1. Empa−Swiss Federal Laboratories for Materials Science and Technology, CH-9014 St. Gallen, Switzerland
2. Agroscope Reckenholz-Tänikon, Research Station ART, CH-8046 Zurich, Switzerland
3. University of Johannesburg, Doornfontein 2028, South Africa
4. EPFL−Ecole Polytechnique Fédérale de Lausanne, CH-1015 Lausanne, Switzerland
5. Eawag−Swiss Federal Institute of Aquatic Science and Technology, CH-8600 Duebendorf, Switzerland
6. Federal Office for Agriculture FOAG, CH-3003 Bern, Switzerland