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Nonlinear heat effects on African maize as evidenced by historical yield trials

Nature Climate Change volume 1, pages 4245 (2011) | Download Citation


New approaches are needed to accelerate understanding of climate impacts on crop yields, particularly in tropical regions. Past studies have relied mainly on crop-simulation models1,2 or statistical analyses based on reported harvest data3,4, each with considerable uncertainties and limited applicability to tropical systems. However, a wealth of historical crop-trial data exists in the tropics that has been previously untapped for climate research. Using a data set of more than 20,000 historical maize trials in Africa, combined with daily weather data, we show a nonlinear relationship between warming and yields. Each degree day spent above 30 °C reduced the final yield by 1% under optimal rain-fed conditions, and by 1.7% under drought conditions. These results are consistent with studies of temperate maize germplasm in other regions, and indicate the key role of moisture in maize’s ability to cope with heat. Roughly 65% of present maize-growing areas in Africa would experience yield losses for 1 °C of warming under optimal rain-fed management, with 100% of areas harmed by warming under drought conditions. The results indicate that data generated by international networks of crop experimenters represent a potential boon to research aimed at quantifying climate impacts and prioritizing adaptation responses, especially in regions such as Africa that are typically thought to be data-poor.

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  1. 1.

    & The potential impacts of climate change on maize production in Africa and Latin America in 2055. Glob. Environ. Chang. 13, 51–59 (2003).

  2. 2.

    , , & Socio-economic and climate change impacts on agriculture: an integrated assessment, 1990–2080. Phil. Trans. Biol. Sci. 360, 2067–2083 (2005).

  3. 3.

    et al. Prioritizing climate change adaptation needs for food security in 2030. Science 319, 607–610 (2008).

  4. 4.

    & Robust negative impacts of climate change on African agriculture. Environ. Res. Lett. 5, 014010 (2010).

  5. 5.

    , , & Breeding for yield potential and stress adaptation in cereals. Crit. Rev. Plant Sci. 27, 377–412 (2008).

  6. 6.

    , & The effect of drought and heat stress on reproductive processes in cereals. Plant Cell Environ. 31, 11–38 (2008).

  7. 7.

    , , & Spatial variation of crop yield response to climate change in East Africa. Glob. Environ. Change 19, 54–65 (2009).

  8. 8.

    , & Wading through a swamp of complete confusion: How to choose a method for estimating soil water retention parameters for crop models. Eur. J. Agron. 18, 75–105 (2002).

  9. 9.

    et al. Rice yields decline with higher night temperature from global warming. Proc. Natl Acad. Sci. USA 101, 9971–9975 (2004).

  10. 10.

    et al. Rice yields in tropical/subtropical Asia exhibit large but opposing sensitivities to minimum and maximum temperatures. Proc. Natl Acad. Sci. USA 107, 14562 (2010).

  11. 11.

    , , & Breeding for improved abiotic stress tolerance in maize adapted to southern Africa. Agr. Water Manage. 80, 212–224 (2006).

  12. 12.

    & in Predicting Crop Phenology (ed. Hodges, T.) 115–131 (CRC Press, 1991).

  13. 13.

    & Nonlinear temperature effects indicate severe damages to US crop yields under climate change. Proc. Natl Acad. Sci. USA 106, 15594–15598 (2009).

  14. 14.

    , , & Water deficit timing effects on yield components in maize. Agron. J. 81, 61 (1989).

  15. 15.

    & The importance of the anthesis-silking interval in breeding for drought tolerance in tropical maize. Field Crop. Res. 48, 65–80 (1996).

  16. 16.

    & Water deficit effects on corn. I. Grain components. Agron. J. 62, 652–655 (1970).

  17. 17.

    , , & Breeding for Drought and Nitrogen Stress Tolerance in Maize: From Theory to Practice (CIMMYT, 2000).

  18. 18.

    , , , & Physiological and morphological traits associated with spring wheat yield under hot, irrigated conditions. Aust. J. Plant Physiol. 21, 717–730 (1994).

  19. 19.

    & World Maize Facts and Trends 1997/98 (CIMMYT, 1998).

  20. 20.

    et al. Input subsidies to improve smallholder maize productivity in Malawi: Toward an African Green Revolution. PLoS Biol. 7, e1000023 (2009).

  21. 21.

    & On the use of statistical models to predict crop yield responses to climate change. Agric. Forest Meteorol. 150, 1443–1452 (2010).

  22. 22.

    Rising atmospheric carbon dioxide concentration and the future of C4 crops for food and fuel. Proc. R. Soc. B 276, 2333–2343 (2009).

  23. 23.

    , & Farming the planet: 2. Geographic distribution of crop areas, yields, physiological types, and net primary production in the year 2000. Glob. Biogeochem. Cycles 22, GB1022 (2008).

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We thank A. Lee, M. Burke, H. Sanchez and V. Hernandez for help processing data, and B. Rajaratnam, M. Roberts and M. Burke for helpful comments on the manuscript. This work was supported by the Rockefeller Foundation.

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  1. Department of Environmental Earth System Science and Program on Food Security and the Environment, Stanford University, Stanford, California 94305, USA

    • David B. Lobell
  2. International Maize and Wheat Improvement Center (CIMMYT), Apartado Postal 6-641, 06600 Mexico D.F., Mexico

    • Marianne Bänziger
    • , Cosmos Magorokosho
    •  & Bindiganavile Vivek


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D.B.L. and M.B. conceived the study, M.B., C.M. and B.V. designed and implemented crop trials, D.B.L. analysed data and drafted the paper, and M.B., C.M. and B.V. helped to interpret results and contributed to the writing.

Competing interests

The authors declare no competing financial interests.

Corresponding author

Correspondence to David B. Lobell.

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