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/575944
50 SportsTurf | October 2015 www.sportsturfonline.com Q&A with Pamela Sherratt O ur baseball outfield is very uneven. Difficult footing for outfielders and even our ZTR bounces too much while mowing. We are contemplat- ing rolling in advance of fall aerate/overseed to smooth the surface but would love some experienced advice. Can you lead us to any resources? All athletes deserve a consistent, even playing surface and many times rollers can help achieve that. First to consider is the type of roller. There are many types of rollers, including walk-behind, ride-on, or pull-behind. Turf rollers should always have rounded edges, to prevent damage to the turf. Rollers come in all sizes and weights, but are typically 300-2,000 lbs. in weight or greater; this equates to approximately 3-15 lbs. per square inches (psi) load applied to the soil surface and is similar in weight to vehicular traffic, like ride-on mowers. While there is no set weight for ath- letic field rollers, on native soil fields the maximum recommended weight is 1 ton (2,000 lbs.). The weight of a roller can be increased by filling the roller with a mate- rial like water, sand or cement. The action of a roller is similar to that of vehicular traffic (e.g. ride-on mowers). The stress at the soil surface is proportional to tire pres- sure, or psi. Therefore, a roller or mower with tires inflated to 15 psi will apply 12-15 psi pressure to the soil surface. What's also interesting to note is that the force applied dissipates as a function of depth. For higher loads, the stress penetrates more deeply into the soil. How much stress a certain soil can withstand depends upon many factors. In particular, soils' ability to resist compaction depends upon soil texture (sand or native soil) and moisture content. Benefits of rolling include: To smooth out uneven surfaces after winter heave or heavy traffic. Rolling cannot rectify poor grades, but is used to address minor surface undulations To produce a firm surface that would be considered "faster." Rolling is a common practice in golf green and soccer field man- agement to increase speed short-term To produce a firm surface critical for those sports that require ball bounce, such as tennis, cricket, and baseball Rolling is often used on newly seeded or sodded turf areas to aid turf: soil contact and speed-up establishment Mowing patterns, typically created by the rear roller on a cylinder mower, can also be achieved by using a roller There have been some research reports of rolling reducing disease inci- dence, such as dollar spot, on golf greens. This is directly related to the use of lightweight rollers used first thing in the morning, whereby the roller is helping to remove dew/guttation water from the leaf tissue. Issues associated with rolling: ] Rolling does not improve turf quality. In fact, over use results in turf thinning and quality is significantly reduced Soils that are wet and/or frozen are susceptible to surface compaction. Overuse of rollers will also result in surface com- paction. It is critical that rolled fields are regularly aerated Soils that are too dry will not benefit from the impact of rolling. Furthermore, if the turf is wilted or dormant it will be severely stressed and may die. Rolling should only be carried out if grass is actively growing Fields with 100% grass cover and a moderate thatch layer are less likely to be affected by rolling as a method to increase field "speed" Never roll fields that have disease problems, particularly infectious diseases like gray leaf spot, pythium, or brown patch Finally, rolling frequency is a decision that should be made by the field manager and coach on a field-by-field basis. Factors such as athlete safety and playability, soil moisture, recovery time and turf qual- ity all come into play. As a general rule of thumb, rolling should only be carried out "as-needed," not routinely. This may be once per year in the spring (after winter soil heave) or several times during the playing season to keep the field safe and playable if grass cover is lost. Lastly, keep in mind that athletic fields are already prone to compac- tion, so any rolling that is carried out should always be counter-balanced by a strong aeration program. ■ ST Rolling athletic fields Questions? Send them to 202 Kottman Hall, 2001 Coffey Road, Columbus, OH 43210 or sherratt.1@osu.edu Or, send them to Grady Miller at North Carolina State University, Box 7620, Raleigh, NC 27695-7620, or email grady_miller@ncsu.edu ›› As a general rule of thumb, rolling should only be carried out "as-needed," not routinely. This may be once per year in the spring (after winter soil heave) or several times during the playing season to keep the field safe and playable if grass cover is lost.