Abstract:
The patterns of distribution of particle size and free Fe20 3 (Na-dithionite-extractable (Fe(d) and NH.-oxalate-extractable (Fe( 0) were studied in five representative soil profiles in south-western Nigeria. The soils were found to vary from slightly acid to strongly acid. Organic carbon decreased with increasing depth. The pattern of distribution of free fc,o, was related to that of clay in two of the soil profiles (!bule and Adio series). However, in the other three soil profiles (\jare, Owena and ltagunmodi series), free Fe,03 distribution was not related to clay. Silt content did not show any definite pattern of distribution. The content of free Fe2O had reached advanced stage of crystallinity or aging in the soils because of the low Fe(o)/Fe(d) ratios in the soil profiles
