Limits of conservation agriculture to overcome low crop yields in sub-Saharan Africa
Contenu
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Titre
Limits of conservation agriculture to overcome low crop yields in sub-Saharan Africa
Nature Food
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Créateur
Marc Corbeels
Krishna Naudin
Anthony M. Whitbread
Ronald Kühne
Philippe Letourmy
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Sujet
Agriculture
Developing world
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doi
10.1038/s43016-020-0114-x
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Résumé
Conservation agriculture (CA) has become a dominant paradigm in scientific and policy thinking about the sustainable intensification of food production in sub-Saharan Africa. Yet claims that CA leads to increasing crop yields in African smallholder farming systems remain controversial. Through a meta-analysis of 933 observations from 16 different countries in sub-Saharan African studies, we show that average yields under CA are only slightly higher than those of conventional tillage systems (3.7% for six major crop species and 4.0% for maize). Larger yield responses for maize result from mulching and crop rotations/intercropping. When CA principles are implemented concomitantly, maize yield increases by 8.4%. The largest yield benefits from CA occur in combination with low rainfall and herbicides. We conclude that although CA may bring soil conservation benefits, it is not a technology for African smallholder farmers to overcome low crop productivity and food insecurity in the short term.
