The Effect Of Bush Clearing On Soil Properties, At Cheetah Conservation Fund Farm In Otjozondjupa Region, Namibia

Abstract

The thesis discusses the problem of bush clearing as they affect soil quality, its productivity and environment in the semi-arid areas. In this case, land clearing came as a result of bush encroachment control mechanism. Bush encroachment is a form of land degradation present prominently in semi-arid areas. Namibia is affected by bush encroachment on a massive scale. The phenomenon is currently understood to affect large part of the country, causing severe economic losses for Namibia, in both the commercial and communal farming areas. The primary aim of the study was to investigate the effect of bush clearing on soil quality, particularly the soil macro-nutrients, N, P and K.

The study was conducted on one farm, Cheetah Conservation Fund (CCF) on two experimental fields. Samples were taken from two differentiated (cleared and non-cleared area) ecosystems. Fifty (50) soil samples were collected at depths of up to 30 cm. In each field 25 samples was collected, the samples were collected at 200 metres interval. The soil was tested for selected macro-nutrients and micro-nutrients. Soil texture and composition was also tested as well as electrical conductivity, pH, and soil organic matter.

The bush encroached site differed significantly from the cleared site with regards to nitrogen content, where high nitrogen content was recorded in the encroached site. The high occurrence of N content in the bush encroached site explain the nitrogen fixation by leguminous trees.

Contrary to the study’s initial hypothesis, which hypothesized that there is no significant difference in SOM between bush-cleared and bush encroached sites, the study found that there is however a significant difference in the median SOM between the two sites.