1. INRA Centre PACA; UR 1115 PSH, domaine Saint Paul, site Agroparc 84914 Avignon cedex 9 France
2. INRA Centre PACA; UR Biosp; domaine Saint Paul, site Agroparc 84914 Avignon cedex 9 France
3. Dep. of Earth and Environmental Sciences, Division Soil and Water Management; Celestijnenlaan 200E BE-3001 Heverlee Belgium