Sensitivity of southern African maize yields to the definition of sowing dekad in a changing climate

• Published in: Climatic change Vol. 106; no. 2; pp. 267 - 283
• Main Authors: Crespo, Olivier, Hachigonta, Sepo, Tadross, Mark
• Format: Journal Article
• Language: English
• Published: Dordrecht Springer Netherlands 01.05.2011; Springer; Springer Nature B.V; Springer Verlag
• Subjects: Adaptation; Agricultural and forest climatology and meteorology. Irrigation. Drainage; Agricultural production; Agricultural sciences; Agriculture; Agriculture, economy and politics; Agronomy. Soil science and plant productions; Atmospheric Sciences; Biological and medical sciences; Cereal crops; Climate; Climate change; Climate Change/Climate Change Impacts; Climatology; Computational efficiency; Corn; crop models; Crop science; Crop yield; Crops; Decision making; Decisions; Earth and Environmental Science; Earth Sciences; Environmental impact; Environmental Sciences; Farms; Food production; Food security; Food supply; Foods; Fundamental and applied biological sciences. Psychology; General agronomy. Plant production; General circulation models; Global Changes; Life Sciences; Maize; rain; Regions; Sciences of the Universe; sowing; Zea mays; Southern Africa; Africa; Adaptation Option; Crop Failure; Crop Model; Future Period; Future Climate; Monocotyledones; Zea mays; General circulation; Modeling; Cereal crop; Dynamical climatology; Climate change; Sowing; Gramineae; Angiospermae; Water requirement; Spermatophyta; Yield
• ISSN: 0165-0009; 1573-1480
• DOI: 10.1007/s10584-010-9924-4

Most African countries struggle with food production and food security. These issues are expected to be even more severe in the face of climate change. Our study examines the likely impacts of climate change on agriculture with a view to propose adaptation options, especially in hard hit regions. We use a crop model to evaluate the impact of various sowing decisions on the water satisfaction index (WSI) and thus the yield of maize crop. The crop model is run for 176 stations over southern Africa, subject to climate scenarios downscaled from 6 GCMs. The sensitivity of these simulations is analysed so as to distinguish the contributions of sowing decisions to yield variation. We compare the WSI change between a 20 year control period (1979–1999) and a 20 year future period (2046–2065) over southern Africa. These results highlight areas that will likely be negatively affected by climate change over the study region. We then calculate the contribution of sowing decisions to yield variation, first for the control period, then for the future period. This contribution (sensitivity) allows us to distinguish the efficiency of adaptation decisions under both present and future climate. In most countries rainfall in the sowing dekad is shown to contribute more significantly to the yield variation and appears as a long term efficient decision to adapt. We discuss these results and additional perspectives in order to propose local adaptation directions.