Abstract Planting pits are rain water harvesting structures that trap water and nutrients in surface runoff and rain water falling directly into the pits. Planting pits have been promoted for improving crop yields without considering the nutrient dynamics. To contribute to this knowledge, a study was conducted to determine the soil nutrient content after four seasons of growing sorghum and pigeon pea in rotation in “Chololo” and “Five by Nine” pits. Two planting pits; “Five by Nine...
Abstract Effects from past climate, natural disturbances and human activities are significantly impacting negatively on current day processes in tropical indigenous trees forests. Most of the indigenous trees mostly hard woods have been logged by human activities. Warburgia ugandensis is a tree that is highly valued for its medicinal properties, timber, poles and fuel wood. Consequently, its population and distribution has been on the decline due to environmental and anthropogenic impacts. T...
Abstract Determination of crop growth parameters of maize helps assess the performance of the crop for food security. A study was conducted in two seasons covering 2012 and 2013 to establish optimal irrigation and nitrogen fertilizer rates for drought tolerant hybrid maize (Zea mays L.), DK8031 variety, in sandy loam soils using furrow irrigation. Four additive irrigation levels (119.05 mm, 238.10 mm, 357.15 mm and 476.2 mm) were allocated the main plots while five nitrogen fertilizer rates ...
Abstract Soil Collembola communities were sampled along a gradient of land use intensification in Taita-Taveta, Wundanyi division, Coast Province during the wet season (October-November 2007) and dry season (February- March 2008). This gradient ranged from Natural undisturbed land use to intensively cultivated (disturbed) horticulture fields. The eight land use types (LUTs) were stands of (1) Pinus patula, (2) Cypress lusitanica, (3) Indigenous forest, (4) Fallow, (5) Pennisetum purpureum, (...
Abstract Populations of soil-dwelling Collembola were monitored on a land use gradient ranging from Natural forests to intensively cultivated land during the wet season October-November, 2007 and dry season February-March, 2008. Eight land use types (LUTs) which included stands of; Eucalyptus saligna, Vitex keniensis, Pennisetum purpureum, indigenous forest, fallow fields, Cammelia sinensis, Coffea africana and Zea mays intercropped with Phaseolus vulgaris were sampled for Collembola in Embu...
Abstract Common bean (Phaseolus vulgaris L.) production in Kenya has not reached its potential yield due to various abiotic and biotic factors. Anthracnose, caused by Colletotrichum lindemunthianum and root rots caused by Pythium species are major production constraints. Landraces are preferred by farmers in Kenya due to yield stability and tolerance to some stresses. However, there is little information on the genetic diversity of the landraces and the level of resistance to anthracnose and...
Abstract The smallholder cropping systems have an adverse effect on greenhouse gas (GHG) emissions to the ecosystems due to varied contribution to the GHG budgets. Further, the uncertainty on the contribution of an individual anthropogenic trace gas (CH4, CO2, and N2O) to the GHG emissions is rising due to disproportionate concentration contribution. The general objective was to quantify GHG emissions from selected cropping systems and asses N2O dynamics. The specific objectives were to: i) ...
Abstract The adverse effects of climate change and increasing human population have put pressure on scarce water resources used in crop production. This consequently threatens the food and nutritional security of the growing human population. Vegetables are short season crops that are sensitive to water deficits during growth, leading to low productivity, poor marketability and reduced household incomes. Use of controlled irrigation in production of vegetables is considered a sustainable rou...
Abstract Rust (Uromyces appendiculatus) (Pers.:Pers.) Unger., is among the most destructive pathogens constraining the production of common beans (Phaseolus vulgaris L.) in Kenya. The study's objectives were to (i) determine the prevalence of bean rust in central and western Kenya; (ii) evaluate common bean genotypes for host resistance to rust disease under field and greenhouse conditions; (iii) characterize the Ur gene in a French bean breeding line MU#13; and (iv) identify SSR markers lin...
Abstract Worldwide, commercial production of French bean (Phaseolus vulgaris L.) is constrained by diseases, key among them being the bean common mosaic virus (BCMV) and bean common mosaic necrosis virus (BCMNV). These potyviruses are the most devastating to common bean farmers and can cause total yield loss under heavy infestation. The objective of this study was to characterize the BCMNV resistance in commercial French bean cultivars and initiate a breeding program against the disease. A s...
Abstract Sorghum is a major staple food source in many African countries. In Kenya, it is cultivated by small-scale farmers. Gadam sorghum is the common variety mainly grown for brewing, manufacture of animal feeds and sorghum cakes. However, its yield is about 0.8 t ha- which is low compared to international standards. This is exacerbated by birds' that tend to have a preference for it. The use of birds' resistant sorghum varieties containing higher amounts of tannin than Gadam is a strateg...
Abstract Human activities have potential adverse effects on freshwater ecosystems, which sustain a wide range of ecosystem services such as the provision of potable water, nutrient cycling, and a habitat for organisms such as decomposer macro-invertebrates. The effect of these activities with regard to water quality and invertebrates has been established and well documented. However, information on the effect of human activities on leaf litter breakdown as an indicator of river ecosystem int...
Abstract Climate change has greatly affected food production and food security. Erratic temperature rises and inconsistent precipitation have greatly influenced productivity of crops and livestock. The impacts have gotten much more pronounced among small scale farmers in Kenya whose farming activities are climate reliant. As a component of climate change adaptation, selecting suitable climate smart agriculture (CSA) technologies that can alleviate these adverse consequences is critical. The ...
Abstract Human-related activities are known to have deleterious effects on the water quality of aquatic ecosystems globally. However, there is limited information on the impact of similar perturbations in tropical regions, especially the River Chania in Kiambu County, Kenya, which is an important source of water for humans and animals and also provides habitat for a variety of flora and fauna along its length. The aim of this study was to determine the spatial and temporal variations of sele...
Abstract African horned melon (Cucumis metuliferus) is an indigenous crop belonging to the family Cucurbitaceae. The crop has been neglected despite its high potential. Therefore, to conserve the biodiversity of this crop, there is need to promote its domestication and production. However, this can only be realized if its morphology, agronomic and nutritional value is understood. The objective of this study was to determine the agromorphological performance and nutritional composition of hor...