The effect of spent engine oil (SEO) on soil properties and growth of maize (
Zea mays
L.) was
investigated. Five treatments (0.0, 0.2, 0.4, 0.6 and 0.8 l/kg) of the spent oil were applied to soil in perforated poly
bags with maize stands at four weeks after sowing. Soil analysis showed that SEO had no effect on both the pH
and texture of the soil. Organic C, N and Mg in the contaminated soils increased compared to the control. There
was decrease in concentration of P due to soil contamination. Heavy metals (Fe, Cu, Zn and Pb) concentrations of
soil increased with increasing concentration of oil. Plant height, root number and root length of maize plants
grown in the contaminated soils were adversely affected. The grain yield of the plants in the contaminated soils
was significantly reduced
