Effect of Spent Engine Oil on the Soil Properties and Growth Parameters of Green Amaranth (Amaranthus viridis Linnaeus) in a Laboratory Condition in Lagos State, Nigeria

Abstract

Increased discharge of spent engine oil in the environment due to increased use of automobiles and other engines and their subsequent maintenance is a matter of great environmental concern. This study assessed the effect of spent engine oil on soil properties and the growth performance of Amaranthus viridis in a laboratory setting in Lagos State Nigeria using standard methods. Viable Amaranthus viridis seeds were sown in soil contained in five plastic containers treated with 100ml, 75ml, 50ml, 25ml and 0ml (as control) of spent engine oil, separately. Each treatment had three replicates. Measurements of the plant’s leaves, leaf area and height of shoot were taken at a 7-day interval up to sixty-three days. The physicochemical parameters of the spent engine oil-polluted soil were also analyzed at the beginning and at the end of the experiment. Data generated from this study were analyzed using SPSS, separating mean differences at 5% level of significance (p < 0.05). The levels of nitrogen and potassium were lower in the contaminated soil than the control while the levels of phosphorus were higher in the spent engine oil-contaminated soil. Sodium, calcium, iron and lead concentrations in soil increased with increasing amounts of spent engine oil. The spent engine oil had an effect on the pH and the total organic carbon. In comparison to the control, Amaranthus viridis grown in the polluted soil had adverse effects on the number of leaves, plant height, and leaf area. These results showed that spent engine oil affects both the quality of the soil and the growth parameters of the plant (Amaranthus viridis) which can be used to inform farmers and agriculturalists how adverse the effect of spent engine oil is to our plants and ecosystem.