Evaluation of technical feasibility of physical soil and water conservation structures in Ijara watershed, Nonno district, west Shewa zone, Oromia, Ethiopia

Ethiopia faces severe challenges from soil degradation primarily caused by soil erosion. To address this issue, the Ethiopian government has implemented various interventions, including physical soil and water conservation (PSWC) measures. These measures play a crucial role in mitigating soil erosion and nutrient loss, thereby safeguarding agricultural productivity and sustainability. This study assesses the technical suitability of PSWC structures implemented through mass community mobilization in the Ijara watershed, located in Nonno District, West Shewa Zone, Oromia, Ethiopia. The evaluation employed a topographic transect walk method to examine existing PSWC structures across fields with varying slope gradients (upper, medium, and lower slopes). Measurements of key parameters, including stone bund length, height, top width, bottom width, and spacing, were carefully conducted in three fields. The recorded dimensions of the stone bunds were compared against the recommended standards outlined in the Ministry of Agriculture’s Soil and Water Conservation Guidelines. The findings revealed that the majority of the implemented stone bunds exceeded the recommended specifications value for dimensions such as length, spacing, and height. However, deviations were observed in certain areas, such as the top width on the upper slope, which measured 0.48 m compared to the standard of 0.5 m. On the lower slope, the bund spacing (20 m) adhered to the prescribed standards. The study attributes these deviations to gaps in the knowledge and skills of farmers, which hinder the consistent achievement of technical standards in the study area. To address these shortcomings, greater emphasis should be placed on the quality and design of SWC structures rather than their spatial coverage. More consideration should be given to the technical quality and layout of SWC structures rather than the coverage area to reduce the observed technical errors on the established stone bund and continued technical support, regular follow-ups, and targeted training programs are essential to ensure the effective and sustainable use of these conservation structures in the study area.