Effects of soil and water conservation practices on selected soil properties and crop productivity in the Beles River Basin, Ethiopia

Abstract

Soil and water conservation practices (SWCP) have been widely applied in the highlands of Ethiopia to combat land degradation, increase crop productivity, and enhance soil properties. However, information on these practices is limited for the lowlands, particularly for the Beles River Basin (BRB). This study aimed to evaluate the effects of SWCP on crop productivity and selected soil properties in the warm, sub-humid lowlands of the middle BRB. The experiment was conducted using a randomized complete block design with three replications. Five treatments were evaluated: conventional practice (C), conservation agriculture (CA), vetiver grass strips (VGS), soil bund (SB), and Fanya juu (FJ). Finger millet, soybean, and maize were grown in consecutive years. Soil and agronomic data were collected from the plots. Results showed that soil attributes and crop productivity were significantly influenced by SWCP ( P < 0.05). The highest values for soil moisture (22.3%), soil organic carbon (2.55%), total nitrogen (0.22%), available phosphorus (2.22 mg/kg), and cation exchange capacity (23.3 cmol + /kg, and the lowest bulk density (1.11 g/cm) were observed under CA compared to C. Similarly, CA increased grain and biomass yield by 63.2% and 58.5%, respectively. The use of CA decreased Striga infestation and significantly ( P < 0.05) increased the days to maturity, thousand-seed weight, and grain and biomass yields of finger millet and maize. Partial least squares regression identified SOC, TN, and CEC as the most influential predictors of grain yield. Continued monitoring is recommended to assess the long-term impacts of physical SWC measures on crop productivity and soil quality.