Soil Compaction Can Harm Your Lawn (4-4-11)

Proper fertilization, mowing, watering, and pest management are all key factors in keeping our lawns healthy and beautiful. However, there is one serious event that often occurs on many of our heavier soils regardless of maintaintenance. That event is soil compaction.

Compaction is a physical process that slowly reduces the pore space between soil particles, thus making it extremely difficult for oxygen, water, and nutrients to move into the soil where turf roots can utilize them.

Compaction also prevents the escape of carbon dioxide from the soil. As compaction increases roots become shallow, the turf canopy begins to thin and eventually the compacted soil will not be able to support a lawn at all.

Following a good rain, or thorough irrigation, if you can push a slim steak knife blade or screwdriver into the soil with ease soil compaction is probably not an issue. However, if you can’t, more than likely roots can’t either.

Since compaction is created by a physical process we can reduce it by performing another physical process called aerification. This process is simply described as making small openings into the soil at depths of 2-10 inches depending on the equipment used.

For most practical purposes homeowners can rent small lawn aerifying equipment from rental equipment businesses. These power aerifiers will have several hollow tubes or tines that make approximately 3/4-inch openings into the soil to a depth of 2-3 inches that allow oxygen, water and nutrients to move easily into the soil. As the roots push the soil particles around compaction is reduced.

The frequency a lawn will need to be aerified will depend mainly on soil type and the amount of traffic the lawn receives as traffic is the major culprit for compaction whether it is from recreational play, pets or mowing equipment. Wise traffic management can help reduce the frequency of compaction. Avoid heavy play or equipment use when the soil is wet. Changing travel patterns on successive mowing prevent the wheels of the mower tracking the same paths all the time.

Published April 4, 2011

Dr. Wayne Wells is an Extension Professor and Turfgrass Specialist. His mailing address is Department of Plant and Soil Sciences, Mail Stop 9555, Mississippi State, MS 39762. wwells@ext.msstate.edu