1. Department of Soil Management and Soil Care, Ghent University, Ghent, Belgium
2. Department of Soil Sciences, School of Agricultural Sciences, University of Zambia, Lusaka, Zambia
3. UNESCO International Hydrological Programme, 7 Place de Fontenoy, Paris
4. Department of Geology and Soil Science (WE13), Laboratory of Soil Science, Ghent University, Gent, Belgium