Best BMPS for sports turf
Use best management practices when dealing with sports turf user groups.
By Mike Jiggens
Within the professional turf and grounds maintenance industry, the sports turf sector is lagging behind when it comes to best maintenance practices, those attending Sports Turf Canada’s September field training day in Oakville were told.
Boyd Montgomery, the Toro Company’s North American sports field and grounds regional business manager, said the golf industry developed best management practices several years ago.
“The sports turf industry has not really had those,” he said, adding the Sports Turf Management Association is working “feverishly” on developing BMPs. “You want to use best management practices when you have those conversations with some of those user groups and what really needs to be done on the field to deliver on those expectations.”
User group expectations are a key aspect toward the design of a maintenance and operations program. Montgomery said that when he was previously a sports field manager in Ohio, soccer groups wanted fields mowed at a half-inch or less, noting the turf was an older Kentucky bluegrass cultivar that struggled at three-quarters of an inch. Meeting with user groups allowed him to learn of their field expectations and gave him the information he needed to consider what could be done to deliver on their requests.
“At least have some open discussion on what it would take to be able to meet what they’re asking for.”
Field wear and tear is perhaps the biggest challenge facing sports turf managers, but all too often they are forced to play with the hand they were dealt, Montgomery said.
“Unless you have the luxury of being able to build a brand new complex, you are stuck with the hand you are dealt. You’re going to walk into a facility and deal with what is there.”
The sports turf manager must understand what it is he’s dealing with, including knowledge of the soil and the nutrients present, he said, likening it to a patient requesting a specific type of medicine from a doctor before he’s examined. A doctor won’t prescribe any type of medication until after he’s conducted a number of tests that leads to a proper diagnosis.
“It’s the same thing with turf management. When you walk into a facility, you really need to get an understanding of what you’re dealing with.”
This involves soil and nutrient testing. “If you’ve not done any of those, you need to do it. If you’re into any type of a fertility program and you’ve not done nutrient testing, you’re just throwing money down the drain.”
Sports turf soils range from gravel to clay in terms of particle size, and managers need to understand their soil types to ensure they are properly managed.
“That will dictate how you set up your maintenance practices as you go forward and take care of them.”
At the top of the list of cultural practices that need to be performed on sports fields is aeration, Montgomery said. It is a “game changer” that will allow fields to perform well and recuperate from the activities taking place upon them. Aeration has several benefits that include improved air and water infiltration, growth stimulation, thatch reduction and seedbed preparation.
Montgomery said the objective of aeration is to disrupt 15 to 30 per cent of a field’s surface by pulling several cores. The practice isn’t done just once and it’s done, he cautioned.
“You need to be sure you have a program in place to do that.”
Pulling cores involves a significant amount of cleanup afterwards and that can pose a challenge to sports turf managers who may not have a sufficient window of opportunity to pull cores and let them either decompose or be worked back into the soil prior to an on-field event.
“When you’re looking at doing an aerification program, the key is figuring out how you can mix it up a little bit.”
Aerating “wall to wall” four times a year was his standard practice when working in Ohio. Although he found the time for a successful aeration program (usually in between fall and spring soccer seasons) that included north-south, east-west and crisscross patterns, he acknowledged not everyone may have the time for such an extensive program.
“It’s awesome to do it wall to wall, but it may not be what you have the time or luxury to be able to do.”
Montgomery said his windows of opportunity for aeration began to shrink as he moved further along into the program, and micro aerification was subsequently performed. Lacrosse had begun in early March when there was still some snow on the ground, and athletes “beat the heck” out of his fields.
“Lacrosse is a very tough sport on a natural turf field.”
He said the local lacrosse group was given use of a soccer field, turning it into a “muddy mess” and perturbing the soccer groups. To address the wear and tear to the field, Montgomery’s staff turned to micro aerification by using walk-behind machines. Only specific areas of the field were addressed such as the goal and scrum areas and other spots that experienced severe wear. Aeration was done after each game and sometimes twice a week, depending on the field’s severity. Pre-germinated seed was spread afterwards and followed by topdressing. Spreading seed in March was a bit of a gamble, he admitted, acknowledging they would be lucky to realize a 10 per cent catch, “but we stayed consistent with that.”
The micro aerification strategy helped turn a field destroyed in its first year into one that retained consistent playability.
“Aerification can really help your field improve. It also helps with infiltration of moisture, allowing it to get down deeper into your soil structure.”
Montgomery said if a field’s soil structure is compacted, causing water to sit on top, the turf’s roots aren’t going to want to search out for moisture. The deeper they are able to go, the better off the field will be.
Coring and dragging the material back into the soil helps control the “sponginess” of the thatch layer. Montgomery shared his thoughts about the various types of aeration, promoting hollow tine aeration as the most effective means for relieving compaction.
“It helps with thatch reduction and will help with drainage. The drawback is that anytime you are doing anything to a turf surface that’s a living, breathing organism, you potentially damage the turf.
Hollow tine aeration is labour intensive because cores that are pulled either have to be dragged back in or collected and removed from the surface.
Solid tine aeration requires less labour and can be done when activities are taking place on the field. When using hollow tines, soil is removed from the ground but with solid tines, the sides and bottoms of the holes get tightly packed.
“It’s at least a benefit that you can get out there and poke some holes to allow some of those nutrients and the air to get down into the soil.”
Montgomery said the head groundskeeper for the Minnesota Twins uses a Toro ProCore walk-behind aerifier to aerate the outfield area on game day, using solid mini tines to target areas that are beginning to show wear. He said the practice is so unnoticeable that outfielders aren’t aware holes have been poked into the ground.
“The technology has gotten good enough to be able to go out there and do it and not impact the player and activity on the surface.”
Deep tine aerification is a practice done perhaps only once a year, Montgomery said, and is often a contract job. It allows the sports turf manager to get deeper into the soil, but there are safety measures that need consideration.
“The key for deep tine aerification is you need to know what is under your soil.”
Irrigation and electrical lines can be compromised if they weren’t placed at the proper depth and, if the sports turf manager doesn’t look into what’s buried beneath the surface, he may be faced with some costly repairs following aerification. Deep tining machines usually go from eight to 14 inches into the soil.
Montgomery suggested aerifying as much as possible during the season. But, he added, if sufficient water isn’t available in July and August there is the risk of some browning around the aeration holes due to root damage.
A good topdressing program should ideally go hand in hand with aerification. It helps to smooth the playing surface and modify the soil. The key, he said, is to know that topdressing with sand on a native soil field will not improve soil structure drainage.
“If you have a clay field and say you’re going to go out and start doing it with sand, I would tell you that your field will get a lot worse before it gets a lot better.”
Being consistent will eventually lead to improvement, he said, adding it’s important to understand a soil profile in order to match it with a topdressing program.
“Once you commit to a topdressing program and you’ve got your material identified that you’re going to use, make sure you have a consistent source of that throughout the time that you will be topdressing.”
Overseeding a sports field can be tied into aeration and topdressing programs. On football fields, a field worker can take a bucket containing a seed and topdressing mixture and spread it in between the hash marks prior to a game, allowing the players to “cleat it in” during the game.
“Overseeding is a good way to get the turf back into the shape you need. When you look at seed, make sure you’re getting good quality seed. Make sure you don’t have noxious weeds in your seed mix when you’re buying seed from a seed supplier.”
Montgomery suggested exercising caution when mowing, noting that the practice stresses turf and is a shock to the plant. Removal of more than 40 per cent of the leaf tissue can stop root growth for anywhere from six days to two weeks, depending on the amount of tissue removed. He cited the case of a high school that let its sports field turf get away to the point where it had grown to about six inches and then was mowed to one inch.
“The only thing a grass plant knows to do when it’s in shock is to go where its food and reserves are, which are in its roots, and start to use that to regenerate.”
During heavy play, a stressed or shocked playing field is apt to result in “beavertail” divots because there is no root structure to hold the turf together. To maximize the health of the plant, he suggested mowing heights should be matched with a field’s fertility and irrigation programs.