Serosurvey of Coxiella burnetii (Q fever) in Dromedary Camels (Camelus dromedarius) in Laikipia County,Kenya

Dromedary camels (Camelus dromedarius) are an important protein source for people in semi‐arid and arid regions of Africa. In Kenya, camel populations have grown dramatically in the past few decades resulting in the potential for increased disease transmission between humans and camels. An estimated four million Kenyans drink unpasteurized camel milk, which poses a disease risk. We evaluated the seroprevalence of a significant zoonotic pathogen, Coxiella burnetii (Q fever), among 334 camels from nine herds in Laikipia County, Kenya. Serum testing revealed 18.6% positive seroprevalence of Coxiella burnetii (n = 344). Increasing camel age was positively associated with C. burnetii seroprevalence (OR = 5.36). Our study confirmed that camels living in Laikipia County, Kenya, have been exposed to the zoonotic pathogen, C. burnetii. Further research to evaluate the role of camels in disease transmission to other livestock, wildlife and humans in Kenya should be conducted.     

Recovery and germination of Prosopis juliflora (Sw.) DC seeds after ingestion by goats and cattle

Prosopis juliflora is a perennial shrub introduced in the 1980s to the Baringo District in central Kenya, and became highly invasive starting around the late 1990s. This period coincides with a shift of the composition of ruminant herds from formerly cattle to goats in this area. To assess the possible role of this shift in herd structure on P. juliflora spread, we conducted feeding trials and germination tests to determine the capacity of seeds to survive the passage through the intestinal tract of goats and cattle, comparing germination with chemically scarified and untreated seeds. Recovery of seeds eight days after ingestion was lower from goats (7%) than from cattle (15%) dung. Germination dynamics were similar for seeds that had been manually extracted from pods with those recovered after intestinal passage. Chemically scarified seeds germinated fastest and reached a germination rate of 100% within five days. While no apparent scarification effect was observed, the main contribution of endozoochorous dispersal of Prosopis seeds is their release from the enclosing pod segments, their dispersal away from the mother plant and possibly the provision of nutrients by the dung for their establishment and initial growth.     

Effect of Social Capital on Performance of Smallholder Farmer Organizations in Western Kenya

Development literature has recently promoted the use of producer organizations in linking farmers to better-paying commodity markets. However, empirical studies find mixed performance of such organizations. This study examines the producer organizations＇ internal factors that may explain the differences in the performance of producer organizations. The study specifically analyzes the role of social capital, within a producer organization, on the performance of such organization using quantitative techniques. The level of commercialization is used as proxy of organization＇s performance. The study finds that social capital positively affects the performance of producer organizations. These findings imply that development strategies that target the promotion commercialization of smallholder agriculture through producer organizations should pay attention to the internal factors within such organizations.     

Economic performance of the ‘push–pull’ technology for stemborer and Striga control in smallholder farming systems in western Kenya

The ‘push–pull’ technology (PPT), developed in Africa, offers effective control of cereal stemborers and Striga weed in maize-based cropping systems. It involves intercropping maize with desmodium, Desmodium uncinatum, with Napier grass, Pennisetum purpureum, planted as border around this intercrop. Desmodium repels the stemborer moths (push) that are subsequently attracted to the Napier grass (pull). Desmodium also suppresses and eliminates Striga. We assessed economic performance of this technology compared to the conventional maize mono- and maize–bean intercropping systems in six districts in western Kenya over 4–7 years. Ten farmers were randomly recruited in each district and each planted three plots representing the three cropping systems. The cost–benefit analyses were carried out, together with the systems’ net returns to land and labour and their discounted net present values (NPV). Maize grain yields and associated gross margins from the PPT system were significantly higher than those in the other two systems. Although the production costs were significantly higher in the PPT than in the two cropping systems in the first cropping year, these reduced to either the same level or significantly lower than in the maize–bean intercrop from the second year onwards in most of the districts. Similarly, the net returns to land and labour with the PPT were significantly higher than with the other two systems. The PPT consistently produced positive NPV when the incremental flows of its benefits compared to those of the two conventional systems were discounted at 10–30%, indicating that PPT is more profitable than the other two systems under realistic production assumptions. PPT is thus a viable option for enhancing productivity and diversification for smallholder farmers who largely depend on limited land resource. Hence, enhancing farmers’ access to less costly planting materials and promoting quality education and training in the use of this knowledge-intensive technology could stimulate its successful adoption.     

On-farm evaluation of the ‘push–pull’ technology for the control of stemborers and striga weed on maize in western Kenya

The ‘push–pull’ technology is a novel pest management strategy developed for control of stemborers and striga weed, Striga hermonthica, in maize-based farming systems in eastern Africa, where maize is intercropped with desmodium, a forage legume, and Napier grass is planted as a border crop. Desmodium repels stemborer moths while Napier grass attracts them. Desmodium also suppresses the parasitic striga weed through a series of mechanisms ranging from shading to allelopathy through the root system. The technology is currently being disseminated among smallholder farmers in eastern Africa and adoption rates are rising. Our on-station studies have reported efficacy of this technology against the two pests resulting in increased grain yields. The current study was conducted between 2003 and 2006 in 14 districts in western Kenya to assess effectiveness of the technology under farmers’ own conditions. Twenty farmers from each district, who had adopted the technology, were randomly selected for the study. Each farmer had a set of two plots, a ‘push–pull’ and a maize monocrop. Seasonal data were collected on percentage of maize plants damaged by stemborers, the number of emerged striga, plant height and grain yields. Similarly, farmers’ perceptions on the benefits of the technology were assessed using a structured questionnaire. Stemborer damage and striga counts to maize plants were significantly lower in the ‘push–pull’ plots than in the maize monocrop plots. Similarly, maize plant height and grain yields were significantly higher in the former. Farmers rated the ‘push–pull’ technology significantly superior in having reduced stemborers and striga infestation rates and increased soil fertility and grain yields. These results demonstrate that the technology is equally effective in controlling both pests with concomitant yield increases under farmers’ conditions in the districts studied.     

Effects of controlled grazing on a degraded dwarf shrub,annual grass semidesert vegetation type of northwestern Kenya

A degraded dwarf shrub, annual grass semidesert vegetation type in Turkana, northwestern Kenya, was protected from livestock grazing from October 1985 to December 1990. The effects of controlled grazing on plant cover, litter cover and bare ground were monitored to appraise the trend in range condition using grazed transects (GT) and ungrazed transects (UGT). Despite an initial increase, plant cover on the UGT deteriorated in a similar manner to that on the GT. At the conclusion of six years of protection, the cumulative mortality of Indigofera cliffordiana on the UGT exceeded 60 per cent whereas on the GT it was 6 per cent. Furthermore the density of I. cliffordiana on the protected area decreased whereas that on the GT remained substantially unchanged. Aristida mutabilis replaced I. cliffordiana on the UGT but showed little change on the grazed area. Sedera hirsuta disappeared from the GT. On the UGT the percentage of bare ground, despite an initial decline (39.3 ± 7.3 per cent), increased substantially (68.9 ± 15.7 per cent) in parallel with the GT (77.3 ± 4.7 per cent). The results contradict a commonly held view that land degradation only occurs when plants are overused. The findings suggest that degradation can occur in the absence of grazing, especially if the plant species involved are dependent on perturbation. As over-resting eliminates I. cliffordiana, it seems judicious to allow a 2-3 year deferral period followed by moderate grazing if it is to be optimally managed.     

Slow progress with integrated rural development programmes in Kenya's arid and semiarid lands

Integrated rural development programmes (IRDPs) in Kenya's Arid and Semiarid Lands (ASAL) arose out of a recognition that they had been neglected in the past and that levels of poverty, the need to increase production and the threat of environmental degradation merited special attention. The primary goal of the IRDP activities was to increase agricultural productivity, thereby contributing to food self-sufficiency. This goal was reflected in the heavy concentration of resources in natural resource development. Such concentration was frequently at the cost of the development of human resources. Similarly, investment in physical infrastructure and in small-scale industry was neglected. It was expected that IRDPs would be planned and implemented at the District-level and would assist in the establishment of district administrative capacity. Participatory planning at the local level was considered a prerequisite to effective and sustainable integrated development. Sadly, IRDPs have been largely unsuccessful in both primary goals. While the reasons for failure are complex, it appears that two key issues stand out: (a) assumptions about the ability of government agricultural services to develop the potential of the ASAL were unrealistic, and (b) there was a lack of real devolution of power to district administrations, and more noticeably, to subdistrict levels. Despite the difficulties, the attraction of IRDPs to the ASAL remain strong. In a time of declining government budgets, they provide a means of getting funds to the district-level and of catering for the special problems of semiarid environments. The continuing justification for IRDPs may be summarized as follows: (a) there is still a real problem of feeding a growing population in ASAL districts and in high agricultural potential zones; (b) without IRDPs in ASAL districts, standards of living would certainly fall; (c) this may prompt out-migration from ASAL areas into high potential zones; (d) such out-migration would occur in the context of increasing land pressure and rising unemployment in high-potential areas; (e) IRDPs, by sustaining populations within ASAL districts, could contribute to food security in high-potential areas; (f) IRDPs might also contribute to food security in ASAL districts themselves, by strengthening traditional production systems in these areas. The primary goal is to sustain the populations in ASAL districts by improving their food security. Although natural resource management is still necessary, there must be increasing attention paid to human resource development. Only then can a true transfer of power take place to ASAL districts, whereby their people effectively participate in overcoming and managing local problems.     

Nitrate leaching and adsorption in a Kenyan Nitisol

Abstract. ¹⁵N labelled NH₄NO₃ (fertilizer N) was applied at a rate of 50 kg N ha^–1 to an Ando-Humic Nitisol and two maize crops grown on it. About 20 months later, soil cores were taken to a depth of 2.5 m. Leached fertilizer N was found between 1.4 m and 1.8 m deep and was delayed relative to net drainage by between 4.2 and 4.9 pore volumes. Anion exchange capacity (AEC) increased ten-fold down the profile, up to 2.9 cmol_ckg^–1. The delay to fertilizer N leaching was predicted to be between 4.1 and 5.3 pore volumes when calculated from the AEC and from an equation relating delay due to AEC in laboratory columns of repacked soil obtained by Wong et al. (1990b). It was concluded that the nitrate leaching delay equation was also valid in undisturbed field profiles. Two concentration maxima for mineral N were found, which did not usually coincide with the fertilizer N and were thought to result from mineralization of soil organic matter and plant residues at the end of each season. The delay equation overestimated their leaching delay but the results were considered close enough to support the hypothesis for their formation.     

Health and production measures for smallholder pig production in Kikuyu Division, central Kenya

A longitudinal study was carried out in Kikuyu Division (a peri-urban area in central Kenyan highlands) between January 1999 and December 1999 to estimate the baseline parameters on reproductive performance of the sow, as well as health and productivity of grower and preweaning pigs of smallholder herds. Data were collected on 155 breeding pigs, 795 grower pigs and 801 preweaning piglets in 74, 50 and 40 smallholder herds, respectively, using record cards that were updated during monthly visits.

The sow-level medians were: weaning-to-service interval 3 months; interfarrowing interval 6.4 months; number of live-born piglets 9.0; and number of piglets weaned per litter 7.5. The piglet crude morbidity incidence risk was 29%. The cause-specific incidence risks for the important health problems encountered in preweaned piglets were diarrhea (4.3%), pruritus (17.1%), and skin necrosis (4.2%). The estimated crude mortality incidence risk to 8 weeks of age was 18.7%. The cause-specific mortality incidence risks to 8 weeks of age for the important causes of mortality were overlying (9.9%), savaging (2.4%), unviable piglets (2.0%) and unknown (1.9%). Overall, 78.8% of the total live-born piglet mortality occurred during the first week postpartum with 69% of these deaths being caused by overlying. The grower-pig crude morbidity incidence risk was 20% and the cause-specific incidence risks of the important health problems encountered were gut edema (1.3%), pruritus (21.1%), and unknown (2.3%). The crude mortality incidence risk was 3.8% and the important causes were gut edema and unknown causes (cause-specific mortality incidence risks of 1.3 and 1.6%, respectively). The median weight:age ratio and average daily weight gain for the grower pigs were 5.1 kg/month of age and 0.13 kg/day, respectively. For preweaning pigs, the median average daily weight gain was 0.13 g/day.     

Reasons for smallholder farmers discontinuing with low-cost micro-irrigation: A case study from Kenya

The low head drip kit (micro-irrigation) was introduced in Kenya in the late 1990s. It consists of water containers, usually a bucket or a drum(s), raised about one metre to gain gravitational head. The number and length of drip lines used vary according to the areas to be irrigated which can be as low as 15 m². The general objective of this research was to find out why some smallholder farmers in the study areas discontinued micro-irrigation. The research was carried out in 2002 by a survey using face-to-face informal interviews with continuing adopters and those who had discontinued adoption. The study revealed that the majority of farmers who discontinued using micro-irrigation stopped due to lack of maintenance, irrelevant cultural background, and unreliable water supply. The influence of some factors seemed to vary between areas. Homogeneity analysis (SPSS) results associated farmers who discontinued the adoption of the micro-irrigation kit with above factors as well as farmers’ subsidies for acquisition of the kit, the use of the smaller bucket kit, and farmers who did not traditionally grow food crops. The findings suggest critical factors to be addressed for the continued adoption of smallholder micro-irrigation.