1. Department of Earth and Environmental Sciences, Division of Soil and Water Management KU Leuven Leuven Belgium
2. Soil Service of Belgium Heverlee Belgium
3. Department of Biosystems, Division of Crop Biotechnics KU Leuven Heverlee Belgium
4. Department of Crop Sciences, Division Agronomy University of Natural Resources and Life Sciences Tulln Austria
5. Plant Sciences Unit, Institute for Agricultural and Fisheries Research Merelbeke Belgium