Turf & Rec

Features Agronomy Turf Care Equipment
Understanding aeration: keys to healthy turf


October 12, 2016
By Jeremy Opsahl

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Aeration is one of the most valuable turf management practices in the industry. It helps address challenges like soil compaction, layering, poor drainage, poor gas exchange, excessive thatch, the need to modify heavy soils in the root zone, and improves the establishment of sod or overseeding. The key is to choose the right method to match the problem you need to overcome.

Key considerations
Specific problems develop at different times of the growing season. Periods of heavy traffic result in high levels of wear and compaction. And high summer temperatures amplify the need for gas exchange in the root zone.

In addition, aeration imposes a temporary stress on turf. Speed of turf recovery is linked closely to weather conditions and to the stage of the annual growth cycle for different species of turf. Keep these factors in mind when you decide on your aeration plan.

Here’s a quick look at five different aerification processes and some basic recommendations for each.

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Core aerification: the most versatile
Core aerification addresses several turf and soil issues at once. Followed by core removal and sand topdressing, it is the best method of controlling the buildup of organic matter in the root zone in sand-based soils. It also reduces bulk density or compaction, particularly in fine-textured soils.

In the process, gas exchange is improved and drainage channels are created for improved water movement. The cores brought to the surface can also be pulverized and incorporated back into the thatch layer as topdressing. In addition, core removal followed by sand topdressing allows for the permanent modification of the root zone soil profile over time.

Core aerification does impose a temporary stress on turf by opening the canopy and removing a portion of the root mass. Open holes in the root zone also speed soil drying, especially if done during hot and windy weather. As a result, it’s critical to core aerify at a time during the growing season when the turf is growing vigorously to offset the injury and speed healing. Cool-season turf species are best core aerified in the spring and fall during active growth. Warm-season turf species are best core aerified between late spring and early fall when the turf is actively growing. In both cases, aerification should occur early enough to provide sufficient recovery time before active growth subsides.

Solid tine aeration
Solid tine aerification enhances gas exchange between the root zone and the atmosphere. It is a particularly useful practice during periods when turf is stressed and root respiration is high, increasing demand for oxygen and causing an accumulation of carbon dioxide in the root zone.

Solid tine aerification causes less injury to the turf than hollow tines and is an effective solution for increasing soil gas exchange. However, it does not reduce compaction since no soil is removed. Soil bulk density actually increases slightly in the vicinity of the aerification hole as the tine compresses the soil around it upon entry.

Slicing and spiking
Slicing and spiking are similar to solid time aerification, as the primary benefit is to improve gas exchange by creating channels into the root zone. Both are generally shallow treatments and cause minimal injury to the turf.

Deep tine aerification
Deep tine aerification to depths up to 16 inches using both solid and hollow tines has become increasingly popular as a way of breaking through deep layers of compaction. Repeated aerification using conventional four-inch hollow and solid tines results in what is known as a cultivation pan or layer of increased compaction just below the depth of aerification. Another common problem that deep-tine aerification can address is the compaction created during construction of new golf courses or sports fields when significant earth moving occurs. –

Jeremy Opsahl is the global marketing manager at The Toro Company.