Comparative Study of Soils Derived from Sedimentary and Basement Rock Formations of the Lower Ogun River Floodplain, South Western Nigeria

The anisotropic nature of soils makes it imperative to study the associations of soils and regional landscapes for sustainable land use planning and management. This paper examines soil properties involving four catenas on two parent rock formations in two ecological zones. It simultaneously studied the vertical and lateral variations of soil properties in relation to parent materials, slope positions and pedogenetic-geomorphic processes along hillslopes extending over basement complex and sedimentary rock formations of the Lower Ogun River Floodplain. The different parent materials from different parent rocks, slope positions and pedogenetic-geomorphic processes accounted for the intra-profile and inter-profile variations of topsoil and subsoil properties in the landscape. The study demonstrated that in a given hillslope, topsoil and subsoil properties show more significant differences (p<0.05) between diverse rock formations, distinct parent materials and different slope positions than within them. This suggests that the soils are genetically linked due to the influence of relief (differences in elevations) along the hillslope and geomorphic factors (parent materials) which affirms catenary associations of soils along the hillslopes.