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Agriculture is the mainstay of the economies of sub-Saharan Africa as it employs 60% of the active population and contributes up to 35% of the GDP (AGRA, 2014). Yet, agri-food systems are bedeviled with a lot of challenges regardless of the unrelenting efforts made by the scientific community and the flagship agricultural programs initiated by governments of the sub-region. Agriculture in SSA is predominately rainfed and is managed by smallholder farmers who are too cash-strapped to afford the recommended inputs. Cereal yields in SSA, for example, are extremely low and average about 1.6 tons ha− 1 compared to the global average of 3.9 tons ha− 1 (FAOSTATS, 2020). While a plethora of constraints may account for the fragile food systems, prolonged decline in soil fertility, and low and erratic rainfall have been cited as the key biophysical constraints (IFDC, 2007).

These precarious agri-food systems are worsened by the impact of climate change. According to IPCC estimates, climate change-induced drought may shorten growing periods in SSA by an average of 20% by 2050 and cause a decline of 40% in cereal yields (Lobell et al., 2011). While judicious use of fertilizers could improve soil fertility and increase crop yields, smallholder farmers in SSA only use limited amounts of fertilizers. The fertilizer use in SSA is constrained by several factors such as high cost, limited access, and poor producer price. Consequently, smallholder farming systems often rely on inherent soil organic matter (SOM) content to sustain crop production. While SOM can help to maintain soil fertility by enhancing the retention and release of soil nutrients as well as …