The Targa System: An Indigenous Agroecological Knowledge for Synergistic Soil and Water Conservation, Climate Adaptation, and Policy Innovation in Ethiopia

AbstractGlobal agriculture faces interconnected crises of soil degradation and water scarcity, necessitating sustainable land management solutions. Indigenous agroecological systems offer time-tested strategies, but many lack rigorous scientific validation. This study provides a comprehensive analysis of the Targa System, an indigenous terracing technology practiced by the Dhirashe people of Ethiopia. Using a mixed-methods approach—including systematic field surveys (n=100 fields), agronomic measurements (120 soil samples), and structured interviews (n=120 farmers)—this study quantitatively assessed the system’s biophysical efficacy and documented its socio-cultural governance. Results demonstrate that Targa’s micro-catchment design (‘Pootaya’) enhances in-situ rainwater harvesting, retaining 96.2% more rainfall (p < 0.05) and reducing erosion compared to conventional plots. The mandated practice of organic residue management on embankments (‘Moon’) more than doubled soil organic carbon (29.5 g/kg vs. 12.1 g/kg in controls) and significantly reduced bulk density, indicating improved soil health. The System’s high productivity, which eliminates reliance on inorganic inputs, is underpinned by robust social customs that ensure intergenerational knowledge transfer, coordinated crop rotation, and collective weed management. This study concludes that the Targa System is a sophisticated, integrated socio-agronomic framework that effectively synergizes climate adaptation (drought resilience) with mitigation (carbon sequestration). This study provides the critical scientific validation needed to position such indigenous knowledge systems as scalable models for sustainable agriculture in rain-fed regions, while also highlighting limitations regarding labor-intensive requirements for future implementation strategies.