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Presented in partnership with Syngenta
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Grasses take the heat
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In 2001, San Antonio suffered nine months of drought, and its citizens endured frequent and severe water restrictions. In response, Howard Peak, the mayor at that time, asked the San Antonio Water System to come up with a plan that would result in year-round water savings, reducing the severity of restrictions in times of drought.
In developing the new conservation ordinance, the water system received input from numerous groups, including turfgrass producers and landscape and irrigation firms. The resulting ordinance, passed in 2005, has the potential for the city to save 1.3 billion gallons each year or 3 gallons per person per day.
In addition to regulating charity car washes, registering commercial power washers, requiring rain sensors for all residential and commercial sprinkler systems and mandating annual checkups for irrigation systems on golf courses, athletic fields and properties larger than 5 acres, the ordinance has added a provision limiting the turfgrass cultivars used in new construction of homes or businesses. (Golf courses and sports fields are not affected by the restrictions on cultivar use.) The limitations on turf cultivars went into effect Jan. 1, 2007 (www.saws.org).
To determine which cultivars would be recommended for the South Texas city, the San Antonio Water System worked with Turfgrass Producers of Texas, The Rio Grande Basin Initiative and researchers from Texas A&M, led by Extension turfgrass specialist, David Chalmers, Ph.D.
The researchers evaluated 25 turfgrass cultivars for drought resistance at a site on the south side of San Antonio from July 23 through Sept. 20, 2006. All the cultivars were planted in 4-inch-deep soil, which mimics topsoil depth on some lawns, and at a “native” soil depth of 18 inches or more and subjected to a worst-case scenario of 60 days of drought conditions ensured by a 5,000-square-foot rain-out shelter. Following the simulated drought, the grass was irrigated during a very brief 60-day recovery period.
None of the grasses survived drought conditions when they were planted in 4-inch-deep soil, but all of them survived in native soil 18 inches or deeper. Grasses planted in native soil were visually evaluated for drought tolerance and recovery.
As a result of this trial, the city approved more than half of the cultivars tested for use by residential and commercial builders of new construction. Only one bermudagrass was not approved. The other bermudagrasses, Celebration, Common Bermuda, GN-1, Grimes EXP, Tex Turf, TifSport and Tifway were considered acceptable, as were the buffalograss 609, the St. Augustinegrass Floratam, and the zoysiagrasses El Toro, Empire, Jamur and Palisades. Five zoysiagrass cultivars and six St. Augustinegrass cultivars also survived the 60-day drought trial, but did not make the city’s list.
Chalmers emphasizes that one year of research does not produce definitive results. The trials are being repeated this summer to conform to the standard minimum of two years of fieldwork required to meet agronomic standards. “The 60-day recovery (in the first year of the study) was not sufficient for some of the grasses, particularly because part of it was in a cooler period,” says Chalmers.
Future research could include testing the cultivars at various soil depths and under varying irrigation protocols and shade conditions.
Tour Edge Golf, manufacturer of golf clubs, recently installed an indoor golf equipment testing facility in conjunction with Synthetic Turf International, a supplier of putting greens and related synthetic surfaces. The site, which is part of the company’s newly constructed headquarters in Batavia, Ill., includes a 1,000-square-foot synthetic putting green, tee-line driving range cages and short game chipping stations. STI provided its NP50 nylon putting surface for the green and its NF75 synthetic fringe turf for the border. Hitting bays and chipping stations were made with STI’s EZ Tee system, a lifelike synthetic turf designed specifically for driving range tee lines. STI also supplied its Zoysia SoftLawn product to create undulations for uphill and downhill chipping. |
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