Athletic Field Improvement: An Ongoing Process
by Donald V. Waddington
The design, construction, and maintenance of athletic fields should provide playing surfaces that enhance both player safety and performance. The goal of standards development is to provide information related to athletic fields that will promote knowledge and help ensure high quality playing surfaces.
Playing Surface Interrelationships
Construction and maintenance greatly influence the properties of playing surfaces. The properties of a natural surface are those of the soil and turfgrass; the properties of an artificial surface include the pile fiber, backing yarns, and shock absorbing pads beneath the turf; and in infilled systems, where long fiber turf is topdressed with sand, crumb rubber, or both, the infill materials also have properties. Properties affect surface characteristics, which include hardness (impact attenuation), traction, ball rebound, and ball roll. Surface characteristics affect player safety and performance.
Use intensity can alter surface properties and affect surface characteristics. Both properties and surface characteristics can be assessed through testing or through subjective evaluation. Based on these assessments and any related research, standards can be developed that will alter construction or maintenance procedures, and even provide guidelines on use intensity. Assessment and standards development or revision is a continuing process.
Another consideration of playing surfaces is their aesthetic qualities, which are primarily aimed at the sports fans in attendance and television viewers. Some conditions related to player safety and performance can also affect field appearance. An example would be a natural field with heavily worn areas void of vegetation or perhaps weed infested with species that do not offer surface characteristics equal to those of a good turfgrass stand. Logos and other graphics are often painted on the playing surface, and buildup of paint can affect surface characteristics. Various striping or checkerboard patterns are obtained by mowing or rolling turfgrasses in different directions. Differences in light reflection cause these effects, and a common example is the alternate direction of mowing every five yards [4.6 m] on American football fields.
ASTM Symposia Create New Interest
Three major symposia sponsored by ASTMs Committee F08 on Sports Equipment and Facilities helped in creating more interest in sports turf over 15 years ago. The first was the Symposium on the Characteristics and Safety of Playing Surfaces (Artificial and Natural) for Field Sports, which was held in December 1988 in Phoenix, Ariz. This symposium provided the opportunity for the exchange of information among the proponents of natural and artificial surfaces. It was at this meeting that James Beard, then a professor in the Department of Soil and Crop Sciences at Texas A&M University, stated that through efforts within ASTM, proponents of both sides should work together to provide safer playing surfaces, whether natural or artificial. That attitude continues to exist among F08 members, however, the debate over natural or artificial persists among some segments of the sports and turf industries. Next came the First National Symposium on Safety in American Football, also held in Phoenix, in December 1994. Lastly, the International Symposium on Safety in Baseball/Softball was held in December 1995. Papers from these symposia were published in ASTM STPs 1073, 1305 and 1313, respectively.
Athletic Fields Have Lagged in Attention
For many years in the United States, golf courses received the most attention in teaching and research at universities and in product development and sales by industry. The relative youth of the sports turf segment of the turf industry can be illustrated by a comparison with the golf course segment. Golf course superintendents formed a national association, currently known as the Golf Course Superintendents Association of America, in 1926, and this association held its first annual meeting in 1927. In contrast, those responsible for maintaining athletic fields established the Sports Turf Managers Association many years later in 1981, and this organization held its first annual conference in 1986 (in conjunction with GCSAA). A long-time provider of both research and consulting services is the Sports Turf Research Institute, located in England, which was established in 1929. Its Journal of STRI is an excellent source of research papers relating to playing surfaces.
Consider the status of sports turf within the turf industry in the following comments written by Watson et al.1 in 1992 when addressing the turfgrass industry:
In comparison to golf, sports turf is a much larger, loosely affiliated and basically unorganized (except for the Sports Turf Managers Association) segment in the turfgrass industry. Sports turf has been described by Dr. F. V. Grau, President of the Musser International Turfgrass Foundation, as an emerging giant. To realize its full potential, the sports turf industry needs to establish standards for playing surfaces (natural grass and artificial surfaces). Further, there is a need to develop and insist that architects provide sound specifications for design and construction of sports fields.
Finally, there is a need to develop clear and responsible lines of communication between all parties involved in the administration, construction, and maintenance of sports fields.
Those close to the sports turf segment know that gains have been made in athletic field management in recent years and that more improvement is needed.
Standards Related to Playing Surfaces
Following the 1988 symposium on playing surfaces, membership in Subcommittee F08.52 on Miscellaneous Playing Surfaces, part of ASTM Committee F08 on Sports Equipment and Facilities, began to increase. Eventually, F08.52 task groups on natural and artificial turf surfaces became Subcommittees F08.64 on Natural Playing Surfaces and F08.65 on Artificial Turf Surfaces and Systems. New standards coming from the task groups are now the responsibility of these subcommittees. Artificial turf surfaces and systems have been in use since the 1960s, and many differences existed and continue to exist in their properties and performance.
One of the first activities of F08.65 was to develop standard F 1551, Test Methods for Comprehensive Characterization of Synthetic Turf Playing Surfaces and Materials, which presents a list and descriptions of test methods recommended for components as well as the entire system. The abrasiveness of artificial surfaces was a concern of manufacturers and users, and standard F 1015, Test Method for Relative Abrasiveness of Synthetic Turf Playing Surfaces, was approved. The goal in the development of these standards was to gain standardization in the methods of evaluation and to provide guidance to those responsible for testing.
F 1551 lists F 355, Test Method for Shock-Absorbing Properties of Playing Surfaces and Materials, as a method to test hardness. The method utilizes an accelerometer mounted in a cylindrical impact missile to measure the peak deceleration of the dropped missile when it impacts the surface. The harder the surface, the less the impact attenuation and the quicker the missile stops.
Questions from producers and users related to where and how to test and concerns as to a critical upper limit led to the development of standard F 1936, Specification for Shock-Absorbing Properties of North American Football Playing Systems as Measured in the Field. This specification designates test points on the field and establishes an upper limit value that indicates that the field should be repaired or replaced. A number of laboratories and consultants now provide testing according to F 1936. Much of the testing is done on high-end fields (professional and college levels). A similar standard is being developed for soccer field assessment.
One of the first test methods approved by F08.64 was standard F 1702, Test Method for Measuring Shock-Attenuation Characteristics of Natural Playing Surface Systems Using Lightweight Portable Apparatus. This method had been used at Penn State University in research data collection for studies to determine the effects of soil and turfgrass properties on impact attenuation. The lightweight apparatus is well-suited to making repeated measurements on replicated plots with many treatments. The method has been used by other researchers and to assess playing field surface conditions. This method is based on the Clegg impact tester as is standard D 5874, Test Method for Determination of the Impact Value (IV) of a Soil, which was developed by Subcommittee D18.08 on Special and Construction Tests within ASTM Committee D18 on Soil and Rock. Modifications of the Clegg method have been used to measure impact attenuation on soccer fields, bowling greens, tennis courts, and cricket pitches.
One goal of F08.64 is to provide guidance to those responsible for the low-end fields of parks, schools, youth leagues, etc., that do not employ trained sports turf managers and that are often limited in funding for construction, maintenance, and renovation. In general, college and university fields and professional fields are well constructed and maintained, but there are exceptions. Guidance related to athletic fields is available from some universities and commercial companies, trade magazines, and several books. Consensus standards add another source of information. Examples are standard F 2060, Guide for Maintaining Cool Season Turfgrasses on Athletic Fields, and F 2267, Guide for Maintaining Warm Season Turfgrasses on Athletic Fields. Topics such as grass selection, mowing, fertilization, core cultivation, overseeding, and pest control are addressed. Some areas on baseball and softball fields are not grass covered. These areas include skinned areas in infields and warning tracks that should be devoid of vegetation. These areas have been addressed recently by standards F 2107, Guide for Construction and Maintenance of Skinned Areas on Sports Fields, and F 2270, Guide for Construction and Maintenance of Warning Track Areas on Sports Fields.
Putting Greens: Also Playing Surfaces
Golf course putting greens are often built to specifications of the U.S. Golf Associations Green Section. Within these specifications are physical property requirements for the soil, which must be sandy enough to provide good drainage while still holding acceptable amounts of plant-available water. Through joint efforts of the USGA, soil testing laboratories and ASTM, three test methods have been approved for testing these soils. These methods are the responsibility of F08.64 and are as follows:
F 1632, Test Method for Particle Size Analysis and Sand Shape Grading of Golf Course Putting Green and Sports Turf Rootzone Mixes;
F 1647, Test Methods for Organic Matter Content of Putting Green and Sports Turf Root Zone Mixes; and
F 1815, Test Method for Saturated Hydraulic Conductivity, Water Retention, Porosity, Particle Density, and Bulk Density of Putting Green and Sports Turf Root Zones.
These methods are used by USGA-recommended labs, which are accredited by the American Association for Laboratory Accreditation, as well as other labs that do soil testing for putting greens and athletic fields.
Work with Other Subcommittees
Members of the playing surface subcommittees interact with other subcommittees in standards development. Cooperation was extended to Subcommittee F08.54 on Athletic Footwear during the development of draft standard WK486, Test Method for Traction Characteristics of Athletic Shoe Sports Surface Interface. This method will be of great value in evaluating shoes and surfaces alone as well as their interactions. Also, F08.64 members helped in the development of F 1953, Guide for Construction and Maintenance of Grass Tennis Courts, which falls under the jurisdiction of F08.23 on Tennis Courts and Track Surfaces.
Have playing fields improved since the formation of the ASTM playing surface subcommittees? The answer is yes. All one needs to do is look at old movies, newsreels, or photos in old sports magazines to see some of the poor conditions that used to exist on professional and other fields. ASTM F08 is one of many avenues toward improved surfaces. Other organizations, such as universities, the Sports Turf Managers Association, U.S. Golf Association, Golf Course Superintendents Association of America, and Sports Turf Research Institute, which conduct or support research and education related to playing surfaces, have been major contributors to improvements. Also, publishers of trade magazines, books, and research papers related to sports surfaces are contributors. Subcommittees F08.64 and F08.65 have standards in early stages and will continue to contribute to the promotion of athletic fields that enhance player safety and performance. //
1 Watson, James R., Kaerwer, Howard E., and Martin, David P. 1992. The Turfgrass Industry. p. 29-88. In D. V. Waddington, R. N.
Carrow, and R. C. Shearman (ed.) Turfgrass. Agronomy Monograph 32. American Society of Agronomy, Inc., Crop Science Society of America, Inc., and Soil Science Society of America, Inc., Madison, Wis.
Copyright 2004, ASTM International