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: https://read.dmtmag.com/i/266752
10 SportsTurf | March 2014 www.sportsturfonline.com try) that have done extremely well. These were sand-based fields that were sodded with sod grown on fine textured soils; as fine as silt loams. Higher profile examples of these include the Great Lawn in New York's Central Park and two sand-capped soccer fields at Cornell University. In a recent project I was retained by a design firm to write the rootzone and turfgrass specifications for two sand-based fields for the Rush Henrietta School District in suburban Rochester, NY. The rootzone mix was my stan- dard specification taking into consideration local materi- als. I specified a sand-grown sod. At the preconstruction meeting the cost of importing a sand-grown sod was dis- cussed, as it was a concern. I explained that the use of a sand-grown sod was the standard of the industry and that using such reduces the risk of soil incompatibility prob- lems. But then I shared my experience of successful proj- ects where soil-grown sod was used on sand-based mixes, making it clear it was not my recommendation. I further explained that if there was a problem, regardless of the cause, that they would have no problem finding an expert to say that sod incompatibility was the problem. The risk was theirs to take. The school district would realize thousands of dollars in savings if they used a local, soil-grown sod. They de- cided it was worth the risk. Before construction began we built a mockup of the field profile using the proposed rootzone mix and sod. Since this was done in winter, the study was conducted in a small growth chamber. I applied about 2 lb. P 2 O 5 /1000 square feet from triple superphos- phate and a pound of nitrogen from urea to the mix pre- plant. The fertilizers were mixed into the top 2 inches. The sod was watered lightly to wet the sod twice daily with a deeper watering every 3 days. By week two I backed off on the water to once every 3 days without any prob- lem. In 25 days we had dense rooting to a depth of 6 inches (Figure 2). This study provided the school district with some level of comfort in their decision. The sod was a blend of Kentucky bluegrass cultivars with a small amount of Thermal bluegrass grown on a loam soil (49% sand, 42% silt, 9% clay). The football field was sodded in late July with temperatures well into the 80s. By the time of the first game was played 8 weeks later, roots were deep and dense (Figure 3). I have to note that the sands used to make the root zone mixes in the Rush Henrietta fields as well as the Cornell sand-capped fields were coarser than a USGA greens sand. The fact that these coarser sands may provide better aeration and higher oxygen diffusion rates may have contributed to the massive and deep rooting we ob- served. I'm not sure I would be as comfortable using a soil-grown sod transplanted onto a sand on the fine end of USGA greens construction guide- lines. But then, we aren't talking about greens. If a soil-grown sod is used on a sand-based field, I think it will be especially important that the sports field manager employ a core cultivation program to include harvesting or sweeping the cores, fol- lowed by sand topdressing. In the long term it will be best to remove as much of Field Science Figure 2. Left: Rooting of sod 25 days after sodding in growth chamber. Figure 3. Right: Rooting of soil- grown sod on sand- based mix, 7 weeks after installation.