1. Division of Agricultural and Environmental Chemistry, Institute of Agriculture, Warsaw University of Life Sciences-SGGW, Nowoursynowska 159, 02-776 Warsaw, Poland
2. Institute of Crop Science and Resource Conservation, University of Bonn, Katzenburgweg 5, D-53115 Bonn, Germany
3. Department of Agricultural Sciences, University of Helsinki, P.O. Box 28, Koetilantie 5, FI-00014 Helsinki, Finland
4. Department of Soil Science, Erosion and Land Conservation, Institute of Soil Science and Plant Cultivation—State Research Institute, Czartoryskich 8, 24-100 Puławy, Poland