CHARACTERISTICS, CLASSIFICATION, EVALUATION AND GENESIS OF SOILS OF KALAMBAINA AREA, SOKOTO STATE, NIGERIA.
AbstractA detailed soil survey was conducted in Kalambaina area of Sokoto state, Nigeria, in order to obtain comprehensive data for the characterization, evaluation and classification as well as postulating the genesis of the soils. Three soil units (U1, U2 and VL) equivalent to soil series were mapped in the area. The morphological, physical and chemical characteristics of the soil units show that they best classify as Typic Ustipsamments, Lithic Ustorthents, and Aquic Haplustalfs respectively (USDA Soil Taxonomy) and correspondingly as Haplic Arenosols, Eutric Leptosols and Gleyic Luvisols in the FAO-UNESCO soil legend.
Soil units U1, U2 and VL were classes IItn, IVd, and Vw according to Land Capability Classification (LCC). Similarly soil unit U1 and VL are irrigable and soil unit U2 is provisionally non-irragable. Suitability classification for urban land use (residential building) revealed that only Soil unit U1 is highly suitable while other are not due to severe limitations.
Regarding the genesis of the soils, they have formed in parent materials of aeolian and colluvial origin deposited in late- Holocene over a surface cut in Kalambaina formation. Majority of the soils are underlain by continuous or discontinuous petroplinthite (ironstone hardpan) developed over the Kalambaina formation in a climate more humid than present. It is evident that because of the relatively dry (semi-arid) climate, the pedogenic processes that have operated and are operating to differentiate the soils consist of rapid humification and mineralisation of organic matter, homogenization and aggregation mainly. Some argillation and lessivation seem to be occurring in some profiles where seasonal fluctuating water table improves the soil moisture regime somewhat and has created a favourable seasonal wetting and drying conditions.
Nigerian Journal of Soil Science Vol.4 2003: 50-59