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Botswana University of Agriculture and Natural Resources (BUANR) 2017

Vegetation and soil conditions around water points in ranching and communal grazing systems in the hard veld and sandveld of Botswana

Seletlo, Zibanani

Titre : Vegetation and soil conditions around water points in ranching and communal grazing systems in the hard veld and sandveld of Botswana

Auteur : Seletlo, Zibanani

Université de soutenance : Botswana University of Agriculture and Natural Resources (BUANR)

Grade : Master of Science (MS) in Animal Science 2017

Résumé parteil
Artificial water sources or boreholes were introduced in Botswana to mitigate surface water scarcity in rangelands and aid livestock production. Gradually piospheres were observed, areas close to water points experienced high grazing pressure, trampling, and excreta deposition as animals congregate at a reduced area for water, causing changes in vegetation and soil conditions. The magnitude of grazing and animal movements reduces as animals move away from water points as an area of impact increases. Nonetheless, whether the above phenomenon takes place in different grazing management systems and ecological zones is poorly understood. Therefore the objective of this study was to investigate the effects of distance around water points, grazing management systems (ranches and communal grazing areas) and ecological zones (hardveld and sandveld) on vegetation and soil conditions. Vegetation conditions included grass species abundance, woody plant density, and plant diversity (grass and woody) and soil conditions included soil pH and mineral status. In each zone, 2 ranches and 2 adjacent communal grazing areas were used for this study. One water point was used as a reference point for 4 randomly placed transects of 1000m in length radiating in different directions from the water source at each site. Four plots measuring 50mx20m were placed at intervals of 250 m along each transect. Within the 50m.x20m plot, grass species abundance was estimated in a 10mx10m plot while woody plant density was estimated in the 50mx20m plots. Shannon-Wiener index was used to calculate plant species diversity. For soil conditions, soil samples were collected in the first and last 50mx20m plots along each transect. At each sample plot, a soil sample was collected as a composite sample from 5 randomly collected samples that were mixed together in a bucket. From the mixture a composite soil sample was collected so as to avoid small spatial 1variations. All soil samples were analyzed for soil pH, macro (Mg, Ca, K, Na, P and N) and micro (Fe, Mn, Zn and Cu) minerals.

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Page publiée le 20 décembre 2022