Edited by Robert John Scholes, University of the Witwatersrand, Wits, South Africa, and approved November 3, 2016 (received for review June 28, 2016)
The question whether sub-Saharan Africa (SSA) can be self-sufficient in cereals by 2050 is of global relevance. Currently, SSA is amongst the (sub)continents with the largest gap between cereal consumption and production, whereas its projected tripling demand between 2010 and 2050 is much greater than in other continents. We show that nearly complete closure of the gap between current farm yields and yield potential is needed to maintain the current level of cereal self-sufficiency (approximately 80%) by 2050. For all countries, such yield gap closure requires a large, abrupt acceleration in rate of yield increase. If this acceleration is not achieved, massive cropland expansion with attendant biodiversity loss and greenhouse gas emissions or vast import dependency are to be expected.
Although global food demand is expected to increase 60% by 2050 compared with 2005/2007, the rise will be much greater in sub-Saharan Africa (SSA). Indeed, SSA is the region at greatest food security risk because by 2050 its population will increase 2.5-fold and demand for cereals approximately triple, whereas current levels of cereal consumption already depend on substantial imports. At issue is whether SSA can meet this vast increase in cereal demand without greater reliance on cereal imports or major expansion of agricultural area and associated biodiversity loss and greenhouse gas emissions. Recent studies indicate that the global increase in food demand by 2050 can be met through closing the gap between current farm yield and yield potential on existing cropland. Here, however, we estimate it will not be feasible to meet future SSA cereal demand on existing production area by yield gap closure alone. Our agronomically robust yield gap analysis for 10 countries in SSA using location-specific data and a spatial upscaling approach reveals that, in addition to yield gap closure, other more complex and uncertain components of intensification are also needed, i.e., increasing cropping intensity (the number of crops grown per 12 mo on the same field) and sustainable expansion of irrigated production area. If intensification is not successful and massive cropland land expansion is to be avoided, SSA will depend much more on imports of cereals than it does today.
Author contributions: M.K.v.I., L.G.J.v.B., J.W., P.G., and K.G.C. designed research; M.K.v.I., L.G.J.v.B., J.W., P.G., J.v.W., N.G., L.C., H.d.G., K.W., H.Y., H.B., P.A.J.v.O., K.S., and K.G.C. performed research; M.K.v.I., L.G.J.v.B., J.W., J.v.W., N.G., H.d.G., D.M.-D., P.A.J.v.O., M.P.v.L., O.A., S.A.-N., A.A., A.B., R.C., K.K., M.K., J.H.J.R.M., K.O., and K.T. analyzed data and results; M.K.v.I., P.G., and K.G.C. wrote the paper; H.d.G. database and visualization; and O.A., S.A.-N., A.A., A.B., R.C., K.K., M.K., J.H.J.R.M., K.O., and K.T. collected data.
The authors declare no conflict of interest.
This article is a PNAS Direct Submission.
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