Skip to main content

Thank you for visiting You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.


No silver bullets for African soil problems

Conservation agriculture is being used increasingly around the world (H. Buffett Nature 484, 455; 2012). But many of the claimed benefits of minimal or no-tillage farming — such as carbon sequestration and boosting crop yields — are far from proven (K. E. Giller et al. Field Crop Res. 124, 468–472; 2011).

Several of these conservation techniques are good agricultural practice: to sow with the first rains, to rotate crops, to fertilize them appropriately and to return crop residues to the soil. But in the absence of herbicides (a reality for many African smallholders), tillage can save labour, allows farmers to plant early and controls weeds. It helps to prevent runoff and erosion if the soil is not protected by mulch, for which smallholder farmers often lack the organic resources.

My view is therefore that an across-the-board recommendation of conservation agriculture is misplaced (Nature 483, 525–527; 2012). Given the enormous diversity of African smallholder farming systems, locally adapted, best-fit technologies are needed (K.E. Giller et al. Agric. Syst. 104, 191–203; 2011).

Farming-systems analysis will identify for whom and where different intensification strategies are most likely to help.

Author information



Corresponding author

Correspondence to Ken E. Giller.

Rights and permissions

Reprints and Permissions

About this article

Cite this article

Giller, K. No silver bullets for African soil problems. Nature 485, 41 (2012).

Download citation


Quick links

Nature Briefing

Sign up for the Nature Briefing newsletter — what matters in science, free to your inbox daily.

Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing