Photo Caption: The highly porous, 1-inch deep AirDrain (right) offers an alternative to the 4-inch deep gravel layer in the standard USGA putting green design (above left).
The USGA supported a research project at Texas A&M University to evaluate Airfield Systems as an alternative to the USGA method for putting green construction. The Airfield green would provide an economic alternative where the cost of gravel or transportation costs to haul gravel are prohibitive. The Airfield design utilizes a highly porous, one-inch grid in place of a four-inch deep gravel layer. The Airfield System has been used successfully on several football, soccer, and baseball fields in the United States.
Three different sands in combinations with three gravel sizes were tested in the greens along with the same three sands and four different woven geotextiles on the Airfield drain. Periodically during the course of the study, the individual test greens were irrigated until water drained from the greens. The amount of water stored in the different rootzones was then measured for 48 hours.
Airfield designed test greens stored about a half-inch more water than United States Golf Association designed greens. The woven geotextiles used in the Airfield greens with an apparent opening size of 0.2 mm to 0.43 mm did not clog with silt or clay. However, the woven geotextiles prevented the passage of rootzone sand particles into the drainage layer. In fact, the research indicated that the tested sands had more impact on small particles leaving the columns than the woven geotextiles tested. The results indicate that the Airfield System design could be used as an alternative to the USGA method for putting green construction.
The USGA Recommendations of a Method of Putting Green Construction will undergo review in 2014. At that time, the Airfield design as well as other new technologies will be considered for inclusion in the USGA recommendations.