标题：Assessment of soil fertility status of Vertisols under selected three land uses in Girar Jarso District of North Shoa Zone, Oromia National Regional State, Ethiopia
摘要：Abstract
Background
Land use changes from forests to farmland and grazing land and subsequent changes in soil physical and chemical properties that results in soil fertility decline are widespread activities in Ethiopia. Particularly, this is the most practiced activities in highland areas of the country. The objective of this study was to assess the soil fertility status of Vertisols under different land uses in Girar Jarso District. A total of 18 disturbed and undisturbed soil samples were collected using augur and core samplers. Data were analyzed through analysis of variance (ANOVA) using the statistical analysis system (SAS version 9.00).
Results
The result showed that the soil physical parameters such as soil particle size, bulk density and total porosity, and most of soil chemical parameters (pH, organic carbon, total N, available P, cation exchange capacity and exchangeable acidity) were significantly different among land uses. Percent of sand content was lower in cultivated land than those of grazing and forest lands. On the other hand, the clay percent under cultivated land use was significantly higher than the grazing and forest lands. Bulk density was higher in cultivated land compared to grazing and forest lands; whereas, total porosity was lower in cultivated land than the others two. Soil pH in cultivated land was significantly lower than the grazing and forest lands. The results of organic carbon and total nitrogen were also lower in cultivated land than those of forest and grazing lands. Available phosphorus result was higher in soils of cultivated land than the soils of forest and grazing lands. Lower cation exchange capacity coupled with higher exchangeable acidity was recorded in cultivated land than the grazing and forest lands.
Conclusion
The result of this study implies that soil fertility management of Vertisols need to focus on strategies which improve the soil physical and chemical properties. Thus, integrated soil fertility management, particularly lime treatment should be applied on strong acidic soils of the cultivated land.
