Agricultural Sciences

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    Determination of sediment, water quantity and quality for swat modelling of sedimentation in the Makoye reservoir, southern province, Zambia.
    (University of Zambia, 2020) Muchanga, Manoah
    Reservoir sedimentation is one of the temporally and spatially distributed challenges facing managers of small reservoirs today. Fluvial system formed the geomorphological plinth of the study. The study was motivated by the problem of sedimentation in the Makoye Reservoir (about 60500 m2), which had been affecting 474 pastoralist households rearing over 10,000 cattle. The objectives of the study were to: (i) determine the bathymetry of the Makoye Reservoir at different temporal scales; (ii) measure the long-term quantity of sediment deposited in Makoye Reservoir; (iii) determine the short-term real time sediment settling rate in the Makoye Reservoir; (iv) examine concentration levels of selected physical and chemical parameters of water for livestock in Makoye Reservoir; (v) evaluate the efficiency of Soil Water Assessment Tool in simulating sedimentation in the Makoye Reservoir; and (vi) to develop a conceptual model for understanding sedimentation process in small reservoirs in Zambia. The study used Critical Analytical Experimental Research Design implicitly inspired by Critical Empirical Analytic Paradigm. Five bathymetric surveys were conducted using a Remote Controlled Hydrographic Survey Boat with the aid of an inflatable boat. Sediment pits (195) were dug across the dry reservoir bed with aid of picks, ranging poles, measuring tape, Differential Global Position System and iron pegs. Real time sediment depth was measured using SediMeter SM3A, whose 36 Optical Backscatter Detectors captured sediment depth with resolution of 0.001 mm. The data inputs for Sediment simulation included the 90m Shuttle Radar Topography Mission Digital Elevation Model (SRTM DEM) , weather data, soils and landuse maps. Three soil samples (50cm) were collected using augers, and suspended and settled sediment samples were collected using grass carpets and coring. Bathymetric data was analysed using 3D Spatial Analysts Tools (3DSATs) in ArcGIS 10.3 and spreadsheet Microsoft Excel. This enabled determination of volumes, surfaces areas and development of hypsometric curves showing relationship among water depths, volume and surface areas. Real time sediment data was analysed using descriptive statistics and time series. Simulated sediment data was analysed using SUFI-2 in SWATCUP 2012. Soils, sediment and water physico-chemical analysis were done in the Soils Sciences and Environmental Engineering laboratories at the University of Zambia, respectively. Seasonal comparison of reservoir's bathymetries and water volumes showed drastic changes in average depths and volumes of water (24,830.93 m3 to 75,974.21 m3). This supply was below the water demand for cattle due to diverse physical processes (weather conditions, drainage hydro-geomorphology and mainly, sedimentation). On average, the real time daily sediment settling rate was 0.0003 m/day. Between 1988 and 2017, the average rate of long term sedimentation was 5,834.12 tonnes/year. SWAT efficiently simulated sediment with both r2 and NSE at 0.77 and 95PPU at 57 percent. Sediment was sourced from Agricultural land (35%) grazing land (26%), deciduous forest (22%) and range-brush land (17%). Water quality was influenced by sediment upstream and 80 percent of its chemicals parameters were within Maximum Permissible Limits for cattle. The study designed a conceptual model on understanding and simulating sedimentation by integrating sediment depths from Sedimeter SM3A and regression model, which can be adapted to different spatial and temporal contexts. Conclusively, the reservoir was highly silted with about 54 percent of its capacity reduced. Community and government agencies awareness on how to reduce sedimentation in the catchment is highly recommended. Key Words: Bathymetry, Geomorphology, Sedimentation, Sedimeter SM3A, SWAT Modelling
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    Utilization of plant functional traits in mitigating over-exploitation of high ethnobotanical value plants of Chongwe district, Zambia.
    (The University of Zambia, 2023) Mwambo, Matthews
    Traditionally valued wild indigenous plants play a critical role in various ethnic groups. Ethnobotanical value of plants differ according to the regions and ethnic groups. Despite the rich ethnobotanical value of tropical plants, there is still limited knowledge and no documentation on specific plant species use in Chongwe district. Besides, little effort has been made to cultivate them ex-situ or in-situ in Zambia leading to their decline. This may be due to limited knowledge in indigenous plant regeneration bringing about a challenge in optimizing their germination that can help in their restoration. Studies have shown that ethnobotanically valued plants are susceptible to over-harvesting leading to a reduction in plant abundance. This research, therefore, sought to highlight the plant species of high ethnobotanical value and study the effect of fruit weight, seed shape and seed depulping on seed germination and seedling emergence to propose optimal methods in improving seed germination performance. Ethnobotanical data was collected using convenience and snowball sampling methods. Semi-structured questionnaires were administered to fifty informants. Interviews were conducted in Nyanja, Bemba and English depending on the preference of the informants. Local names and the uses of the plant were recorded. It was found that most of the plant species in Chongwe were used for medicine purpose (33.6%) and Fabaceae emerged as the most used plant family. Out of the twenty most ranked native species in terms of cultural value, eight fruiting species of highest ethnobotanical value were exposed to experimentation to determine whether variables (fruit weight and seed shape) and treatments (depulped not washed and depulped washed) affected germination performance from August 2020 to January 2021. A stratified randomized design layout was used to place seed pots in the plant shed in the Department of Biological Sciences for an even v distribution of environmental parameters among treatments and to eliminate bias. Primary ethnobotanical data obtained from questionnaires was analysed using Excel while the experimental analysis on germination performance was done using Statistical Package for Social Science (SPSS). This study showed that seedling emergence were significantly affected by seed shape (P < 0.05) as seedling emergence reduced from spherical to spindle seeds Germination rate was significantly affected by fruit weight (P < 0.01) with a negative correlation coefficient of (-1.000) as germination rate increased with the reduction in fruit weight. Depulping and washing of seeds had a significant effect on germination percentage (P < 0.05) with 61.5% depulped washed seeds germinating. Germination percentage increased significantly for the depulped washed seeds compared to the pulped (13.5%) and depulped not washed seeds (25%). Therefore, selecting seeds from smaller fruits and spindle shaped seeds of the studied species and as well as depulping and washing the seeds can give a high germination percentage. This can contribute to sustainable management of ethnobotanically valued species. Keywords: Ethnobotanical values; Plant functional traits; Seedling Emergence; Germination Rate; Germination Percentage.
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    Sustainable intensification of management practices in cassava production systems of Luapula province of Zambia.
    (The University of Zambia, 2022) Kaluba, Peter Kasolota
    Cassava (Manihot esculenta Crantz) is a staple food and a main source of income for several smallholder farmers. However, its yields are low at about 6 t/ha, lower than actual yields of 20–25 t/ha in Zambia. The main objective of the study was to assess sustainable management practices in cassava production systems among smallholder farmers in Luapula Province of Zambia. A baseline study aimed at understanding cropping management practices and their effects on selected soil nutrient adequacy levels and tuber yield was carried out. Using baseline results, a field experiment was conducted aimed at assessing the performance of cassava under lime, fertilizer and grain legume intercropping on exhausted soils. Common bean being the most intercropped légumes in cassava systems with low grain yields at 0.5 t/ha partly due to leafy defoliation, an, assessesment of the effects of leaf defoliation intensity and fertilizer on growth, RUE and yield of three common bean varieties was conducted. The data generated from these experiment was analyzed using the linear mixed models at 5% levels of significance using the R software. Multiple regression analyses was performed on significantly correlated variables. The study found K and P to be highly suitable for optimal cassava production, although yields declined by 209 and 622 kg/ha at 12 and 36 for each year of cultivation without fertilizer application. Field use in the study area was limited to 8–9 years due to soil nutrient depletion. The synergistic effect of exchangeable K on growth was limited by the low to moderate availability of soil organic carbon (SOC), Ca, Mg and low N. These limited the growth and consequently reduced intercepted radiation and low yields, thus the need for routine balanced fertilizer regimes. On average, for every kg of cassava yield loss in intercropping was compensated by 0.46 kg soybean, 0.20 kg common beans and 0.26 kg of cowpea. Cassava LAI, RUE, tuber yield and grain legume yields were significantly increased by liming, fertilizing and legume species intercropping. The use of amendements achieved cassava yields obtained between 24–36 MAP under shifting cultivation at 12 MAP. The RUE reductions were higher in fertilized than unfertilized treatments. Fertilizing indeterminant growth habit common beans enhanced growth, producing optimal grain and biomass yield at 25% defoliation intensity. To promote adoption, liming, fertilizing and legume intercropping at 25% defoliation intensity in cassava production systems should be conducted on exhausted soils in farmer‘s field
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    Assessment of pica and associated factors among pregnant women attending antenatal clinic at Chelstone level on hospital and Mtendere clinic, Lusaka district, Zambia.
    (The University of Zambia, 2022) Ngoma, Thelma
    Pica prevalence rate among pregnant women is estimated to be about 52% to 86% in African countries. In Zambia, there is paucity of evidence on the prevalence of pica in the country despite the evidence in literature of harmful health outcomes for both mother and child. The aim of this study, was to establish the prevalence of pica and associated factors among pregnant women at Chelstone Level-one Hospital and Mtendere clinic, in Lusaka District in Zambia. The study was cross-sectional and utilized mixed methods in data collection and analysis. The study population included pregnant women aged 15 - 49 years. Data was collected using structured questionnaire which had sections for demographic and socio-economic characteristics and anthropometry. Mid-upper arm circumference (MUAC) was measured using a non-stretchable adult MUAC tape for pregnant and lactating women and the haemoglobin concentration was measured using the Abx-micros automated machine. Statistical Package for Social Sciences (SPSS) version 23.0 was used to analyse data. Descriptive statistics were used to describe the study population. A chi-square test was conducted to establish the association between pica and various categorical variables including the haemoglobin levels and the women’s nutritional status. Logistic regression was conducted to establish factors that are independently associated with pica. A total of 372 pregnant women were interviewed in this study. Majority of the participants 48.7% (n=181) were between the ages of 26-35 years. Prevalence of pica in the present study was 38.2% (n=142). Soil [84.6% (n=120)} was the most consumed and favoured followed by ice {11.9% (n=17)}, charcoal {3.5% (n=5)} was the least consumed. Majority of participants indulged in their pica practice due to cravings {62% (n=88)}, sensory reasons such as the pleasant texture, taste, or smell {16.9% (n=27)}, for controlling nausea and vomiting {15.5% (n=22)} and others. There was no significant association between nutrition status, hemoglobin level and pica practice. However, logistic regression showed a statistically significant association between history of pica and pica practice (OR=0.169; 95%CI: 0.100-0.286; p=0.00). The study accentuates the need for health education and counselling on pica among pregnant women. Key words: Pica, Pregnant women, Nutrition status, Heamoglobin
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    Prevalence and incidence of hypertension and diabetes mellitus in HIV infected persons on HAART in Chongwe district in Lusaka province.
    (The University of Zambia, 2022) Hamoonga, Bona Mwiinga
    The Zambia National strategic plan (ZNHSP)-2011-2017 highlights the need for risk factor stratification at the community level to form the basis of incidence and prevalence data, which are currently inadequate. This research aims to determine the prevalence and incidence of hypertension and diabetes among HIV infected patients on Highly Active Anti-Retroviral Therapy (HAART) and its association with ARVs use. A retrospective cohort study was used using the SMART CARE electronic database in Chongwe district to assess 2,070 HIV infected persons on HAART. Data was analyzed using SPSS version 20, and analyzed using Chi-square Kruskal-Wallis for analysis of variance, and logistic regression was used to establish the determinants of hypertension and type II diabetes mellitus among HIV infected persons on HAART. 33.8% HIV positive clients on HAART had hypertension, and an incident case fatality rate of 85.7 cases per 1000 PYFU of hypertension. The prevalence of hypertension was significantly higher (χ2=49.238, df=1; p<0.001) among men (64%) than among women (49%). The prevalence of hypertension also differed significantly (χ2=11.194, df=2; p=0.004) among different age categories and was highest (57.2%) among the 18-45 years age bracket. This study also found a significant correlation between hypertension and age of client in years (p=0.009). The study also found an incident rate of 37.4 cases per 1000 PYFU of T2DM. This study also established no significant differences in the prevalence of type II diabetes mellitus between women (26%) and men (23%). However, the prevalence of diabetes differed significantly ((χ2=10.043, df=2; p=0.007) among different age categories and was highest (27.5%) among the 56 years and older age bracket. Results of logistical regression analysis for the determinants T2DM and hypertension show that ART combination (p=0.001), age category (p=0.011) and cigarette smoking (p=0.0460) significantly added to the prediction model for T2DM outcome; and that ART combination (p=0.004), sex (p=0.001), family history of hypertension (p=0.007) and cigarette smoking (p=0.001) had significant associations with and significantly added to the prediction model for hypertension outcome. HIV positive clients on HAART had high prevalence and incidence of hypertension and type II diabetes mellitus. HAART combination regimen of two NRTI classes plus either a PI or INSTI were associated with higher incidence of hypertension whilst combination regimens of two NRTIs plus an NNRTI or INSTI and combination therapy of NRTI+NNRTI+INSTI were associated with higher incidence of type II diabetes mellitus in HAART treated clients.