SportsTurf provides current, practical and technical content on issues relevant to sports turf managers, including facilities managers. Most readers are athletic field managers from the professional level through parks and recreation, universities.
Issue link: http://read.dmtmag.com/i/433388
www.stma.org December 2014 | SportsTurf 17 cultivation during summer stress limit what existing grass and new seed can do. Before overseeding and fertilization are considered in a fall maintenance program, cultivation should be Step #1. De-compaction aeration softens the soil deep; examples of solu- tions include: deep tine aerator; soil wave aerator (e.g., Imants Shockwave, Redexim VertiQuake); soil air refresher (e.g., Koro Recycling Dresser). De-compaction aeration is softening the soil down below a 6-inch depth. De-compaction allows for deeper rooting of existing turfgrass, allows better irrigation and rainfall infiltration, and softens the entire field surface for safety and play- ability. Timing: De-compaction aeration should take place a minimum of 3x during the fall season (or as much as budget allows). A deep tine or soil wave machine can be run the same day as a field event, so even if the field is under high traffic de-compaction aeration can take place. Soil air refreshing deep for de-compaction requires a 7-10 day break and also can take place at the end of the fall season. Surface aeration opens up the surface; examples of solutions include: rapid tine aeration (coring tines/solid tines/needle tines/ knife tines); linear slicing (blades or solid slicing rollers); and soil refreshing aeration. Surface aeration has multiple positives in the fall. Surface aeration is any type of aeration that vents the surface (top 3-4 inches) for air, water infiltration, and to soften the field for player safety. Using hollow tines to core aerate removes organic matter build up and/or sod layer and creates channels for air and topdressing (if it fits into the budget). Core aeration is labor inten- sive with the clean up of plugs, but the benefit outweighs challenge. Core aeration and solid tine aeration equally create holes for seed to fall into for seed to soil contact when overseeding. Slicing can open more surface area than most tine aeration methods to open the surface of the field as well and promote healthy plant growth Timing: The type of surface aeration used is to be dictated by the schedule of use. Core aeration could require a break of up to 7-10 days. On native soil, solid tine aeration and/or slicing can take place with play on the field immediately after. Sand could need a 3-5 day break in order for the surface to become stable again before play. Soil air refreshing down to a 4-inch depth requires a 5-7 day break to grow in the slices. Verticutting Examples of solutions: There are a wide range of sizes and types of verticutting machines available. Verticutting is extremely effective in the fall, especially in conjunction with overseeding. Verticutting removes some thatch build-up, opens up the black layer that can build during summer with heavy watering, and will promoted Kentucky bluegrass density and durability. Like core aeration, the clean up from verticutting can labor intensive. But just as core aera- tion, the benefit outweighs the challenge. Timing: Verticutting can take place with a 3-5 day break and in no effects stability or playability of a field. For practice, a field could be verticut the same day as play. The cultivation technique of universe fraze mowing has now proven to be a valuable practice. This is especially true in the fall on Kentucky bluegrass in combination with overseeding. Similar to verticutting, universe fraze mowing promotes Kentucky bluegrass density and durability while removing thatch and organic build- ups. But instead of removing 11-15% of material like verticutting, universe fraze mowing removes up to 100% of the material to the desired depth. That depth is set above the growing point of the Kentucky bluegrass to allow re-generation. Universe fraze mowing also removes poa annua plants that are short rooted from summer stress, the poa annua seed bank on top of the field, and other weed seed that has accumulated. Universe fraze mowing also helps smooth the field surface. Timing: The depth or aggressiveness of Universe fraze mowing varies depending on the window of time the field as off. A light Universe fraze mow cleans the very top of a field and can take place in a window of 10-14 days. Going more aggressive to remove more organic and poa annua can require up to 21-35 days, depending on the age of the field and the amount of prior maintenance. OVerseeding Once fall cultivation is addressed/planned, overseeding should be addressed. Overseeding in conjunction with the cultivation can added effectiveness to both practices. When preparing to overseed, consider a few different things: Seed selection: New genetics in fescue, Kentucky bluegrass, and ryegrass are changing what is possible for fields and overseeding. Fast germination, increased aggressiveness for spreading and filling in, and stronger roots for establishment and quicker playability all exist. Also lowering demands for dark green color is being replaced with an appreciation for aggressiveness and durability unlike ever before. All lead to a new world for seeding. For an example, see www.sportsturfonline.com and read the article by Julie Adamski about a Kentucky bluegrass field that went from seed to play in 35 days. That feat has provided an example and confidence for grass field managers exploring using new seed varieties. Additionally, the genetic improvements now make fescue and ryegrass capable of existing on high traffic fields together, in with Kentucky bluegrass, or even on their own. No longer do grass field managers have to hold their breath during disease stress times with these varieties. Do your homework on what is available from the seed companies you have existing relationships with, but consider possibly branching outside those relationships as well to find what For an example, see www.sports turfonline.com and read the article by Julie Adamski about a Kentucky bluegrass field that went from seed to play in 35 days.