EFFECT OF SPENT ENGINE OIL ON THE NUTRIENT CONTENT AND UPTAKE OF AMARANTH

ABSTRACT

A potted experiment on the effects of levels of spent engine oil (SEO) contamination, remedied with spent mushroom substrate (SMS), on the nutrient content and uptake of amaranth (Amaranthus hybridus) was conducted in the Screen house of the Department of Crop Science, Faculty of Agriculture, University of Benin, Benin City from June to August 2023. Three spent engine oil concentrations (0, 5 and 10g per 10kg soil) and four spent mushroom substrate concentrations (0, 200, 400, and 600g per 10kg soil) was set up in a 3 x 4 factorial arrangement and fitted with a completely randomized design (CRD) and replicated three times. Data were collected on precropping soil properties, fresh and dried herbage yield, and plant tissue analysis. Soil physical and chemical properties before cropping with Amaranth showed that SEO had no effect on the soil particle size. Organic C, H+ , Al3+ in the contaminated soils increased compared to the control. There was decrease in the concentration of P, total N, exchangeable cations due to soil contamination. The nutrient content and uptake of plants grown in the SEO contaminated soil were adversely affected. There was a significant (P=0.05) low level of mineral elements and uptake in plants grown in SEO polluted soil and increased in heavy metal content. Nutrient content and uptake of the plants that were grown in the soil that was not contaminated with SEO was significantly higher than the values observed for plants grown in the soils contaminated with SEO. SMS increased the soil nutrient content and reduced total hydrocarbon content. SMS inclusion improved the nutrient content, uptake and reduced heavy metal content of Amaranth.