Soil compaction causes serious damage and can only be reversed very slowly and at significant cost. Compaction restricts root growth and reduces infiltration of water into soil. It can increase runoff, which may lead to greater flooding, increased erosion, and the transfer of potential pollutants (including nutrients and pesticides) to surface waters. As the air getting into the soil is also restricted, the biological activity and root growth is affected. This reduces the fertility of the soil and, more specifically, the availability of plant nutrients.