Impacts to Soil Structure From Rutting

Soil Structure

• Soil is defined as a mixture of three different-sized particles. Sand particles are the largest, followed by silt and the smallest are clay particles. Individual sand particles have a very weak attraction to each other. A soil with lots of sand has a very poor soil structure. Making ruts in a sandy soil causes very little damage. When a soil has a lot of clay and silt, the three sizes of particles adhere much more strongly. Plant roots secrete organic compounds that also serve to glue tiny soil particles together. A soil's structure is a measure of the aggregates of sand, silt and clay that have formed in it. The clods are arranged in certain loose structures that allow plants and organisms to interact with the soil.

Vehicle Weight

• When a vehicle drives over the soil, its weight crushes the soil structure. Some soils with lots of clay can withstand more weight than a loam soil. All soils are damaged to some degree by vehicle traffic. The heavier the vehicle, the more soil will be compacted. Farm machinery has been designed to distribute its massive weight over as much surface area as possible so as to not rut the soil. Even with this precaution, rutting and soil compaction still occurs. Ruts in the soil are areas where the soil structure has been completely obliterated. Rutted areas tend to accumulate water because the soil particles have become so closely packed together.

Moisture

• Driving on a wet soil is much more likely to cause ruts. When the soil is wet, the sand, silt and clay particles are lubricated. Wet soil compacts easily. The soil particles can slide together and fill pore spaces when pressure is applied. It is detrimental to soil structure to work it when it is wet. Soil is most likely rutted when it is wet. Ruts formed when the soil is wet will last a long time and be difficult to remove since they are so deep and indicate highly compacted soil.

Treatments

• Crop rotation with a rest period where the field is left fallow is a good treatment for soil compaction. Different crops require different management practices. No-till crops reduce the number of trips over a field by heavy equipment, which can help build soil structure. It takes decades to repair soil structure. Rutted areas are particularly difficult to restore to their natural state. Planting clover and other deep rooting plants helps to create soil pores and better structure.