Impacts of Opuntia ficus-indica cultivation on soil physicochemical properties across semi-arid and arid ecosystems of Tigray region, Northern Ethiopia

Cactus species is increasingly recognized as a nature-based solution for restoring degraded drylands, yet quantitative evidence of its influence on soil quality across contrasting arid environments remains limited. This study evaluated the effects of three cactus canopy covers (bare, scattered, and dense) on soil physicochemical properties in two zones (EST=Eastern zone and SE=Southeastern zone) of Tigray, Ethiopia. Soil samples were analyzed for key indicators of soil quality, including moisture content (MC), bulk density (BD), pH, electrical conductivity (EC), soil organic carbon (SOC), total nitrogen (TN), available phosphorus (P), exchangeable bases potassium (K), calcium (Ca), magnesium (Mg), sodium (Na), and cation exchange capacity (CEC). Results showed that canopy cover significantly (p < 0.05) influenced SOC, TN, P, and exchangeable cations with dense canopy exhibiting the highest values. Soil moisture content was significantly (p < 0.05) higher in SE than in EST, whereas soil pH also varied significantly between the two sites. In contrast, bare soils consistently showed the lowest nutrient status, indicating severe soil degradation. The findings demonstrate that cactus vegetation acts as an ecosystem engineer by creating fertility islands that promote nutrient accumulation and improve soil functioning in dryland ecosystems. Integrating cactus-based vegetation management into restoration programs may therefore be an effective strategy for enhancing soil quality and supporting sustainable land management in semi-arid and arid regions.