International Centre for Soil Fertility and Agricultural Development (IFDC)
Kenya Forestry Research Institute
Institute Nationale de l’Environnement et de Recherche Agricole (INERA)
Centre Ecologique Albert Schweitzer
University of California, Department of Plant Sciences
Tropical Soil Biology and Fertility Institute (TSBF-CIAT)
Netherlands Organization for Scientific Research/Tropics and Developing Countries (NOW-WOTRO)
Below Ground Biodiversity (CSM-BGBD Project)
MICROBES Project (IRD-France)
The soil maps of Africa (EU digital archive of soil maps)