Simulated traffic on turfgrass topdressed with crumb rubber

Abstract

Topdressing plays a vital role in turfgrass subjected to traffic. Sand is commonly used for topdressing; under a suboptimal growing conditions, however, methods to maintain wear tolerance are limited. There has been recent interest in using crum rubber from recycled tires as an amendment for turfgrass areas. A topdressing study was initiated in July 1993 to determine the effect of crum rubber on turfgrass systems subjected to traffic. A factorial randomized complete block design with three replications was implemented with two crumb rubber particle sizes (large, 6.0-2.0 mm; small, 2.0-0.05 mm) and five topdressing rates (0.0, 17.1, 34.2, 44.1, and 88.2 t ha-1) on a 1-yr-old Kentucky bluegrass-perennial ryegrass (Poa pratensis L.-Lolium perenne L.) stand. In 1993 and 1994, 96 passes were made with a Brinkman traffic simulator. Surface hardness characteristics measured were peak deceleration, time to peak deceleration, and impact duration. The small crumb rubber size was more effective in increasing impact time periods than the large crumb rubber, but had no effect on peak deceleration values. Shear resistance values decreased by as much as 40% as crumb rubber volumes increased in 1993, but were increased by 20% in 1994 after rubber particles had settled to the soil surface. There was generally an increase in turf cover under traffic as crumb rubber rates increased above 34.1 t ha-1, and the small crumb rubber was more effective in 1993. Our results suggest that crum rubber can alter surface characteristics and increase wear tolerance of turfgrass exposed to traffic.