Healthy Injection for the Greens

by Shane Sharp

Republished from Golfdom magazine, March 2005.

Machine uses high-speed, water-based system that’s changing the way superintendents handle routine aeration.

For superintendents, the sales pitch is becoming increasingly difficult to resist. Imagine a machine that injects 500 to 700 pounds of topdressing per 1,000 square feet of turf - up to 250 percent more than a traditional application. Now imagine three of these machines knocking out all 18 greens in one day. Lost revenue? What lost revenue? All 18 putting surfaces will roll as smooth as the hood of a newly waxed car in just under an hour. Oh, and if the upper rootzones need some soil amendments or nutrients to go along with the sand, no problem. Consider it done.

The Challenge

The apparatus in this proposal comes courtesy of DryJect® 21st Century Aeration™. DryJect utilizes a high-speed, water-based injection system that’s changing the way superintendents handle routine aeration.

A Zamboni-like machine with a row of 10 high-pressure injectors blasts aeration holes about the size of a little finger through the rootzone. Both the spacing (3 inches to 10 inches) and the depth (up to 10 inches) are adjustable. The machine uses a patented venturi system to pull up to 8 cubic feet of topdressing material (or soil amendment) per 1,000 square feet without disrupting the surface.

“It’s an excellent new technology to incorporate sand into the upper rootzone,” says Patrick O’Brien, Southeast regional director of the USGA’s Green Section. “The sand incorporated can be counted in the overall total of topdressing applied to the greens annually for the purpose of the organic matter dilution program. The technology can incorporate large amounts of dry sand through the cones of the machine with high-pressure water.”

Striking Gold

The DryJect service and its sand injection technology were not designed by a couple of rocket scientists with an inexplicable penchant for golf course maintenance.

Rather, DryJect as it exists today is a product of the blood, sweat and tears of a mining engineer from Sweden and his American partner. In 2000 Peter van Drumpt and Chris des Garennes purchased the license, patent and parts for what would become DryJect from Land Pride, a division of Great Plains Manufacturing. The partners then set out to put theory into practice by fine-tweaking the design to make it more durable and efficient.

“They had the machine and technology, they just couldn’t get it to work,” van Drumpt says.

“Whenever you are dealing with a machine that uses water, it is tricky business. We redesigned it, and we've made it work.”

Not only have they made the machine work, they have developed a successful business model that is capturing significant market share along the East Coast. Aware that it would be cost-prohibitive for courses to purchase the maintenance-intensive DryJect machines, van Drumpt and des Garennes grow the business by selling franchises. Twenty-four DryJect franchises are sprinkled along the East Coast, the majority in Pennsylvania, New Jersey and Ohio.

“We’ve also penetrated the Carolinas, and we are starting to go after the Southern California market,” van Drumpt says.

Take Your Best Shot

Bob Graunke wasn’t hit over the head with the DryJect sales pitch. He did, however, end up having a fateful conversation with a DryJect franchiser at a conference in Orlando, Fla., about using the machine for injecting greens with something other than sand.

“I wanted to know if you could use gypsum in the machines to soften the soil and move water through quickly,” says Graunke, certified superintendent at Tidewater Golf Club in Cherry Grove Beach, S.C. “Because of our proximity to the [Atlantic] ocean, that’s a big issue for us.”

Big enough that Tidewater is on its third set of greens in 15 years. After two unsuccessful attempts at growing bentgrass, Tidewater officials opted for TifEagle bermuda two years ago. The hardy ultradwarf has been a success so far, says Graunke, but a chemical application issue shortly after the installation left him and his staff scrambling for a remedy.

“We were applying a lot of charcoal to combat it so we started to get charcoal buildup,” Graunke says. After the DryJect representative confirmed he could use gypsum as a soil amendment in the machine, Graunke contracted with a South Carolina-based franchise for a test run. After a few weeks, the buildup was virtually eradicated. But Graunke also noticed the late-spring transition from Poa trivialis to bermudagrass was smooth.

“In 3 acres of green surface we put down 23 to 25 tons of topdressing,” Graunke says. “We are able to run golfers through the course as we are doing it. The beauty of the hydrojet is that once you inject the material you are able to blow off the excess material, water the greens, roll them, and they are ready to putt. We even do it during peak season because we don't have to worry about forfeiting the revenue.”

Not forfeiting revenue was also a major concern for Todd Gribling, golf course manager at the Timers at Troy in Elkridge Md. The greens on the Alt Clark/Ken Killian-designed course had started to develop significant amounts of black layer three years ago, despite being only 8 years old at the time. Regular aerification wasn’t eliminating the problem, so Gribling contacted a local DryJect franchiser about testing the machine on the chipping green.

“We were able to get down 10 inches into the green,” Gribling says. “With regular aerification we were getting down 6 inches, and we just couldn’t get to the black layer. We decided to try it on all 18 greens. Two hours after we did it, the greens were playable. We were able to get down about 9.5 inches on all the greens.” By having playable greens just two hours after the DryJect treatment, Gribling says the course saved around $10,000. And while the black layer has almost been eradicated, Gribling says he will continue to use the DryJect service even after it’s gone.

“It really firms up our greens because we get the amount of material in there we need, and it is packed with water pressure,” he says. “It is good preventative maintenance.”

Both Graunke and Gribling agree that DryJect is not a replacement for routine aerification. Rather, the machine can be used to strengthen the green, apply soil amendments and, in Tidewater’s case, ease the transition between cool-season and warm-season grasses. O’Brien believes this is a prudent approach, and he cautions superintendents about looking at DryJect as a complete aerification solution.

“Since it does not remove any organic matter from the rootzone, it is not a substitute for aeration,” he says. “It is technology to incorporate sand into the upper rootzone.”

“I believe the DryJect service is more of a topdressing practice and not truly an aeration of the greens,” he continues. “The hole made by the sand blasting into the rootzone does provide added air and water movement where it occurs, but it is the sand added into the upper rootzone that dilutes the organic matter that is the major benefit.”

Shane Sharp is a freelance writer based in Charlotte, N.C.