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/678624
12 SportsTurf | June 2016 www.sportsturfonline.com FIELD SCIENCE O ur firm was approached by a local California agency to prepare a feasibility study to assess the use of soil-based fields as an alternative to natural grass or artificial turf for athletic sports purposes. The report aimed to identify relevant examples of soil-based field applications and to assess the benefits and drawbacks. At the beginning, we believed the task would be relatively straightforward. After reaching out to a large number of California cities, counties, sports organizations, regional soccer organizations and related nationwide professionals, what was thought to be a common playing surface yielded few examples. In fact, there were only three examples found anywhere in the United States, two in the State of Washington and one in California. In Bremerton, WA the Pendergast Regional Park has two full size "dirt" soccer fields that included sports field lighting. The fields were built in 1995 using a sand/silty sand mixture that included a full sub-drainage system designed to accommodate the 50 to 60 inches of rain the area received annually. The goal was to create a low-cost facility that could recover quickly from a rain event. Early on, the fields worked well with only light maintenance required, however over time the heavy rains created significant channeling in the play surface that ultimately silted the drain system, compromising the integrity of the field. The fields have sports lighting, but are only used for an occasional practice, not for organized play. The city, which provides little or no maintenance to the two fields, is considering synthetic turf if or when funding becomes available. In Bellevue, WA the school district created small dirt based fields that could be used by the Lake Hills Soccer Club. The fields were created to complement each campus with an alternative to natural grass, which had difficulty surviving the areas wet season. The dirt surface, which resembles decomposed granite more than soil, was believed to require less maintenance and would support the club's growing micro team program. The school district is currently in the process of a multi- year program to convert their fields to synthetic turf because children tracking in mud and dirt into the school buildings caused significant damage to floors, walls and doors in the school's hallways and classrooms. "THE PIT" The community of Trona is located in the California desert near the China Lake Naval Weapons facility. The facilities staff from high school developed an all-dirt field opposing ■ BY BY DEREK C. MCKEE & GARY HOVER DIRT FIELD ASSESSMENT REPORT football teams like to call "The Pit." The dirt football field was ultimately created, as a last resort, to provide local nighttime football to the small desert community. The fact that potable water is such a premium, coupled with the effects of the high desert heat, the high salt native soil, and the relentless wind, left the school with limited options for providing the community with a sports field. Synthetic turf was not an option not only because of the initial cost or the extreme heat typical with turf fields, but the difficulty of keeping the wind driven sand out of the infill. According to staff at the school, a field could be completely covered with sand overnight. Only after all attempts to grow natural grass failed did the school decide to experiment by building a dirt field at the school's Griffin Stadium. The Los Angeles Times produced a 2009 article and video documenting the dedication required for the small community to enjoy Friday night football. The school appears quite happy with the field, especially when it gives their team a home field advantage. Outside of the US, the use of soil-based fields (native material) is quite common, especially in developing countries. The use of maidans, or large, unprogrammed open spaces, is prevalent throughout India, the Middle East and parts of Europe. Maidans are used for a host of community activities in addition to sports. There are also examples of soil-based fields in certain regions of Japan where local clubs prefer to introduce very young players to fast-paced play, all the while discouraging unnecessary falling. After researching precedents, we began to study the theoretical application of soil-based fields. A number of professionals with knowledge in soil design were contacted to learn how they might approach developing a usable soil-based field. The surface universally recommended is similar to a quality baseball/softball infield. Most infields are a mixture of sand, silt and clay that is imperially developed to the desired mix. If maintained properly, these fields will require frequent watering to provide for a resilient surface. POSSIBILITIES Using that as our general approach, we present three design alternatives with varying drainage methods and soil composition. Each alternative provided the client with Outside of the US, the use of soil-based fields (native material) is quite common, especially in developing countries.