Characterization of agriculture-related land degradation in eastern and western parts of Botswana

Abstract

A study was carried out during 1998-2001 with the objective of, firstly, assessing the impact of cultivation on soil quality, and secondly, evaluating the effects of human and animal activities on soil erosion and range resources. A Topical Rapid Rural Appraisal (TRRA) based on rapid appraisal approaches, was conducted in three benchmark villages in Bobirwa Sub-district. A diagonistic survey report provided similar information for Kgalagadi District. Three benchmark sites were located in Bobirwa Sub-district and two others in Kgalagadi District. Soils were characterized at benchmark sites and in the laboratory for physiochemical properties. Soil erosion was monitored using embedded nail technique. At all benchmark sites, trends show a deterioration of soil quality, both in terms of nutrient depletion and poor physical properties for cultivated soils in comparison to uncultivated soils. There is visible evidence of environmental degradation of land resources resulting partly from considerable soil trampling and loosening during the dry season by livestock. During the wet season, the loosened soil is washed down elsewhere and/or deposited at watering points. The confounding effects of drought, overgrazing, poor management and ever-increasing utilization of veld products have led to the decline of a considerable number of tree and grass species.