African Geographical Review
Volume 29, December 2010

Research Article

Terrain and Land Use Influence on Patterns of Soil Properties in a Micro-Catchment on Mt. Elgon, Uganda

Yazidhi Bamutaze, Moses M. Tenywa, Mwanjalolo J. G. Majaliwa, Petter Palesjo, and Festus Bagoora

Soil properties are important indices of land degradation and productivity potential. In this study, we evaluated the interrelationship between selected soil properties vis-à-vis land use and slope gradient in a small catchment on Mt. Elgon in Uganda. The studied properties were soil texture, soil acidity, soil organic carbon, nitrogen, phosphorous, potassium, calcium, magnesium and sodium. Two predominant land uses on Mt. Elgon; Annual Land Use (ALU) and Perennial Land Use (PLU); and three slope gradient categories; low gradient (0-15%), moderate gradient (15-30%) and steep gradient categories (>30%) were considered. Each land use-slope category was replicated twice. Results show that soil acidity (3.7%) and available phosphorus (82.4%), were the least and most varying properties respectively. Although mean values of most properties were greater under PLU, the effect of land use was not significant (p>0.05) on all properties except sodium. On the contrary, slope gradient significantly affected (p<0.05) soil condition acidity, potassium, Sodium, silt and clay, while soil depth also had significant effects (p<0.05) on soil organic carbon, soil acidity, potassium, nitrogen, silt and clay. Interestingly, the steep slope gradients registered greater mean values for most properties, underpinning the complexity of geomorphic and pedogenic processes in mountain environments. Overall, the terrain factor as opposed to land use imposes a significant effect on the variability of soil properties.

Key words: soil properties, land use, hypsometric curve, ecosystem stability, Uganda, Mount Elgon