Current yields in sub-Saharan Africa are well below what could be achieved given the region's farmable land and annual rainfall. The area receives more rainfall per year than other breadbaskets around the world. Given these factors, there is a persistent narrative that sub-Saharan Africa has the potential to become a grain breadbasket if production is intensified.
A lack of data on soil depths that will support root growth has limited rigorous evaluations of how well sub-Saharan soils can support high, stable yields. This is a critical parameter because deeper soils can buffer against rain-free periods.
Soils in the U.S. Corn Belt are deep and young, laid down during the past 20,000 years, whereas sub-Saharan soils are weathered and much older, dating back at least 540 million years. In the U.S. Corn Belt, the soils are deeper than 1.5 meters.