Assessement of physicochemical properties of soils under different land use types in debello kebele, limu kossa district, jimma zone, southwest Ethiopia

Abstract

The study was conducted at the Debello Kebele, located in the Limu Kossa District of Jimma Zone in the Oromia Regional State. The purpose of the study was to determine the level of selected soil physiochemical properties of the three land use types (cultivated, graze and forest lands) based on the soil depths from 0-20 cm and 20-40 cm. The soil samples were collected from representative land uses with its replications then, finally eighteen total composite soil samples were collected from depths under six soil samples. Generally, comparisons between cultivated, grazing and forest land use types revealed a high significant difference on major soil fertility parameters. Soil texture (sand, silt and clay) studied was significantly affected (P ≤ 0.05) by land use. In contrast, the other physical properties such as bulk density, particle density, total porosity were not significantly (P > 0.05) different. Among land use types, the highest mean clay (69.84%) and bulk density 1.32 g/cm 3 values were obtained in the cultivated land. Considering the land use types, the highest soil pH (H 2 O) (5.13) and the lowest (4.5) were recorded in the subsurface soil layer of forest and surface soil layer of cultivated land, respectively. Moreover, the range of (4.5-5.13) soil reaction in the surface and subsurface layers of all land use types of the study area were strongly acidic with pH (H 2 O) as well as pH (KCl).On the other, hand the highest average mean values of available P (9.13 mg/Kg), and SOM (6.79%) were recorded in the surface soil layer of the cultivated and forest lands. In addition, the highest mean values of available EA (4.13 cmo (+)/Kg), CEC (41.50)cmol(+)/kg) and TN (0.34%) were recorded in the surface soil layer of the cultivated land ,but TN in the forest land. The mean value of exchangeable bases (Na, K, Ca and Mg) were higher (0.24, 1.58, 8.67, and 5.75 cmol(+)/kg) on the subsurface of the forest land .The contents of available micronutrients (Fe, Mn, Zn and Cu) under the different land management practices were significantly different (P ≤ 0.05) . The highest mean values Fe (27.42 cmol (+)/Kg ),Cu (3.41 cmol (+)/Kg) ,Zn (2.99 cmol (+)/Kg )were obtained at surface layer cultivated land but, Mn( 48.20 cmol (+)/Kg) obtained at surface layer forest land .