Prescription Athletic Turf® Field System

Prescription Athletic Turf® (PAT®) has been regarded as the premier design for natural grass fields since its introduction in the early 1970s. Over the ensuing two decades PAT fields were installed in collegiate and professional stadiums across the US because it offered attributes beyond all other field options. In the recent years, The Motz Group’s redesigned PAT system has been installed in premier sports venues in Europe, South America, Australia and the US.

The essence of PAT is to provide ideal turf growing conditions by means of complete water management, something not achieved with any other field designs. It is the most technologically sophisticated and comprehensive system available in the world.

THE MAJOR DESIGN COMPONENTS THAT ALLOW PAT® UNPARALLELED WATER MANAGEMENT CAPABILITY:

1. The field is excavated to a dept of 300mm below finish grade, with the floor of the field made perfectly flat. The entire field is then wrapped with an impervious polyethylene barrier, essentially creating a watertight “bathtub”.

2. Laid across the floor of the field is an extensive grid of exclusively manufactured drain tubes, manifolded together to create a continuous matrix. The matrix discharge lines, which are below the grade of the field floor, empty directly into the storm water system of lift station, or into the vacuum chamber. This airtight chamber is fitted with submersible discharge pumps and remote vacuum pumps.

3. Once the lines are in place and connected to the vacuum vault and an overhead irrigation system is installed, the field is filled with processed sand that meets exacting specifications for sizing and gradation. The sand is laser graded flat and grassed with the appropriate turf species.

4. Into the sand are set a series of patented water level gauges that continuously measure plant available moisture.

5. A computer operating customized software in Windows format integrates the entire system. The system can be set to either control all functions automatically (irrigation, drainage, conservation, as described below), based on the electronic readings sent from the water gauges, or allow for some of the operations to be handled manually.

A PAT® SYSTEM IS A MULTIFUNCTIONAL SYSTEM

SUB-IRRIGATION
By closing off the drainage valves and introducing water onto the barrier through the drain tube matrix, the field can be completely irrigated from the base up. Water moves upward from the field floor through capillary action, replenishing in a much more efficient manner the moisture necessary to maintain the optimal air-to-water ratio in the rootzone.

CONSERVATION
When the rootzone reaches optimum moisture levels the system's self-contained design maintains the condition for extended periods, dramatically reducing the frequency of overhead irrigation. In combination with subirrigation, these features become a vital component of the system, particularly in arid or water-restricted areas and desalination zones.

GRAVITY DRAINAGE
Water is removed from the field profile by gravity flow. Effusion, and thus the rate of field drying, are restricted by how fast gravity can pull water through the sand profile and move it through the drainage tube matrix. With all other things being equal, gravity is the limiting factor for drainage on virtually all-athletic field designs currently available, except PAT.

VACUUM DRAINAGE
When water falls on the field faster than gravity can remove it the system activates vacuum drainage and water is forcibly removed at a rate of 100,000 gallons per hour. Under either drainage mode, however, only that water which is in excess of optimal levels is removed from the system, allowing maximum use of available water supplies.

In addition to the four primary functional modes above, The Motz Group designed system affords greater flexibility in meeting the client's site-specific needs. Some of the features that can be custom-engineered into a project include:

WATER RECYCLING
In addition to PAT's unique ability to conserve moisture, the system's water management features can be further enhanced by capturing and re-using effluent water. Placed into holding tanks or retention basins instead of the storm water system, drainage water can be re-applied either through overhead or sub-irrigation.

The effluent's chemical characteristics may be monitored to assure acceptable water quality and when necessary, recycled water can be mixed with domestic/desalinated supplies. Significant reductions in water usage can be achieved.

ROOTZONE HEATING
In geographical regions which require subsurface heating to maintain a playable surface, the system design can be slightly altered to provide fully automated, extremely efficient and cost effective hot water heating. This is not an "add-on" system but one that can be included at substantial savings over conventional cabling or tubing systems.

CROSS SECTION OF PERSCRIPTION ATHLETIC TURF FIELD SYSTEM

1. The perfectly flat, laser leveled playing surface, planted with the appropriate cool or warm season turf, is ideal for sporting and non-athletic events.

2. Root strength, canopy density and rapid recuperation - the vital signs of rugged durability - are maximized with pure, precisely graded rootzone sand.

3. PAT's patented low-profile drain matrix minimizes both installation time and construction difficulties while achieving highly efficient water movement.

4. The heat-welded polyethylene barrier creates a contained profile and allows precise control of the rootzone moisture level.

5. Water is removed from the rootzone through gravity or vacuum-enhanced drainage and is returned to the rootzone through sub-irrigation and/or water recycling.

6. The barrier water level, calculated to produce the targeted air/water ratio in the root zone, is continuously monitored by patented gauges. The system’s computer analyses the data and automatically initiates moisture management functions to maintain ideal turf growing conditions.