The impact of declining soil fertility in sub-Saharan Africa and what can be done to address this issue is the subject of an article on the website of the Thomson Reuters Foundation.

With an increasing population (three quarters of which live on farms) and an increasingly unpredictable climate, Mali’s food security is threatened. A major part of the problem is declining soil fertility. The area of land under cultivation in the country is continually expanding, fallow periods are getting shorter and crop yields are low.

“Sustainable soil management is urgently needed because land degradation is a huge burden, particularly in developing countries,” says the article, citing findings made by the Montpellier Panel in their No ordinary matter report that nearly 3.3 per cent of agricultural GDP in sub-Saharan Africa is lost annually due to soil and nutrient losses.

The article looks at a range of farming practices that have been shown to improve soil fertility and how these might be scaled-up in the region.

For example, incorporation of the leguminous tree, Faidherbia albida in agroforestry systems can help improve soil health through its nitrogen-rich leaves. The tree also helps soils to retain water and provides a source fodder and firewood. But to upscale this requires the financing Faidherbia nurseries and ensuring there is labor available to collect and apply composting leaves to fields.

Other techniques with promise include stone bunds and zaï planting holes combined with the application of organic or inorganic fertilizer, microdosing and growing legumes and crop varieties tolerant to low levels of phosphorus. The article discusses these, among others, and some of the impediments to up-scaling.

“To ensure these improved practices are adopted on a large scale, we need to invest in sharing the proof they work,” says the article, adding the need to work through farmers’ organizations and networks

Read the full story: Can 'down to earth' innovations keep hunger at bay in the Sahel?