, Germany.
Water Sci Technol. 2008;58(12):2295-302. doi: 10.2166/wst.2008.821.
For the Federal State of Lower Saxony, Germany, nitrogen management options are developed and implemented in three pilot areas using new participation approaches and technologies suitable for programs of measures to reduce diffuse pollution from agriculture. As a target value for water protection measures a nitrate concentration in percolation water of 50 mg/l as an average for a larger area defined by the groundwater bodies and their hydrogeological subdivisions has been defined. An integrative emission model is used to simulate the interactions between agricultural practice, nitrogen surpluses and the nitrogen flow through the soil and aquifer to the outflow into surface waters. The actual nitrate concentrations in percolation water are calculated for the entire Federal State of Lower Saxony considering site-characteristics, N-surpluses, water balance and denitrification in the soil. The tolerable N-surpluses needed to meet the environmental target are quantified as averages for each of the hydrogeological subdivisions by "backward" calculation using this model system. The required reduction of N-surpluses was estimated by comparing the tolerable N-surpluses with the actual state of nitrogen emission. For the evaluation of the amount and efficiency of water protection measures, the required reduction of N-surpluses to accomplish the environmental target is quantified, using the current status as a reference.
对于德国下萨克森州，采用适合农业面源污染减排措施计划的新型参与方法和技术，在三个试点地区制定并实施了氮管理方案。作为水保护措施的目标值，已确定由地下水体及其水文地质分区界定的较大区域内渗滤水中硝酸盐浓度平均为50毫克/升。使用综合排放模型来模拟农业实践、氮盈余以及氮通过土壤和含水层流入地表水的过程之间的相互作用。考虑到下萨克森州整个联邦州的场地特征、氮盈余、水平衡和土壤中的反硝化作用，计算渗滤水中的实际硝酸盐浓度。通过使用该模型系统进行“反向”计算，将满足环境目标所需的可容忍氮盈余量化为每个水文地质分区的平均值。通过将可容忍氮盈余与氮排放的实际状况进行比较，估算出所需的氮盈余减少量。为了评估水保护措施的数量和效率，以当前状况为参考，量化实现环境目标所需的氮盈余减少量。
