Gardening Technique Unit Screen//v.1

Soil compaction is the result of foot or vehicle traffic. The pressure packs the soil tightly, squeezing the pores closed. Compacted soil contains little air, restricting root growth to the surface levels. Also, roots have difficulty in penetrating the dense soil. Water penetrates the soil slowly, making irrigation difficult. Some soils, especially clay soils and some loamy sands, are more susceptible to compaction than others, and dry soil has more resistance to compaction than wet soil. Soil compaction should be corrected before planting in the area. Different techniques are needed in planted and unplanted areas.

Before planting: Till the soil to loosen the compaction. Large areas that are badly compacted require the use of a rotary tiller. Organic matter should be mixed in as the soil is tilled. (For information about adding organic matter to the soil, see Organic Matter.) If the compaction was caused by heavy construction equipment, it may be necessary to have the soil loosened to a depth of 2 feet with a chisel plow. Foot traffic compacts only a couple of inches of surface soil.

In planted areas: Relieve compaction in planted areas by aeration, using the type of aerator that removes cores of soil. Aerate when the soil is moist but not muddy. Make passes over the compacted ground in alternate directions until holes are within 3 inches of each other. You may leave the cores on the soil, or drag a heavy board over them to break them up.

Preventing compaction: The most effective way to prevent compaction is to keep traffic off the soil. Make paths, or place fences or shrubs to act as barriers. If heavy equipment must be driven across the soil, make sure the soil is as dry as possible at the time. If foot traffic can't be kept off an area, mulch it with 4 inches of gravel or rocks.

Back to the top