Landwirtschaftliche Ursachen hoher Sulfatgehalte in gefördertem Trinkwasser

Abstract

Increasing sulphur concentrations in groundwater raise a problem for many waterworks. This dissertation explores the influence of agricultural land use on the sulphur concentration of seepage water considering two catchment areas. The areas under investigation are located in Saxony and Lower Saxony in Germany. Methodically, the investigation is based on calculations of nutrient balances on farm, stable and field levels. Balances are established for the nutrients N, P, K, Mg and S. Subsequently, the seepage water and the leaching of sulphate and nitrate are quantified by applying the models SULFONIE and HERMES.The analysis for Saxony reveals that the present agricultural land use does not lead to increased leaching of sulphur into the groundwater. Soil samples show high quantities of sulphur in loamy and clayey soils. These accrue to the previous agricultural land use and atmospheric deposition from the 1980s. Measurements were approved by modelling.In Lower Saxony the sulphur balance is slightly increased due to a high life stock density. However, the analysis reveals that there is no risk for a raised sulphur concentration in the seepage water because of high seepage rates.Concluding, the dissertation examines impacts of possible future agricultural land uses on seepage water and leaching of sulphur. The following scenarios were modelled: Area-wide application of sulphur fertilizer, organic agriculture, climate change.