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/77829
field equates to roughly 600 tons, costing $12,000 to $36,000 de- pending on material specifications and availability. Field managers should be aware that not all topdressing material will provide the results they are looking for, i.e. improved infiltration rates and sur- face stability. For instance, topdressing sand containing excessive amounts of course particles, and poorly graded sand, which may be as cheap as $10 per 1,000 lbs, will compromise stability. Sands con- taining more than 10% silt (0.002 to 0.05 mm) and clay (<0.002), on the other hand, will compromise drainage (Table 1). When shopping for topdressing material have a physical analysis done before selection, look for well-graded sand, with <5.0% fine gravel (>2.0 mm) and ≤ 10% silt+clay. The "Topdressing Material Recommendations for Athletic Field Use" (Table 1) suggest 2-5% very fine sand (0.05-0.1 mm), 2-5% silt and 2-5% clay. Material meeting these recommendations will increase the stability of the sand, without compromising infiltration rates. Materials meeting these standards will likely be a specialized soil blend for athletic field use and cost around $30 per 1,000 lbs. Field managers may also opt to use topdressing that conforms to USGA (2004) root- zone recommendations, which are designed to maximize drainage. Sands conforming to USGA recommendations may have little to no fine material (<10% very fine sand, silt and clay combined), which may reduce surface stability in comparison to materials con- forming to "Topdressing Material Recommendations for Athletic Field Use." However, field managers in locations that receive heavy rainfall may be willing to compromise some stability for maximum drainage. Topdressing material conforming to USGA recommenda- tions will likely be readily available and cheaper ($20-25 per 1,000 lbs) than the specialized athletic field soil blend previously discussed. PREVENTING SOIL CONTAMINATION After an adequate sand layer (2 inches) has been accumulated over time, light topdressing (0.25-inches annually) and annual cultivation should be used to prevent the accumulation of organic matter on the playing surface. If hollow or side-eject tines are used for cultivation purposes, special care must be taken to remove soil cores or prevent tines from penetrating to depths greater than the sand topdressing. If native soil is excavated by the hollow tines and deposited on top of the sand layer they must be removed to prevent the drainage system from being compromised by the poorly draining subsoil. A simple al- ternative to prevent this problem from occurring would be verticut- ting, which would allow field managers to address organic matter accumulation without disrupting the soil profile. For best results the selected cultivation method should be coupled with sand topdress- ing, pairing these cultural practices will ensure that the voids created by cultivation are filled with sand, allowing the system to maintain rapid infiltration rates in the long run. It is important to note that field managers and topdressing sup- pliers should work together regularly testing material to ensure that topdressing specification remain consistent over time. If a field www.stma.org SportsTurf 15