Effects of altitudinal gradient and soil depth on selected soil physical properties in Hakim Gara shrub land of Harari Region (Eastern Ethiopia)

The study was conducted to investigate the effects of altitudinal gradient and soil depth on selected soil physical properties in Hakim Gara shrub land of Harari Region of Eastern Ethiopia which is good for oilseed crops groundnut, sunflower, safflower and niger. Soil samples were collected along altitudinal gradients of the land features between 2001 and 2113 m above sea level at 0-20 and 20-40 cm depths. The soil texture was mainly loamy and loamy sand except at a few sites that had silt loamy textural class. Bulk density and particle density at different soil depths exhibited increasing trend between the range from 1.12 to 1.40 g/cm3 and 2.35 to 2.65 g/cm 3, respectively in all sampling sites. While there was decreasing trend in total porosity between 52.12 to 46.17 %. Clay, silt and total porosity were positively correlated with altitude while sand content, bulk density and particle density were negatively correlated with altitude. Sand content, bulk density and particle density also were positively correlated with soil depth from that bulk density was significantly correlated with depth while clay, silt, and total porosity were negatively correlated with soil depth.