Agricultural Sciences

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    An assessment of nutritional knowledge, dietary practices and nutritional status of female students attending tertiary institutions in Lusaka, Zambia
    (The University of Zambia, 2019) Muzeya, Mahamba Verity
    University students tend to adopt unhealthy dietary practices when they move from a family home to attend school. Lack of quality foods can undermine health and wellness, leading to malnutrition and in the long run non-communicable diseases. Furthermore, malnutrition in women of reproductive age can increase risks of poor maternal health outcomes. Studies have shown that nutritional knowledge if implemented can lead to improved dietary practices and healthier lifestyles. It is observed that women are particularly affected by the nutrition transition, exemplified by a shift from traditional to globalized diets in urban populations. This study aimed at assessing the association between nutritional knowledge, dietary practices and nutritional status among female students aged 20- 35 years in three tertiary institutions of Lusaka. A total of 290 students participated, and a validated self – administered questionnaire consisting of students’ socio-demographic, nutrition knowledge and dietary practices was used. A food frequency questionnaire established individual students’ food intake. Weight, height and waist circumference were measured. Data were analyzed using Statistical Package for Social Sciences (SPSS Version 23) and MS Excel. Results indicated that the mean age for students was 22± 0.39 years. The median body mass index was 23.8 kg/m2 and interquartile range of 6.55 kg/m2. Students with normal body mass index were 53.8%, overweight and obesity were at 23.2 % and 15.5 % respectively, 7.42 % of students were underweight. The median waist circumference was 77cm with the interquartile of 14 cm, 83.8% had normal waist circumference and 16.2% had abdominal obesity. The mean nutritional knowledge score was 66.3% ±17. Students indicated that they obtained nutritional information from the internet followed by television. General dietary practices indicated that 62.1 % of the students exhibited poor dietary practices. Meal patterns before tertiary school and current meal patterns indicated that students had reduced eating breakfast, lunch and supper (p < 0.05), snacking on daily popcorn, potato chips and fruits was observead. There was no statistically significant ssociation between students’ nutritional knowledge scores and , asbody mass index well as with waist circumference. Further findings showed that there was no significant association between dietary practices and nutritional status of female students (p > 0.05). In conclusion, despite most students having a normal nutritional status, the prevalence of overweight and obesity was still notable. Also, despite students possessing adequate nutritional knowledge, they still exhibited poor dietary practices.
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    Effect of biochar amendment on the bioavailability of lead (Pb) in contaminated soils of Kabwe, Zambia.
    (The University of Zambia, 2019) Munthali, Kabenuka
    Biochar is an organic residue combusted under low oxygen conditions, resulting in a porous, low-density carbon-rich material. Biochar has the potential to reduce pollutant mobility when used as an organic soil amendment. Until recently, Biochars’ potential has not been extensively evaluated for this purpose. To that purpose, a greenhouse experiment was conducted to assess the effect biochar derived from maize corncobs on bioaccumulation of Lead (Pb) in Chinese cabbage (Brassica pekinensis) and Tithonia (Tithonia diversifolia). The soil biochar mixture was made on biochar/soil weight basis at the rate equivalent to 0 (control), 2, 4 and 8 % biochar of the soil weight which was seven (8) kg. The plants were grown in pots at the above mentioned four application rates and these application rates were replicated four times. The study results showed that there were no significant differences (p > 0.05) in the available Pb in the 0, 1 and 8% treatments for the Tithonia and Chinese Cabbage Pb contaminated soils. When the various plant parts were analyzed for Pb uptake across all treatments, only Tithonia at the application rate 8% had recorded a significant reduction (p<0.05) and a decreased uptake of 23.8% when compared to the control. Additionally, biomass yield comparison across all treatments showed that biochar application rate of at 8% significantly (p<0.05) increased yield at the rate of 20.3%. The results indicated that Pb could not be significantly (p<0.05) leached out of the soil profile. Thereby, implying that biochar application decreased the bioavailable Pb as well as its mobility at a higher application rate of 8%. Thus, this study provides results that show that biochar has the potential to reduce available Pb in contaminated soils.
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    Genetic analysis of tolerance to aluminum toxicity in maize (zea mays).
    (The University of Zambia, 2019) Ndeke, Victoria
    Aluminum (Al) toxicity causes high yield losses and is directly linked to acidic soils. Application of lime can ameliorate this problem, but it is costly and not feasible for small scale farmers as they need to purchase both seed and lime. Developing maize varieties that are tolerant to Al toxicity is cheaper and feasible for small scale farmers. The purpose of this research was to i) identify maize genotypes with tolerance to Aluminum toxicity, ii) evaluate the general and specific combining abilities for the inbred lines and crosses respectively, iii) investigate the type of gene action conditioning tolerance to aluminum toxicity in tropical maize, and iv) determine if shoot length can be used as an indirect selection criterion for Al tolerance. Fourteen maize inbred lines (CZL 083, L151, L552, CZL0814, CML312, L12, L3233, CML511, L917, L2, CML538, L5522, CML 457, and CZL04007) were evaluated in hydroponic conditions containing different concentrations of Al (0, 5, 10, 15 and 20mg/ L) in a 14 x 5 factorial completely randomized design with 3 replications at the University of Zambia, plant physiology laboratory. Five parameters were measured: root length, shoot length, number of root hairs, root and shoot biomass on eleventh day after seed placement. Highly significant differences (P=0.001) were noted for both root and shoot lengths. The results showed that inbred line CML 538 was highly tolerant while inbred line L151 was the most susceptible with mean lengths of 15.44 cm and 6.11 cm respectively. To address objective ii, eleven inbred lines were selected and mated in an 8 male (4 moderately tolerant and 4 susceptible) x 3 female (resistant) North Carolina Design II. Results revealed that GCA effects due to both males and females were highly significantly (P= 0.001) different from zero for root biomass. The shoot length GCA effects (8.75 and 12.81) due to both male and female respectively were significant (P=0.01). Similarly, the GCA effects due to females and males for root length were significant P= 0.01 and P=0.05 respectively. The SCA effects for the shoot length and root biomass were significant (P= 0.02). Both additive and non additive gene action were identified to be important for the root length as indicated by a Baker’s ratio of 0.49. The association of root length to shoot length was significant (correlation [r] = 0.72)
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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.