Comparison of Physicochemical Properties in Soils of Floodplains Developed on Shale Stone and Basement Complex Materials in Cross River State, Nigeria

This study evaluated the physicochemical properties of floodplain soils developed on shale stone and basement complex materials in Cross River State, Nigeria. A total of thirty composite soil samples were collected, fifteen from each parent material, at a depth of 0–30 cm using a soil auger. Laboratory analyses were conducted to determine selected physical and chemical properties. Descriptive statistics (mean, maximum, minimum, and range) and inferential statistics (t-test) were employed to compare soils derived from the two parent materials. Results indicated that basement complex soils were predominantly sandy loam, whereas shalestone soils were mainly sandy clay loam and loam. Soil reaction ranged from strongly acidic in basement complex soils to slightly acidic in shalestone soils. Organic carbon was moderate across both soil types, while total nitrogen was generally low. Available phosphorus was low in shalestone soils but moderate in basement complex soils. Exchangeable calcium (Ca) and magnesium (Mg) were higher in shalestone soils, whereas basement complex soils recorded lower values; exchangeable potassium (K) was low in both soils. Exchangeable acidity (Al3⁺ and H⁺) was low, and both cation exchange capacity (CEC) and base saturation were high. Effective CEC was notably higher in shalestone soils. Overall, shalestone-derived soils exhibited superior nutrient status compared to basement complex soils, indicating that the two soil types require distinct agronomic management. Floodplain soils over shalestone show higher crop production potential due to slight acidity, moderate organic carbon, elevated exchangeable Ca and Mg, high CEC, and base saturation. To optimize soil productivity, fertility management strategies should prioritize liming and practices that enhance organic matter, nitrogen, and exchangeable cations.