Can Sub-Saharan Africa feed itself? Tripling cereal production with minimum fertilizer use and emissions

Demand for five cereals (maize, millet, rice, sorghum and wheat) is projected to increase between 2015 and 2050 by a factor 2.8 in sub-Saharan Africa (SSA) due to population increase and dietary changes. In theory, SSA could meet this demand, but only just so, on existing cereal cropland area. Yields would have to increase between 2015 and 2050 from current levels, which are about 20-40% of the agronomic yield potential under rainfed conditions, to ca. 80% of that potential. This is an unprecedented rate of yield increase for rainfed systems in the world.

To enable the required yield increases, crop nutrient requirements will have to increase enormously, to – for example – an average minimum requirement of 140 kg nitrogen (N)/ha for maize, which is the most widely planted cereal in SSA. This is equivalent to a 15-fold increase between 2015 and 2050. If cereal demand will be fulfilled in SSA, by 2050, greenhouse gas emissions from cereal production will be at least 50% higher than in 2015 due to the larger production, regardless whether scenarios of intensification or crop area expansion will be followed. Intensification of cereal production with sufficient and efficient use of fertilizers will lead to lowest GHG emissions, but requires excellent agronomy.