1. Agroecology and Organic Farming Group, University of Bonn, Hennef, Germany
2. Department of Organic Farming and Cropping Systems, University of Kassel, Witzenhausen, Germany
3. Biodynamic Research Association, Galten, Denmark
4. Crystal Lab, Ottersum, Netherlands
5. Forschungsring e.V., Darmstadt, Germany
6. Department of Organic Food Quality and Food Culture, University of Kassel, Witzenhausen, Germany