EFFECT OF TYPES OF ORGANIC WASTE ON SOIL CONTAMINATED WITH SPENT ENGINE OIL IN UMUAHIA METROPOLIS, ABIA STATE.
Onwuka, M. I. and Igwe A.C.
Department of Soil Science and Meteorology
Michael Okpara University of Agriculture, Umudike, Nigeria
E-mail: ifyonwuka2000@yahoo.com or onwuka.ifeoma@mouau.edu.ng
ABSTRACT
An incubation study was conducted at Michael Okpara University of Agriculture Umudike to evaluate the effect of types of organic waste on soil contaminated with spent engine oil in Umuahia Metropolis. The treatments were poultry manure (PM), goat dung (GD), kitchen residue ash (KRA), maize husk ash (MHA) and a control (C). The wastes were applied at 4t/ha and replicated three times in Completely Randomized Design (CRD). At the end of the incubation, the effects of the treatments were measured on soil pH, exchangeable acidity, organic carbon, available phosphorus and total nitrogen. Other parameters determined were exchangeable calcium, potassium, magnesium, lead, cadmium and chromium. All the data were subjected to the analysis of variance (ANOVA) and the differences between the treatments means separated using the least significant differences at 5% probability level. Linear correlation analyses were done using the GENSTAT package. The result obtained showed that organic wastes significantly (p < 0.05) increased soil pH, available phosphorus, total nitrogen, organic carbon, exchangeable calcium, potassium, magnesium and percentage base saturation over the control. The organic wastes also significantly (p < 0.05) reduced lead, cadmium chromium and exchangeable acidity. Among the organic wastes tested poultry manure significantly (p < 0.05) increased available phosphorus, total nitrogen and percentage base saturation and significantly (p < 0.05) reduced lead and chromium. Kitchen residue ash, on the other hand significantly (p < 0.05) increased soil pH and exchangeable calcium, while goat dung significantly (p < 0.05) increased the soil exchangeable magnesium. The soil pH significantly (p<0.001) and negatively correlated with lead, cadmium and chromium while the exchangeable acidity significantly (p<0.001) and positively correlated with lead, cadmium and chromium. Further research is recommended for the field application of the treatment.
Key words: Organic waste, spent engine oil, contaminated soil, incubation