Establishment of Perennial Ryegrass in Soil with Simulated Petroleum-based Spills and Remediation

Abstract

Petroleum-based spills on turfgrass often occur during lawn care maintenance. The damages caused by hydrocarbons to turfgrass can be long lasting and difficult to correct because of the stable and toxic nature of hydrocarbons. The objective of this study was to compare the effectiveness of using detergent, nitrate nutrient, humic substance, and activated charcoal to enhance bioremediation and turf recover after gasoline, diesel, and hydraulic fluid spills. The turfgrass quality and reestablishment of perennial ryegrass (Lolium perenne) reseeded at 0, 1, and 2 weeks after spills were evaluated. The results showed that using a liquid humic substance to remediate soil and reseed immediately after a gasoline spill was a practical method to reestablish acceptable turfgrass quality in 5 weeks. The most significant injury to perennial ryegrass caused by gasoline was bleaching of green tissues. Gasoline caused negligible residual herbicidal effects under the remediation regime in this study. However, diesel or hydraulic fluid showed phytotoxicity and residual effects in the contaminated soil for more than 2 months. Seeds applied immediately after diesel and hydraulic fluid spills lost viability as a result of the herbicidal effect of these hydrocarbons. As a result, reseeding was only successful 4 months after diesel and hydraulic fluid spills. Therefore, the time span for reestablishing perennial ryegrass turf may be too long for practical purposes in the lawn care industry.