University research centers put turf to the test

For close to a decade a pair of university research centers have put turf to the test. And as their influence continues to grow, their reach in the sports turf world extends, leading researchers, turf companies (natural and artificial) and entire sports leagues in new directions.

Since debuting in 2009, Penn State University’s Sports Surface Research Center, and in 2011 the University of Tennessee’s Center for Athletic Field Safety, have championed efforts to test sports surfaces, learn how turf interacts with equipment and players and support efforts to improve the durability and playability of sports turf of all kinds.

“Our overall focus and goal is safety and playability to the athlete,” says Dr. Andrew McNitt, director of the PSU center and coordinator for the university’s Turfgrass Science Undergraduate Program. But from there, the center wants to also help sports turf managers improve their craft and get manufacturers and sports officials to think in new ways when it comes to designing surfaces.

South of State College, PA almost 600 miles, the University of Tennessee center, led by Dr. John Sorochan, aims to improve the quality of turf fields, no matter the budget or expertise of those maintaining it.

Along the way, both centers run multiple studies and expand focuses to encompass a variety of research, all geared toward improving sports turf, whether in the NFL’s most pristine stadium or a city-owned park continually mobbed by children.

Sorochan and McNitt were both instrumental in starting their respective centers. Since landing at Tennessee in 2002 and working in turfgrass since 1992, Sorochan helped start the Tennessee center. McNitt, working with Penn State since 1984 and as faculty since 1998 has seen much change since the inception of his center. “You conceive of something out in the future and when you get there, things are different than you thought it would be,” he says.

At PSU, McNitt has recently concentrated on improving sod quality for lay-and-play fields. As field managers get less time to prepare new sod—what was once months often turns to days—McNitt wants the entire industry to understand the ramifications. The NFL (both McNitt and Sorochan work personally with differing aspects of either the NFL or the NFL Players Association when it comes to field quality) instituted a rule that all resodding must wrap 48 hours prior to game time. “Basically, field managers were getting pushed and pushed and the league decided something might not get done in time,” McNitt says. “This idea of resodding continuously as a maintenance practice is growing. Because sod isn’t on the field very long it has limited ability to change hardness.”

McNitt says his center wants to take technology to the sod farm to help them understand how to manage turf akin to finished fields, allowing for the immediate use of drop-in fields. A pair of recently published papers from the center investigated growth regulators, fertilizers schemes and sod on plastic in relation to lay-and-play. As the lay-and-play concept turns more efficient and cost effective, McNitt expects it to move more mainstream, allowing locations that did have resodding continually as an option in their budget explore the concept. “If you run the numbers,” he says, “and extend it out over 20 years, the numbers are pretty favorable.”

New for 2018, the PSU Sports Surface Research Center placed a focus on evaluating ways to measure surface hardness. With so many measures already available, McNitt says “a lot of dust in the air” muddies the world of evaluating fields for hardness, let alone how that hardness relates to concussions. “The hurdle in this process is not which tool to use, the hurdle is no one is testing their fields,” he says. “Let’s lower that hurdle and put out the cheapest reliable one to get people testing their fields and get the discussion going. We are evaluating all of the tools.”

Ongoing work at PSU includes a rolling database of fiber wear—McNitt says he wants to see new submissions to help keep it current and requires that a piece be cut and submitted from a field manager, not a manufacturer—and how cleated footwear interacts with differing surfaces.

As both PSU and Tennessee study footwear relationships with turf, it allows the centers to partner with biomechanics researchers and move work inside labs.

Sorochan says the main area of interest in Knoxville features surface interactions. Beyond how cleats respond to turf, Tennessee has started investigating how a soccer ball reacts to differing surfaces. Take a look at Major League Soccer stadiums, for example; five have artificial turfs and the others a mix of warm- and cool-season grasses. “The way the ball interacts with the surfaces are different,” Sorochan says. “We want to gauge how they are doing and what can be done.” Using high-speed video, slow-motion capture to measure ball angles, time of contact, exit speed and more, the center explores scenarios where artificial turf can play more like natural grass and how turf can create a more uniform experience.

Current research also has Tennessee exploring hybrid turf systems, such a SISGrass, that stitches artificial fibers into the root base to “act like rebar to stabilize the sand.” Seen in half a dozen World Cup fields in Russia and expected in Green Bay’s NFL field, Tennessee is testing the system with bermuda and bluegrass to look at the tolerances of the hybrid system.

While the breeding programs at Oklahoma State University and the University of Georgia have developed excellent new varieties, Sorochan says, it was the testing at Tennessee that helped push new varieties mainstream. The in-center testing showed the superior wear tolerance of new grass, resulting in a handful of NFL stadiums becoming early adopters.

With so many unique angles of study, each center relies not only on three full-time equivalent researchers, but a stable of graduate and undergrad students. Collaborations, such as with biomechanics, from within the university and across other institutions allow for continually diversifying work.

Often that diversity comes not only from researcher interest, but funding sources. When a young center, McNitt says he was chasing money and publishing papers to find research dollars, but now that the center has an established reputation, he can put a focus on improvement and not worry about every individual study opportunity. Sorochan says his center launched with a 100% focus on natural grass. But as university graduates were entering the workforce dominated by artificial surfaces, “we had to learn to understand it” and expand the scope of the center.

Funding models for both centers look similar. FieldTurf, the Pennsylvania Turfgrass Council, and the Keystone Athletic Field Managers Organization (an STMA chapter) represent Penn State’s big three donors. FieldTurf, the primary funder from the start, gifts money to the university for research with no strings attached. “We have discussions,” McNitt says about the relationship and potential studies. “They have good ideas at times and they have some bad ideas at times. They have been very generous to us and we use that (money) not just for synthetic, but it also funds a portion of our natural turf.”

AstroTurf has proven one of the biggest supporters of research at Tennessee, but has really funded more natural turf research “than anyone I know,” Sorochan says. “The goal for AstroTurf is to understand the baseline of what natural grass is and get their artificial turf as close to it as possible,” he says. “That is what kicked off the start of the center.”

Additional funding comes from Carolina Green, SIS Pitches, The Motz Group, Brock International and others.

Even as research defines best practices for some of the highest-level fields in the country, Sorochan says he hopes the 99% of fields with poor budgets, little maintenance and the most use reap the greatest reward over time. With two centers now well established, Penn State and Tennessee have the expertise to set the tone in all things sports turf research, no matter the surface.


Tim Newcomb has written about stadiums and turf for Sports Illustrated, TIME, Wired and more. Follow him on Twitter at @tdnewcomb.