Assessment of Soil Physico-Chemical Properties in a Selected Oil Spill Environment of Nigeria

Background and Objective: The increase in soil pollution problems with reported cases of oil spills draws significant attention that must be addressed in most oil-reaching communities in Nigeria. This study considers the assessment of soil properties in some selected oil spill environments in Ilaje Local Government Area, Ondo State, Nigeria. Materials and Methods: Four sample sites of oil spills (Ugbo, Etikan and Aheri) and non-polluted adjacent fields (Mahin) were selected for the study. Forty composite soil samples were collected from a pre-determined depth of 0-30 cm of the soil profile. Soil properties examined include particle size distribution, bulk density, water holding capacity, soil organic matter, pH, Ca²⁺ Mg²⁺ K⁺ Na⁺, CEC, base saturation, total hydrocarbon, oil and grease, available phosphorus and total nitrogen. Co-efficient of variation and correlation analysis techniques determined variability and relationship among soil properties. Results: The study reveals that, silt and clay contents have over 25% of the textural composition with the homogeneous spread of soil in the study area. The polluted soils have low water holding capacity, acidic values between 4.14 and 4.79 and low nutrient cations, with extreme variabilities of silt, Mg²⁺, H⁺, SOM, Ca²⁺, K⁺, Na⁺, oil and grease. Conclusion: However, a significant concentration of soil nutrients at the control site was recorded. With the trends of spills and impacts on soils in the study area, this study recommends urgent efforts in averting further spill occurrence to ensure soil protection and revitalization.