[1] Univ Kassel, Organ Plant Prod & Agroecosyst Res Trop & Subtrop, D-37213 Witzenhausen, Germany
[2] Univ Ouaga 1 Pr Joseph KI ZERBO, Univ Dedougou, Agron Pedol Gest Ressources Nat, 04 BP 7021, Ouagadougou, Burkina Faso
[3] Ruhr Univ Bochum, Dept Soil Sci & Soil Ecol, Inst Geog, D-44780 Bochum, Germany