Compacted Soils are Dangerous for Your PlantsCompost & Soil Last Updated On 04/16/2022
When you take a look at the soil, you may be surprised to note that about half of it is channels and gaps. These channels and gaps are what allows water, nutrients and oxygen to reach down to the plant's root system.
If the soil becomes compacted, those channels and pathways are compressed and squeezed together. It reduces the oxygen, water and nutrients plants can receive. They are unable to reach the roots, which is bad for your plants. Compacted soil can't "breathe".
Why Does the Soil Need to Breathe?
The soil needs to breathe because there are many organisms living in it. Plant roots are just one thing. Don't forget abut worms, algae, fungi, bacteria and other organisms. All of them need access to all the helpful elements and gasses. If the soil is compacted, they can't live.
A compacted soil is very dense, with no space to hold moisture and air. It means all the plants and animals needed for a healthy ecosystem will struggle to survive. This is how the soil slowly "dies".
How Does a Soil Become Compacted?
There are many ways in which soil can become compacted. Sometimes, it's due to its structure. Clay soils are more prone to this than sandy soils because individual particles are much smaller than sand particles. It means they can bind more closely and easily stick together.
On a lawn, the most common reason for soil becoming compacted is through use. Any activity on the soil, from playing football to mowing or having a party in the garden will contribute to compacting and it will get the soil particles squashing together. It's even worse if the soil is wet, because this is how the air gets squeezed out more easily. In this situation, the soil will dry without any air pockets.
Effects to the Plants
All healthy grass plants need a strong and healthy root system. Roots enable plants to absorb more nutrients out of the soil and they also make it reach water deep in the soil. Roots also give plants great stability and enable the plant to repair itself quickly. Plus, roots allow the plant a greater tolerance to environmental stress (such as drought). For this reason, it's important that the roots are getting enough nutrients, water and air, and this can't happen when the soil is compacted.
Grass grown in compacted soil will usually be weak, thin and it will grow very slowly. New seeds will rarely germinate. The whole area will gradually become thinner and weaker. If you observe these things on your lawn it's a clear sign the soil is getting compacted.
Luckily, it's possible to make your lawn and garden healthy again through soil aeration. Lawn aeration is a treatment used to relieve a compacted lawn and to make the soil breathe. The goal is to make the soil in your garden be healthy, with channels and passages, instead of a compacted mess that is not good for your plants.
Photo credit: Chiot's Run