School of Agriculture, Environment, Water and Natural Resources Management (BC)
http://repository.seku.ac.ke/xmlui/handle/123456789/125
2024-03-29T06:33:52ZEffect of nitrogen fertilizer on nitrogen use efficiency and yield of selected sorghum genotypes in semi-arid regions of Kenya
http://repository.seku.ac.ke/xmlui/handle/123456789/7217
Effect of nitrogen fertilizer on nitrogen use efficiency and yield of selected sorghum genotypes in semi-arid regions of Kenya
kathuli, peter; Kinama, J. M.; Kitonyo, O. M.; Nguluu, Simon N.; Muui, C. W.; Muasya, Reuben M.
Sorghum production in semi-arid lands is constrained by inadequate soil moisture and low nitrogen. Research was carried out between 2018-2020 to determine the effect of nitrogen fertilizer on nitrogen use efficiency, yield on selected sorghum genotypes and genotypes suitable for low soil fertility in semi-arid lands. The experiment was a randomized complete block design in a split-plot arrangement with 11 sorghum genotypes in the main plot and nitrogen (0, 6.5 and 32.5 kgha-1) as the sub-plots in three replicates. Nitrogen use efficiency (NUE) and its indices agronomic efficiency (AE), nitrogen internal utilization (IE), physiological efficiency (PE), nitrogen recovery efficiency, nitrogen harvest index (NHI) and partial factor productivity (PFP) were obtained from sorghum yield data and nitrogen uptake. The results showed that nitrogen application at 6.5 kgha-1 and 32.5 kgha-1 significantly increased grain yield, stover weight and total dry matter (TDM) by 43% and 116%, 39% and 85% and 42% and 57% respectively. Sorghum genotypes TTKKIAMA6, KTIRASTAMMA4, SNYAKTOSA5, and MKNKKIRWMA2 had significantly higher grain yield and low N uptake implying they are N-efficient. NUE of sorghum decreased with increasing N application. Nitrogen internal utilization efficiency (IE) was significantly higher at zero N application rate implying better N assimilation by sorghum genotypes at low N. AE, PE, RE and PFP were all significantly higher at 6.5 kg N ha-1. All tested genotypes had significantly high NUE (90 to 1148 kgkg-1, RE (27 to 94 kgkg-1), AE (41 to 139 kgkg-1), PE (27 to 84 kgkg-1) and IE (41 to 139 kgkg-1) than the check (Gadam). It was concluded that sorghum genotypes yield parameters were increased by nitrogen application, NUE was highest at low N levels and its indices were significantly higher at 6.5 kg Nha-1. Four genotypes were found to be highly N-efficient and are recommended for sorghum improvement.
DOI https://doi.org/10.37425/eajsti.v4i2.546
2023-03-01T00:00:00ZApplication of vermicompost fertilizer in aquaculture nutrition: review
http://repository.seku.ac.ke/xmlui/handle/123456789/6820
Application of vermicompost fertilizer in aquaculture nutrition: review
Musyoka, Sonnia N.; Nairuti, Rita
Semi-intensive aquaculture using ponds is among the most common practices of fish production, whose output depends highly on the ponds’ natural primary productivity. With the increased sustainability and health concerns with artificial fish feeds and chemical fertilizers, organic manure has been credited as a cheap, safe and sustainable alternative source of aquaculture nutrition. Apart from supplying nutrients to the phytoplankton, organic manures supply food directly to zooplankton and fish, provide substrate for microbes and improve water and pond sediment quality. Vermicompost fertilizer (excrete of earthworms) has been recognized as a potential pond fertilizer because it has superior nutritional quality (of up to five times), contains microbes, and is in ready-for-uptake form. Besides, the vermicompost contains humic acid, which has antibiotic properties, and promotes fish gut health, stress management, and immune systems. Nonetheless, the application of vermicompost fertilizer in aquaculture is still not a common practice. Therefore, this study reviews the concept of vermiculture vis-à-vis pond fertilization and the various utilizations of the vermicompost in fish farming. This is to enable fish farmers to make an informed decision on identifying and selecting proper biofertilizer, which can increase yields and cut costs of production, thus maximizing profits and improving resource utilization.
DOI: 10.5772/intechopen.100326
2021-10-27T00:00:00ZA review on the occurrence of some potentially harmful elements in the natural environment and their health implications: examples of fluoride, iron and salinity in the South-Eastern Kenya region
http://repository.seku.ac.ke/xmlui/handle/123456789/6329
A review on the occurrence of some potentially harmful elements in the natural environment and their health implications: examples of fluoride, iron and salinity in the South-Eastern Kenya region
Gevera, Patrick K.; Cave, Mark; Dowling, Kim; Gikuma-Njuru, Peter; Mouri, Hassina
Makueni, Machakos and Kitui Counties, located in the Arid and Semi-Arid land (ASAL) region of south-eastern Kenya, receive low and unreliable rainfall which necessitates a high dependence on groundwater for potable, domestic and agricultural purposes. The geology of the region is dominated by metamorphic rocks of the Precambrian Mozambique Mobile Belt and Tertiary-Pleistocene volcanic rocks both of which are known to have highly variable concentrations of diverse naturally occurring potentially harmful elements. The geochemical composition of local soils and groundwater reflect the chemistry of the parent geological material and this constrains the type and concentrations of elements and nutrients in drinking water and locally produced food. This review reports the occurrence of some commonly reported potentially harmful elements, fluoride (F−), iron (Fe) and salinity, in groundwater, farm soil and commonly consumed food crops in parts of south-central Kenya and considers their potential health implications.
Drinking water issues are documented. The presence high F− in drinking water is associated with dental fluorosis in Machakos and Makueni Counties. Iron in Makueni and Kitui Counties is associated with an undesirable brown colour and taste in drinking water. Salty water is a common drinking water problem in most parts of Kitui and Makueni Counties that has led to the abandonment of shallow wells. Groundwater and spring water analysis show elevated F− (max. 9.30 mg/l), Fe (max. 7.60 mg/l) and salinity (max. hardness, chloride (Cl−) and magnesium (Mg) of 950 mg/l, 260 mg/l and 122.40 mg/l, respectively). In soils, elevated F− levels were reported in Kitui County while acidity and salinity in soil were reported throughout the region. The effects of high F− soils are not reported, but acidic and saline soils were found to be unproductive for maize and green grams farming.
Chemical and nutritional analyses of food crops grown in the area are essential to determine overall health implications on the local population. Detailed soil and groundwater geochemical databases are required in the region in order to assess the potential health implications of the natural environment on the local population.
DOI: 10.1007/978-3-030-53893-4_19
2021-08-02T00:00:00ZGovernance and Challenges of Wildlife Conservation and Management in Kenya
http://repository.seku.ac.ke/xmlui/handle/123456789/6285
Governance and Challenges of Wildlife Conservation and Management in Kenya
Okori, Joseph J.; Nyamasyo, Stephen; Amwata, Dorothy A.
Wildlife in Kenya is both a national resource and a key source of revenue for the government. Wildlife and tourism are interdependent and essential sectors in Kenya’s socio-economic development agenda. This chapter reviews the contribution of wildlife to tourism, wildlife management approaches, policy and legal framework, stakeholder involvement, as well as the challenges facing wildlife conservation and management. The insights and approaches illustrated may be used to formulate and implement solutions to enhance wildlife conservation and management for the benefit of all stakeholders. Kenya is at a crossroads with wildlife management. It is recommended that Kenya embrace a more holistic management approach that integrates effective political and related governance frameworks. This chapter proposes a novel vision of conservation in Kenya that includes additional space for wildlife, the adoption of a zero-tolerance policy on corruption and wildlife crime, substantial stakeholder participation, and a community-based approach to conservation.
https://doi.org/10.1007/978-3-030-64682-0_4
2021-06-27T00:00:00Z