National Research Repository

The National Research Fund was established under the Science, Technology, and Innovation (ST&I) Act of 2013. The Fund facilitates research for the advancement of science, technology, and innovation. One of its core functions is to compile and maintain a national database of research and innovation projects funded by the Fund, as well as those funded by other agencies. In light of this, the National Research Repository is an online knowledge resource that provides stakeholders, researchers, research policymakers, and the public an easy access to information on Kenya's research landscape. The repository also enhances the assessment of research impacts and integration of research innovations and solutions into the national development plans and policies.

 

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Analysis of the Spatial Relationship between Cattle and Wild Ungulates across Different Land-Use Systems in a Tropical Savanna Landscape
(2018-02-04) Kinga, Geoffrey W.; Mironga, John; Odadi, Wilfred O.
In many African savanna landscapes, domestic and wild herbivores cooccur across different land-use systems, but the role of land-use in shaping their spatial relationship is poorly understood. We evaluated the spatial relationship between cattle and wild herbivores categorized by body sizes and feeding habits across different land-use types, namely, private ranches (PR), transitional lands (TRL), and pastoral grazing areas (PGA), in Laikipia County, Kenya. Cattle and wild herbivores spatial distribution data were obtained from Kenya’s Department of Resources Survey and Remote Sensing (DRSRS). Spatial relationships between cattle and different wild herbivore guilds were analyzed using Ripley’s bivariate function. In PR, wild herbivore guilds showed significant attraction to cattle at short distances. In TRL, wild grazers, mixed feeders, megaherbivores, and medium-sized ungulates exhibited significant attraction to cattle. Additionally, repulsion was observed between cattle and browsers at short distances under this land-use system. In PGA, wild grazers, mixed feeders, and megaherbivores repelled strongly with cattle at short distances while browsers and medium-sized ungulates were significantly attracted to cattle. Cattle and wild herbivores were more randomly and independently distributed in PR than in TRL and PGA. These spatial relationships imply better coexistence between cattle and wild herbivores in PR than in TRL and PGA.
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Propagation And Regeneration Of Important Indigenous Tree Species In Kakamega Forest, Kenya
(International Journal of Innovative Research and Advanced Studies (IJIRAS), 2018-08-01) Busuru, Carolyne; G., Obwoyere; Kirui, Bernard
This study evaluated regeneration potential of P. africana vis a vis Olea capensis and Croton megalocarpus, identified the seed for propagation and suitable sowing media that gives optimum germination results. An experiment was set to evaluate these. Seeds were collected prepared, germinated under the different media types and germination percent monitored. The data was collected on mean germination percent in different media ratio and statistical analyses conducted. The results indicated that There was significant difference in the timing of the collection of seeds (F 2, 60, f=24.47, P<0.001). Germination rate was significantly lower in stored seeds compared to the other two seed collection stages i.e. mature green seeds and mature ripe. There was a significant ‘medium’ effect on the germination of C. megalocarpus (F6,62, f=4.84, p<0.001), Prunus africana (Chi- square test = 14.10, d. f= 6, p = 0.029) and O. capensis (Chi –square test = 18.33, d. f= 6, p = 0.005). From the results, it was concluded that the best seed for propagation of P. africana is seed freshly harvested, mature and ripe even without any pre-treatment. It is therefore recommended that P. africana seed should be sown in sand: sawdust 1:1 immediately after harvesting for optimum germination.
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Effect of Land Use on Leaf Litter Decomposition in Upper Mara Streams, Kenya
(Egerton University, 2018-01-18) Tsisiche, A.; M’merimba, C.; Mbaka, J. G.
Modification of riparian vegetation via land use change alters leaf litter processing rates in streams. This study aimed at investigating the effect of land use change from forestry to agriculture on leaf litter decomposition in the upper Mara River catchment, Kenya. The study involved collecting, drying and weighing leaves of Eucalyptus saligna (exotic) and Macrocalyx neubotonia (native). About 6g of each leaf species was enclosed in litter bags measuring 11 x 11cm and mesh size of 10mm. The bags were exposed randomly in six streams; three draining agricultural and three draining indigenous forests. They were later retrieved at intervals of 0, 1,3,7,14,28 and 48 days, dried and weighed. The difference in processing rates of Eucalyptus leaves were statistically not significant (insert test and statistics) between streams draining indigenous forest (mean -k = 0.039±0.009, pooleddata) and streams draining agricultural areas decaying Macrocalyx leaves were –k = 0.095±0.005 in streams draining agricultural areasand k=0.062±0.01 for streams draining indigenous forest. The two values differed significantly (t = 2.892, d.f=4, p= < 0.05). Significant differences in processing rates were also evident between Eucalyptus and Macrocalyx leaves in streams draining indigenous and agricultural forests respectively (ttest, p<0.05). It would take 63 and 69 days for 90% of leaves of Eucalyptus to be processed in agricultural and forested streams respectively whilst Macrocalyx leaves would take 24 and 53 days. Processing rates for the two leaves were generally higher in agricultural streams than in forested streams most probably due to higher nutrients especially Phosphate concentration arising from agricultural land. In all the study streams SRP had significant correlation with decay rates for both species. Significant differences in processing rates observed between the two leave species could be attributed to differences in leave toughness and the presence of inhibitory compounds in eucalypts. The findings of this study suggest that land use change interacts with change in the composition of riparian tree species to influence decomposition ratesof leaf litter in streams. This has implications on theEgerton J. Sci. & Technol. Volume 16:functional organization of shredders and nutrient cycling in streams. This study confirms that land use activity has an effect on litter decomposition rates in Upper Mara catchment streams. However Eucalyptus decomposition did not respond to change in land use activity because of its poor quality which masks the land use effect.
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VEGETATION, WILDLIFE AND LIVESTOCK RESPONSES TO PLANNED GRAZING MANAGEMENT IN AN AFRICAN PASTORAL LANDSCAPE: PLANNED GRAZING ENHANCES PASTORAL RANGELAND PRODUCTIVITY
(John Wiley and Sons Ltd, 2017-02-22) Odadi, Wilfred; Fargione, Joe; Rubenstein, Daniel
Rangelands are vital for wildlife conservation and socio-economic well-being, but many face widespread degradation due in part to poor grazing management practices. Planned grazing management, typically involving time-controlled rotational livestock grazing, is widely touted as a tool for promoting sustainable rangelands. However, real-world assessments of its efficacy have been lacking in communal pastoral landscapes globally, and especially in Africa. We performed landscape-scale assessment of the effects of planned grazing on selected vegetation, wildlife and cattle attributes across wide-ranging communally managed pastoral rangelands in northern Kenya. We found that planned grazing enhanced vegetation condition through a 17% increase in normalized difference vegetation index (NDVI), 45-234% increases in herbaceous vegetation foliar cover, species richness and diversity, and a 70% reduction in plant basal gap. In addition, planned grazing increased the presence (44%) and species richness (53%) of wild ungulates, and improved cattle weight gain (>71%) during dry periods when cattle were in relatively poor condition. These changes occurred relatively rapidly (within 5 years) and despite grazing incursion incidents and higher livestock stocking rates in planned grazing areas. These results demonstrate, for the first time in Africa, the positive effects of planned grazing implementation in communal pastoral rangelands. These improvements can have broad implications for biodiversity conservation and pastoral livelihoods.
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Optimization of Binary Mixtures of Biodiesel and Fossil Diesel for Clean Energy Combustion
(Springer Nature, 2019-05-31) Mosonik, Bornes C.; Kibet, Joshua K.; Ngari, Silas M.
There is an urgent interest initiated to develop clean energy resources with the aim of reducing exposure to environmental pollutants and explore model fuels that can hasten the achievement of clean energy combustion. This work investigates various ratios of biodiesel and commercial diesel in order to propose model binary fuels for clean energy combustion. Accordingly, diesel blends of ratios 1:1, 3:2 and 2:3 were each pyrolyzed at a contact time of 5 s in a quartz reactor at 1 atmosphere pressure. A model temperature of 500 °C was explored in these experiments. The charcoal content for pure fossil diesel was compared with the binary diesel residue. Gas-phase molecular components were determined using Gas chromatography (GC) coupled to a mass selective detector (MSD). Elemental composition of thermal char was determined using Smart Elemental Analyzer. Radical intensities for the three types of char (biochar, bio-fossil char, and fossil char) were measured using an X-band electron paramagnetic resonance spectrometer. It was noted that at a ratio of 2:3 (Biodiesel: Fossil diesel), harmful molecular products reduced significantly, 76–99%. Elemental analysis data indicated that the carbon content from commercial diesel was very high (≈ 70.61%) as compared to approximately 53% for biodiesel-fossil diesel mixture in the same ratio 2:3. Interestingly, the free radical content was reduced by nearly 50% in favour of the biodiesel/fossil diesel mixture. These results are encouraging and suggest that a better optimized fuel mixture has been found for better clean energy combustion.