1. Rothamsted Research, West Common , Harpenden, UK
2. Department of Soil Science and Environment, University of Zimbabwe , Harare, Zimbabwe
3. School of Biosciences, University of Nottingham , Sutton Bonington, UK
4. Department of Crop and Soil Sciences, Lilongwe University of Agriculture and Natural Resources , Lilongwe, Malawi
5. Department of Agricultural Research Services , Lilongwe, Malawi
6. Department of Forestry and Environmental Management, Mzuzu University , Mzuzu, Malawi
7. Zambia Agriculture Research Institute, Mount Makulu, Central Research Station , Lusaka, Zambia
8. School of Agricultural Sciences, University of Zambia, Great East Road Campus , Lusaka, Zambia
9. Department of Geography, Geospatial Sciences and Earth Observation, University of Zimbabwe , Harare, Zimbabwe
10. Department of Nutrition, HIV and AIDS, Ministry of Health , Lilongwe, Malawi
11. Inorganic Geochemistry, Centre for Environmental Geochemistry, British Geological Survey , Nottinghamshire, UK