Build better fields by thinking first
Sports turf managers must do their homework
Sports turf managers must do their homework and not “put the cart before the horse” when looking to build new sports fields or renovating existing ones, a turfgrass and agronomic consultant told an audience of industry professionals attending September’s Sports Turf Canada field day activities.
David Smith, principal of DCS & Associates of Gravenhurst, Ont., spoke about athletic field construction at the forum held at Richmond Hill, Ont.’s Richmond Green Sports Centre, noting better fields are built when a great deal of thought is applied to how they are going to be put together.
He said he has experienced numerous occasions in his travels when a municipality wishes to build a new sports field and then wants to start construction the following day.
“And then we’ll figure how to manage it when we’re done.”
The first thing a sports turf manager needs to do before embarking on such a project is to take inventory of an existing field earmarked for repair or replacement or at a brand new site that might be located in the midst of an open area or a forest setting. In either situation, an inventory must be done to learn the type of soil present.
“Is there a lot of sand? Is it a heavy soil underneath? Do we have a lot of shade and, if we do, how are we going to deal with that? Contrary to what a lot of people believe, grass doesn’t grow in the dark. If you can’t get eight full hours of sunlight on your turf, then you’re going to be struggling with that turf for a long, long time.”
Water is another issue that must be considered before embarking on a sports field construction or rebuild project. Water’s availability and quality are important considerations, Smith said, adding that if it is recycled water high in soluble salts, it becomes a factor. At the same time, will there have to be an accelerated drainage system in place to deal with poor quality water, he pondered.
“If that water is going on at the top, you have to have a way to get it out at the bottom.”
The sports turf manager must know if he plans to use on-site soils or if his intention is to amend his existing soils or if he wishes to have new soils specially built.
“If we’re going to have them built, that’s a whole new program.”
A field’s purpose must also be established before construction begins, Smith said.
“Who’s going to play on it? How often are they going to play on it? Are they going to play at night?
If night play is likely, he said it necessitates a need for lighting. If the field is to be located near a residential area, there must be an acceptance by the community for additional evening illumination.
Such issues must be resolved before a shovel goes into the ground, Smith said.
If an existing field is to be renovated, considerations such as layering must be considered, he said, suggesting a real soils investigation be conducted.
“You need to know what’s there. If left field is layered and you’re going to repair it, then you need to know how to make sure it doesn’t happen again.”
Dealing with thatch, compaction
Thatch present on an existing field needs to be addressed, Smith said, to determine whether or not it is a serious issue or whether or not it is causing other problems.
If soil is heavily compacted, water will have difficulty moving through the profile. The average root zone for an athletic field is about 12 inches. A conventional soil aerator works to a depth of three to four inches.
“If you want water to move to the bottom of your drainage, you have to keep that open. You can cut little slits in there and fill them full of sand to the surface until the cows come home, and that field is not going to drain. You have to break the compaction in fields. You have to build fields so you can break them.”
Smith added drainage goes well beyond incorporating it into a field, noting the water has to go somewhere.
Another consideration to be made when contemplating the construction of a new field is the presence of pests, especially if the site is the same as the location of a previously closed field. If pests were responsible for the original field’s demise, there is a good chance they could return, he said.
If it’s decided a field cannot be repaired and a new one should be constructed instead, its expectations must be assessed, Smith said. Among the considerations to be made include the number of annual usage hours it is expected to have.
A sports field is only as successful as the tender written for it, he said, stressing all specifications should be included. He said he has seen many instances in which a contractor works to a tender poorly put together.
“It’s very, very important that tenders be given a great deal of consideration and the specifications of how we’re going to build these things.”
Permitting is equally important, he added.
Selecting the right team to help build the field is vital, Smith said. This includes not only those responsible for building the tenders, but the contractor, sub-contractors, individuals responsible for growing in and maintaining the field, and suppliers of such key components as drainage pipe and tile.
Synergism is the key, he said, and team members who have successfully worked together in the past prove to be an asset.
“You don’t want to have a quarrel on your project.”
Everyone involved in the project needs to “be on the same page” and understand the end goal. The cream rises to the top when the right team members are selected, Smith said.
Clear objectives need to be established for each individual member and for the team itself. Smith said if assistance is required to put tenders and plans together, sports turf managers need to know where to find the help needed “because it’s a big job.”
Sports Turf Canada has published a couple of manuals to help guide decision makers along the right path toward proper sports field construction and maintenance practices. Information contained within the publications will help sports field managers determine the category of field that meets a field’s objective as well as where it should be built and how it will be used.
Smith urged his audience to read other books as well, especially those dealing with construction and soils. Different soil types have different irrigation and drainage requirements, he said.
Understand soil types
Understanding soil types is imperative when considering different category fields. He said golf course sand is excellent in the construction of a category one field, but won’t work with other categories of fields.
“It’s disastrous if you use it to cut heavy soils to make a category three field.”
Growing mediums for category one fields are probably the most complicated and most difficult to manufacture, he said.
Finding the right people to help choose the right type of sand is vital, Smith said.
Creating topsoil blends is a complicated process. For the blends to succeed, they must be done right and done consistently, he said, recommending category two field construction because it’s easier to find the right materials for the category and more accurate blending can be achieved. A lot of silt and clay from heavy soils are the result when blends are manufactured for category three fields. If it’s in situ topsoil, it’s not a problem, but when it’s manufactured it can be difficult to hit the right targets.
“One of the biggest issues in manufacturing the soils is clay balls.”
Smith said they must be broken up and blended properly, adding it’s sometimes best to just leave the topsoil alone and not change it.
It’s fine sands that slow down the percolation rates on athletic fields and plugs them up so that they won’t drain.
“When you start putting fine sand into heavy soil, you’re building a sponge that will hold 12 inches of water without dripping, so all the drainage in the world won’t make that field work properly. It just becomes extremely tight. You’ve got to build them with much, much coarser sand.”
In Canada, ice and winter injury are among the top threats to the health of sports fields. Having good surface drainage is an important way to lessen the threat, he said, adding the incorporation of sufficient slope is a means to promote better surface drainage.
In addition to good surface drainage, soil drain depth is important, Smith said. Drains should be placed deep, at about 45 centimetres.
“You’ve got to have those pipes down.”
If the plan is to sod the newly constructed field, use caution, Smith said.
“Why go to all the trouble and expense of building a field and then sodding it with the low bid?”