ABSTRACT

Five soil profiles were studied along a toposequence located on a coastal plain sand parent material in Ikwuano Local Government Area of Abia State in South eastern Nigeria. The profile pits were sited at the crest (A) upper slope (B), middle slope (C) lower slope (D) and valley bottom (E) positions. The profile pits were described and soil samples from identifiable horizons were taken for laboratory analysis. The data obtained showed that the colour for most of the soils vary from black (1OYR 2/1) to brownish black (1OYR 3/1) at the surface horizon while in the subsurface horizon the soil vary from dark brown (7.5YR 4/4) to reddish brown (SYR 4/6) except pedon E were the colour matrix vary from brown (7.SYR 4/4) to orange (7.5 YR 6/6). The texture ranges between loamy sand and sandy loam at the surface of the soil to sandy clay loam at the sub-surface. The percentage organic carbon and total nitrogen contents of the area are generally low. Phosphorus and potassium are very low to moderate. The pH level of the soil ranges from 4.4 — 6.1 indicating that the soil is very acidic to moderately acidic. The ECEC is very low with base saturation ranging from 28.4 to 96.4%. According to USDA Soil Taxonomy the soils in pedon A, B, C, and D belong to the soil order of Alfisol while pedon E belong to soil order of Ultisol. Pedons A,B,C,and D belong to sub-group of typic Kandiudalf while pedon E belong to the sub group of typic Kandiaquults in the USDA soil classification systems.