1. Institute of Soil Science and Soil Geography, University of Bayreuth, D‐95440 Bayreuth, Germany
2. Soil Fertility Research Institute, Mládežnická 36, SK‐97405 Banská Bystrica, Slovakia
3. Institute of Technical Geology and Applied Mineralogy, Technical University Graz, Rechbauerstr. 12, A‐8010 Graz, Austria