New generation soil property maps for Africa (ISRIC 2017)

[last updated in 2017]

Knowledge of soil properties such as organic carbon content, clay content and pH is vital for agriculture and climate change analysis in Africa. ISRIC has launched a new type of freely accessible soil property maps for Africa. The maps contain predictions of seven soil properties at six standard depths at 1 km resolution. The soil property maps as well as the software to generate them are available for download under a Creative Commons licence.

Which crops are suitable 100 kilometres south of Ouagadougou in Burkina Faso? What is an optimal fertilization regime for the East coast of Kenya? How much carbon dioxide is stored in Congo by saving its rainforests? It is often difficult to answer such questions accurately without information on soil properties such as sand-silt-clay content, bulk density or mineral content. Unfortunately accurate soil information has been difficult to obtain, which explains why African soil properties are rarely considered in agricultural planning and environmental modelling. The aim of the Africa Soil Information Service (AfSIS), an international programme funded by the Bill and Melinda Gates Foundation, is to improve this situation, among others by creating up-to-date digital soil property maps at high spatial resolution.

ISRIC has made the first version of digital soil property maps, drawing on 12,000 geo-referenced soil profile records from 37 countries. The records were collected from over 300 data sources, ranging from digital databases, books, reports and articles. The legacy soil profiles, together with a large amount of remote-sensing based images of vegetation, climate and terrain relief, were used to estimate the soil properties for the non-desert parts of Africa. The accuracy of the estimates was also calculated.