Soil quality evaluation under different land use types in Kersa sub-watershed, eastern Ethiopia

Abstract

Soil quality, which can be inferred using indicators that interact synergistically, is affected by land use types and agricultural management practices. This study assessed the status of soil quality under three adjacent land uses (cultivated, grazing, and fallow) in Kersa subwatershed (622 ha). Soil samples were collected from the surface soil (0–20 cm depth) of the identified land uses with three replications and the soil quality parameters were analyzed. A minimum data set of soil quality indicators were selected from physical, chemical, and biological parameters using the literature review and expert opinion method. Linear scoring functions were used to give the unitless scores for the selected data sets, which were then integrated into a soil quality index (SQI). The results revealed that bulk density, aggregate stability, pH, cation exchange capacity (CEC), available P, and soil organic carbon (SOC) had a significant difference in SQI among the different land uses. The soil quality indices were 0.69 for grazing land, 0.62 for cultivated land, and 0.59 for the fallow land. The SQI of all the land uses falls in the intermediate soil quality (0.55 < SQI < 0.70) class. In almost all the quality indicators assessed, the grazing land was superior to the cultivated and fallow lands. Therefore, implementing management practices that enhance soil quality like organic matter-controlled systems is imperative for sustainable agricultural production in the study area.