1. Centre for Crop Systems Analysis, Wageningen University, Wageningen, The Netherlands
2. IRAD, Multi-purpose Research Station Dschang, Cameroon
3. Agro-facility, Wageningen, The Netherlands
4. Ministry of Agriculture and Rural Development, Department of Crop Production, Yaoundé, Cameroon
5. Department of Soil Quality, Wageningen University, Wageningen, The Netherlands