Feature Article - February 2006
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Tough Turf

Getting athletic fields in good shape is both complicated and not-so-complicated

By Kyle Ryan

Turf types

Of course, turf comes in all flavors and varieties, and what type gets used depends on geographic location, sport, season (warm or cool), coaches' preferences and the amount of activity it will endure. The many fields that are part of the Waukegan Park District use a Kentucky bluegrass/ryegrass mix, both of them cool grasses. Fasbender's fields in Oregon use Kentucky bluegrass, which is perhaps the most popular type for sports. In Columbia, Mo., where Brad Fresenberg is a turfgrass specialist for the Division of Plant Sciences at the University of Missouri, the school's natural-turf fields use warm-season Bermudagrass, though its baseball field uses tall fescue, a cool-season grass.

Turf's vulnerability depends on a number of factors, such as activity and field profile. According to an STMA survey, the most popular event at the nation's sports complexes was softball, followed by soccer, baseball and football. In general, warm-weather grasses like Bermudagrass or even St. Augustine grass tend to be a little more resilient, according to Fasbender.

The two most common athletic field grasses are Kentucky bluegrass and Bermudagrass. Bluegrass is a cool-season grass that tends to grow densely with a deep, rich green color. Although it can tolerate cold winters, it tends to stress out during extremely hot weather, so it requires a lot of watering to stay functional in warm climates. In drought conditions, it can go into dormancy, but it thrives in sunny areas.

Bermudagrass specializes in hot temperatures and thus has an innate resistance to droughts. It also grows dense and dark green with a deep root system. It tolerates heavy traffic and can recover from injuries more quickly than other types of grasses. It doesn't, however, like shade; Bermudagrass needs the sun's full attention to grow properly.

Some areas, like the Waukegan Park District, have activity on their Bermudagrass fields after the grass goes into dormancy. So the fields also feature a slight mix of ryegrass, a fall grass that buds when Bermudagrass fades away. The area's harsh winters don't allow for much of anything beyond that, but areas in slightly warmer climates—what Trigg calls the "transitional area," southern Ohio, Kentucky, southern Indiana and southern Illinois—can sustain ryegrass deeper into the fall. Fields in those areas often have a full transition from Bermudagrass to ryegrass, though that also can cause problems.

"I know there's several facilities that had temperature changes and fluctuations that have not been consistent," Trigg says. "[So] that ryegrass is not fading out, or the Bermudagrass temperatures aren't heating up fast enough for it to kick in, so you get like a turf mix of both ryegrass and Bermuda, which is not a favorable field surface, and of course they're a challenge to maintain."

Trigg favors a lot of fall work to prepare fields for the spring season, such as heavy aerification (punching holes in the soil to allow air and water to enter it more easily), overseeding and fertilization.

"We get the call each year for earlier and earlier use of the facilities when the weather changes," Trigg says. "Of course April, but even some requests to use to start practicing in March. So we've definitely learned the more we can prepare our sites and facilities for the fall months before we put them to bed until the winter, [the better]."

A field's durability also depends on what lies beneath the surface: natural soil or sand. Sand-based systems drain better (and thus play better in wet conditions) and help prevent soil compaction. According to STMA's survey, sports managers expressed a 3-to-1 preference for sand-based fields. But native-soil fields (without sand) generally have stronger soil and retain nutrients better than their sandy counterparts.