A healthy lawn begins with a base of healthy soil. Hard, dense soils are badly compacted, which isn't healthy. Fortunately, the problem is reversible if you know how to spot it and treat it.
There are several ways soil beneath a lawn can become compacted. Mowing is one culprit, as the wheels of the mower can create compacted ruts across the lawn from repeated travel. Walking on the lawn, especially if you tend to follow the same path, will also lead to compaction. Driving or parking equipment is another common cause of lawn soil compaction.
Although all lawn soils will compact over time, the severity of ease of compaction also has to do with the soil structure. Clay soils are more prone to compaction because they consist of small particles that easily get pressed together. A lack of organic matter in the soil can also increase the chances of compaction.
The most obvious symptom of soil compaction is poor grass growth. Grassroots won't be able to easily penetrate and spread through compacted soil, so the grass will become sparser over time. Further, moisture, oxygen, and nutrients will also be less likely to penetrate a badly compacted surface, thus leading to weak and dying lawn grasses.
Although compact soils tend to be dry, they can seem wet and boggy after irrigation or rain. This is because moisture cannot penetrate into the soil, so it instead pools on top. An area that begins to drain poorly could very well be suffering from compaction.
Fortunately, compacted soil can be remedied with a two-prong approach. The first prong is a reversal of the compaction. A lawn service can perform a core aeration, which removes plugs of soil so that water and air can enter. They will also perform regular dethatching to prevent a layer of dead grass from compacting on top of the soil.
The second prong is prevention. Installing paths where you regularly walk, for example, will prevent compaction. Avoid parking on the lawn, and when mowing, walk a different pattern each time. Further, ask your lawn service to add a soil conditioner or compost during routine fertilizer treatments. These will add organic matter to the soil, which helps it better resist compaction.
Lawn compaction isn't something that can be ignored if you want healthy grass. Contact a lawn maintenance service to determine solutions to aerate your soil for a greener lawn.