Wednesday, November 15, 2006

Differentiating Between the Influence of Wear and Soil Compaction on Turfgrass Stress.

William M. Dest1, Karl Guillard1, and Jeffrey Ebdon2. (1) University of Connecticut, 1376 Storrs Road, Unit 4067, Storrs, CT 06269, (2) Univ. of Massachusetts, 12F Stockbridge Hall, Amherst, MA 01003, United States of America

Wear and soil compaction are the major cause for turfgrass stress in maintaining athletic field turf. While there have been numerous studies to evaluate these factors separately, few studies have been conducted to assess which of these two factors have the greatest influence on plant stress and what is the effect of their interaction. A field study was established on a native silt loam and sand rootzone matrix in 2004 at the Joseph Troll Research Center, University of Massachusetts. The compaction treatments were applied using a Vibro-Tamper prior to seeding the plots. The plots were seeded with a mixture of Kentucky bluegrass and perennial ryegrass on September 14, 2004. The treatments were set out in a randomized complete block design with three replications in both soils. Plots were mowed at 30 mm cutting height. The establishment rate from the fall 2004 to early June 2005 was significantly reduced in the compacted plots over both soils with most of the reduction in percent cover associated with the sand rootzone matrix. Late fall/winter color was significantly better on the non-compacted treatments compared with the compacted plots on the silt loam while the reverse in color was observed with plants growing in the sand rootzone. Penetrometer values were significantly greater on the compacted versus the non-compacted treatments. Wear treatments were imposed on September 13 and 22, 2005. There was significant injury on both dates due to wear compared to the non-wear treatments, however recovery was slower to occur after the second wear treatment. Species counts in June 2006 indicated that ryegrass increased significantly in wear and compacted treated plots. No treatment effect on leaf strength, shoot moisture, and leaf turgidity was observed. Effects of wear and compaction on cell wall components, rooting depth, pore space distribution and bulk density will be discussed.