Effect of Oil Pollution on Soil Properties and Performance of Maize (Zea Mays) Grown on Soil derived from Coastal Plain Sand in Obio Akpa, Akwa Ibom State

Abstract

The study was conducted to determine the impact of oil pollution on the soil qualities and performance of maize (zea mays) cultivated on sand from the coastal plain in Obio Akpa, Akwa Ibom State. The investigation was conducted out at Akwa Ibom State University's teaching and research farm. Soil samples were obtained from a depth of 0 to 30 cm. Ten (10) kg of soil samples were weighed into 45 experimental pots with a capacity of 12 litres each. The pots were laid out in 3 x 5 split plot arrangement fitted into randomized complete block design (RCBD) with three replications.  The main plots were the three treatment sources (kerosene, engine oil and crude oil) and the subplots were the five rates of treatment (0ml, 40ml, 60ml, 80ml and 100ml). The treatments were applied two weeks before planting. Plant emergence (germination rate) after two weeks, plant height, leaves length, number of leaves, stem girth, fresh weight and dry weight were measured.  The results showed that pots contaminated with crude oil and engine oil were significantly higher (p <0.05) in sand fraction and lower (p <0.05) in clay fraction after the experiment than before the experiment. Kerosene raised the soil pH from 4.4 to 4.8; crude oil raised the soil pH from 4.4 to 4.6 while engine oil raised the pH from 4.4 to 4.7. Mean organic C of plots contaminated with kerosene and crude oil were significantly higher (p <0.05) after the experiment than before the experiment. The trend was Kerosene > crude oil > engine oil. The mean available P before the experiment was significantly higher (p <0.05) than that of plots contaminated with kerosene, crude oil and engine oil. after the experiment. Kerosene, crude oil and engine oil contamination raised exchangeable Ca and exchangeable Na content of the soil and reduced exchangeable Mg, K, potential acidity, ECEC and base saturation. Germination rate, number of leaves, plant height, leave length, stem girth, fresh weight and dry weight decreased with increasing contamination rate.  The trend was 0 ml > 40 ml > 60 ml > 80ml > 100ml. Further investigation should be carried out to identify plant that can tolerate crude oil pollution and remediation should be carried out to regain the originality of the soil.