The Storage of Organic Carbon in Dryland Soils of Africa

Abstract

By definition, drylands include arid, semi-arid and dry sub-humid zones. They represent about 43% of the total surface area of the African continent and cover more than 70% of agricultural land. About 50% of the population of Africa lives in these areas and is significantly vulnerable in terms of food insecurity. Climate change, which is expected to increase the frequency and severity of extreme weather events, will exacerbate the vulnerability of these lands if effective adaptation and resilience actions are not undertaken. The livelihoods of most dryland populations depend on natural resource-based activities, such as agriculture and livestock. Forced to meet urgent short-term needs, households resort to unsustainable practices, resulting in strong pressure on the natural resources, loss of biodiversity and severe soil degradation. One of the crucial factors considered as a cause and a consequence of agroecosystem vulnerability in dry areas is soil degradation. Various interacting processes of such degradation include water and wind erosion, salinization, and loss of organic matter (OM). These processes lead to a decrease of the soil health, productivity, as well as its capacity of reducing carbon (C) emissions into the atmosphere.