Limits of conservation agriculture to overcome low crop yields in sub-Saharan Africa
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.
| Main Authors: | , , , , |
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| Format: | article biblioteca |
| Language: | eng |
| Subjects: | F01 - Culture des plantes, F08 - Systèmes et modes de culture, agriculture de conservation, rendement des cultures, productivité des terres, http://aims.fao.org/aos/agrovoc/c_264f7edd, http://aims.fao.org/aos/agrovoc/c_10176, http://aims.fao.org/aos/agrovoc/c_4176, http://aims.fao.org/aos/agrovoc/c_166, |
| Online Access: | http://agritrop.cirad.fr/596238/ http://agritrop.cirad.fr/596238/1/596238.pdf |
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| Summary: | 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. |
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