Papers by Benedict Kayombo
World Journal of Advanced Engineering Technology and Sciences
The Revised Universal Soil Loss Equation (RUSLE) model integrated with Remote Sensing (RS) and Ge... more The Revised Universal Soil Loss Equation (RUSLE) model integrated with Remote Sensing (RS) and Geographical Information Systems (GIS) was positively validated to spatially assess soil erosion risk in the Taung Watershed of Ramotswa Agricultural District during the period 2000 – 2020. The estimated annual soil erosion averaged 12.04 and 12.74 t/ha/year in 2000 and 2020, respectively. The Land Use/Land Cover (LULC) and soil type were found to be key determinants of high soil erosion hazard when using RUSLE. The soil erosion assessment tools enabled prioritization of high erosion prone areas in the study area for soil conservation planning and watershed management.
Global Journal of Engineering and Technology Advances
The Soil Loss Estimation Model for Southern Africa (SLEMSA) model integrated with Remote Sensing ... more The Soil Loss Estimation Model for Southern Africa (SLEMSA) model integrated with Remote Sensing (RS) and Geographical Information Systems (GIS) was positively validated to spatially assess soil erosion risk in the Taung Watershed of Ramotswa Agricultural District during the period 2000 – 2020. The estimated annual soil erosion averaged 11.77 and 12.57 t/ha/year in 2000 and 2020, respectively. The Land Use/Land Cover (LULC) and topography were found to be key determinants of high soil erosion risk when using SLEMSA. The soil erosion assessment tools enabled prioritization of high erosion prone areas in the study area for soil conservation planning and watershed management.
World Journal of Advanced Engineering Technology and Sciences
Soils are a potentially viable sink for atmospheric carbon and could contribute to mitigating glo... more Soils are a potentially viable sink for atmospheric carbon and could contribute to mitigating global climate change. Soil Organic Carbon (SOC) content exhibits considerable spatial variability both horizontally (land use) and vertically (soil profile). Land cover land use (LCLU) is one of the key determinants of SOC stock, hence there is a significant variation of SOC across different LCLUs. This study aimed to investigate the spatial variability of SOC across different LCLUs in the Greater Gaborone region of Botswana. Remotely sensed data used for image classification was obtained from the United States Geological Survey (USGS) Earth Explorer (www.usgs.gov). The imagery used in this study was Sentinel-2A obtained in the month of March with cloud content of less than 10% for easy interpretation. Image classification was done using a supervised classification method based on a Maximum Likelihood classifier. The major LCLU types identified in the area included water bodies, trees domi...
World Journal of Advanced Engineering Technology and Sciences
A study was conducted in Dinogeng Agricultural Extension Area (DAEA) of Kgatleng District, Botswa... more A study was conducted in Dinogeng Agricultural Extension Area (DAEA) of Kgatleng District, Botswana, with the objective of assessing current soil erosion risk (using 2020 Landsat imagery) resulting from the Integrated Support Programme for Arable Agricultural Development (ISPAAD) that was launched in 2009. The Soil Loss Estimation Model for Southern Africa (SLEMSA) tool integrated with Geographical Information System (GIS) and Remote Sensing assessed the soil erosion risk in the study area. The results indicated that 88% of DAEA has low to moderate soil erosion risk (0 – 2 tha-1yr-1). Only 12% of the study area experience very high to extreme high erosion risk (5 - ≥10 tha-1yr-1) along the streams, at steep slopes and areas of bare land. Common practice calls for conservation measures to be applied on areas with high soil loss. This study has underscored the role of topography and soil erodibility, as natural factors, in driving soil erosion.
Changes in land cover and land use (LCLU) have been observed in the greater Gaborone area of Bots... more Changes in land cover and land use (LCLU) have been observed in the greater Gaborone area of Botswana since the 1980s. These changes are driven by human and livestock population pressures, rapid urbanization, and socioeconomic and industrial development. Being able to predict LCLU changes is useful for policy and land use planning. Advances in geospatial modelling techniques have become central to the monitoring and assessment of past and future LCLU changes. This study employed the Module for Land Use Change Evaluation (MOLUSCE) to simulate LCLU in 2042 based on the current LCLU. Classified Landsat images from 1988 and 2002 and Sentinel 2A images were used to simulate the likely LCLU changes between 2022 and 2042. Model validation was done by comparing the Kappa statistics for the simulated and actual 2022 LCLUs. The Kappa coefficients for the actual and simulated images were 0.93 and 0.79, respectively. The simulation results showed a projected increase of 65.81 km2 and 28.19 km2 ...
World Journal of Advanced Engineering Technology and Sciences
A greenhouse experiment was conducted at Botswana University of Agriculture and Natural Resources... more A greenhouse experiment was conducted at Botswana University of Agriculture and Natural Resources for 10 weeks (19 March – 28 May 2019) under irrigated conditions. The objective of the experiment was to evaluate the effect of vermicompost on the growth and yield of beetroot (Beta vulgaris) under (i) four doses of vermicompost, (ii) three doses of mineral fertilizer, and (iii) ordinary soil (as control). A randomized complete design had polyethylene pots with 8 treatments, namely 4 doses (5, 10, 20 and 30 tonne/ha) of vermicompost, 3 doses (50, 100 and 200% of 50 kg bag/ha) of NPK (2:3:2) and ordinary soil (as control), of three replicates. Data on growth and yield parameters were analyzed using the Statistical Analysis Software computer package (SAS version 9.3). Analysis of variance and means were separated using Duncan’s multiple range test at 5% confidence level. The results of this study showed that 30 tonne/ha vermicompost treatment gave great potential to increase the performa...
This study assessed the socio-economic potential of the Rain Water Harvesting (RWH) techniques fo... more This study assessed the socio-economic potential of the Rain Water Harvesting (RWH) techniques for crop production in the semi-arid area of Bobirwa Sub-district, Botswana. The main methods used to collect the data were the Participatory Rural Appraisal (PRA) approaches and researcher-farmer managed field experimentation. The data collected included the constraints to crop production and available ways of conserving soil moisture in the study area. Viability, acceptance and perception of farmers towards RWH technologies in the Sub-district were also assessed. Constraints faced by farmers in arable farming were identified as low and unreliable rainfall, pests and diseases and lack of farm implements (ranked in order of severity). Researcher-farmer managed trials were carried out with various catchment area sizes against a cropped area of 25 m2. Catchment area sizes were 25m2, 50m2, 75m2 and no catchment, resulting in catchment area to cropped area ratios of 1:1, 2:1 3: 1 and 0:1 (a co...
Chapter 1 presents an approach that enables water managers to assess suitability of RWH in a give... more Chapter 1 presents an approach that enables water managers to assess suitability of RWH in a given area by taking advantage of the capabilities of Earth Observation techniques and fuzzy multi-criteria analysis. With the Fuzzy AHP approach, unlike traditional AHP, the decision maker's attitude towards risk is adequately reflected by an optimism index while the degree of confidence is handled using a-cut. Chapter 2 analyzes an investigation of soil surface conditions and their runoff generation potential by means of field experiment and model predictions. Chapter 3 characterizes soil tillage surface conditions on their runoff generation potential using micro-catchment RWH systems and appraises these RWH systems resulting from different tillage systems on crop performance. Chapter 4 assesses the socio-economic potential of the RWH techniques for crop production in the semiarid area of Bobirwa Sub-district, Botswana. The results showed a catchment area to cropped area ratio of 3:1 h...
Conservation agriculture (CA) is an important alternative farming system in the control and impro... more Conservation agriculture (CA) is an important alternative farming system in the control and improvement of the soil regimes in vertisols for increased crop production. A field experiment was conducted at the Department of Agricultural Research station at Pandamatenga, Northern Botswana during the 2015-2017 planting seasons. The objective of the experiment was to evaluate the effects of CA technologies on sorghum grain yield in the vertisols of Pandamatenga region. A randomized complete block design was used for the on-station field experimentation. The design had trial plots with four treatments, namely No tillage (NT), No tillage + mulch (NT+M), Minimum tillage (MT), and broad bed and furrow (BBF), with four replicates rotated between sorghum and cowpea. Sorghum grain yield results were analysed using the Statistical Analysis Software (SAS version 9.2). Analysis of variance and means were separated using Duncan’s multiple range test at 5% confidence level. On average no tillage (59...
World Journal of Advanced Engineering Technology and Sciences, 2020
This study was conducted at Pandamatenga of Chobe District in northern Botswana. The main aim of ... more This study was conducted at Pandamatenga of Chobe District in northern Botswana. The main aim of the study was to evaluate the Decision Support System for Agrotechnology Transfer (DSSAT) model in the prediction of sorghum yields under Conservation Agriculture (CA) technologies. A field experiment was conducted at the Pandamatenga Agricultural Research station during the 2015-2017 growing seasons. A randomized complete block design was used for the on-station field experimentation. The design had trial plots with four treatments, namely No Tillage (NT), No Tillage + Mulch (NT+M), Minimum Tillage (MT), and Broad Bed and Furrow (BBF), with four replicates rotated between sorghum cowpea. Sorghum grain yield results were analyzed using the Statistical Analysis Software (SAS version 9.2). Analysis of variance and means were separated using Duncan’s multiple range test at 5% confidence level. The DSSAT model was evaluated using the experimental data and weather data for the growing periods...
Journal of Engineering Research and Reports, 2018
The impact of partially treated wastewater on the water quality of Notwane river stretch in the G... more The impact of partially treated wastewater on the water quality of Notwane river stretch in the Gaborone region of Botswana was investigated. Water samples collected at effluent discharge point and three other sampling sites downstream were analyzed for pH, temperature, Biological Oxygen Demand (BOD5), Ammonia-nitrogen (Ammonia-N) and Nitrate-nitrogen (Nitrate-N). Sampling was conducted bi-weekly between February 2013 and April 2013. The ranges of measured parameters were: pH (7.6-8.5), temperature (22-23ºC), BOD5 (11.2-27.0 mg/l), Ammonia-N (2.4-60.5 mg/l), Nitrate-N (20.6-28.6 mg/l). Analysis of variance, Games-Howel multiple comparisons and Pearson correlation were used to separate variable means. The results signal river non-point pollution due to runoff inflow of organics mainly from land use and domestic waste dumping by nearby dwellings. Temperature, BOD5, and pH range values were all within the Botswana Bureau of Standards (BOBS) limit while the maximum Ammonia-N and Nitrat...
International Journal of Plant & Soil Science, 2016
Botswana Journal of Agriculture and Applied Sciences, Sep 8, 2014
A study to document indigenous knowledge (IK) and best-bet practices (BBPs)was carried out during... more A study to document indigenous knowledge (IK) and best-bet practices (BBPs)was carried out during Phase I (2003-2004) of Desert Margins Programme (DMP), whose overall objective is to arrest land degradation in the desert margins of Africa through demonstration and capacity building activities. The documentation work was executed in Bobirwa Sub-district and Kgalagadi District using a structured questionnaire, the sample size of which depended on the identification ability of initial informants for more respondents. The study showed the importance of IK on the effective functioning of the traditional leadership to monitor-and-ensure adherence. Traditional leadership played an important role in protecting some animals and trees and continuously ensured there were active advisors to assist in monitoring the environment. The study further showed that past (indigenous and best-bet) practices were labour intensive and capable of exploiting limited amounts of natural resources which could only satisfy the needs at household level. The predominant existing practices in both districts are the vegetation practices. These practices such as selective cutting of trees, grass cutting using hands or sickle, and harvesting medicinal roots/tubers by replacing soil thereafter, have contributed to sound management of natural resources. Arable practices have, however, undergone some phenomenal transformation including use of tractors for cultivating large areas across the slope. Expanding human population and its associated demands on the environment necessitate the impending need to realign conflicting legislation and implement environment-compatible policies to sustain existing BBPs. Keywords : Botswana, indigenous knowledge (IK), past and existing best-bet practices (BBPs), sustainable natural resources management
World Journal of Advanced Engineering Technology and Sciences, 2021
The adoption of conservation agriculture among small-scale farmers is still low despite the prove... more The adoption of conservation agriculture among small-scale farmers is still low despite the proven economic and environmental benefits of the technology. This study was conducted at Pandamatenga of Chobe District in northern Botswana. The main aim of the study was to determine the factors that influence the adoption of Conservation Agriculture (CA) in the study area. A structured questionnaire was used for the collection of the socio- economic and demographic characteristics of the sampled smallholder rainfed farmers. The socio - economic characteristics of the smallholder rainfed farmers included land holding size (ha), labour availability, livestock possession, education level, and farming experience. Demographic characteristics considered in the study included smallholder rainfed farmers’ age, marital status, gender, and average number of family members in the household. Data was analysed using descriptive statistics and the logistic regression model. The results have shown that ...
Conservation agriculture (CA) is an important alternative farming system in the control and impro... more Conservation agriculture (CA) is an important alternative farming system in the control and improvement of the soil regimes in vertisols for increased crop production. A field experiment was conducted at the Department of Agricultural Research station at Pandamatenga, Northern Botswana during the 2015-2017 planting seasons. The objective of the experiment was to evaluate the effects of CA technologies on sorghum grain yield in the vertisols of Pandamatenga region. A randomized complete block design was used for the on-station field experimentation. The design had trial plots with four treatments, namely No tillage (NT), No tillage + mulch (NT+M), Minimum tillage (MT), and broad bed and furrow (BBF), with four replicates rotated between sorghum and cowpea. Sorghum grain yield results were analysed using the Statistical Analysis Software (SAS version 9.2). Analysis of variance and means were separated using Duncan’s multiple range test at 5% confidence level. On average no tillage (59...
Journal of Rural and Development, 2016
Rain water harvesting (RWH) is described as concentration, collection, storage and use of rain fa... more Rain water harvesting (RWH) is described as concentration, collection, storage and use of rain fall via runoff for various purposes such as domestic, livestock and agricultural use. RWH systems can be classified as macro, mini, micro and in-situ. A study was carried out during the 2013/14 cropping season to (1) characterize the soil tillage surface conditions on their runoff generation potential using micro-catchment RWH systems and (2) appraise the micro-catchment RWH systems resulting from different tillage systems on crop performance. For the first objective, a Completely Randomized Block Design comprising of three blocks of runoff/catchment plots measuring 25 m2, 50 m2 and 100 m2 were laid out. Within the same plots/ rainfall catchment, the following four soil surface conditions were imposed: Ploughed with mouldboard surface (PS), Ploughed with mouldboard and un-weeded surface (UP), Ploughed with mouldboard and subsequently harrowed surface (HS) and naturally vegetated surface (...
Rain Water Harvesting (RWH) is any system that encompasses methods for collecting, 12 concentrati... more Rain Water Harvesting (RWH) is any system that encompasses methods for collecting, 12 concentrating and storing various forms of runoff for various purposes. Agriculture in 13 semiarid tropics depends on the vagaries of weather, especially of the rain. Without 14 doubt, the greatest climatic risk to sustained agricultural production in these areas, 15 including Botswana, is rainfall variability. RWH has the potential to mitigate spatial and 16 temporal variability of rainfall. Many methods of evaluating suitability for RWH, however, 17 have limitations and/or drawbacks.
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Papers by Benedict Kayombo