Growth Performance of Grain Amaranth (Amaranthus Cruentus L.) on Spent Engine Oil Contaminated Soil Bioremediated With Two Bacterial Co-Cultures and Organic Amendments

The advent of bioremediation technology has helped scientists to proffer sustainable solutions to problems associated with environmental pollution. This study was staged to assess the growth of Amaranthus cruentus L. on spent engine oil (SEO) contaminated soil that had been subjected to bioremediation. Two bacterial co-cultures; Pseudomonas aeruginosa+Alcaligenes faecalis and Streptococcus pyogenes + Enterococcus faecalis were bio-enhanced with organic amendments; powdered cow dung (PCD), powdered cocoa pod husk (PCPH) and compost made from cow dung (CD) and cocoa pod husk (CPH) with a view to reclaiming SEO soil at three levels of contamination. It was a factorial experiment laid out with completely randomized design (CRD). Subsequently, amaranth seeds were sown on the experimental pots in the screen house. Results indicated that at two weeks after sowing (2WAS), compost produced significant (P < 0.05) and the highest plant heights (6.5, 7.5 and 6.1 cm) on all the SEO contamination levels studied compared with other organic amendments. Compost produced the highest (6.0) number of leaves compared with other organic amendments on 10% SEO contamination level while all the other organic amendments produced the same number of leaves (4.0) on 15% SEO contamination level. In respect of the stem girths measured in this study, significant performance was recorded at 2WAS, four weeks after sowing (4WAS) and six weeks after sowing (6WAS) (P < 0.05). The significant feat that the bioremediation agents utilized in this study recorded has further confirmed these agents as good candidates that can be adopted in ensuring the reclamation and restoration of SEO ravaged agricultural land.