Mechanical aeration provides an excellent, and probably the only, means of correcting or alleviating soil compaction which may be quite serious on many lawn areas. Compaction occurs primarily in the surface area of the lawn. A compacted layer as thin as ¼ to ½ inch can greatly impede water infiltration, nutrient penetration, and gaseous exchange between the soil and the atmosphere. Compaction of this type in the surface layer of soil can be corrected or reduced by the use of suitable aerating equipment.