Effect of Oil Pollution on Soil Properties along Pipeline Right of Way at Osisioma Ngwa, Abia State, Nigeria

Abstract

The study examined the effects of oil pollution on soil properties along pipeline right of way at Osisioma Ngwa, Abia State, Nigeria.A transect of 50 m x 500 m was laid along the oil pipeline right of way and also in the control plot (natural forest) of 1.5 km away from the oil pipeline. Soil samples were collected at 50 m interval from 9 selected sample points within the laid transect along the oil pipeline right of way and control plot using a properly calibrated soil auger and core samplers. The soil samples were collected in the topsoil (0-20 cm depth) and subsoil (20-40 cm depth) into well labeled polythene bags. Thus, 36 soil samples were collected for laboratory analysis using standard methods. Descriptive and inferential statistics (pairwise t-test and Spearman Rank Statistics) were to analyze the data. Findings revealed that sand content was predominant in the study area. Clay was significantly higher in the control plot than polluted soil (t=2.347; p=0.006). The mean bulk density was significantly higher in the polluted plot than the control plot (t=4.107; p=0.03). The soil pH was significantly more acidic in the polluted soil than the non-polluted soil (t=4.283; p=0.004). The total organic C and total N were significantly lower in the polluted soil than the non-polluted soil while slight variation was observed in available P, exchangeable Ca and exchangeable Na between the polluted soil and non-polluted soil. However, exchangeable Mg and exchangeable K were significantly higher in the control soil than the polluted soil. The exchangeable acidity, Zn, Pb and Cu were significantly higher in the polluted soil than the non-polluted soil.Total hydrocarbon was significantly correlated with pH (r=0.696; p<0.05); available P. (r= 0.660; p<0.05) and EC (r=-0.672, p<0.05). The study recommended among others that liming should be employed to neutralize and reduce the acidity level in the polluted soil.