Submitted to: Equus
Publication Type: Popular Publication
Publication Acceptance Date: December 14, 2005
Publication Date: February 27, 2006
Citation: Singer, J.W. 2006. Equus - Consultant's column. Equus. p. 91-92.
Soil compaction is one of the main factors limiting horse pasture productivity and persistence. Compaction reduces pore space in soil that in turn reduces water infiltration and air transfer. Compacted soils not only store less water, but compaction also makes it more difficult for plant roots to grow. The combination of less water holding capacity and reduced root volume will reduce pasture productivity, particularly during dry periods. Limiting compaction can be accomplished by rotating hay racks and watering stations, and limiting pasture access during wet soil conditions. Reversing compaction is possible, but requires time and management to restore soil productivity. During the renovation period, it will be necessary to fence off an area slightly larger than the highly compacted zone. Once a seeding establishes, letting it grow without grazing pressure and mowing it occasionally will increase the likelihood that it will persist. Although a backhoe will not be required to renovate this area, a rototiller should be used to loosen the soil in the top 6-8 inches. Once the soil is loose, adding organic amendments such as a mature compost will increase the water holding capacity of the soil. Add about a 2-3 inch layer of compost on the surface of the loose soil and incorporate it using the rototiller. At this point you could plant the pasture mix best suited to your soil conditions and climate or you could use a plant known for its ability to fracture subsoil compaction, such as a sorghum-sudangrass hybrid. This plant is a summer annual and the seed is widely commercially available. For best results, mow the sorghum-sudangrass when the plants are about 3-4 ft tall, this will cause the roots to grow deeper in the soil profile to help breakup subsoil compaction. If you follow this recommendation, you can plant your pasture mix the following spring. For best results, incorporate the seed and water if dry soil conditions develop until the plants are about six inches tall. Applying compost, using a deep-rooted plant, or both should restore pasture plant productivity and persistence to this bare spot.