The Effect of Wear and Soil Compaction On Sod Rooting and Plant Recovery From Wear Injury.

Damaged areas in sports fields from wear are often sodded at a time when sporting events are rescheduled before complete rooting of sod into underlying soil. The objective of the study was to examine the influence of wear and soil compaction on sod rooting and spring recovery. The sod was installed on a silt loam soil (coarse silty mixed nonacid, mesic Typic Udifluevent) and a sand rootzone in 2008 and 2009 at the Joseph Troll Turf Research Center, University of Massachusetts, Amherst. Compaction treatments were applied using a plate vibrator compactor prior to sodding. Wear treatment was simulated with a steel brush guided over the plots by movable tracks. The plots were established using a Kentucky bluegrass (Poa pratensis L.) sod blend in September 2008 and 2009. Wear was initiated one month after sod installation in both years and applied 6 times through November of each year. Treatments were set out in a randomized complete block design with 3 replications. Wear significantly reduced rooting strength in the fall and the following spring compared to the non-wear treatment. Root initiation from counts taken in mid-March 2009 and 2010 was significantly reduced by wear. There was also a significant reduction in root biomass due to wear from samples taken in July 2009 and 2010. Soil compaction significantly reduced root biomass below 8 cm at the same time; however there was no effect from soil compaction on rooting at the 0 to 8 cm depth. Sod on the silt loam soil from wear treatments was fully recovered by 30 April, 2009. Full recovery from wear in the sand rootzone was not complete until 17 June, 2009. The same trend in recovery was shown by the spring 2010 ratings. Wear main effects accounted for 80% of the variation in rooting and recovery.