Effect of Slope Position on Soil Physico-Chemical Properties with Different Management Practices in Small Holder Cultivated Farms of Abuhoy Gara Catchment, Gidan District, North Wollo

摘要

The research work was conducted on eroded soil at the Abuhoy Gara Catchment, which is located in the Gidan District of North Wello Zone in the Amhara National Regional State to determine the effect of slope position on soil physico-chemical properties. Soil samples were collected from higher-slope, middle slope, intermediate slope and lower slope positions at two depths, surface (0-15 cm) and subsurface (15-30 cm) soil layers. Results showed a significant difference among the physicochemical properties of higher, middle, intermediate and lower slope soils. Clay fraction of the lower slope (27.08%) was the highest followed by middle slope (26.67%), intermediate slope (23.34%) and higher slope (22.92%). Conversely, sand (60%) was highest at higher slope and followed by middle slope (57.08%), intermediate slope (51.67%) and lower slope (49.58%), respectively. Likewise, Ca (8.41 cmol(+)/ kg), Mg (3.19cmol(+)/ kg), K (1.43cmol(+)/ kg), CEC (17.58cmol(+)/ kg), total nitrogen (0.104%), organic carbon (1.88%) and Available phosphorous (9.52 ppm) at higher slope followed by middle slope, intermediate slope and lower slope, respectively. The deterioration in chemical properties of lower slope as compared to other slopes were presumed to be due to continuous cultivation for longer period of time and past soil erosion effect that removed the soil organic matter and other plant nutrients. This study results concluded that increasing extent of continuous and intensive cultivation with minimum conservation practices and erosion due to slope effect can further deteriorate soil properties. The control of such damaging effects would require proper soil conservation strategies such as proper land leveling, afforestation, crop rotation, fallowing, terracing and inclusion of restorative crops in cropping systems on these lands.