Soil Characterization and Classification in Granite‐Dominated Rock Formations of Beles Watershed in Tigray, Northern Ethiopia

The study was conducted in the Beles Watershed, northwestern Tigray (northern Ethiopia), to characterize and classify soils using the pedologic approach at a 1:25,000 map scale. Thirteen representative soil profiles were described, and 30 disturbed and 30 undisturbed soil samples were collected for physical and chemical analyses. Morphological properties varied widely: soil depth ranged from shallow to very deep, drainage was moderate to well drained, and color ranged from very dark gray to yellowish brown (dry) and brown to very dark brown (moist). Soil structure ranged from weak fine granular to strong angular blocky, while consistency varied from loose to extremely hard (dry), loose to extremely firm (moist), and nonsticky to very sticky and nonplastic to very plastic (wet). Textural classes ranged from sandy loam to clay. Chemical analyses included pH, electrical conductivity (EC, dSm −1 ), available phosphorus (avP, ppm), organic carbon (OC, %), total nitrogen (Nt, %), cation exchange capacity (CEC, cmol (+) kg −1 ), exchangeable sodium (ex.Na), potassium (ex.K), calcium (ex.Ca), magnesium (ex.Mg), and percentage base saturation (PBS). The soils are dominantly slightly to moderately acidic, low in OC, Nt, avP, PBS, low to moderate (ex.K, Na, Ca), high in CEC, and ex.Mg. Based on the analytical results, three major soil reference groups and seven soil units were identified: Leptosols (46%): 17% Haplic Leptosols (Dystric), 14% Cambic Leptosols (Dystric, Loamy), 6% Skeletic Leptosols (Dystric), and 8% Lithic Leptosols (Haplic), Cambisols (30%): 17% Leptic Cambisols (Dystric) and 14% Vertic Cambisols (Dystric), and Vertisols (24%): 24% Cambic Vertisols (Eutric). Overall, the soils of the watershed are characterized by low fertility, largely due to soil acidity, low organic carbon, and low base saturation. Topography and land use practices are the main drivers of this low fertility status. To sustainably improve soil productivity, the following measures are recommended: implement area closure and soil–water conservation practices in steep areas. Apply organic amendments and soil test–based nitrogen (N) and phosphorus (P) fertilizers in gently to moderately sloping areas. Ensure that developmental activities are tailored to specific soil types within the watershed. The management practices should be a community‐based watershed approach.