Changes in Soil Physical Properties Utilizing an Air Injection System on Two Bermudagrass Athletic Fields.

Air injection systems may be a new tool to relieve soil compaction. These devices release bursts of compressed air into soil to depths ranging from 23 to 30 cm. The objective of this study was to determine if an air injection system can relieve soil compaction on established 'Tifway' hybrid bermudagrass (Cynodon dactylon x C. transvaalensis) athletic fields. Plots were arranged in a randomized complete block design with three replications on a compacted silt loam high school athletic field in Knoxville, TN from July 1, through August 15, 2014. Treatments consisted of a non-treated control with no air injection, air injection (AI) once every 15 days, and AI once every 30 days. Both AI treatments were applied with the Air2G2 (G.T. AirInject, Jacksonville, FL) configured to an injection pressure of 820 kPa, a probe pressure of 1,035 kPa, and using 23 cm long probe on 45 by 45 cm spacing. No traffic was applied during the study. Regardless of AI treatment frequency, surface hardness was reduced by 19% immediately after treatment application. In addition, AI treatments decreased soil bulk density by 15% and increased total porosity by 17% in the top five cm. The non-treated plots did not see a change in surface hardness, bulk density, or porosity due to AI treatment. There were no differences in percent green turfgrass cover among treatments. In conclusion, air injection systems can reduce surface hardness, bulk density, and increase porosity of silt loam soils on athletic fields. However, long term effects and application frequencies need to be investigated further.