Crumb Rubber Depth Is More Important than Particle Size for Improving Bermudagrass Traffic Tolerance

• DOI: 10.2135/cropsci2017.03.0168
• Publication Date: 2017-08-17T20:51:23Z
• Authors: Kyley H. Dickson; John C. Sorochan; Jim T. Brosnan; John C. Stier; John M. Zobel; Adam W. Thoms
• Keywords: 0401 agriculture, forestry, and fisheries; 04 agricultural and veterinary sciences

Crumb rubber (CR) generated from recycled tires has been used as a topdressing medium on cool‐season turfgrass athletic fields to increase tolerance to simulated traffic events (STE). Research was conducted at the University of Tennessee Center for Athletic Field Safety (Knoxville, TN) to determine optimal CR particle size and topdressing depth combinations for use on ‘Tifway’ hybrid bermudagrass [Cynodon dactylon (L.) Pers. × C. transvaalensis Burtt Davy]. Five CR topdressing materials varying in particle size and uniformity were evaluated; however, all were within 2.0 to 0.5 mm in diameter. Topdressing was applied to plots during 2011 and 2012. Each CR topdressing material was evaluated at three depths: 0.6, 1.3, or 1.9 cm. A non‐topdressed control was included for comparison. Twenty‐five STE were applied using a Cady Traffic Simulator. Traffic tolerance was quantified using digital image analysis to measure percentage green cover. Surface hardness differences were assessed using a Clegg Soil Impact Tester. Non‐topdressed control plots had percentage green cover reduced to <50% after only 12 STE compared with 18 to 20 STE for plots receiving CR at 0.6 to 1.9 cm (P < 0.001). No practical differences in percentage green cover were detected among CR particle sizes. Surface hardness decreased as topdressing depth increased, with minimal effects of CR particle size. Our findings indicate that CR topdressing can improve hybrid bermudagrass tolerance to STEs and that application depth was a more important factor in selecting CR topdressing than particle size.