For High-Use Fields, Creativity with Seeding in The Fall Supports A Durable Field All Year Round
Early September is the ideal time for overseeding and improving high-use, cool-season fields. Soil surface temperatures, still at peak from summer heat and high sun angle, encourage quick seed germination, while cooler night temperatures reduce the heat stress on emerging seedlings. Coincidentally, September is one of the most high-use times of the year for sports fields. Fields often remain open daily, so creative practices are required to meet demand and improve overall field quality. Here are some practices and ideas to consider when creating a September seeding program.
Soil Compaction Relief
Soil compaction relief on a high-use natural grass field via aerification is ALWAYS the focus. Spring and summer play on high-use fields build soil compaction at a high rate, so regular, ongoing aeration will help manage the compaction. Importance elevates as preparation for September overseeding and heavy use begins. Soil compaction relief can be split into 2 parts; both are extremely important in their own way, but neither is a substitute for the other.
- Deep Compaction Relief (DCR)
The goal of DCR is to soften the soil profile to stimulate existing grass recovery and support future seedling growth and development. The softer soil profile will increase air space to stimulate roots and microbial activity; improving soil health. Infiltration will also be improved, allowing rainfall and irrigation to penetrate the full profile with ease. DCR should take place at the beginning of the September seeding process and should follow again within 8 weeks.
Examples of DCR Solutions:
- Deep tine (Redexium, Wiedenmann, Soil Reliever)
- Soil wave aerator (Redexium VertiQuake, Imants ShockWave)
- Soil air refresher (Koro Recycling Dresser)
- Surface Aeration (SA)
The goal of SA should be to open as much surface area as possible to increase air exchange and infiltration of water and increase seed to soil contact for improved germination. Opening a high percentage of the surface will increase the exchange of air and will better allow fertilizer and water into the upper root zone.
For tine selection, keep it simple and aim to open the maximum surface area without losing stability. 3”x 2” spacing can yield between 3-4% surface impact, whereas 2”x 2” spacing can yield 8%. The 2”x 2” spacing should be the maximum spacing to achieve proper surface aeration, no matter the tines selected. Hollow tines are most helpful if there is organic accumulation on the surface, but solid tines can also be successful in improving air exchange and infiltration in conjunction with routine topdressing.
Examples of SA Solutions:
- Rapid tine aeration (ProCore, Aeracore)
- Linear slicing (blades or solid slicing rollers)
- Soil refreshing aeration (KORO Recycling dresser)
Make sure to ask questions of your fellow grass field managers and work to create even more solutions to these challenges. Your field, as well as many fields in the future of sports turf will thank you!
Seeding a high-use field can pose challenges such as moisture regulation and damage from traffic, especially when closing fields isn’t an option. Depending on equipment, seeding can occur in the middle of play.
With a slit seeder, seedlings germinate while buried under the soil, adding a layer of protection from traffic. This is often the best option for seeding high-use fields and is typically done in multiple directions. The next best option lies in dimple seeders. These are popular because of even coverage, but unless the seeder can penetrate the soil, the true benefit of the dimples isn’t realized. Adding weight to the frame to encourage penetration into the soil can help.
Many field managers also spread seed with broadcast spreaders and allow the players to “cleat it in”. This strategy can work on sand-based fields, but for the majority (soil-based fields), play can cause the soil to re-compact and lock up, deceasing seed survival. The best practices accompanying broadcast seeding involve surface aeration machines to create holes for the seed to fall in to, followed by sand topdressing.
Plant debris from excess growth and outside sources accumulate on the surface to create thatch and organic build up. This accumulation hurts playability among other critical agronomic concerns. Thatch removal before overseeding is an excellent time clean this accumulation in preparation for incoming seed. This will create a seed bed and support quick re-establishment. Examples of organic management techniques may include: verticutting, spring tine harrowing, brushing, fraise mowing, and Universe® Fraze Mowing.
Getting good seed-to-soil contact is critical for germination to prevent seed from drying out. Seed coating technology has improved to aid in providing more constant moisture, fungicide, soil surfactants, and even fertilizer, all in one package. Seed coating will improve germination, but ultimately poor seed-to-soil contact can have very detrimental effects.
Putting all the work into a proper fall seeding program is important but can just as easily go to waste with improper seed selection. Utilizing the best genetics possible for establishment, durability, and recovery should be essential in the decision-making process, especially for a high trafficked turfgrass stand.
Plant breeding is focused on the core needs of high-use fields. Quick germination and aggressive growth are the 2 that are the biggest focus. The aggressive growth to push stronger, deeper roots leads to a reduction in water need. Overall, all new varieties are achieving excellent disease resistance, but varieties will still show differing characteristics, so some research is warranted. Depending on the field uses and locations, one of these species might be the best fit for you.
New varieties of Kentucky bluegrass germinate in 7 days or less and spread in less than 21 days. The aggressive growth drives roots that make Kentucky bluegrass extremely drought tolerant as well. High-use fields should be seeding with a minimum of 2 lbs. in their September seeding. In low budget situations only seed the high-use areas and let the less stressed areas survive on their own.
Just as with Kentucky bluegrass, there are Perennial ryegrass varieties that are setting themselves apart for germination and durability. Using Perennial ryegrass in the September seeding is a good idea for fields that are receiving a large amount of use in the later fall and / or in the early spring. Repeating a ryegrass seeding later in September can benefit as well on a high-use grass field to keep pushing plant populations into the fall.
Tall fescue is an excellent variety because of its rooting ability. Think of using fescue as a “stabilizer” for a high-use grass field. If the field is primarily fescue already, as many of high-use fields are, then adding more fescue is not needed. Instead, spend your time and money on Kentucky bluegrass for its aggressiveness. The Kentucky bluegrass roots can push deeper in conjunction with the existing fescue roots, making a surface stronger and more.
A September seeding approach in 2018 should not be identical to 2017. It is a complex challenge to get fall seeding established on a high-use grass field. And yes, there are many, many other ideas out there as solutions to meet the challenge. Hopefully some of ideas reaffirm your current maintenance practices, or even help in shedding some light on something new. Make sure to ask questions of your fellow grass field managers and work to create even more solutions to these challenges. Your field, as well as many fields in the future of sports turf will thank you!