Rooting for food security in Sub-Saharan Africa

Authors

Nicolas Guilpart, University of Nebraska-LincolnFollow
Patricio Grassini, University of Nebraska-LincolnFollow
Justin Van Wart, University of Nebraska-LincolnFollow
Haishun Yang, University of Nebraska-LincolnFollow
Martin K. van Ittersum, Wageningen University & Research
Lenny G.J. van Bussel, Wageningen UniversityFollow
Joost Wolf, Wageningen University
Lieven Claessens, International Crops Research Institute for the Semi-Arid Tropics
Johan G.B. Leenaars, ISRIC–World Soil InformationFollow
Kenneth G. Cassman, University of Nebraska-LincolnFollow

Date of this Version

2017

Citation

Environ. Res. Lett. 12 (2017) 114036.

Comments

© 2017 The Author(s).

Abstract

There is a persistent narrative about the potential of Sub-Saharan Africa (SSA) to be a ‘grain breadbasket’ because of large gaps between current low yields and yield potential with good management, and vast land resources with adequate rainfall. However, rigorous evaluation of the extent to which soils can support high, stable yields has been limited by lack of data on rootable soil depth of sufficient quality and spatial resolution. Here we use location-specific climate data, a robust spatial upscaling approach, and crop simulation to assess sensitivity of rainfed maize yields to root-zone water holding capacity. We find that SSA could produce a modest maize surplus but only if rootable soil depths are comparable to that of other major breadbaskets, such as the US Corn Belt and South American Pampas, which is unlikely based on currently available information. Otherwise, producing surplus grain for export will depend on expansion of crop area with the challenge of directing this expansion to regions where soil depth and rainfall are supportive of high and consistent yields, and where negative impacts on biodiversity are minimal.