MICROMORPHOLOGICAL AND MINERALOGICAL EVALUATION OF ULTISOLS IN NIGERIA

Micromorphological and mineralogical properties can provide insights and aid interpretation of soil classification.The main objective of the study was to increase the understanding of soil classification through evaluation of micromorphological and mineralogical properties of soils. With a view to determining if differences in properties could be used. Based on the geological map sheet used to identify different parent materials, eight (8) profiles were dung and described and five distinct soil types were identified and mapped as soil units A, B, C, D and E. Results obtained revealed that micromorphology of surface horizon in basaltic soils shows a porous (compound packing) and crumb microstructure. The groundmass consists mainly of fine iron hydroxides in crystallitic micromass. Compound coatings of radial distributed and isotropic (¿amorphous¿) iron hydroxides line the pores. Granitic surface horizon was mainly crumb with vughs and channels microstructure. In addition high clay content which complexes humus and thus reduces its ability to move downward in the profiles. The analysis should help shed some light on microbrafics and the work would be useful to Micropedologists.