Aeration
Lawn aeration involves the removal of small soil plugs out of the lawn. Aeration is achieved using a machine having hollow tines or spoons. Known as core aeration, it extracts half inch to three-quarter inch diameter plugs of soil and deposits them on your lawn. Aeration holes are typically 1" to 3" inches deep and approximately 6" apart.
Core aeration increases the activity of microrganism that decompose thatch, increases water, oxygen, and nutrient movement, improves rooting, and helps prevent runoff of fertilizer.