Electronic Field Guide » Restoration & Goals » Soil Compaction » Repairing Soil Compaction

Prepared by Patrick Drohan (Ecosystem Science and Management)

If compaction has already occurred, the extent of the problem can be defined using a variety of techniques.  Surface or subsurface soil bulk density can be estimated by removing a volume of soil and determining its rock-free, dry weight. Related to bulk density is a measure of a soil’s penetration resistance.  A metal rod is typically pushed into the soil under a certain force and the resistance to the rod’s penetration is determined; greater penetration resistance is related to greater bulk density. 
If compaction has been identified on the site, and the problem extends deep into the subsurface, compaction can be alleviated through “subsoiling,” lifting and loosening the soil with a deep tillage tool such as a straight or parabolic shank attached to heavy equipment. Compaction should be alleviated to the depth of the affected soil.  This should be determined by examining a nearby native soil of the same U.S. Department of Agriculture soil series. Subsoiling will bring up rocks, which may be undesirable in an agricultural setting. Subsoiling is best done during summer or fall, when soil conditions are not too wet or too dry. In some cases subsoiling may be cost-prohibitive or cost-ineffective. The plot may then by used for storage or allowed to develop naturally for wildlife.
A management and vegetation plan can help reduce compaction and prevent future damage. For example, reestablishing vegetation will help reduce erosion, begin to introduce root channels, and restore soil organic matter.