1. University of Bonn, Institute of Crop Science and Resource Conservation, Soil Science and Soil Ecology, D-53115 Bonn, Germany, University of Dortmund, Institute of Environmental Research (INFU), D-44221 Dortmund, Germany, Forschungszentrum Jülich GmbH, Institute of Chemistry and Dynamics of the Geosphere IV, Agrosphere, D-52425 Jülich, Germany, Swiss Federal Institute of Aquatic Science and Technology, CH-8600 Dübendorf, Switzerland, and Berlin University of Technology, Institute of Ecology, Department...