Browsing by Author "Kizza, Sarah"

Now showing 1 - 5 of 5
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    Analysis of persistence soil nutrient status in abandoned cattle kraals in a semi arid area in Botswana
    (2010-12) Kizza, Sarah; Otlogetswe, Totolo; Perkins, Jeremy; Olusegun, Areola
    The aim of this study was to analyze the depletion of soil nutrients with time on abandoned kraals in a peri-urban area of Botswana. Active kraals are enriched with nutrients through the accumulation of animal droppings and this study was aimed at assessing how long the impact of this soil nutrient enrichment persists after kraal abandonment. A total of 25 disused kraals, that had been abandoned for periods ranging from 1 to 45 years were sampled. The soil parameters analyzed included particle size distribution (%), bulk density (g/cm3), pore space (%), moisture content (%), pH in water and KCl solution, EC (µS/cm), organic matter (%), CEC (meq/100g), exchangeable Ca++ (cmolc/kg), Mg++ (cmolc/kg),K+ (cmolc/kg), Na+ (cmolc/kg), nitrogen [NH4-N (mg/kg), NO3-N (mg/kg), TKN (%), and Olsen P (mg/kg). Results showed that soil nutrient concentrations on abandoned kraals generally were significantly higher than at the control sites. Soil nutrient concentrations decreased with time as abandoned kraals retrogressed towards their pre-kraal conditions. However, the effects of soil nutrient enrichment from animal wastes persist long after kraal abandonment. For example, soil Olsen P, Ca++ and Mg++ levels in kraal sites that had been abandoned for over 45 years were still significantly higher than in the control sites. In a pastoral system such as is practiced in Botswana where kraal manure is not used as soil amendment, the whole ecosystem suffers as soil nutrients are transferred and concentrated at isolated spots (kraals).
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    Design of an Improved Cooking Stove Using High Density Heated Rocks and Heat Retaining Techniques
    (Journal of Renewable Energy-Hindawi, 2018) Bantu, Anthony A.; Nuwagaba, Gilbert; Kizza, Sarah; Turinayo, Yonah K.
    In sub-Saharan Africa, dependence on wood fuel has caused significant depletion of vegetative resources. Whereas there exist hundreds of improved cooking stoves, many have not reached their maximum potential because their designs are predominantly focused on either fuel efficiency or reduced smoke. This research designed and fabricated an improved charcoal stove using high density rocks and heat retaining techniques.The aim was to retain heat and minimise heat losses in cooking devices with a sole purpose of reducing the amount of fuel used during cooking. The stove design herein incorporates the interaction of physical and thermal properties of granite rocks with heat loss theories to give a thermal efficient unit. The stove was estimated to cost US$ 36 which compared favourably with most of the improved charcoal stoves on international market (US$ 3–50 US$). This study revealed that, by introducing the new stove design and insulation, the granite rocks depicted high thermal storage properties with potential for reducing fuel use by over 78% with reference to the open fire stove.The designed granite rock stove therefore paves way for the use of high density rocks in improved cook stoves to achieve high performance energy efficient systems that can sustainably put to use vegetative resources.
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    Herbaceous and Woody Plant Properties in Abandoned Kraal Areas in a Hardveld Botswana
    (2011) Kizza, Sarah
    Herbaceous and woody plant species in abandoned traditional kraals were investigated. To achieve the aim of this study, nutrient status of soil in addition to vegetation composition and communities from the kraal sites were analyzed and results compared with those from control sites. A total of 25 kraals that had been abandoned between 5 and 45 years were sampled. Data were analyzed using multivariate procedures; a two-way indicator species analysis (TWINSPAN), detrended correspondence analysis (DCA) and canonical correspondence analysis (CCA) to establish classification of the plant communities. The significant environmental variables identified with t-values above 2.1 that determined the composition and patterns of the plant communities were organic matter, plant available nitrogen, calcium and moisture content. The results show major differences in soil physio-chemical properties and also in patterns and composition of vegetation communities between kraals and their surrounding areas. Evidence from the results show that kraal areas play an important role in determining key resource areas by influencing systematic distribution of nutrients. With kraals tending to increase the heterogeneity in the natural distribution of nutrients, it is apparent that animal waste deposited in the kraals modify vegetation patterns as high nutrient tolerant species gain competitive advantage over those that are not. The findings provide some important information that could explain herbaceous and woody species community patterns particularly in semi-arid environments where livestock management by the use of traditional kraals is a common practice.
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    Influence of Shea Tree (Vitellaria paradoxa) on Maize and Soybean Production
    (PLOS ONE, 2019-04-09) Ogwok, Gertrude; Alele, Peter O.; Kizza, Sarah
    Vitellaria paradoxa provides many benefits to farmers within the Shea belt. However, increased threats to it necessitate its conservation, and one common approach is the practice of agroforestry. A number of studies have shown that Shea tree has influence on crop production, and yet, some of these studies were done using single season experiments or bioassays using mature Shea tree components. In this study, the seasonal influence of young and mature Shea trees on Maize and Soybean yields was investigated using field experiments in Otuke district of northern Uganda, where, Shea tree parklands are dominant and Maize and Soybean are used for food security and income. Our results show that there are differential responses of maize and soybean yield to rainy seasons and physiological variations of Vitellaria paradoxa with age. We find yield reduction for maize more pronounced than yield reduction for soybeans under different Shea age (Mature and Young) for two rainy seasons. We attribute the variance to the differential maize and soybean responses to Vitellaria paradoxa shading and its differential allelopathic inhibition of these crops. We recommend that Soybeans should be preferred to maize when planting under Shea canopy.
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    Species Richness and Nutritive Values of Fodder and Their Relationship With Soil Characteristics in Ugandan Rangelands
    (Science Publishing Group, 2018) Kyoshabire, Christine; Kizza, Sarah; Rollanda, Karumuna
    A study was conducted to determine the species richness and nutritive values of fodder and their relationship with soil characteristics in the Ugandan rangelands. The aim of the study was to determine the current status and nutritive values of fodder species and their relationship with soil characteristics. Four fodder species Panicum maximum - Guinea grass, Spartinaalterniflora - Cord grass, Hyperreniarufa -Jaragua/thatching grass and Acacia spp were selected for the study. The species were counted to determine their richness in their rangelands and also tested to establish their nutritive values. The focus on nutritive values was on CP, NDF, Ca, P and K. The research also determined the soil characteristics pH, OM, N, P and K. Results of the study show that the fodder species were below the recommended levels of species richness in the rangelands. Spartinaalterniflora (Cord grass) had the largest coverage of 109.1Km2 (22.4%) out of 486Km2 in the rangelands while Acacia had the lowest coverage of 10.2 Km2 (2.1%). All the soil characteristics were below the minimum concertration levels apart from P and there was a significant difference in soil characteristics across the different locations (P<0.05). Average pH was 6.63, OM was 0.5%, and P was 74.09ppm while K was 17cmoles/kg. The most nutritious fodder species was Panicum maximum (Guinea grass). However all the fodder species were below the recommended nutrient levels. The mean concentration level of CP in all the fodder species was8.95%, Ca was 1.29%, P was 0.4%, K was 1.59% while NDF was 29%. There was no significant difference in level of concentration across all the fodder species (P>0.05). Reduction of overstocking; growing of Panicum maximum (Guinea grass) at farm level; and rotation of animals are recommended.