1. Soil and Irrigation Research Centre, School of Agriculture, College of Basic and Applied Sciences, University of Ghana, Kpong, Ghana
2. Department of Soil Science, School of Agriculture, College of Basic and Applied Sciences, University of Ghana, Legon, Accra, Ghana
3. International Institute of Tropical Agriculture, Kano, Nigeria
4. Savanna Agricultural Research Institute, Nyankpala, Tamale, Ghana