The term ‘Soil Compaction’ refers to the naturally occurring condition when something heavy compresses the soil to such an extent that the air spaces within the soil are squeezed out.
The knock-on effects which can arise as a result of this happening are many, and can worsen if the soil is on the heavy side with a moderate to high clay content.
The first could be poor lawn growth as in the picture above. Or other plant material can become stunted.
The second effect, since many of the previously open air passages have now been squeezed out is flooding because the soils ability to drain itself has now been lost. Mosses and lichens etc. will have a tendency to grow on the surface of compacted soil.
Poor root growth equals poor top growth – the one naturally follows the other.
Finally, the incidence of earth worms and other important soil fauna will reduce, having a further impact upon both soil aeration and drainage, and a gradual reduction in soil fertility due to the lack of organic matter conversion for which these small creatures have evolved to improve. Decomposition can then change from Aerobic to Anaerobic which is without oxygen, and can give rise to a sulphur-like smell.
As with many things in life, it is easier to prevent than to cure. So the advice is this, keep off soil and lawns if it is wet, and aerate your lawns and fork through your borders to help to maintain a healthy soil.