Turf, meaning natural grass in this case, and landscapes can become a very big part of people’s lives. They bring beauty and tranquility along with property value, a cooling effect, wildlife, pollinators, produce oxygen and reduce runoff. In some cases, these areas become an active part in everyday life, meaning that we, children and pets will play and/or traverse them. This, along with many other factors, will lead to soil compaction. What to do?

What is Soil Compaction?

Soil compaction is simply defined as the compression or pressing together of soil particles. This, in turn, reduces large pore space and overall pore volume. The result of repeated compaction over time ends in a loss of soil structure and a higher-density soil. Finer soils—those of higher clay composition and wetter soils tend to become compacted more readily and to a greater degree whereas sandy or coarser soil systems will resist compaction to a point.

Why is Soil Compaction Bad?

A well-structured soil profile holds and conducts water, nutrients and air efficiently. All of these components are critical for good root development and plant health.

A reduction in pore space, or compacted soils, will often slow or impede water infiltration, leading to drought stress. Airflow or gas exchange is also limited, reducing the available oxygen needed by roots. While plant roots can manage waterlogged soils for a time, extended periods can lead to oxygen deficiency symptoms like yellowing and wilt.

Additionally, compacted soil can make plants exert greater force to grow roots through the profile. Restricted root growth can lead to nutrient and water deficiencies in the wake of reduced root system development, not to mention the reduction in soil microbiology. Soil microbes, bacteria and others that make up the rhizosphere (rootzone) will all require oxygen for respiration and the lack of can create a less vibrant community.  

How Does Compaction Happen?

The most common reason for compaction is traffic. Anything from foot traffic, to mowing, fertilizing and any other equipment traversing the area will compact the soil. Even rainfall, as vital as it is, can lead to soil compaction.

While in many places the lawn is where life happens, there are some common-sense, physical methods to help reduce some of the traffic. Creating non-growing (stone, etc.) types of walkways in areas commonly passed through or diverting traffic and encouraging a more scattered pattern will also slow the progress.

Over the last three or more decades, equipment manufacturers have engineered their machines to have a lighter feel by increasing tire width, using lighter-weight materials and redistributing weight.

What to Do About Compaction?

The bottom line here is that physical intervention is the only reliable way to reduce compaction.

Aeration is a key cultural practice to help alleviate soil compaction. Additional benefits of aeration include improved water, air and nutrient movement as well as a reduction of thatch. In many areas, aeration is paired with overseeding where the holes will provide seed-to-soil contact for good germination.

In highly managed turf situations, topdressing is often part of the process where sand, or sand mixes, are spread across the area to improve playing surfaces.

There are several considerations when it comes to aeration ranging from tine sizing, tine spacing, timing and the use of solid versus hollow tines. Some of these topics have been hotly debated over the years, but there are a few things that remain important, including the take-home message.

On residential and commercial lawns, aeration once per year should be sufficient, and I prefer fall especially if you are overseeding. For highly managed turf, the saying that I always heard was, aerate as often as the club will tolerate, the process is disruptive.

There are a couple of final thoughts to help slow soil compaction. Growth regulators (PGRs) will help to reduce top growth, which can potentially reduce mowing frequency. Also, adjusting nitrogen-based fertility rates and frequency can reduce mower traffic. Pay close attention to the slow-release component and opting for higher percentages of coated, slowly available nitrogen can reduce the need for more frequent mowing. Also, using combination products and tank mixes will diminish the amount of application equipment traffic.

Lastly, where soils are more prone to compaction (finer, clay-based soils), consider the introduction of materials that will help maintain soil porosity including sand and EMPRO Soil Enhancer.

Lean on Us for Help Solving Soil Compaction Issues

Feel free to contact myself or Pat Gross, Ewing’s Tech Team with for soil compaction solutions, as well as any turfgrass questions. Email me at klewis@ewingos.com or call/text 480-669-8791.