Compacted soil reduces the rate of water distribution through the soil to plant roots. In addition, compacted soil reduces air space available for plant roots and will therefore stunt root growth. And if poor drainage from an excess of water being held in the soil and poor aeration aren't enough to convince you of the undesirability of compacted soil, increased erosion will make you think again, as the water landing on the surface runs off elsewhere because the hard surface on the soil prevents penetration of the water. This article is a basic primer in getting started on ridding your garden or land of compacted soil.