In Your Turf: Feb. 1998, Is Turf the Answer to Tire Disposal?

Few things bring home the message of waste in our country as starkly as a picture of a tire disposal site. Endless stacks of used, useless rubber paint a repulsive picture of our industrialized society.

Still, tires are a necessary evil, as long as vehicles need to roll down the road. All of which begets the question, What to do with the used tires?

Tire recyclers have found some creative solutions, but few are as interesting as the use of a crumbed form of old tires in the care of turf.

Presently, there are two companies marketing crumb rubber for turf JaiTire Industries, Denver, Colo., and American Tire Recyclers, Jacksonville, Fla. JaiTire’s product, Crown III, is promoted as a topdressing. Their claim is that once worked into the thatch, the product acts as a cushion for the crown of the turfgrass plant, preventing it from damage in heavy wear areas.

ATR markets crumb rubber under the name Rebound, and it is sold as a soil amendment. The product must be added to soil before the turf is planted, and the company claims the product promotes turf vigor, reduces compaction and is a safer surface for activities such as sports.

ABOVE GROUND. The concept of using crumb rubber on turf started at Michigan State University, East Lansing, where turfgrass researchers discovered that the topdressing method provides benefits. Since 1990, John Rogers, MSU associate professor of turfgrass science, has been testing the effects of crumb rubber topdressing on turf.

MSU was awarded the patent to use crumb rubber as a turf topdressing last April, and is working with JaiTire on further research and distribution. Corny Snyder, JaiTire’s director of marketing, said that the product is being used on nearly 1,400 sites across the country, from athletic fields to home lawns.

The product is applied about ¾-inch thick across the lawn, nearly covering the turf in black crumb rubber. The product is then raked in, giving the appearance of a dark compost over the turf. It takes about two weeks for the rubber to get worked into the thatch.

Snyder indicated that because the rubber is actually lighter than the soil, it stays on the top layer, maintaining its benefits. At the same time, there haven’t been any reports of problems with loose rubber running off or being shuffled off turf and creating a mess on sidewalks or driveways.

Other issues that would seem to be logical problems, such as heat build-up at the crown of the plant, have not proven to be an issue, according to Snyder. On the contrary, the product seems to act as an insulator the heat stays on the surface, but below the surface the temperature is normal, Snyder said.

According to research published by MSU, incorporated crumb rubber absorbs more heat in the spring, resulting in earlier green-up. Summer heat becomes less of a problem when turf density increases and shades the surface of the crumb rubber layer.

The product has also shown the ability to hold water in the soil, reducing the need for turf irrigation. Studies examining this effect are being started at Texas A&M, College Station, this year, Snyder noted.

However, there isn’t any independent research available on the effect of the crumb rubber layer on pesticide efficacy as of yet, although there hasn’t been any evidence so far that there are potential problems, according to Snyder.

Disposal, which is such an enormous issue with tires, is not a problem if turf or soil laden with crumb rubber needs to be removed. Most landfills have banned tires, but there are no special requirements for the disposal of crumb rubber, Snyder noted.

DOWN UNDER. The Rebound product marketed by ATR has been marketed largely to communities and sports field maintenance managers for two reasons: the installation requires a complete renovation, and the most documented benefit is reduced compaction that results in a safer playing surface.

Turf Diagnostics and Design, an independent research facility in Olathe, Kan., backs up ATR’s claim that a playing surface is safer when Rebound is amended to the soil. Testing indicated that a 30 percent reduction in the severity index, which is based on the likelihood of a head injury resulting from impact with the ground, is achieved.

Other benefits, such as improved drainage and stronger turf roots, may be a factor, but the difference may not be great enough to warrant amending the soil for these reasons.

Jennifer Meyer, horticulturist, Brevard County Parks and Recreation, Merritt Island, Fla., said that comparably maintained fields with and without the crumb rubber have not differed significantly in terms of appearance and performance.

THE HOMEFRONT. These products have tested well in sports and athletic turf, but could they ever gain the widespread favor of professionals to help maintain homeowners’ and commercial site turf?

One of the key elements of the discussion will be the state governments, who have the responsibility of finding places to dispose of the more than a quarter million tires that are discarded each year. Some state governments have implemented a tire disposal fee that is funding grant programs designed to provide crumb rubber at no cost to park and recreation departments and athletic field managers. It is possible that these programs could be expanded, allowing the more extensive use of crumb rubber by a more diverse base of end users.

Crumb rubber may have applications beyond turf as mulch, which is being tested by Brevard County, according to Meyer. It looks like pine bark from a distance, Meyer observed, so it has a pleasant appearance. However, the wire is still embedded in the rubber, and it’s cut in large pieces so you can’t use it in areas where kids play and could pick it up and throw it around. We’re trying it in some background beds, and so far it seems to be working well.