Research
Geochemical Assessment of Soils around Metal Recycling Industrial Areas in Ikorodu, Southwestern Nigeria
Baseline geochemical assessment of an area within latitude 006o431N and 003o441N and longitude 003o311E and 003o371E was carried out in other to provide information on the rate of contamination/ pollution caused to the soils by the iron and steel industries` activities around Ikorodu area. 11 soil samples were collected, prepared and analysed using Inductively Coupled Plasma Mass Spectrometry (ICP-MS). Interpretation of the analysis results was carried out for their metal contents. Lead has the highest concentrations in soils (9945ppm) while Manganese was the most widely distributed metal in the area of study with a mean concentration value of 8414ppm. Further geochemical evaluation of the soils using Geo-accumulation Index, Enrichment Factor, Contamination Factor, and Pollution Load Index, revealed significant concentration of lead and zinc in the environmental media from within the study area while the other elements have minimal concentration in the environmental media studied. The Enrichment Factor calculated also showed extremely high enrichment of lead in the soils of the study area (621). The contamination factor calculated showed that Pb and Zn are the elements contaminating the soils mostly. While zinc moderately contaminated the soil of the study area with a contamination factor of 4, lead extremely contaminated the soil with a contamination factor of 89. The other elements showed less contamination of the soils of the study area. The Pollution Load Index (PLI) showed the soils of the study area are not highly polluted (PLI<1) but highly contaminated.
Genesis and Classification of Soils on a Toposequence Underlain by Mica Schist in Ife Area, Southwestern Nigeria.
The study was conducted to establish the morphological, physical and chemical properties of soils on a toposequence underlain by mica schist in Ife Area, identify the pedogenic processes that produced the soils and establish the taxonomic and fertility capability classes of the soils. The toposequence was delineated into five physiographic units and soil profile pits were established, described and sampled at each unit. The soil samples collected from each of the genetic horizon were subjected to routine analyses following the procedures in methods of soil analysis. Taxonomic and fertility capability classification of the soils were carried out. The colour and texture of the soils change in response to changes in slope position and drainage condition along the toposequence The soil’s colour ranged from reddish brown to dusky red (5YR 3/2- 2.5YR 3/2) in the surface and yellowish red (5YR 4/8) to reddish yellow (7.5YR 6/6) in the subsoil at the higher position of the toposequence while it range from dark brown (7.5YR 4/2) to dusky red (2.5YR 3/2) in the surface and red (2.5YR 4/ 6) to reddish yellow (7.5YR 6/6) in the subsoil at the lower position. Texturally, the soils varied from sandy clay loam in the surface to sandy clay in the subsoil all through the pedons sampled. The soils were moderately acidic to neutral (pH 5.2 – 6.7) at the surface and strongly acidic to moderately acidic (pH 4.4 - 5.7) in the subsurface. They were characterized by low exchangeable bases which were in the order Ca> Mg> K> Na irrespective of slope position with low to moderate organic matter content. The soils were classified as Typic Kanhaplustults and Aquic Haplustults (USDA soil taxonomy) Plinthic Luvisols, Gleyic Luvisols and Eutric Luvisols (FAO-UNESCO). The agronomic constraints of the soils were acidic reactions, low nutrient reserve and gleying, hence dominant FCC unit of soils in the study area was SC keh. The soils studied were highly-weathered, low in inherent fertility and
