Thursday, November 16, 2006 - 9:00 AM

Soil Compaction Evaluation with the Spectrum Technologies SC-900, Before and After a Rolling Stones Concert at Petco Park.

Larry Stowell, PACE Turfgrass Research Institute, 1267 Diamond St., San Diego, CA 92109, Wendy Gelernter, Pace Turfgrass Research Inst., 1267 Diamond Street, San Diego, CA 92109, and Luke Yoder, Petco Park, 100 Park Blvd., San Diego, CA 92101.

PETCO Park in San Diego, California is the home of the San Diego Padres professional baseball team.  The field was constructed using USGA specification root zone sand and was grassed using Bull’s-Eye bermudagrass that is overseeded with perennial ryegrass during the winter.  In November 2005, a Rolling Stones concert stage weighing more than 70 tons, in addition to extra seating facilities, was constructed on the field. To assess the level of soil compaction caused by these activities and to determine the depth of cultivation needed to relieve it, soil compaction was evaluated before and after the concert. A Tripod Data Systems Recon 400 computer running HGIS GIS software from StarPal was used to distribute 64 sample points throughout the field on a 12.2 m grid.  A Trimble AgGPS 132 sub-meter GPS receiver was used to navigate to each sample location. Before and after the concert, a Spectrum Technologies SC-900 recording compaction meter coupled to the Trimble AgGPS132 was used to collect soil compaction data in 2.5 cm increments, to a depth of 30 cm.  Longitude and latitude were automatically recorded by the SC-900.  The trend in soil compaction revealed significant increases in soil compaction in the top 10 cm following the concert.  However, compaction levels exceeded a mean of 2 mPa (generally considered the compaction level that reduces root development by 50%) at the 10 cm depth both before and after the concert.  Before the concert, compaction exceeded a mean of 4 mPa at the 15 cm depth; after the concert, the 4 mPa level was reached at a depth of 12.7 cm. Due to the high compaction levels observed both before and after the concert, cultivation was carried out to a depth of 15 cm prior to re-sodding the field.  Geospatial analyses will be discussed.