Characteristics and classification of soils derived from Awi sandstone formation in Awi, Akamkpa local government area of Cross River State, Nigeria

Soils derived from Awi sandstone formation in Awi, Akamkpa LGA of Cross River State, Nigeria were studied along a toposequence with a view to classifying them taxonomically, assessing their potentials and suggesting appropriate management strategies. Three profiles were dug at the crest, middle slope and lower slope of the landscape. The morphological properties of these soils: colour, soil structure, soil consistence, drainage, boundaries and root inclusions were recorded in the field. These soils were deep (>100 cm), with sandy loam surface texture over sandy clay to sandy clay loam subsurface textures. These soils had hues of 10 YR - 5 YR with sub angular blocky structure and a sticky consistence (wet) and bulk density of 1.0 - 1.7 g/cm3 with total porosity of 22 - 38 %. Soil reactions in H2O were acidic (pH 4.7- 5.8). These soils have Organic Carbon of 14.4 - 38.1 g/kg; total nitrogen 1.2 - 3.3 g/kg; available phosphorus 4.1- 8.3 mg/kg; exchangeable acidity (H+) 0.5 - 11.9 cmol/kg; Cation Exchange Capacity (CEC) 2.0 - 6.0 cmol/kg and base saturation 20.0 - 52.5 %. The soils were classified according to the USDA Soil Taxonomy as Typic Kandiudults and correlated as Dystric Acrisols as per FAO- WRB for soil resources. It is recommended that soils fertility management practices should focus on reducing leaching of basic cations from the soils through mulching, planting of cover crops, crop rotation, adoptions of zero tillage as well as planting of acid tolerant crops and application of liming materials to reduce the strong acidity in these soils.