Tips From The Pros

SPORTS FIELD MAINTENANCE - SOCCER HAS A SOD ISSUE

Here in North America, soccer (or football as it is known through most of the world) is growing. Fans in the US are showing up for high-level games and this has got promoters searching for larger venues and playing in stadiums not designed for soccer. More and more, these host venues are baseball parks and the skinned areas of the field need to be sodded for the soccer game. Additionally, soccer players, especially at the elite levels have a strong favor for natural grass fields. To get around this, promoters have gone to installing a natural grass sod temporarily over the top of an artificial turf field for one game, or a short series of games. And while the host venue welcomes the additional revenue, the results can best be described as mixed when it comes to field quality on the newly lain sods. There have been several downright failures, but also some overblown visiting team comments for high-profile games and the sport would be well served to address this with some sort of guidelines or standards for the sod maintenance at the farm, harvesting and installation techniques. This can be done and done well. But too often poor quality sod and techniques coming from low bids are ruining everyone’s fun. Hide and watch as we will undoubtedly see more issues, especially when the elite European clubs come over this summer for their friendlies. The problems tend to occur at venues where this type of project is a “one-off’ scenario and there is not experience or history in such work from either the venue or the sod producer. This seems to be the case with the full-field artificial turf sod-overs done for soccer games. The baseball clubs that are increasingly hosting soccer at their parks are often more experienced in such work and there are fewer problems with the playing surface. But I often wonder how our truly talented groundskeepers can get the skinned areas back to the level of perfect demanded by professional baseball, especially when they often only have a day or so to complete the work. We all know that getting the dirt right at this level takes time.

Here’s another of my calls for field standards and guidelines. Some basic specifications for the projects could solve a lot of the problems. First, the event organizers and leagues need to understand that all sod is not the same and sod projects for such events must be well planned in advance, with specific maintenance at the farm. Harvesting techniques are different for sports field sods and so are installation techniques. A simple set of post-installation field tests could go a long way in combating the culture of soccer which seeks to often criticize the playing surface at venues other than their own.

Below, I offer some very basic tips for success. The scope of this blog doesn’t allow for a solid treatment of the subject, but some basic principles which can go a long way to avoiding failure. When in doubt, hire professionals and listen to them.

Turf Tips 101:

April and May in the middle and northern parts of the US are when many field repair projects get launched with the start of the summer construction season. Repairing damaged areas with sod can best the best method, especially when a quick return to play is required. In today’s era of growing field use and field shortages, sod becomes a more and more attractive solution and is seen more as routine field maintenance than only for unanticipated rescue situations. Yet we too often see field failures when a part or all of the field is sodded. The are many reasons such a project fails, but almost always the quality of the sod and the sod work is involved in the failure in some way. We have to start getting better sod, and we have to get better at sod work.

Basic Tips:

Prepare in advance. A well-managed sports field will have a continuous relationship with at least one local sod producer. Waiting until you have a field in need of repair to go shopping for sod risks failure. It takes time to produce a good sports field sod. It’s not the same as sod for lawns.

Maintain at the farm as close as you can to the host field maintenance plan. Mowing height and frequency should be the same at the sod farm as it will be when you bring it into your field. Cutting, rolling, transporting and installing sod is stressful enough for the plant, why add scalping stress to the menu? Always better to raise the mowing height (within reason) once at the stadium rather than to lower the mower height. Fertility and irrigation programs should be managed as close as possible also. Keep nitrogen fertility lean at the farm, especially in the spring on cool-season turfgrasses. You can’t just start the specialized maintenance at the farm a few weeks before harvest, it has to be a season long maintenance program to work well. You are adding to the production cost of the sod and dollars to the project, but it shouldn’t have to be excessive and it’s always way less expensive than sod that fails. Match the cultural practices like aerification and topdressing also. You’ve got to topdress at the farm for sports turf sod, I believe. (see thatch below). Do not let even one Poa annua (Annual bluegrass) plant or any other weeds to establish in your field at the farm, especially any perennial grassy weeds like Poa trivialis (roughstalk bluegrass).

Match the soil as closely as possible. We could go on for hours here, but just know that many sports field sod projects fail due to not enough attention being paid to the soil that the sod is grown in. The idea is to conduct basic and inexpensive soil texture tests for both your field and at the sod farm. If you don’t know how to interpret the results and see if your sod soil will ‘marry’ to your field’s soil. It has to do with particle sizes and generally if you install a significantly finer textured sod on a relatively courser rootzone soil, you will tend to hang water in the sod or ‘perch the water’ in the sod because of the finer textured soil in the sod. Drainage issues are the result. When in doubt, have a qualified agronomist look at the test results and make written recommendations for you, especially on sand-based fields.

Err on the side of too thick when cutting. Traditional lawn sod is typically harvest relatively thin (about ½ inch – 1.2cm). This rarely works for high traffic sports fields, especially when play must begin soon. Sod can hold up on a field but still come up in flaps when not cut thick enough because there is a natural ‘shear-zone’ created at the bottom of the sod that can last for several months or even years. When the going gets tough, the sod fails at this shear line and classic sod flapping shows its ugly head. Professional football fields in the US typically install at between 1.5-1.75 inches thick (3.8-4.5 cm) in order to avoid shear-zone issues.

Manage the thatch at the sod farm. Thatch is good for lower level sports and youth sports where the damage is a cumulative trampling and bruising versus the more ripping and tearing of higher cleated play. A very distinct thatch more than about ¼ inch thick, in my opinion, will create another possible shear-zone right at cleat depth. Like a loose piece of carpet on a smooth concrete floor. The solution starts way back at the farm with regular topdressing at appropriate rates. Mixing soil in with the thatch as it develops is the idea, minimizing or ideally eliminating the thatch shear zone for sod that will host higher-level cleated play.

Harvest and Transport. Do a test cut a couple of days in advance and have someone watching harvest to ensure only quality cut sod is loaded on transport trucks. Consider refrigerated trucks during the warmer months and don’t let sod rolls over heat, which they will tend to do after a few hours, especially when moist. The better sod producers will even put small data-loggers in the sod rolls that track temperature during transport. Threshold limits can be set. After a few hundred miles, trucking plans can get very complex when trying to expedite delivery. Many venues specify that the sod must be at the stadium no more than 24 hours after harvest, which is pushing the limits logistically with transport but can and has been done. If the sod producer is not experienced in the difficult logistics of cut, transport and timing, you are risking problems. No doubt, we should be using plastic grown sod for these types of projects because of the toughness and lack of root-pruning. More on plastic grown sod in a later blog…

Allow time and install carefully. Don’t get in a big hurry to harvest and install all the sod at once, unless that is manageable. The work is difficult and crews can get sloppy after a full day of working with such a heavy product; poking and pulling the sod too much will tend to loosen the surface and can make it bumpy. Use a sidekick on thick-cut sod to get the best results. I believe it almost eliminates post-install seam mitigation and makes for a tighter surface. (see video below) We can infer this from the fact that typically up to 5% extra is needed in the sod square-footage total when a sidekick is used. Use ONLY big flotation tires on all the installation equipment, especially on the installer. You don’t want to rut the previously lain roll or the rootzone as you install the next row of sod. Lay plywood for protection if you must, but don’t rut up your sod during its installation! Insert (embed) here my YouTube video of sidekick being used recently at Sports Authority Field in Denver

Inspect your seams after install. Inspect them again. Mitigate all the gaps and ensure player safety before you let them out.

Roll and topdress. Rolling the post-install sod will flatten and firm-up a newly installed sod. Use a roller and weight appropriate for the project and sod. In my experience, rolling the same direction as the sod rolls works best, at least for a few weeks when everything has settled in better and rooting has begun. Topdressing the newly lain sod will go a long way to smooth the surface and seem depressions and allow for better play and ball roll. Topdress the entire surface with an appropriate soil. Match the sod soil which should match your rootzone soil ideally. Broom in carefully and slowly after topdressing.

The bottom line with sports field sod work is to do it right the first time. All the extra work and treatments will add costs to the sod, but it will always be less expensive than a very public failure.

Resources of the Month:

The University of Florida Turfgrass Science department has a great service for rapid diagnostics for turfgrass disease. With all the easy and inexpensive ways to ship samples overnight, you can get a preliminary assessment in 24 hours.

A good site for Metric/English conversions. Also good for converting within a system of measurement (e.g. feet to miles).

Next time a player says your field is too slick, show them this study.

End Quote:

“Knowing trees, I understand the meaning of patience. Knowing grass, I can appreciate persistence.”

Hal Borland