Climate-adapted companion cropping increases agricultural productivity in East Africa

AbstractProduction of cereals, the main staple and cash crops for millions of farmers in sub-Saharan Africa (SSA) is severely constrained by parasitic striga weed Striga hermonthica, stemborers and poor soil fertility. A companion cropping system known as ‘push–pull’ overcomes these constraints while providing additional soil fertility and forage grass benefits to smallholder farmers. To ensure the technology's long-term sustainability in view of the current and further potential aridification as a consequence of climate change, drought-tolerant crops, Brachiaria cv mulato (border crop) and greenleaf desmodium (intercrop), have been identified and incorporated into a ‘climate-adapted push–pull’. The aims of the current study were to evaluate effectiveness of the new system (i) in integrated control of striga and stemborer pests and (ii) in improving maize grain yields, and to evaluate farmers’ perceptions of the technology to assess potential for further adoption. 395 farmers who had adopted the technology in drier areas of Kenya, Uganda and Tanzania were randomly selected for the study. Each farmer had a set of two plots, a climate-adapted push–pull and a maize monocrop. Seasonal data were collected in each plot on the number of emerged striga plants, percentage of maize plants damaged by stemborers, plant height and grain yields. Similarly, farmers’ perceptions of the benefits of the technology were assessed using a semi-structured questionnaire. There were highly significant reductions in striga and stemborer damage to maize plants in the climate-adapted push–pull compared to the maize monocrop plots: striga levels were 18 times lower and stemborer levels were 6 times lower. Similarly, maize plant height and grain yields were significantly higher. Mean yields were 2.5 times higher in companion planting plots. Farmers rated the climate-adapted push–pull significantly superior in reducing striga infestation and stemborer damage rates, and in improving soil fertility and maize grain yields. These results demonstrate that the technology is effective in controlling both weeds and pests with concomitant yield increases under farmers’ conditions. It thus provides an opportunity to improve food security, stimulate economic growth, and alleviate poverty in the region while making agriculture more resilient to climate change

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

Farmers' knowledge and perceptions of the stunting disease of Napier grass in Western Kenya

Production of Napier grass, Pennisetum purpureum, the most important livestock fodder in Western Kenya, is severely constrained by Napier stunt (Ns) disease. Understanding farmers' knowledge, perceptions and practices is a prerequisite to establishing an effective disease management approach. Using a random sample of 150 farmers drawn from Bungoma, Busia and Teso districts of Western Kenya, this study sought to: (i) assess farmers' perceptions and knowledge of Ns disease, including its effects on the smallholder dairy industry; (ii) record farmers' current practices in managing Ns disease; and (iii) identify Ns disease management challenges and intervention opportunities in order to develop an efficient integrated disease management approach. The majority (867%) of the farmers were aware of Ns disease and observed that it was spreading rapidly in the region, which was perfectly predicted by farmers' access to agricultural information (marginal effect=0164), indicating a need for extension platforms for knowledge sharing among the industry stakeholders. The disease had affected Napier grass yields so most farmers could not feed their livestock on the amounts they produced, and they were buying Napier grass. Those who relied on income from selling Napier grass received less due to loss in productivity. Milk production had reduced by over 35%. The cause of the disease was unknown to the farmers, with no effective disease management strategy available to them. An integrated disease management approach needs to be developed to fit within the mixed farming systems, supported by simple decision aids

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

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

Determinants of adoption of climate-smart push-pull technology for enhanced food security through integrated pest management in eastern Africa

Food security attainment in Africa has been hindered by poor yields of cereals that serve both as staple and cash crops for the majority of smallholder farmers. Among the various constraints responsible for lower yields are the parasitic weed Striga, and Stemborer pests whose control has remained a challenge. The International Centre of Insect Physiology and Ecology (icipe) with partners developed a novel conservation agricultural technology termed ‘push-pull’, based on companion cropping that effectively controls both constraints simultaneously. However, the effects of climate change threatened its expansion into drier areas where Striga is rapidly spreading. Further adaptation of the conventional (original) push-pull technology was thus achieved through identification and incorporation of drought tolerant companion crops, and the procedure termed ‘climate-smart’ push-pull technology. With maximum adoption of the adapted technology, food security in the drier agro-ecologies would be enhanced through increased cereal yields. Adoption, however, depends on how well technology dissemination is implemented. The objective of this study was to quantify the potential adoption and impact of climate-smart push-pull technology ex ante in order to plan for its wide scale dissemination. Using a sample of 898 respondents (360 in Kenya, 240 in Tanzania, 298 in Ethiopia), multinomial logit and marginal rate of return (MRR) methods were used to analyze the findings of the ex ante baseline survey. These showed a high potential for adoption of climate-smart push-pull as 87.8 % of the overall sample were willing to adopt; 92.1 % in Tanzania, 88.6 % in Ethiopia and 84.3 % in Kenya. Gender, perceptions of Striga severity, technology awareness and input market access were the most likely factors that would positively influence the decision to adopt (marginal effects 0.060, 0.010, 0.042, and 0.738 respectively). The MRR was 109.2 % for sorghum and 143.4 % for maize, implying an expected positive impact to the community should they adopt the technology

Cumulative effects and economic benefits of intercropping maize with food legumes on Striga hermonthica infestation

The parasitic weed Striga hermonthica, commonly known as striga, is a major biotic constraint to maize production in sub-Saharan Africa (SSA) where it causes serious food insecurity and poverty in smallholder farming communities. We previously discovered an effective control method for it involving intercropping cereals with fodder legumes in the genus Desmodium, commonly known as desmodium. The objectives of the current study were to evaluate cumulative effects of intercropping maize with the commonly grown food legumes on striga infestation, and to establish any economic benefits of the same. Treatments comprised maize plots planted in monocrop stands or intercropped with five different food legume species or desmodium. Intercropping maize with desmodium gave the most consistent and significant suppression of striga. Out of the food legume intercrops, only crotalaria, groundnut and greengram intercrops had significantly lower striga counts and only in some of the cropping seasons. Grain yields were consistently and significantly higher with desmodium intercrop, although they were also increased with food legume intercrops compared to maize monocrop, thus confirming superiority of intercropping with legumes over maize monocrop. Although production costs in terms of total labor and variable costs were significantly higher for the intercrops than for the maize monocrop, total revenue and net benefits were significantly higher in the former, especially for desmodium. The desmodium intercrop gave the highest economic benefits followed by crotalaria and greengram intercrops. These results confirmed the effectiveness of desmodium in suppressing striga and improving yields and economic returns to smallholder farmers. They also showed that it is profitable to invest in food legume intercrop systems, especially the crotalaria and greengram systems, and indicate that intensifying maize cropping systems through integration of these food legumes in combination with other approaches can contribute to an integrated management of striga and provide a more sustainable and profitable productive system to smallholder farmers