Fertility Status of Soils under Different Land uses at Wujiraba Watershed, North-Western Highlands of Ethiopia

In Ethiopian highlands, land use changes, mainly, from natural vegetation to cultivated lands brought about rapid nutrient depletion. Intensive and continuous cultivation of land without proper management resulted in decline in soil physical, chemical and biological properties which aggravate crop yield reduction and food shortage. The present study, therefore, is designed to investigate the effects of different land uses on soil fertility status in the Nitisols of Wujiraba watershed. Twenty seven soil samples were collected randomly depth wise (0 - 15, 15- 30 and 30 - 45 cm) from the cultivated, forest and grazing lands. Data were analyzed using the two ways ANOVA in RCBD with three replications. Land use and soil depth showed a significant (P ≤ 0.05) effect on soil physicochemical properties. The highest f (57.8%), OC (4.6%), total N (0.28%), available S (11.1 ppm), CEC (42.2 cmol+ kg-1), exchangeable bases (Ca (22.2), K (0.76) and Na (0.58 cmol+ kg-1)) and available micronutrients ( Fe (14.2), Mn (24.1) and Zn (2.9 ppm)) were recorded on the surface layer of the forest land while lowest pH/KCl(5.03) and highest available P (5.5 ppm) on the surface layer of cultivated land. The results revealed that soil fertility declines as land use changed from forest to grazing and cultivated lands. Hence, it is possible to infer that continuous and intensive cultivation depletes plant nutrients greatly which urge to take measures for maintaining its fertility status of the cultivated soils in the study area.