Reliable and affordable soil information is crucial for well-informed sustainable land management decisions related to food production, land use planning, climate change adaptation and mitigation as well soil health monitoring in Africa and abroad. The EU-H2020-funded Soils4Africa aims to provide an open-access, online soil information system (SIS) with a set of key soil health indicators and underpinning data, accompanied by a methodology for up-to-date and repeated soil monitoring across the African continent. The soil information system will become part of the knowledge and information system of FNSSA and will be hosted by an African institute.
At least 16,000 carefully selected safe agricultural locations across Africa were sampled using well-documented field campaign protocols available in different languages. All the samples are currently being analyzed for selected soil properties based on user needs including soil nutrients mostly P which does not predict very well, heavy metals, exchangeable bases, particle size distribution and pesticide residues (Wageningen University) in the ARC-Soil Climate and Water analytical laboratory in Pretoria, South Africa. All the samples are analysed with a fast, affordable, environmentally friendly, non-destructive, reproducible, and repeatable mid-infrared spectroscopy analysis. At least 20% of these samples are analyzed using wet chemistry methods for a rich, new soil spectral library and soil database. Both the spectroscopy and wet chemistry analyses follow well-documented methods as well as Standard Operating Procedures. A subset of the samples will be submitted to the Global Soil Spectral Calibration Library and Estimation Service (GSCLES) initiative to promote linkage of spectral libraries globally, to evaluate quality, to provide African coverage to the GSCLES and to provide a standardized and rich soil spectral library resource for labs in Africa that may want to start using MIR spectroscopy in future.
Preliminary results show good agreement (R2>0.70) between measured and predicted soil properties namely; organic carbon, total nitrogen, soil pH, particle size distribution, CEC and exchangeable bases among others. These are promising findings for the project and will contribute significantly to the SIS. The African-based SIS will enable policymakers, agri-businesses, scientists and other stakeholders to make well-informed decisions concerning sustainable intensification of agriculture and boosting food security.