Climate-smart push–pull: Resilient, adaptable conservation agriculture for the future

The ‘push-pull’ system (www.push-pull.net) effectively controls serious biotic constraints to cereal production in Africa, insect pests (stemborers) and striga weed, while improving soil health and biodiversity. The companion cropping system, developed by the international centre of insect physiology and ecology (icipe), Rothamsted Research and other partners, makes smallholder farms more resilient often with a tripling of yields. It involves attracting stemborers with trap plants (pull) whilst driving them away from the main crop using a repellent intercrop (push). Chemicals released by intercrop roots induce abortive germination of the noxious parasitic striga weed. The companion plants provide high value animal fodder, facilitating milk production. Furthermore, soil fertility is improved due to the nitrogen fixing intercrop and soil degradation is prevented. Recently, the push-pull system has been adapted to drier and hotter conditions linked to climate change by identification and incorporation of drought tolerant companion crops (http://www.push-pull.net/Climate-smart_Push-Pull.pdf). This climate-smart push-pull directly responds to rising uncertainties in Africa’s rain-fed agriculture due to the continent’s vulnerability to climate change. The new companion crops, Desmodium intortum and Brachiaria Mulato II hybrid, can withstand extended periods of drought stress with no water. To date push-pull has been adopted by over 96,000 smallholder farmers in eastern Africa whose maize yields have increased from about 1 t/ha to 3.5 t/ha. Low-input technologies that address several production constraints and deliver multiple benefits are more relevant for African smallholder farmers but also have useful lessons for agricultural systems in the developed world.