Rooting for food security in Sub-Saharan Africa. (17th November 2017)

• Record Type: Journal Article
• Authors: Guilpart, Nicolas; Grassini, Patricio; van Wart, Justin; Yang, Haishun; van Ittersum, Martin K; van Bussel, Lenny G J; Wolf, Joost; Claessens, Lieven; Leenaars, Johan G B; Cassman, Kenneth G
• Is Part Of: Environmental research letters. Volume 12:Number 11(2017:Nov.)
• Publication Date: 2017-11-17
• Subjects: food security -- sub-saharan Africa -- yield gap -- maize -- soil depth -- water requirements; Environmental sciences -- Periodicals; Human ecology -- Research -- Periodicals; Environmental health -- Periodicals; 333.7
• DOI: 10.1088/1748-9326/aa9003
• Languages: English
• ISSNs: 1748-9326

Abstract

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.