OIL PRODUCING AND AGRO-ECOLOGICAL AREA IN THE NIGER DELTA, NIGERIA: CASE OF OIL SPILLAGE (Published)
Environmental evaluation review (EER) is considered useful indicator of post mortem analysis of oil polluted soils. This research hypothesized that crude oil spillage has strongly influenced on soil properties dynamics of some Ultisols. The study was conducted on soil samples collected from crude oil spilled sites (n= 46), between two months and five years after spillage. The soil texture ranged from sand to loam, while the colour varied from dark brown (7.5 YR 3/2) to dark yellow grayish brown (10 YR 5/2) and was generally dark brown within two month of the spillage. Soils in some locations on the surface appeared to be fertile. However, this colour only occur to a depth of a few centimetres and then change to a mottled yellow-grey indicating that anaerobic conditions may exist for part of the years. Total heterotrophic bacterial counts (THBC) during 2012 varied from nil to 40.0 X 104 cfu/g soil with a mean value of 6.85 X 104 cfu/g on the surface soil and from nil to 35.0 X 104 cfu/g soils averaging 6.35 X 104 cfu/g in the subsurface layer. But in the control sites, THBC ranged from 10 to 15.0 X 104 cfu/g (20.0 X 104 cfu/g) and 8.0 to 30.0 X 104 cfu/g (22.67 X 104 cfu/g ) in the respective layers of surface and subsurface soil. . Based on the relationship of these components, careful management of land is required to create an ideal condition for optimum plant growth and healthy soil.