Impact of Tillage Remediation on Soil Microarthropods and Nutrients Hydrocarbon Contaminated Soil Ecosystem at Ikarama Community. Bayelsa State, Nigeria
GBARAKORO, T. N., OGELE, E. J. and UMEOZOR, O. C
Nig.J. Entomol. 33: 103 -110 (2017)
ABSTRACT: Impact of tillage remediation on soil nutrients and its relationship with soil fauna abundance in hydrocarbon contaminated soil ecosystem was assessed at lkarama community, Bayelsa
State, Nigeria, where Shell Petroleum Company, Nigeria carried out remediation. The assessment which lasted for six months was undertaken at three sites (1yr-3yr- Post remediated sites, control) each measured at 30m x 30m divided into four sub-plots in a split plot Design. Composite soil sampling was done each month at 5cm depth from each study site and taken to the laboratory for nutrient analysis including, total organic carbon, total organic matter, nitrogen, phosphorus, potassium and total hydrocarbon concentration. Results showed that total hydrocarbon concentration was 1.4038mg/kg
(control), 237.3mglkg (lyr-remediated) and 120.119mglkg (3yr post remediated sites). Percentage
total nitrogen was 6.826% (control), 5.386% (lyr-post remediated) and 5.985%mglkg (3yr-post remediated). Total phosphorus and potassium was 15.408mg/kg and 7.5l6mg/kg (control), 14.078mg/kg and 8.626mg/kg (lyr-post remediated sites) and 16.403mg/kg and 7.912mg/kg (3yr post remediated sites). The control sites recorded a concentration of26.36% total organic carbon, and 45.45% total organic matter. At 1yr postremediated sites, itwas 49.18% total organic carbon, 84.79% total organic matter. In 3yrs post remediated sites, total percentage organic carbon was 38.86% and total organic matter was 67.01 %. Abundance of soil microarthropods was recorded as 375 (control), 88 (lyr post remediated) and 162 (3yr- post remediated) sites. Tillage remediation indicated that the ecosystem is returning at a very slow rate, as there was a slight decrease in organic nutrients from the control to the remediated sites.
Keywords: Organic matter, organic nutrients, remediated sites, soil nutrients, soil microarthropods,
total hydrocarbon concentration.