Abstract
Background: Soil chemical properties have changed under different land-use systems and soil depth layers either by increasing or decreasing. Hence, scientifically information on the soil chemical properties dynamics under different land-use systems and soil depths are crucial for best land management practices, and to avoiding ecological negative impacts of it for sustainable development. The study aimed to evaluate the soil chemical properties dynamics under different land-use systems and soil depths in the central highlands of Ethiopia. The land-use systems included natural forest, four exotic tree plantation species (Eucalyptus globules, Cupressus lusitanica, Grevillea robusta, and Pinus patula), grassland, grazing land, and cropland. Results: The analysis of variance (ANOVA) for the majority of soil chemical properties of OC, TN, Avial. P, soil pH, EC, CEC, and exchangeable bases (Ca, Mg, K, Na) were showed that significant variations among land-use systems (P<0.0001). The highest mean values of OC (3.49 % DM ), TN ( 0.31 % DM) , Avail.P (31.52 mg/kg of soil ), CEC ( 33.63 meq/100gm soil), Exch. Ca (17.13 cmol(+)/kg soil), Exch. Mg (5.37 cmol(+)/kg soil), and Exch. K ( 3.60 cmol(+)/kg soil) were observed under natural forest than others of land-use systems. The results also showed that the lowest mean values of OC (1.47 % DM), TN (0.13 %DM), soil pH (5.38), CEC (18.98 meq/100gm soil), Exch. Ca (9.93 cmol(+)/kg soil), Exch. K (1.20 cmol(+)/kg soil), and Exch. Na (0.22 cmol(+)/kg soil) were recorded under cropland than other land-use systems. The highest mean values of EC (3.47ds/m), and Exch. Na (0.60 cmol(+)/kg soil) were observed under Eucalyptus globulus plantation forest. The overall mean values of OC, TN, Avail.P, CEC, Exch. Mg, Exch. Ca, Exch. K, and Exch. Na accumulation at the topsoil layer was higher than that of the subsoil layer except for soil pH and EC. Conclusion: In general, the majority of soil chemical properties under cropland and Eucalyptus globulus plantation forest were poorer than the soils subjected to other land-use systems which indicated that changes in land use systems were significantly affected soil chemical properties.