1 Institute for Sustainable Agriculture, CSIC, Cordoba, Spain.
2 AgroParisTech, UMR GQE-Le Moulon, Institut National de Recherche pour l'agriculture, l'alimentation et l'environnement (INRAE), Gif-sur-Yvette, France.
3 BETA Technological Center, University of Vic, Vic, Spain.
4 Centre for Crop Systems Analysis, Wageningen University and Research, Wageningen, Netherlands.
5 Department of Crop Production Ecology, Swedish University of Agricultural Sciences, Uppsala, Sweden.