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SummaryIndigenous Tswana pigs are mostly found in Southern Botswana. There is concern that the breed may become extinct due to the low usage of the breed and the lack of implementation of a comprehensive conservation strategy. The objectives of this study were to identify places where indigenous Tswana pigs are kept in Gaborone Agricultural Region and document the numbers, distribution, management and utilisation of these pigs. A formal questionnaire was administered to all indigenous pig farmers who could be identified. The data was analysed using procedure frequency in Statistical System Analysis. A total of 51 indigenous pig farmers were interviewed, of these 71%, 16% and 14% were in Southeast, Kgatleng and Kweneng districts respectively. Only one farmer kept crossbreeds with the majority keeping pure indigenous Tswana. A total of 124 sows, 23 boars, 32 castrates and 211 piglets were counted in this region. All the pigs were kept under the communal system. None of the farmers surveyed kept records and they exhibited limited knowledge of pig farming and improved management. Pigs were kept for home consumption with very few sold, given out as gifts or loaned out. Pig fat was used as a by-product to make soap and a lubricant in traditional leather rope making. The farmers’ perception of indigenous pigs is good; they claim that the pigs posses traits of economic importance such as high heat and drought tolerance, which are of great significance in the harsh climatic conditions of Botswana. There is a need to undertake conservation efforts for this breed given that it survives and reproduces under harsh climatic conditions and sub-standard management. More research and further action is required to increase the production of this breed.

This study was aimed to determine the extent to which Prosopis species had invaded four settlements (Bokspits, Rappelspan, Vaalhoek and Struizendam) located in the Kgalagadi Desert south west of Botswana, investigate the perceptions of the communities about the existence of the species in their environment and assess possible control options for the spread of Prosopis plants in the area. Prosopis plants were sampled in 42 quadrats of 625 m 2 along a 70 km Prosopis invasion gradient from Struizendam to Rappelspan. Using the Global Positioning System (GPS), the locations of all quadrats were established. The distribution map of Prosopis plants was produced using ArcGIS 9.2 (ESRI Inc.). Questionnaire survey and focused group discussions were used to collect data on the perceptions of rural communities about the species. A total of 342 respondents comprising 139 males and 203 females were interviewed, and four focussed group discussions were conducted. The results indicated that the invasion of Prosopis species was prominent in and around settlements suggesting that anthropogenic activities had a significant role in the spread of Prosopis plants in the area. The perceptions of rural communities about Prosopis plants appeared to be moulded by the impacts of the plants on their livelihoods as well as their micro-economic status. The respondents (71.30%) expressed the view that the invasion of Prosopis species negatively affected the livelihoods of the communities in the study area. They identified eradication as the preferred method of controlling the spread of Prosopis plants. On the contrary, this study recommended the integrated environmental management paradigm as the best options for the control of the spread of Prosopis plants in the area.

The aim of this research was to investigate the interactions between Prosopis plants and soils in the Kalahari area, south west of Botswana. The underlying assumptions of the research were that Prosopis plants significantly enhanced the nutrient content and improved the condition of soils in the study area, and that the height and canopy size of Prosopis plants affected the interactions between Prosopis plants and the soils. Firstly, soil samples were collected under 42 randomly selected Prosopis plant canopies and in the spaces between Prosopis plant canopies at the depth of 0-20 cm and 60-80 cm. Secondly, soil samples were collected under 45 randomly selected Prosopis plant canopies of three different categories of height and canopy size at the depth of 0-10 cm. The soil samples were analysed for soil organic carbon, pH, total nitrogen (N), electrical conductivity (EC), calcium (Ca), sodium (Na), potassium (K), and magnesium (Mg). Soil collected under Prosopis plant canopies and in the spaces between Prosopis plant canopies showed statistically significant difference in the soil organic carbon content (F = 2.68, P = 0.05, α = 0.05), pH (F = 44.81, P < 0.001; α = 0.05) and electrical conductivity (EC) (F = 3.75, P = 0.01, α = 0.05). Statistically significant difference was also observed in the comparison of soils existing under Classes 1, 2 and 3 Prosopis plant canopies in relation to pH and EC (F = 6.56, P = 0.01 and F = 4.77, P = 0.01 respectively at α = 0.05). Therefore, it was concluded that the fundamental assumptions of the study were valid.

Spatial variability of selected soil attributes were investigated in the Kgalagadi region. Soil samples were collected along transects at Hukuntsi, Tshane, Lokgwabe and Lehututu at 50 m, 200 m, 500 m, 1000 m, 2000 m and 5000 m from water sources located in areas of different land use types. Sampling depth was 0 - 10 cm, 50 - 70 cm and 100 - 120 cm. Samples were analysed for pH, EC, SOC, and P. Soil pH and EC were relatively high around CGA Pans, while SOC and P were generally low in the whole study area. It was concluded that the assumptions that different land use types existed under various soil environments with different soil properties, and that different land use types influence soil characteristics in various ways in the study area were not true