Passover Christain SHELU

A screen house potted experience was conducted in the Department of Crop Science, Faculty of Agriculture, University of Benin, Benin City in June to August, 2023 to evaluate the effects of different level of spent engine oil (SEO) contamination remediated with spent mushroom substrate (SMS) on the growth and herbage yield of Amaranth (Amaranth hybridus). The experiment involved three spent engine oil contamination levels (0, 5 and 10% v/w per 10kg soil) and four spent mushroom substrate application rates (0, 200, 400 and 600 per 10kg soil) laid in a 3 x 4 factorial arrangement fitted into a completely randomized design (CRD) and replicated three times. Data were collected on plant height, stem girth, number of leaves, leaf area and herbage yield. The results of soil analysis before cropping with Amaranth showed that SEO had no effect on particle size of the soil. Organic C, H+ and Al3+ in the contaminated soils were higher compared to the control. There was decreased in concentrations of available P, total N, exchangeable cations as the SEO contamination level increased. Plant height, stem girth, number of leaves, leaf area and herbage yield of Amaranth plants grown in the contaminated soils were adversely affected as they were significant (P<0.05) reduced in comparison to their performance in unpolluted soils. Application of SMS enhanced growth and herbage yield of Amaranth. Application of SMS remediated the harmful effect of SEO on the plant as it enhanced the growth of the plant. However, higher rate of SMS application reduced growth and 10 herbage yield of Amaranth in comparison to the lower rate. Application of 200g of SMS per 10kg soil produced plants with the highest height (89.2cm), thickest stem(3.42cm), highest number of leaves (28.6cm), largest leaf area (2803cm²) and herbageyield (59.91tha-¹). A combination of unpolluted soil treated with 200g and 400g ofSMS produced the highest herbage yield with 72.9 and 75.1g, respectively. SMS at200g is thereby suggested for Amaranth growers