Alice W. Murage

Achieving food security for one million sub-Saharan African poor through push–pull innovation by 2020

Food insecurity is a chronic problem in Africa and is likely to worsen with climate change and population growth. It is largely due to poor yields of the cereal crops caused by factors including stemborer pests, striga weeds and degraded soils. A platform technology, ‘push–pull’, based on locally available companion plants, effectively addresses these constraints resulting in substantial grain yield increases. It involves intercropping cereal crops with a forage legume, desmodium, and planting Napier grass as a border crop. Desmodium repels stemborer moths (push), and attracts their natural enemies, while Napier grass attracts them (pull). Desmodium is very effective in suppressing striga weed while improving soil fertility through nitrogen fixation and improved organic matter content. Both companion plants provide high-value animal fodder, facilitating milk production and diversifying farmers’ income sources. To extend these benefits to drier areas and ensure long-term sustainability of the technology in view of climate change, drought-tolerant trap and intercrop plants are being identified. Studies show that the locally commercial brachiaria cv mulato (trap crop) and greenleaf desmodium (intercrop) can tolerate long droughts. New on-farm field trials show that using these two companion crops in adapted push–pull technology provides effective control of stemborers and striga weeds, resulting in significant grain yield increases. Effective multi-level partnerships have been established with national agricultural research and extension systems, non-governmental organizations and other stakeholders to enhance dissemination of the technology with a goal of reaching one million farm households in the region by 2020. These will be supported by an efficient desmodium seed production and distribution system in eastern Africa, relevant policies and stakeholder training and capacity development.

Climate-smart push-pull: a conservation agriculture technology for food security and environmental sustainability in Africa

This chapter describes the push-pull technological innovation developed by the International Centre of Insect Physiology and Ecology (ICIPE) in the UK and partners in East Africa, which addresses smallholder agricultural constraints, food insecurity, and environmental degradation and has the potential to equip farmers with the resilience and adaptability they need to deal with climate change. The push-pull technology fits conservation agriculture (CA) principles of minimum soil disturbance in its minimum soil tillage agronomic management, continuous soil cover with a perennial cover crop and plant residue, as well as a diversified cereal-legume-fodder intercropping strategy. The perennial intercrop provides live mulching, thus improving above-ground and below-ground arthropod abundance, agrobiodiveristy and the food web of natural enemies of stem borers, thus effectively controlling major insect pests of cereals. The field implementation of this technological innovation in Africa is discussed, as well as its various benefits.