Age of Soil and Water Conservation Practices on Selected Soil Properties along the Toposequence of Gerado Watershed, Habru District, Eastern Amhara, Ethiopia

Abstract

The government of Ethiopia through community participation has widely implemented soil and water conservation (SWC) measures, especially in the highlands of Ethiopia. However, the effects of these practices on the physicochemical properties of soils have not been well assessed and documented in the study area. Thus, this experiment was conducted to evaluate the effects of SWC practice on selected soil physicochemical properties. Treatments were nonconserved land, 3- and 9-year-old soil conservation practices under three slope positions, namely, lower slope (0–8%), middle slope (9–15%), and upper slope (>15%) positions, and at two soil depths (0–20 and 20–40 cm) with three replications. Accordingly, 54 composite soil samples were collected and analyzed based on standard procedures. The results showed that the age of soil and water conservation practice, topography, and soil depths significantly affected most of the soil properties. Conserving the watershed for nine years improved the subsoil clay content from 37.1 to 46.3%, subsoil soil moisture content from 13.38 to 24.61%, surface total nitrogen content from 18.1 to 81%, available phosphorus content from 13.1 to 33.5 mg kg−1, surface organic carbon from 0.28 to 2.83%, soil carbon stock from 9.26 to 35.59 t ha−1, and surface cation exchange capacity from 21.5 to 57.4 Cmolec kg−1. Therefore, maintaining soil and water conservation practices for long periods can improve soil properties. However, planting different grasses, with the existing physical structures is needed to increase soil nutrient and carbon stock.