Pedological Study of Soils Developed on Granodiorite in Biase Local Government Area of Cross River State, Nigeria

Morphological, physico-chemical and mineralogical properties of soils derived from Granodiorite of Biase, Cross River State, Nigeria were studied with a view to classifying the soil taxonomically, assessing their potentials and suggesting appropriate management strategies. Three profiles were dug on the landscapes of Ikot-Okpara, Betem and Ehom. The micro-morphological properties of soil colour, soil structure, soil consistence, drainage and root abundance were determined in the field. The soils were characterized as follows: deep profiles (>100 cm) with texture of gravelly sandy clay loam to sandy clay; hues of 10YR – 2.5YR; structure of subangular peds with sticky consistence (wet); bulk density values of 1.3 – 1.6 mgm-3; total porosity of 40 .0 – 52.8 %; silt-clay ratios of 0.1 – 1. Others were soil reaction (pH 4.6 – 5.3) H2 0; organic carbon (1.6 – 23.84 gkg-1); Total nitrogen (0.42 – 1.54 gkg-1) ECEC (2.39 – 5.20 cmolkg-1); CEC (4.20 – 6.60 cmolkg-1); available P (2.12 – 11.17 mg/kg); base saturation (35 – 79 %) and minerals such as quartz (80.0 %), kaolinite (12.7 %), microcline (5.80 %) and Sepiolite (0.99 %). According to the criteria of the USDA Soil Taxonomy, the soils were classified as Loamy Skeletal, Mixed IsohyperthermicTypic Kandiudults. Equivalent FAO-World Reference Base for Soil Resources of the soils is Dystric Acrisols. Pedogenetic process of eluviation-illuviation reflecting the weathering process has been occurring in the soils under the humid tropical influence. The soils can be managed by planting acid tolerant crops liming and adopting appropriate cultural practices.