Physicochemical Characteristics, Degradation Rate and Vulnerability Potential of Obudu Cattle Ranch Soils in Southeast Nigeria

Abstract

Obudu Cattle Ranch covers an area of 2400 hactares at an altitude of 900 - 1500 m above mean sea level and is suitable for cultivation of cucumber (Cucumis sativus), tomato (Solanum lycopersicum), Irish potato (Solanum tuberosum), spinach (Spinacia oleracea) cabbage (Brassica oleracea), lettuce (Lactuca sativa) because of its semi- temperate climate. Physicochemical characteristics, degradation rates and vulnerability potential of the soils were studied. Eighteen composite soil samples (0 - 15 and 15 - 30 cm) were collected at interval of 500 m along North-South and East-West transects in nine locations. The soils were characterized as follows: texture of sandy loam for the surface and subsurface soils; pH(H2O) (4.7 - 5.7), organic carbon (4.9 - 74.8 gkg−1), total nitrogen (0.2 - 4.8 gkg−1), carbon-nitrogen ratio (14 - 25), available P (6.66 - 107.89 mgkg−1), effective cation exchange capacity (ECEC) (5.58 - 14.62 cmol∙kg−1) and base saturation (49.37% - 85.28%); the surface soils were generally higher in organic carbon, total nitrogen, available P and ECEC than the subsurface. The Soil Degradation Rate (SDR)/ Vulnerability Potential (Vp) weighted values of texture (3/3), soil pH(H2O) (4/2), organic carbon (1/5) and base sa- turation (2/4) showed moderate to low susceptibility of the soils to degradation or vulnerability. The soils could be managed by liming, practicing crop rotation and using soil conservative measures.