Soil-landscape relationships in the Sokoto-Rima basin, Nigeria

We investigated both the soils and the landscape in the Dange area of the Sokoto-Rima basin of Nigeria. The landscape included both constructional and erosional landforms, which we subdivided into four geomorphic components (summit and shoulder, backslope, footslope, and toe-slope). We identified six soil series to represent soils of that part of the basin. Each soil series occupies a specific geomorphic component of a landform. The soils were classified as Paleustalfs, Haplustalfs, Ustropepts, and Tropaquepts at the great group level of Soil Taxonomy. These soils would be classified as Fluvisols, Cambisols, and Luvisols in the FAO/UNESCO legend of the world soil map. We propose a soil landscape evolutionary model that represents the development sequence of soils and landscapes from the original emplacement of the sedimentary rocks, through periods of climatic changes, to the recent semiarid climate.