1. Dep. of Soil Management; Ghent Univ.; Coupure Links 653 9000 Ghent Belgium
2. VITO, Flemish Inst. for Technological Research; Environmental Modelling Unit; Boeretang 200 2400 Mol Belgium
3. Dep. of Bioscience Engineering; Univ. of Antwerp; Groenenborgerlaan 171 2020 Antwerp Belgium