The impact of soil erosion on soil physiochemical variability on the upper and lower bench terraces in Kigezi highlands

Abstract

Soil erosion is widely recognized as one of the major factor contributing to land degradation globally and adversely affects agricultural production. Soil erosion is more pronounced in the highland areas especially on steep slopes, receiving heavy rainfall. Terraces were established in most of the East African highlands in 1930 to 1960 in a bid to control soil erosion that was alarming. Due to farmer’s practices and continued soil erosion, there have been observed difference in soil quality across the terrace. The aim of this study was to assess the impact of soil erosion on soil variability on the upper and lower bench terrace in Kigezi highlands. To determine the variability in soil parameters, soil samples were collected from three selected bench terraces, sampling from three different points from the upper and three from the lower parts of the bench terrace. The soil samples were then taken to the laboratory for analysis. The results of the study indicated that, soil parameters were not significantly different within blocks but some parameters were significantly different between blocks. % OM and K showed a significance difference between the upper and lower parts of the bench terrace with p-values (p=0.011 and p=0.014) respectively. Other soil parameters assessed had no significance difference between the upper and lower parts of the bench terrace. However, % N, exchangeable bases, %clay, and %silt showed higher concentrations on the lower parts of the bench terrace as compared to the upper parts of the bench terrace. This therefore calls for integration of different soil erosion control measures within bench terraces so as to minimize variability of soil parameters within the bench terrace.