Environ. Res. Lett. 9, 044004 (2014)

Sub-Saharan Africa (SSA) has among the lowest yields in staple food production globally, a situation that climate change is expected to exacerbate. Consequently, when selecting between available management options to improve yields, the efficacy of management practices needs to be compared with expected future conditions as well as those that prevail today.

Christian Folberth, from the Swiss Federal Institute of Aquatic Science and Technology, and colleagues used an agronomic model to project the potential impacts of climate change on maize yields in SSA under different intensification levels. They considered three management options; conventional intensification with a high mineral nitrogen supply and a bare-soil fallow period, and two options with moderate mineral nitrogen supplies and rotation with different nitrogen-fixing crops (cowpea or the tree Sesbania sesban).

They found that, until the 2040s, maize rotation with Sesbania (with the addition of a moderate mineral nitrogen supply) leads to the greatest simulated yield improvement and also has co-benefits for water infiltration and soil-water retention. However, simulated yields declined in all of the management scenarios towards the end of the century.