Field-use capacity: How much play is too much play?
By DR. DON GARDNER
Agricultural and Natural Resources Agent
University of Georgia College of Agricultural and Environmental Sciences
One of the sagest pieces of advice I ever received is: “Beware technical solutions to political problems and political solutions to technical problems.” This caveat has found consistent application throughout my consultation with local government sports field managers who find themselves in a crisis over sports field conditions. The technical problems boil down to field-use capacity imbalance with field construction, management inputs and field-use impacts. The political problems stem from the sports field manager not understanding and/or calculating sports field-use capacity for his fields and effectively communicating the field-use capacity limits up the chain of command and out to users and stakeholders. Provision of good-quality public sports fields is equal parts technical and political expertise.
Sports field-use capacity is the product of field construction times positive, field management inputs, minus field-use impact, yielding the equation SFC = (Fe × MI) − FI. Field-use impact itself is the result of negative maintenance impacts plus field hours times field condition during use FI=(−MI + FH) FC. Examples of negative maintenance impacts are soil compaction by tires of mowing equipment or turf wounding by core aerification operations. These effects are often seen where the tires of mowing equipment travel repeatedly over the same track when performing edge clean up. The entire equation reads SFC = (FC × MI) − (−MI + FH) FC. There are five major variables to be managed to produce the field-use capacity for a given field. Of these variables, field construction is the closest to being a constant. If well-constructed, it becomes a constant benefit to field capacity. If poorly constructed, it becomes constant obstruction to field capacity.
Management inputs are usually defined and confined by annual budgets and therefore are subject to change on an annual basis. Field hours respond to social factors and generally trend up annually. Field conditions at the time of play are likely the most volatile variable and can change on an annual basis. Canceling long-scheduled play due to inclement weather is difficult for American football, in spite of the fact that a single game on an inundated field can easily destroy a field for a season and require a minor renovation to restore it to playing condition.
Field construction is a critical component of field-use capacity. Inadequacy in field construction is difficult, if not impossible, to overcome with management inputs, and then only a long period of time and at much greater ultimate cost than that of proper initial construction. “Sports Fields: A Manual for Design Construction and Maintenance,” by Puhalla, Krans and Goatley should be considered the current standard for sports field construction.
I know of elected officials and local government top management who would never think of building a road, a building or a parking lot on poor soil because they know it will not work. It is false economy and the inevitable failure of the facility will reflect poorly on them. These facilities are all made of dead things. Yet these same, otherwise-competent managers will ignore published industry standards and exceed to construction of sports fields with swamp muck, pond bottom and gumbo clay and expert living turf to perform.
In addition to the direct construction materials and biologics for the sports field proper, air drainage, both surface and subsurface water drainage and surrounding light interception by nearby trees and buildings also have a direct effect on sports turf performance and field playability. Substandard field construction generally dooms even the best sports field manager to technical failure.
The sports field-capacity equation can be simplified if we can assume the field is built to industry standard. Given standard field construction, the condition of a field becomes a function of maintenance inputs minus field-use impact.
Grady Mill, in North Carolina State University publication AG-726-W 01/2010 BS, “Maximizing the Durability of Athletic Fields,” provides a major tool in linking field-use capacity to play house. With standard inputs, he projects sustained good field conditions with 200 hours of play or fewer per year. Good field conditions with some thinning of turf and localized wear areas are expected at 400 to 600 hours of use. Fair field conditions are expected at 800 to 1,000 hours of play. Over 1,000 hours of play should be rewarded with significant turf loss, field surface damage and increased potential for athlete injury.
These guidelines assume implementation of all management inputs to support field health and playability. Few of those managing public sports field have the political support to limit play hours to match the level of maintenance inputs available to maintain field standards. The challenge remains trying to match play hour to field capacity.
If a field has light field use of 200 hours or fewer per year, evenly spaced over the growing season, a routine maintenance program with two core aerification treatments per year is likely adequate to maintain an excellent quality playing surface. If the number of play hours increase and the maintenance inputs remain the same, the field quality will decrease to the level that existing maintenance supports. If additional appropriate maintenance inputs are applied to the field to counteract the field-use impact, the quality of the filed will recover to the level supported by the management inputs. “Designing, Constructing, and Maintaining Bermudagrass Sports Fields,” by McCarthy, Miller, Walz and Hale, provides the industry standard in the southeastern United States for management inputs as well as construction outlines.
At a certain point increased play impacts cannot be overcome by increased management inputs. Dr. Dave Minner’s “Grass System Response to Traffic and Recovery” provides an excellent detailed account on a single page of traffic response by turf. When field-use impacts exceed the physical and biological ability of the turf to respond to the desired playing condition in a timely manner, the sports field manager has the following options: reduce use hours on the field to the point turf regeneration can occur; resod the substandard turf areas to reduce the time a field is offline at the cost of field revocation; or accept reduced field quality and increased exposure to liability for player injury.
The value of any theory is found in its ability to accurately predict real-world results when it is applied. The best real-world model I have encountered is the city of Houston, Texas, Sports Field Management Division, managed by Anthony Wise under the leadership of Director Joe Turner and Deputy Director Abel Gonzales. In outline, fields are allocated for competitive, recreational or practice play with respectively decreasing input allocation. Play hours are tracked, and once a preset amount of play hours is reached, a field is taken out of play for renovation followed by a 28 consecutive-day rest period. The turf density standard of 98 percent coverage must be attained before returning a field to play. Field managers can cancel play in inclement weather.
In order to meet the coverage standard, the middle of football and soccer fields are typically resodded. Political and financial support for management decisions is generated and maintained by effective communication and a team building with stakeholders. The field conditions are a result of timely application of turf management technologies made possible by effective cultivation of community support: equal parts technology and politics.
Knowing the field-use capacity for your sports fields will not prevent conflict over the use of the fields, but it will also make a conversation such as the following possible:
“Sir, weather radar shows a front with anticipated rainfall of 2 inches expected to hit us two hours before game time tonight. If it hits, we might want to consider canceling the game to preserve the field.”
“What happens if we don’t reschedule?”
“If we play in an inundated field, I expect we will need to deep-tine aerify and resod before letting play back on the field. We will lose the field for a month, and the home game in two weeks will have to be moved to the practice field. It will cost $11,000 for that option, for the field revocation, plus $4,000 to rent temporary lights and bleachers for the next home game. Or we could have thick-cut sod installed on the game field and be ready for the next home game at a cost of $35,000. Then, this summer, we will probably have to remove the thick-cut sod and put in regular-cut to be ready for next season. That is another $11,000. If neither of those are viable solutions, I will have to take the field out of play for the rest of the season, and we will move the rest of the home games to the practice field, which means more light rentals.”
“All this because of a little rain?”
“No, sir. All this because the universities are scouting all our teams and don’t want to end a player’s chance at college or pro ball because our field isn’t safe. Tell me what you want me to do.”
Article reprinted with permission from “Recreation and Parks in Georgia” magazine, Summer 2014 issue
I am doing the course in “Sports Turf Management” in Australia. I found this article in your magazine by Dr. Ron Gardner most informative. It answered a lot of the questions I had. My role is basically micromanagement of a few different types of fields and his information help answer most of my questions.
Thank you for access to this excellent publication.