Doug Lowe’s Top 5 Reasons Why Aerification is a Must

Now that we find ourselves in the midst of the active growing season the membership will certainly observe the staff engaging in a several highly intensive cultural programs.  At the top of that list is aerification.  Most people accept the long term benefits but that does not always make it any easier to agree with the process. As we recently completed a large scale aerification on the Farm course and are set to aerify those same areas on the Farm course I think a thorough understanding of the reasoning behind aerification would be appropriate.

5 Top Reasons We Aerify
1. Control thatch
2. Ability to provide increased firmness and corresponding green speeds
3. Extract excessive organic matter accumulation
4. Improve Soil Gas Exchange
5. Allow the plant the ability to maintain an effective root system throughout the growing season

Aerification is an important cultural practice. If you read the newsletter you will see we discuss this topic several times each year.  Through aerification we; 1) extract excessive accumulation of organic material; 2) improve soil gas exchange; 3) stimulate new root development; 4) stimulate microbial activity; and 5) improve the plants ability to withstand biotic and abiotic stresses.

Greens Aerification

Having said that, there are still plenty of golfer skeptics! Aerification is one of the most despised cultural practices when it comes to the golfer as it disrupts the playing surface; is usually done during the prime playing seasons; and according to most golfers has no redeeming features other than to decrease green performance and raise one's golf score. On the other hand, aerification is likely the most important cultural practice that a turf manager can perform. Why? Simply put to maintain a root system under the target plant. The plant's response is to maintain density enabling it to tolerate traffic, and resist ball marking; maintain a deep effective root system to withstand limitations on water quantity and water quality; maintain healthy plant growth to tolerate biotic and abiotic stresses. 

Aerification Plugs

Aerification is an active process of removing excessive organic matter (OM) in the upper root zone. As plants grow; roots, stolons and rhizomes will develop increasing the level of organic material in the upper soil profile. The more plant growth, the healthier the plant in providing a superior playing surface. The down side is organic accumulation. Left unchecked, the level of Organic Matter can actually create a high OM layer which by itself can change the dynamics of the root zone. Periodic monitoring of the root zone is proactive in maintaining a uniform balance in the amount of OM, Sand, Silt and Clay throughout the soil profile. If an organic layer accumulates near the surface it can restrict water and air flow into the root zone. During periods of high abiotic stress (heat stress) the plant demands much more plant available moisture and soil oxygen. Restrict either and the root will also be restricted.

Greens Topdressing

OM will seal the soil surface from water and air infiltration; accumulate salts from Evapotranspiration (combined loss of water through evaporation & transpiration) and effectively cause suffocation of the root zone. Ever wonder why roots are shorter in the heat of the summer, in short they suffocate. The OM restricts the availability of soil oxygen, which under high soil and air temperatures is quickly depleted due to a rapid level of root respiration. A simple resolve to this problem is to recognize that aerification is not an annual event; it is an event that should occur frequently and with a purpose. Aeration does not have to always include extracting cores, it can also be accomplished by using solid tines [VENTING] to continually create vertical shafts of air space deep into the root zone profile. These VENT shafts are in reality MACROPORES, the site of gas exchange, excessive moisture evaporation, and points of moisture and soil gas infiltration.

Fairway Aerification

Root growth and maintenance requires frankly a lot of soil oxygen, one of the best ways to deliver is to aerify and especially during the periods of high demand. Aerification for the purpose of OM extraction should be done during the period of time the plant is most active. This assures that the physical hole created by removing OM will heal rapidly. The USGA in their wisdom has suggested that 20% of the upper root zone cavity should be extracted on an annual basis.

Aerification during the most active growth period of the year will aid in extracting OM. The timing is really species dependent (Bermudagrasses and Zoysiagrasses have the most active period during the summer, whereas the Bentgrasses are the most active in the early spring or late fall). Periodic monitoring of the organic layer will aid in determining how frequently core aeration is required. Maintaining an OM layer of 3/8” –1/2" in depth or 3-4% volume by weight is acceptable and will provide good plant response, excess of that can cause problems during the heat of the summer. 

Solid Tine versus Coring Tine

VENTING the greens through the summer months to generate and maintain active macropores is most important and must be done frequently. Along with providing excellent moisture and gas exchange, the improvement in soil gas exchange also supports and stimulates microbial activity and therefore enhances the rate of OM decomposition. Combined with light frequent top dressing (dilution of OM), the core removal (extraction), and the microbial activity (decomposition), the root zone will be supportive of a deeper more effective root and healthier Turfgrass plant.