Characterization and Classification of Soil on Varying Lithology in Okigwe Imo Southern Eastern, Nigeria

Abstract

The field study was carried out in Okigwe South-eastern Nigeria. Three profiles were sunk in soils of each of each parent material. Soil samples were subjected to routine and standard laboratory analysis for selected physic- chemical properties. The morphological and physic-chemical properties of the soils varied widely, sand size particles dominated other particle sizes with the mean values of 448, 538 and 648 g kg-1 on sandstone, while soils derived from Imo clay shale was 583 g kg-1 for Umuna. Clay in Imo Clay Shale and bulk density recorded highest values at NIHORT 1, 416 and 15 g kg-1 respectively. All pedons exhibited sandy clay loam on topsoil and relatively more clayey subsoil. Total nitrogen correlated positively and significantly (0.5) with organic matter in both soils. Clay correlated negatively with ECEC in sandstone and positively in clay shale, and both were not significant. The soils derived from false bedded sandstone (NIHORT 1, 2 and 3) were classified according to USDA soil Taxonomy as Inceptic Paleudults which translate to Dystric Nitisols in WRB system. Soils from Umuna were classified as Typic Hapludalf USDA and soils from NIHORT 1, 2 and 3 were classified as class II of the USDA capability classification system. Umuna was classified in class III. In conclusion the soils of these two parent materials sustain farm produce, if proper land use practices and special conservation for selected crop production are adopted.