SportsTurf provides current, practical and technical content on issues relevant to sports turf managers, including facilities managers. Most readers are athletic field managers from the professional level through parks and recreation, universities.
Issue link: http://read.dmtmag.com/i/391471
www.stma.org October 2014 | SportsTurf 35 The type of field chosen, native or sand-based, will depend on several factors; these include: The soil conditions that exist at the site The weather during the playing season How often the field will see use While it is less expensive to go with the soil on-site, the professionals warn against making that the primary factor in determining what type of field to have. "The first big difference between natural soil fields and sand- based fields is cost," says Dan Wright of Sports Turf Co., Inc., in Whitesburg, GA. "Drainage is the biggest issue with natural soil fields. Since there are no under-drains on a natural field, all drainage is surface drained." This, he notes, calls for specific grading of the field. "The goal is to get the water off the field the shortest and quickest way possible. Once the water is off the field, it must be captured and moved into some drainage swale and ultimately into a storm drain. The crown on a soccer and football field usually is at least 1.5 – 2 percent. For a baseball field, the infield should be sloped at least one percent and sloped toward the foul lines in order to get water off the infield, and the outfield should be sloped from the infield arc to the outfield fence at least 1.5% but no less than 1.25%." The need to move water off the field, he notes, can create a main- tenance nightmare, since many fields wind up being graded from the outfield fence to the home plate drain. The long path for water to travel usually results in an unplayable field following a rain. "Sand-based fields, whether native or non-native, are usually always advantageous," notes Mark Wrona of URS in Grand Rapids, MI. "Natural grass multi-purpose athletic fields, even those with a well- drained sand base systems and regular maintenance, should not be expected to remain in excellent condition if the number of game/events exceeds 30 per year." Professionals will perform soil tests at the site where the field is to be constructed, and will make recommendations based on the soil content and on its ability to allow water to percolate down from the surface in a given amount of time. Just remember, says Wrona, the professionals know what they're talking about. Two starkly contrasting scenarios come to mind as cau- tionary tales. "At one school facility, a multi-field complex was built over a gravel pit, so in their wisdom, school officials allowed clay soil from the adja- cent region to be dumped over their native gravel site with the thought of saving on watering costs. With a new thick clay layer spread over the native gravel, less water was required to water the field complex, but after only several events during our normally wet spring season here in Michigan, the fields would turn to mud. The situation was remedied decades later by stripping off much of the clay and mixing the remaining clay with underlying native sand and then reseeding.