Goal as a turf manager should be to provide adequate nutrition that promotes turf density and in turn improves field safety and playing conditions.
Many factors will influence the ultimate fertility program you develop including: grass species, soil type, time of year, intensity of field use, performance expectations, specific sport, budget, equipment, available labor, etc.
Some managers develop their sports field fertility program based on their experience, turf performance and generally accepted guidelines.
However, routine soil testing that provides baseline information on the phosphorus, potassium status, pH and organic matter content coupled with tissue testing can add precision to your management decisions.
Soil testing is an important routine management practice and an essential tool when developing a fertilizer program that promotes good turf growth while protecting the environment.
Keep in mind that turf will not benefit from the addition of fertilizer if there are adequate levels present in the soil and in the plant. Excess nitrogen applications will be harmful to turf growth and can have a negative environmental impact. Most soils have adequate levels of phosphorus so supplemental applications in most cases may not be necessary. When adequate soil levels of potassium (K) are present there is no benefit from applying more K. In fact high applications levels can inhibit root growth and excessive levels have been shown to increase the incidence of some diseases, like mold.
Nitrogen (N), phosphorus (P) and potassium (K) are called “macronutrients” because they are needed by the plant in relatively large quantities. Nitrogen (N) is the nutrient that primarily controls turf growth and density and is required in the largest amount.
When adequate nitrogen is provided the turf will have a vigorous root system, high shoot density, maximum recuperative potential and tolerance to environmental stress. Also, varieties that have a color response to nitrogen will darken up when fertilized. Inadequate or low levels of nitrogen will reduce shoot density, stress tolerances and ability to recover as fast from traffic damage, and favor weed encroachment and certain diseases like rust, red thread and dollar spot. Excessive amounts of nitrogen can be detrimental to the turf by reducing rooting, stress tolerance and wear tolerance. Excessive nitrogen can also increase thatch and favor diseases that thrive in high nutrient situations like snow mold, leaf spot and brown patch.
There is no reliable soil test for nitrogen so other factors are used in determining the amount of nitrogen that is needed. However, soils with more than 6% organic matter require less nitrogen. You can select nitrogen fertilizer sources that are water soluble and have quick release properties, fertilizers that have slow release properties or a combination of both.
Why Aerification is Crucial
Aeration is an important annual service for warm-season turf type grasses such as Bermuda, Zoysia and St. Augustine grass. Golf courses and athletic fields may aerate several times per year, but for most residential yards, aerating once per year is sufficient.
Aeration is the mechanical process of removing thousands of “plugs” from your yard. These plugs are about the size of a wine cork. This process is performed by a large machine similar to a lawn mower, however, these machines are much heavier and harder to maneuver than mowers.
The process of aerating your lawn has several benefits. Here are 3 reasons you should consider aerating your lawn:
- Aeration de-compacts the soil, allowing roots to grow deeper and therefore improving survivability during times of drought.
- Aeration allows water and fertilizers to better penetrate into the soil.
- Aeration helps remove thatch (straw, reeds, palm leaves, or a similar material).
The most overlooked benefit of aeration is root splicing. The roots of spreading grasses such as Zoysia and Bermuda are cut as the plugs are pulled. When these surface roots (called Stolons) are cut, they will spread in multiple directions, resulting in a thicker, healthier lawn.
Verti-cutting or vertical mowing, is the process of mechanically removing thatch build up in your yard. Thatch is the layer of dead biomass (roots and stems) between the soil and green grass. It is important to know how thatch develops, in order to help maintain a healthy lawn. Grass with vigorous growth habits and lawns on a highfertility program build up thatch more frequently.
Thatch will also accumulate when the soil pH is either too high or too low, if the grass is cut infrequently, or when it is too tall, and when there is soil compaction. Core aeration is effective in managing lower amounts of thatch, but may not completely manage a lawn with thatch problems. Thatch that is less than 1/2” deep is beneficial to the lawn because it shades and cools the turf. Thatch that is thicker than 1/2” prevents water and fertilizer from penetrating the surface.It also reduces pesticide effectiveness and can create a home for harmful insects and disease organisms. Lawns with heavy thatch have a spongy feel.
Moisture in thatch will evaporate more quickly than moisture in soil, so water doesn’t reach the soil. In addition, grass roots will begin to grow in the thatch layer, making the lawn less drought resistant.
This is why verti-cutting is considered the best method for preparing the soil for overseeding. A verticut slices grooves in the soil creating an area for the small grass seed to fall and wash when seeding. It is this contact with the soil that is so important. Simply spreading the seed on the crusted soil will result in poor germination and an uneven stand.
- Winter Rye Applications
Rye grass is an annual grass that lives for one season and dies out. Rye grass is useful for creating a green lawn in the winter by overseeding an existing lawn.
Rye can also be mixed with other seed types such as Bermuda for winter hydroseeding. The rye will come up immediately while the warm season seed will remain dormant until spring. About the time the rye is dying out, the warm season grass will be well established.
Annual rye grass is an excellent choice for erosion control because it establishes quickly. Although it is annual, it can reseed itself naturally and grow new turf each fall if conditions are favorable.
If you’re wanting to keep your lawn green year around, try planting rye grass. If you have questions about caring for your lawn or seeding rye grass, please contact your preferred landscaper.
Winter rye grass usually establishes itself in about 3 weeks.