VARIATION OF SOIL MORPHOLOGICAL PROPERTIES ALONG A LITHOSEQUENCE ON BASEMENT COMPLEX GEOLOGY OF NIGERIA

Résumé

Morphological properties are inherent properties that expressed the nature and properties of the parent material from which soils are formed. The variation of morphological properties of soils was evaluated along a lithosequence of soils formed from schists and older granite in the basement complex geology of Nigeria. The soils were mapped and the morphological properties were described on the field following the standard procedure. The colour of soils on schists ranged from 5YR, 7.5YR to 10YR (moist) while on older granite it
ranged from 2.5YR, 5YR, 7.5YR to 10YR (moist), all the soils on older granite have sandy loam texture at the surface and there is increase in cohesion down the depth of the profiles of soils studied. There were variations in colour, texture and structure between the parent materials and horizons (p≤0.05). The pedogenic processes observed are: plinthization, humification, melanization,  braunification, ferritization, ferralitic weathering, elluviation and illuviation (argilluviation), insitu weathering and faunal pedoturbation. The following soil management options were recommended: construction of contour ridges along with the maintenance of plant cover, utilization of wetland areas for fisheries and dry season farming, maintenance of plant cover, incorporation of crop residues and soil crusting.