Razorbacks return to natural grass

It’s not every day that a sod farm gets a call from a football fan asking if he can bring his hog to roll around in their turf fields. But that’s just what happened to Bobby Winstead when it was announced that the University of Arkansas’ Donald W. Reynolds Razorback Stadium, (the team mascot is a razorback hog), would be converting from synthetic turf back to natural grass. Once word got out that Winstead Turf Farms, located near Memphis, was growing the sod for the stadium’s renovation, the phone started to ring. Winstead, president of Winstead Turf Farms, respectfully declined the hog’s frolic in the grass.

Apparently, Razorback fans are pretty excited about the change. And they’re not alone.

Indeed, interest is so high in the Razorback stadium field’s renovation to natural grass that the University of Arkansas created a mini-website dedicated to tracking the conversion process. The site features a timeline, and videos to watch the removal of the synthetic surface, as well as a time-lapse camera that allows fans to quite literally watch the Tahoma 31 bermudagrass grow at the sod farm. Check it out for yourself.

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A brief history

Pat Berger, CGCS, Director of Sports Turf Operations for the past 18 years at Arkansas, says this renovation marks the fourth time the field at Razorbacks stadium has flip-flopped between natural grass and synthetic turf.

  • From 1938 to 1968: Razorbacks stadium was built with a natural grass field. It remained that way for 30 years.
  • From 1968 to 1994: Berger says the team played on an early form of AstroTurf.
  • From 1995 to 2009: In this time period, the Razorbacks played on Tifway 419 bermudagrass. Eventually, Berger changed the field over to a seeded variety, Riviera bermudagrass. Berger says he liked the Riviera for the flexibility of throwing out more seed when needed, but that the Riviera struggled in the stadium’s shade and cold, and winter desiccation was an issue.
  • For the 2010 season: The then-new head coach preferred synthetic turf, and the field was renovated again, back to an artificial surface.
  • 2019: The field returns to natural grass, with a cold tolerant, drought resistant bermudagrass as the surface.

Why natural grass

When new Head Coach Chad Morris joined the Razorbacks in December 2017, he wasn’t shy about his preference for natural grass over synthetic. A few months later in March 2018, he told the Arkansas Democrat-Gazette, “I’m a natural grass type of guy. I love being on a grass field. There’s nothing better than that in college football, or football period.”

According to Berger, the shelf life of a synthetic field is generally an 8- to 10-year period. With the artificial surface aging out, a decision had to be made regarding a renovation. Berger researched the pros and cons of installing a new synthetic field vs. putting in a new natural grass field. He consulted with Dr. Doug Karcher and Dr. Mike Richardson, turfgrass scientists on staff at the University of Arkansas, to get their feedback on possible natural turf varieties. He created a presentation filled with applicable information to help Athletic Director Hunter Yurachek, Coach Morris and University elite make an informed decision.

Among the information provided were the advantages and disadvantages of natural grass vs. synthetic turf:

Natural grass advantages and disadvantages

  • Perceived Safer
  • Cooler Playing Surface
  • Environmentally Friendly
  • Cultivar with Cold Tolerance needed
  • Fertilizer/Pesticides
  • Water Usage-Plants
  • More Maintenance/Cultivation
  • Less adaptive to outside events
  • Cold Temp Discoloration – overseeding or painting needed

Synthetic turf advantages and disadvantages

  • Perceived less safe
  • Weekly Light Maintenance
  • Warmer Surface
  • Biochemical Apps
  • Water Usage-Stability and Flushing
  • Multi-functional Surface
  • Care taken in disposal
  • Color Resistant to Weather
  • Cold Tolerant

Berger expanded on the list, saying several factors played a role in the decision to convert to natural grass. Heat tests Berger conducted on the synthetic field yielded temperatures “up to 165 to 175 degrees” in the heat of the day which “takes the legs out of a player.” And, Berger adds, “The coaches get more players who would rather play on natural grass than synthetic.”

Player safety was a consideration. “Natural grass is more forgiving on the body,” Berger says. “There are more injuries to ankles and lower extremities on synthetic turf.”

A study published in January of this year in the American Journal of Sports Medicine titled “Higher Rates of Lower Extremity Injury on Synthetic Turf Compared With Natural Turf Among National Football League Athletes: Epidemiologic Confirmation of a Biomechanical Hypothesis” confirms this: “Biomechanical studies have shown that synthetic turf surfaces do not release cleats as readily as natural turf, and it has been hypothesized that concomitant increased loading on the foot contributes to the incidence of lower body injuries.” 

Even equipment costs were considered in the decision. Berger says although the stadium had been artificial turf for a decade, the University still owns turfgrass maintenance equipment used for other grass surface sports such as baseball and softball. Therefore, buying new equipment was not an issue.

The Razorbacks’ record also tells a story. “We were a better team on natural grass then we are on synthetic,” Berger says. “I’m happy we’re going back. The AD and the coach and the people of Arkansas are overwhelmingly excited about going back to natural grass.”

Why Tahoma 31

With Coach Morris, the self-proclaimed natural grass guy, the verdict to replace the plastic surface with natural grass came as no surprise to Razorback fans. The selection of Tahoma 31 bermudagrass came, in no small measure, on the enthusiastic recommendations of Drs. Karcher and Richardson, which were based on the results of the National Turfgrass Evaluation Program (NTEP) studies in cold and drought tolerance, as well as the wear-tolerance research conducted by Dr. John Sorochan at University of Tennessee that showed the variety’s exceptional wear tolerance. In fact, Berger included only this one natural grass variety in his presentation to Yurachek and Morris.

Dr. Karcher, a professor of turfgrass science at the University of Arkansas for nearly 20 years, recalls, “I started hearing rumors in late winter or early spring 2018 that our new coach, Chad Morris, was interested in going to natural grass. The artificial turf was coming up on 10 years, was out of warranty, and needed to be replaced anyway. When I heard this, I started communicating with Pat Berger about what some natural grass options would be for Razorback Stadium.”

The University of Arkansas served as one of the test sites in the most recent 5-year NTEP study of bermudagrass varieties. Karcher compared all the latest cultivars, side-by-side, right there on the same campus and in the same climate as the stadium.

“I shared our information on how Tahoma 31 performed in our trials. I told Pat it would be a good variety,” Karcher says. “It’s safe to say that Pat was a little hesitant about it because it was so new when we started discussing it, and he couldn’t talk to anybody who had been using it at the time (on a sports field). But Dr. Richardson and I thought the data were so compelling, that it looked so good and was so well adapted to northwest Arkansas, that it should be a slam dunk decision.”

Karcher continues, “We had 5 years of really strong data on that grass being managed at a mowing height of less than an inch. It just performed really well year after year, not only with regard to cold tolerance but just its density, color and overall quality of a high-end, dense turf and its potential for a golf course fairway or a high-end athletic field.”

Tahoma 31 was developed by turfgrass breeders led by Dr. Yanqi Wu at Oklahoma State University.   

“I have to tip my hat to the Oklahoma State breeding program, continuing to develop these excellent cold tolerant bermudagrasses with excellent turf quality. They are doing a really good job over there of developing cold tolerant bermudagrass varieties for a wide range of uses,” Karcher says.

Finding a source

The next step was to find a source for the new grass. It’s only 350 miles from Winstead Turf Farms’ location in Arlington, TN to the Arkansas campus in Fayetteville, roughly a 5-hour drive. Berger says the farm’s nearby location was important to save on trucking costs and to get sod in a hurry, should the need for emergency patching arise. “Most sod producers are a good 2 days out,” Berger says.

If Berger needs more sod, he’ll be able to get it at practically a moment’s notice. The team at Winstead Turf Farms is growing sod earmarked specifically for the University.

“One thing we are doing for insurance,” says Winstead, “is we know we only need 75,000 square feet of Tahoma 31 sod for the job, but we are planting about 175,000 square feet for future applications. If they have a concert or something like that, where they need to do some replacement, we’ll always have replacement grass, maintained just like they do at the stadium.”

Not only is this the first college stadium to plant Tahoma 31, the way it is being grown on the sod farm field is also a first for the United States. Over top of the sand profile, the grass roots grow into and through the mesh of a product called the Evergreen Turf Matrix. It’s a system developed in Australia and used widely in that country for soccer and cricket fields. 

“The Evergreen Turf Matrix system is a sand-based profile that includes an interwoven mesh; this, combined with the root system of the turf, gives it maximum strength and stability without compromising drainage or any general turf management practices,” explains Robert Davey, managing director of Evergreen Turf Australia. “It is a ready-play system that allows a quick changeover on a sports field.”

The ready play stabilizing effect of the Evergreen Turf Matrix should assist with the short interval between installation of the grass and when the Razorbacks take to the field for the first time. The grass is slated for delivery sometime in late July or early August, with the intention of giving it at least 2 weeks to acclimate to the stadium before the team’s first game of the season at the end of August.

Renovation details

At the last renovation a decade ago, Berger believed that eventually the field would be converted back to natural grass someday. So, instead of gutting the entire sand profile, he left a little gift for the next sports turf manager to come along. Rather than core out the entire field, he left approximately 3 inches of the USGA rootzone sand mix intact “for the next guy,” never guessing that the next guy would be himself.

To construct the new field, Berger enlisted the expertise of Jeff Salmond, CSFM, former STMA President who worked for the University of Oklahoma for 12 years. Salmond now serves as Vice President of Projects and Corporate Development for United Turf and Track, a sports field construction company based in Arcadia, OK. Berger entrusted Salmond and his crew to strip off the artificial turf surface and ready the field to accept natural grass.

“Our job at United Turf and Track is to remove the gravel layer down to the base of the original rootzone, install irrigation, and reinstall the new sand rootzone,” Salmond says.

How much gravel was there underneath the artificial turf? “A lot,” Salmond says, laughing. To remove the 8-inch thick layer of gravel, Salmond and his crew “hauled out about 150 truckloads with 25 tons per truck.” The process took 7 days.

“It was a very delicate process. We had to protect the gravel from being pushed through the fabric into the rootzone sand,” Salmond explains. “This was accomplished with expert operators on excavator machines. You had to use your brain quite a bit with the machine to be able to slow mop off, (I call it mopping because our guys have experience on oil fields of mopping up a site and getting it ready for construction). We had to use a mop, so to speak, with the excavator to mop the gravel off of the fabric. With the gravel removed, we will take the fabric off, then we’ll install the irrigation system and create a homogenous rootzone that will be 12 inches thick before the sod gets laid on top.”

From there, Winstead Turf Farms will begin the process of harvesting the big roll sod, and packing it into refrigerated trucks for the journey to Fayetteville. Harvesting will begin around midnight the night before so that it may be delivered the next morning before the heat of the day. Each big roll consists of 100 square feet of sod. With the rootzone firmly grown into the Evergreen Turf Matrix mesh, each 1.5-inch-thick roll of sod weighs around 1,500 lbs. At 75,000 square feet needed, Winstead will harvest 750 big rolls of sod for the job. Winstead’s plan is to have a crew at the farm harvesting, while a second crew at the stadium awaits the delivery, ready to lay the sod as soon as it arrives. As soon as the sod is laid, they’ll turn the irrigation system on. It should take no more than 3 days to install the entire field.

When the Razorbacks take the field against Portland State for the 2019 season opener August 31, the teams will be the first to play on Tahoma 31 and the first US teams to play on the Evergreen Turf Matrix system.

To Salmond, going back to natural grass just makes sense. After all, Salmond says, “Arkansas is called ‘The Natural State,’ so they are going back to that for natural grass.”

Stacie Zinn Roberts frequently writes about sportsturf and is the founder of What’s Your Avocado? Marketing and PR in Mount Vernon, WA.