Golfdom, August 2010

S PRACTICAL RESEARCH DIGEST FOR TURF MANAGERS M A I N T A I N I N G H E A L T H Y T U R F IN THIS ISSUE Opportunity Knocks A combination of fertigation and subsurface drip irrigation could provide quality turfgrass while reducing possible nitratenitrogen contamination and water use 62 OUR SPONSORS www andersonsinc com 800 537 3370 Differentiating Between Wear and Compaction By W M Dest How their interaction affects turf stress and J S Ebdon T raffic is broken down into wear and soil compaction but few studies directly compare these two confounding factors and their interactive effects on plant response The objectives of our study were first to differentiate between the influence of wear and soil compaction and their interaction and which had the greater effect on turfgrass stress and species composition and second to compare the effects of soil compaction between a native soil and sand rootzone on their physical properties conducted in the field and their relationship to plant stress Material and methods A field experiment was conducted at the Joseph Troll Turf Research Center at the University of Massachusetts Amherst over a three year period Experiments were established in two soil types a native silt loam and a sand rootzone The compaction treatments were applied using a vibro tamper prior to seeding the plots A 3 inch depth of the topsoil and sand rootzone were removed and the soil below 3 inches compacted with the vibro Tamper to ensure that the soil was compacted to a 6 inch depth below the surface The 3 inches of soil removed was replaced and the Vibro Tamper used again to compact the top 3 inches Wear treatments were simulated with a steel brush set into a frame in which the height of the brush can be set so that injury to the leaves can be adjusted through the setting to compensate for mowing height The brush was guided over the plots by movable tracks set at the edge of the plots Each plot received the same number of oscillations starting at 75 on Sept 13 2005 to as many as 200 over the duration of the experiment Treatments were set out in a randomized complete block design with three replications on each soil Plot size was 4 feet by 4 feet The plots were established with a seed mixture comprised of 25 percent Kentucky bluegrass America and Touchdown and 75 percent perennial ryegrass Fiesta 3 Express and Cutter on Sept 14 2004 The plots were mowed at 125 inch cutting height two to three times per week depending on the season and growth rate Grass clippings were returned The plots were irrigated to maintain active growth After initial fertilization at seeding the sand rootzone plots were fertilized Continued on page 60 www fmc com 800 321 1FMC www JohnDeere com 309 765 8000 www turfgrasstrends com August 2010 TURFGRASS TRENDS 59