Maintenance suggestions for transition zone sports fields

By: Bob O’Quinn

Professional athletes put a lot of value in well maintained natural grass playing surfaces and on the individuals who keep those fields in good condition. According to the “2008 NFL Players Playing Surfaces Opinion Survey,” the vast majority of NFL athletes prefer natural grass fields because, as their statistics indicate, grass fields provide increased career longevity and minimize injuries. Obviously, maintaining a natural grass sports field properly is a small price to pay for the numerous environmental, health and safety benefits that follow.

Not all natural grass fields are created equal. According to John Marman of West Coast Turf Farms (Palm Desert, CA), hybrid bermuda grasses should be installed in the climatic transition zone that divides the geographical northern and southern United States. Hybrid Bermudagrass is a preferred species in the southern and transition zones because of its rhizomes, which help repair the turf from under the surface and the plants’ stolons that help protect the crown and speed its regeneration from the surface.

In the northern zone, Kentucky bluegrass is the preferred species because it is one of the few cool-season grasses that has rhizomes and a significant degree of repairability. Also, Kentucky bluegrass has great cold tolerance and is somewhat more aggressive as far as recoverability for the northern part of the transition zone. Another benefit of turfgrasses with rhizomes is that they tend to be more drought tolerant because of their more extensive root systems.

Professional care and maintenance of a natural grass sports field requires cultural practices, including aeration and top dressing. When the soil becomes compacted from heavy use game after game, aeration is needed to relieve this stress by allowing more oxygen into the rootzone, while promoting deeper rooting and water percolation. Depending upon frequency of use, hollow and solid tine aeration might be needed several times per year.

Individuals responsible for NFL natural grass sports fields know the importance of top dressing to maintain a quality playing field. For anyone not familiar with top dressing, it’s important to be aware of the benefits. Frequent top dressing provides:

1. Better footing for the players.
2. Help in avoiding an organic layering on the surface of the soil.
3. Help in protecting the crown of the grass plants.

How often a field should be top dressed generally depends on the type of field. For natural turfgrass baseball or football fields, light top dressing throughout the season is beneficial. NFL fields are top dressed as often as every couple of weeks — and sometimes right before a game.

When it’s necessary to renovate part or replace all of a natural grass field at the professional level, it’s best to remove the top layer by sod-cutting and disposing of it. Disposing of turfgrass and other plant materials is never an issue because they are all natural organic substances with no negative implications. The next step would be to rototill to a depth of 10 to 12 in. (being careful to avoid irrigation and drainage equipment) to relieve compaction and to help water move freely. Then, the surface should be laser leveled. A pre-plant fertilizer should be applied before the new sod is installed. For high school or middle school sports fields, it’s quicker and more cost-effective to go over the surface with a pulverizer prior to field grading.

For more information about natural grass and to find a professional turfgrass producer near you, please visitwww.Turfgrasssod.org.