1. Department of Soil Science, University of Nigeria, Nsukka, Nigeria
2. Global Station for Food, Land & Water Resources, Research Faculty of Agriculture, Hokkaido University, Sapporo, Hokkaido, Japan
3. Department of Agronomic & Molecular Sciences, Faculty of Agriculture & Veterinary Medicine, University of Buea, Buea, Cameroun
4. Department of Soil & Environmental Management, Faculty of Agriculture, Prince Abubakar Audu University, Anyigba, Nigeria