Victor M. Manyong

Adoption of improved fallows in West Africa: lessons from mucuna and stylo case studies

Traditional shifting cultivation systems can no longer be sustained in West Africa because of rapid increases in human and livestock populations. Short-duration, improved fallows are among the alternative land-management strategies that have evolved. This paper reviews how velvetbean or mucuna (Mucuna pruriens) and stylo (Stylosanthes hamata and Stylosanthes guianensis) management systems were developed and disseminated in West Africa. Mucuna was first adopted by farmers in southwestern Benin between 1988 and 1992, and the number of testers of the innovation rose to 10,000 farmers throughout Benin by 1996. Suppression of spear grass (Imperata cylindrica) was perceived as the main benefit of mucuna fallows. The stylo technology was introduced in the late 1970s, and it was primarily targeted to livestock production in the subhumid monomodal rainfall zone. The uptake of stylo has been relatively slow and modest in West Africa in contrast to the faster rate of adoption of mucuna in southwestern Benin. Some of the contributory factors to the slower adoption of stylo than mucuna include rainfall regime, lack of motivation of livestock keepers, insecure land tenure, limited capability and facilities of extension staff, poor communication among scientists, and unsatisfactory establishment of the crop. Recommendations to increase the adoption of improved fallows include the use of a participatory approach in problem identification, expansion of the genetic base of cover crops for use in fallows, optimization of the multiple benefits of cover crops, management of the improved system, promotional strategies, and appropriate policies.

Using a discrete choice experiment to elicit the demand for a nutritious food: Willingness-to-pay for orange maize in rural Zambia

Using a discrete choice experiment, this paper estimates the willingness to pay for biofortified orange maize in rural Zambia. The study design has five treatment arms, which enable an analysis of the impact of nutrition information, comparing the use of simulated radio versus community leaders in transmitting the nutrition message, on willingness to pay, and to account for possible novelty effects in the magnitude of premiums or discounts. The estimation strategy also takes into account lexicographic preferences of a subset of our respondents. The results suggest that (a) orange maize is not confused with yellow maize, and has the potential to compete with white maize in the absence of a nutrition campaign, (b) there is a premium for orange maize with nutrition information, and (c) different modes of nutritional message dissemination have the same impact on consumer acceptance.

Fertiliser use and definition of farmer domains for impact-oriented research in the northern Guinea savanna of Nigeria

One of the options to alleviate soil fertility constraints for sustainable agriculture in the savannas of West Africa is to develop soil nutrient management technologies from an adequate supply and feasible share of organic and mineral inputs. This paper makes a diagnosis of farm-level use of organic and inorganic inputs, as a basis for the development of technologies.The results from the diagnosis are then used to develop a framework for characterizing farmers for impact-oriented research on soil nutrient management systems. The survey was carried out with 200 farmers carefully selected in two villages in the northern Guinea savanna of Nigeria. The results showed that more than 90% of farmers in both villages used chemical fertilizers. This is contrary to a general belief that they are not widely applied to food crops by small holders in African agriculture. However, up to 81% of the fields received less than half of the recommended 120 because of high costs due, probably to removal of subsidies and inefficient marketing systems. Organic inputs such as animal manure were applied in very small quantities (about 8% of the requirements). However there is evidence of integrated use of inorganic fertilizers and organic manure on some(24%) of the fields. The problem to be addressed is that of the production (and efficient utilisation) of organic inputs in the northern Guinea savanna. Nitrogen deficiency is the most limiting soil nutrient in the cereal-dominated systems of study area. On this basis, farmers were classified into two a-priori groups using a threshold of 30, and multiple quantitative variables were fitted in a discriminant analysis tovalidate the typology. Results indicated that more than 75% of farmers were well classified into two groups that had the characteristics of thea-priori groups. Two others were a typical and included the remaining 25% of farmers. Thus, there are a total of four groups of farmers referred to as farmer domains in this paper. The two domains with 75% of well-classified individuals are suitable for the selection of farmers with whom to conduct applied research or for development activities because they represent the general patterns in the supply and use of soil nutrients in the study area.Although basic research can be done in the four domains, the two atypical groups are most suited for process-level studies to improve the understanding of factors that make the systems either more efficient or less efficient than the two other farmer domains. In either case, representative farmers were easily identified by their highest probability of belonging to a specific domain from the model results. Multivariate models constitute a good framework to make a typology of, and to select farmers for, participatory research and extrapolation of results in the northern Guinea savanna.

Factors affecting the adoption of agroforestry practices by farmers in Cameroon

This paper presents empirical evidence on the impact of socio-economic factors on the adoption of agroforestry practices in Cameroon. The analysis uses primary farm-level data collected from June to December 1996. Three major provinces of the country were covered, namely Centre, Southwest and Northwest Several agroforestry technologies have been promoted among farmers in the zone, including alley farming, improved fallow, live fencing, cut-and-carry fodder and apiculture. The status of adoption of each agroforestry practice is described and factors that affect adoption identified. These are gender of farmer, household family size, level of education, farmer’s experience, membership within farmers’ associations, contact with research and extension, security of land tenure, agroecological zone, distance of the village from nearest town, village accessibility and income from livestock. Research findings indicate that since factors affecting farmers’ adoption of agroforestry practices differ across techniques, generalisation is to be avoided.

ALTERNATIVES TO MUCUNA FOR SOIL FERTILITY MANAGEMENT IN SOUTHERN BÉNIN: FARMER PERCEPTION AND USE OF TRADITIONAL AND EXOTIC GRAIN LEGUMES

SUMMARY In southern B´ enin, the legume cover cropMucunapruriens var. utilis has been widely promoted for soil fertility improvement. Recent findings have shown, however, that the majority of farmers have not adopted it, and that alternative technologies are needed that are both attractive to farmers and beneficial in terms of soil fertility. A survey was carried out in southern B´ enin to determine farmer perception and use of traditional grain legumes and to assess the adoption potential of new low-harvest-index grain legumes. Grain legumes were shown to be integral components of traditional cropping systems and constituted farmers’ most important technology for soil fertility maintenance. More than 80% of respondents expressed interest in testing new, low-harvest-index varieties. Preferred grain characteristics and farmers’ culinary preferences for grain legumes varied between locations and need to be taken into account if new germplasm is to be introduced. It is argued that farmers’ interest and experience in legume cultivation provide an opportunity for the introduction of alternative legume-based technologies such as low-harvest-index grain legumes and techniques for the detoxification of mucuna seed. In addition, efforts should be made to increase the productivity of current legume production systems and to develop mucuna cultivars with reduced L-dopa content.

Multiple insecticide resistance in an infected population of the malaria vector Anopheles funestus in Benin

BackgroundKnowledge on the spread and distribution of insecticide resistance in major malaria vectors such as Anopheles funestus is key to implement successful resistance management strategies across Africa. Here, by assessing the susceptibility status of an inland population of An. funestus Giles (Kpome) and investigating molecular basis of resistance, we show that multiple resistance and consistent plasmodium infection rate are present in Anopheles funestus populations from Kpome.MethodsThe insecticide susceptibility level of collected Anopheles funestus was assessed. Synergist (PBO) was used to screen resistance mechanisms. The TaqMan technique was used for genotyping of insecticide resistant alleles and detecting plasmodium infection levels. The nested PCR was used to further assess the plasmodium infection rate.ResultsThe TaqMan analysis of plasmodial infections revealed an infection rate (18.2 %) of An. funestus in this locality. The WHO bioassays revealed a multiple phenotypic resistance profile for An. funestus in Kpome. This population is highly resistant to pyrethroids (permethrin and deltamethrin), organochlorines (DDT), and carbamates (bendiocarb). A reduced susceptibility was observed with dieldrin. Mortalities did not vary after pre-exposure to PBO for DDT indicating that cytochrome P450s play little role in DDT resistance in Kpome. In contrast, we noticed, a significant increase in mortalities when PBO was combined to permethrin suggesting the direct involvement of P450s in pyrethroid resistance. A high frequency of the L119F-GSTe2 DDT resistance marker was observed in the wild DDT resistant population (9 %RS and 91 %RR) whereas the A296S mutation was detected at a low frequency (1 %RS and 99 %SS).ConclusionThe presence of multiple resistance in An. funestus populations in the inland locality of Kpome is established in this study as recently documented in the costal locality of Pahou. Data from both localities suggest that resistance could be widespread in Benin and this highlights the need for further studies to assess the geographical distribution of insecticide resistance across Benin and neighboring countries as well as a more comprehensive analysis of the resistance mechanisms involved.

Impacts of extension access and cooperative membership on technology adoption and household welfare

This paper examines the impacts of access to extension services and cooperative membership on technology adoption, asset ownership and poverty using household-level data from rural Nigeria. Using different matching techniques and endogenous switching regression approach, we find that both extension access and cooperative membership have a positive and statistically significant effect on technology adoption and household welfare. Moreover, we find that both extension access and cooperative membership have heterogeneous impacts. In particular, we find evidence of a positive selection as the average treatment effects of extension access and cooperative membership are higher for farmers with the highest propensity to access extension and cooperative services. The impact of extension services on poverty reduction and of cooperatives on technology adoption is significantly stronger for smallholders with access to formal credit than for those without access. This implies that expanding rural financial markets can maximize the potential positive impacts of extension and cooperative services on farmers’ productivity and welfare.

Ecoregional research in Africa: learning lessons from IITA's Benchmark Area Approach

SUMMARY Ecoregional research has the potential to help address some of the huge challenges facing agriculture in developing countries by developing technologies that work under different agro-ecological conditions, and the processes by which these technologies can be adapted to work in other areas with similar conditions. The CGIAR system has been developing ecoregional research as a new paradigm for over a decade. In this paper we evaluate one of the most ambitious of these initiatives called the Benchmark Area Approach (BAA) pioneered by the International Institute of Tropical Agriculture. We evaluate the BAA against nine good practice criteria for ecoregional research and finding that the approach is delivering, or has the potential to deliver, on all nine. Many of the lessons learnt from this evaluation will be relevant to current and future attempts to undertake co-ordinated multi-locational research for development.

Measuring the impacts of adaptation strategies to drought stress: the case of drought tolerant maize varieties

This study measured the impacts of drought tolerant maize varieties (DTMVs) on productivity, welfare, and risk exposure using household and plot-level data from rural Nigeria. The study employed an endogenous switching regression approach to control for both observed and unobserved sources of heterogeneity between adopters and non-adopters. Our results showed that adoption of DTMVs increased maize yields by 13.3% and reduced the level of variance by 53% and downside risk exposure by 81% among adopters. This suggests that adoption had a “win-win” outcome by increasing maize yields and reducing exposure to drought risk. The gains in productivity and risk reduction due to adoption led to a reduction of 12.9% in the incidence of poverty and of 83.8% in the probability of food scarcity among adopters. The paper concluded that adoption of DTMVs was not just a simple coping strategy against drought but also a productivity enhancing and welfare improving strategy. The results point to the need for policies and programs aimed at enhancing adoption as an adaptation strategy to drought stress in Nigeria and beyond.

Ecological and Socio-Economic Factors Affecting Agricultural Intensification in the West African Savannas: Evidence from Northern Nigeria

ABSTRACT Agricultural intensification in West Africa is at an early stage and the process is taking place through various pathways. Population pressure and market access are generally considered as major factors driving intensification and crop-livestock interaction. In this paper both ecology and economic factors and their interactions are hypothesized as driving forces in intensification and crop-livestock interaction. Analyses of a survey involving farming households in Nigeria confirm the hypothesis and show that the degree of intensification is higher in the Sudan savanna than the Northern Guinea savanna. Intensification is occurring mostly through higher land and labor use intensity, higher livestock stocking rates and application of more manure per hectare. It is concluded that policies to enhance market access will facilitate the process and that different technological options need to be pursued in the two agroecological zones to facilitate intensification.