From Sports Fields to Golf Course Problem Solver

Editorin Golf

From Sports Fields to Golf Course Problem Solver

By Richard Hurley, Ph.D.

and John Patton - Turfgrass Agronomist , Dennis DeSanctis, Jr. - Turfgrass Agronomist

In 1993 the world was able to witness a revolution in natural turf athletic field construction. The Federation of International Football Association (FIFA) required thatall World Cup Soccer games be played on natural grass. Therefore, a method to install and manage turfgrass indoors was researched and implemented by a team of agronomists at Michigan State University, led by Dr. John N. Rogers, III. For the first time, a portable natural turf field was moved into the Silverdome in Pontiac, Michigan in preparation for the 1994 World Cup Soccer Tournament. The success of this modular field provided the industry the ability to move a natural turfgrass field into a domed stadium for the purpose of hosting a sports event.

A similar system was installed for the practice tee at Baltusrol Golf Club to cope with limited practice tee facilities available for the US Open Championship in 1993. A team led by Dr. Henry Indyk, constructed a modular tee and was successful in providing fresh turf that was free from divots after the practice rounds.

In 1997, Giants Stadium became the first commercial installation of a modular turf system. Unlike other stadiums, Giants stadium has two NFL teams, the New Jersey MetroStars, rock concerts and many other high school and college events. In 2000,Giants Stadium hosted 100 events in 80- days bringing additional revenue to the stadium authority that would otherwise be impossible with a traditional field. In addition to the modular natural grass field presently in Giants stadium there is another 1.2 natural grass fields in reserve modules staged outside Giants Stadium, allowing for the replacement of worn areas on the field as the season progresses.

Description of the Integrated Turf Management System (ITM)®

The name, "Integrated Turf Management System," is an umbrella-statement, referring to the many innovative uses this product encompasses. The current ITM system was designed and refined by GreenTech, Inc of Richmond, Virginia and consists of modules injection moulded from high-density polyethylene. This material is used because the high-density polyethylene is extremely strong and maintains its shape under stress.

Foot locator pads lock the modules together and assure that there are no seams or joints that may disrupt the surface of the turfgrass. The modules are 46 inches square, 8 ½ inches deep and 11 ½ inches deep with the grow-in fences. The modules are forklift accessible from all four-sides. The bases of the modules contain numerous small holes to enable extensive drainage, and at the same time permit gas exchange up into the root zone. There are three-inch fences at the top of the module to stabilize the turf during establishment and transportation. Once the turfgrass is sufficiently established, the fences are folded down resulting in the top three-inches of root zone meshing exactly with the corresponding three inches of the adjoining module. The foot locator pads and the weight of the modules themselves (approximately 800-1000 pounds) prevent any shifting. The Figure below shows a schematic diagram of the module.ITMpalletimage.jpg

Drainage and Rootzone Gas Exchange

The pallet channel network of the ITM system allows for a rapid drainage capacity due to the unimpeded water flow once the water has reached the gravel layer. This is especially beneficial for situations when heavy rains occur during use or in high rainfall climates. The drainage capabilities of the modular turf system greatly exceeds all traditional drainage now installed relying on use of three or four inch perforated pipes spaced ten to fifteen feet apart below the surface, forcing water to move laterally. The ITM system equates to six inch drain pipes at twenty-one inches off centre, in both directions; a capacity often not needed for drainage, but extremely beneficial in the event that it is. Athletic fields should be designed to avoid the occasional catastrophic occurrence of a heavy rainfall during an athletic event, which can create wet and muddy soil conditions, injury to players, and slow turf recovery.

Healthy turfgrass roots require a constant supply of oxygen twenty-four hours a day during the growing season. Carbon dioxide is released by the roots as a by-product of respiration and must move through the soil to be released so that toxic levels will not build up in the soil. A significant benefit of the ITM system is the extensive gas exchange potential with the use of a forced-air system. Oxygen and carbon dioxide movement is allowed through holes and pallet channels beneath the root zone, providing uniform coverage throughout the turf area.


Traditional System vs. Tray Drainage

Golf Course Applications for the ITM System.


Many golf courses have driving range tees that are too small to accommodate the amount of play that they receive. The result of this is a practice tee that is an eyesore with many divotted areas and an economic headache due to the cost of constantly re-grassing. An ITM modular tee has the capability to rotate out old modules that are worn and insert new modules without any play disruption the next day. The superintendent is only limited by the number of the modules in reserve. In addition to practice tees, this concept bodes well for any under-sized, shaded, and/or heavily trafficked tee on the golf course.

An ITM modular tee not only permits the replacement of worn areas, but it also provides a distinct advantage in warm season climates where Bermuda grass tees are over-seeded in the fall of the year with cool season grasses. The use of modular turf allows the avoidance of this unsightly transition period.

The suggested use on tees, practice tees, driving ranges and non-putting green applications are for the ITM modules to be installed directly on concrete or asphalt surfaces:

1. The modules are then filled with approximately four and one-half inches of USGA recommended gravel.

2. A six to seven inch specified root-zone mix is then placed into the module on top of the gravel.

3. After firming the root-zone, the modules are seeded or turfed. During this process the fences on the sides of the perimeter modules are folded in the upright position to provide an even grade across the teeing surface and the fences are folded down between linked modules.

4. After establishment the modules are ready to move in and out as necessary.


Many golf courses have maintenance yards that are not large enough to have an adequate putting green nursery. Because the modules are forklift accessible from all four-sides, it is easy to move turf in and out of areas as needed. Additionally, putting green nurseries in view of the golfers often become unsightly at times when stripped sod areas become weedy. An ITM nursery allows Superintendents to remove the stripped modules from view, dump, and stack the modules to be used again.

Another advantage to having an ITM Portable nursery is having the ability to carry established modules in a maintenance cart, common when plugging out poa annua. This saves time compared to running back and forth to the nursery.

ITM pallet.jpg

GreenTech ITM Module on Forklift Attachment


The GreenTech modules solve many erosion control problems. This application is not for portability; it is solely for permanent erosion control applications. Steve Glossinger, Superintendent of Caves Valley CC in Owings Mills, Maryland discovered this application after brainstorming regarding a severe erosion problem he was experiencing. The erosion was being caused by burrowing muskrats, which led to instability, causing problems when the area experienced rain or irrigation. Installing the GreenTech modules, stabilized with rebar, provided a stable surface and a clean edge (at the waters edge). The burrowing muskrats were also deterred to another area because they could not dig into the module. When compared to other traditional methods, the GreenTech modules are a very economical option. Their structural strength and integrity make this perfect for erosion control. Turf managers are now beginning to try this economic and effective application.


Stabilization with GreenTech Modules is Completed

PUTTING GREENS - "Tray-Drainage Greens"

The ITM system used to build a tray-drainage green is an excellent option now available to superintendents. The modules linked together as a whole form a "tray-drainage system" that is excellent in its ability to move water and air through the soil profile. Tray-drainage greens, as they are called, are the same as a standard USGA green; however, their sub-surface drainage configuration is different. Instead of the standard drain-tile in a herringbone or grid-iron configuration, the module cavities themselves provide the drainage, equivalent to six-inch pipes, twenty-one inches off centre, in both directions.

In a tray-drainage green water moves gravitationally through the soil profile and directly onto the PVC lined sub grade. Compare this to a traditional drainage system where water must migrate through the soil or gravel before reaching a drainage pipe. The tray-drainage system has the capability of moving more water and air through the entire green more efficiently, especially with the addition of a forced air system designed to exchange air or heat/cool the soil, as compared to traditional greens construction.

Tray-drainage greens are recommended for:

1) Geographic areas which have high rainfall and drainage is extremely important.

2) Golf Courses in the Southern U.S. pushing adaptability of bentgrass.

3) Golf courses committed to the use of "forced air systems" (i.e. Sub air for their greens). The tray drainage greens are more efficient in moving air.

4) Greens located in difficult sites that need extra capacity to move water and air through the root zone.

A tray-drainage putting green can be constructed in the following way:

1) A traditional sub-grade is compacted and contoured as desired.

2) A non-porous liner is placed over the sub-grade.

3) The modules are placed directly on top of the liner. The modular trays should be placed to follow the green contours.

4) Modules are sealed with special PVC tape and caulking, to ensure an airtight seal for the forced air system, and to prevent the migration of the root zone over time.

5) The modules are filled to the top, plus one inch above, with pea stone.

6) A filter fabric may be placed overtop of the pea stone layer (optional method).

7) A USGA recommended root zone mix is added above the pea stone.

8) The surface of the green can be turfed using sod, sprigs, or seed.

A research putting green was constructed in the fall of 1999 using ITM modules as a component of construction. GreenTech, Inc. underwrote the project under the supervision of Dr. Trey Rogers and Dr. James Crum. Research is currently underway at the Hancock Turfgrass Research Centre at Michigan State University to investigate the potential benefits of this system when constructing a golf course putting green.

One research component was to determine the feasibility of constructing a contoured putting surface using the modular trays. The incorporation of forced air into the system is also being investigated for potential benefits of optional compatible sub-surface air systems.

Complete results from the research green constructed using ITM modules should be available within one to two years. At this time construction of the modular putting green at Michigan State University has provided extremely promising results. For more information contact Dr. Trey Rogers at Michigan State University.

A putting green at the Peachtree Golf Club in Atlanta, GA was established using the tray-drainage method; it has been a success. Figure 5 shows this green during construction.


Tray-Drainage Green Ready to be filled with pea gravel


Another advantage of modular construction is that the modules may be placed directly upon a hard surface such as asphalt or concrete, allowing all drainage to be collected and recycled. Where irrigation waters command a premium price, this offers a significant advantage. This approach also allows for the capture and recycling of various turfgrass chemicals, in turn reducing the potential for nutrient and chemical ground water contamination.

There is very little special equipment necessary to install modular turf systems. A tractor set of fork attachments is all that is required for most applications. An extended-hoe may be needed for the construction of large tray-drainage greens.

Richard Hurley is a Turfgrass Specialist and Adjunct Professor in the Plant Science Department at Rutgers University, New Brunswick, New Jersey.

For more information on ITM GreenTech in the UK, contact Simon Jacobs on 01268 799592 or e-mail

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