ASSESSMENT OF PHYSICOCHEMICAL PROPERTIES OF SOIL UNDER DIFFERENT LAND USE TYPES AT WUYE GOSE SUBWATERSHED, NORTH SHOA ZONE OF OROMIA REGION, ETHIOPIA

Abstract

Assessing soil physicochemical properties and subsequent implication on soil fertility is essential for understanding the influence of agro-ecosystem transformation on agricultural soil quality and productivity. A study was conducted at Wuye Gose sub-watershed, North Shoa Zone of Oromia Region, Ethiopia, to assess physicochemical properties of soil under different land use types. A total of 12 disturbed soil samples were taken for soil physicochemical properties determination and 24 undisturbed soil samples were taken for FC and BD determination from 0-30 cm depth. Grazing, cultivated, homestead and forest lands were identified. The soil samples were analyzed with standard laboratory procedures. All of the analyzed soil physicochemical properties were varied significantly (P < 0.05) among land uses, except pH and exchangeable Na. Textural classes of grazing land and cultivated land was loamy sand while it was sandy loam in homestead land and forest land. The BD ranged from 1.51 (GL) to 1.13 g/cm3 (HL) and TP varied 57.25 (HL) to 43.04% (GL). Soil water content at FC was ranged from (45.18) in homestead to (36.35%v) in grazing land. Permanent wilting point, in %v, was high (16.99) in homestead and forest to low (8.49) in grazing and cultivated lands. Available water holding capacity was high (36.69) in homestead to low (19.36%v) in grazing lands. The EC in d S m−, 1 was high (0.420) in homestead to low (0.055) in cultivated land uses. The SOC and TN, in %, were high (2.13) in forest to low (1.12) in cultivated and high (0.31) in forest to low (0.12) in cultivated and homestead lands, respectively. The C: N was high (18.91) in forest to low (10.07) in cultivated lands. The Av. P was high (2.52) in homestead to low (0.86 mg/kg) in cultivated lands. The CEC, exchangeable Ca, Mg, K and TEB, in cmol (+) kg −1, were high (27.87) in homestead to low (9.28) in grazing, high (2.83) in homestead to low (1.27) in cultivated, high (5.45) in forest to low (1.81) in cultivated, high (2.00) in homestead to low (0.17) in cultivated and high (10.59) in homestead to low (3.63) in cultivated lands, respectively. The ranges of EDTA extractable Fe, Mn, Cu and Zn, in mg/kg, were 18.10 to 6.42, 12.20 to 6.87, 3.59 to 1.89, and 3.74 to 0.32, respectively. Most of the soil physicochemical properties of the study area varied from land use to land uses. In conclusion, fertility status varies as homestead land > forest land > grazing land > cultivated lands in the study area. Therefore, soil physicochemical management in CL and GL should be highly needed for the study area. For future research direction, soil physicochemical assessment should be done frequently by taking account the site-soil-crop interaction since soil is a dynamic and complex system.