What is a field “Crown“? – The elevated center portion of a sports field, raised to promote the runoff of surface water. (Puhalla, Krans, & Goatley, 1999)
If surface water is not removed from the field:
- Surface becomes slippy and unsafe, as well as providing a poor spectacle
- Soil compaction will occur more readily on cohesive native soils, increasing surface hardness
- Oxygen is excluded from the soil and roots will not grow = grass pulls out during games & grasses will not be as stress tolerant (e.g. drought stress)
- Anaerobic conditions develop, leading to black layer problems & lack of important nutrients
- Cancellation of events/games
- Delayed maintenance practices e.g. mowing
- Increase in pest & disease problems (annual bluegrass etc.) because of wet favorable conditions or reduced grass health
- Soils take longer to warm up, so seed germination is delayed in spring
How high should the crown be for soil fields?
Many professional regulations do not specify or prefer a crown on soccer fields (usually sand-based). The National Federation of State High School Associations recommends the following for native soil fields:
Football – It is recommended there be a slope of ¼ inch per foot from the center of the field to each sideline. Note: The rise from each sideline to the center of the field is 20 inches when the recommended slope is used.
Soccer – An engineered soccer field should have a minimum of one to one-and-one-half percent slope on fields which are surface drained and made up of native soil. For fields with underground drainage, the slope should be no less than one percent slope. Slope is measured from center to side. Under no circumstances should a soccer field be flat.
Surface water moved to the sidelines is usually collected by interceptor drains running along the sidelines.
Refs:
- Ford, P. & Thomas,G. 2002. Drainage Design. Northern Melbourne Institute of TAFE
- NFHS Court and Field Diagram Guide, 2002
- Puhalla,J., Krans,J.,and Goatley,M., 1999, Sports Fields; A manual for design, construction and maintenance, Ann Arbor Press
Authors: P. J. Sherratt & J. R. Street