Occasionally, soil scientists develop tools and guidelines that can be used by others to help assess situations and conditions in the field. Not too long ago Extension Specialist Alice Jones put together a little quiz to help farmers and field technicians assess the potential level of compaction in a field. The quiz, adapted from work by T. Beckman and J. Vogel, leads farmers through a series of questions, the answers to which can be readily related to possible compaction problems.
Compaction comes about as a result of several conditions and situations.
Generally, the most common cause of compaction is excessive traffic when the soil is wet. Both soil strength and soil compressibility are directly related to water content of the soil. As water content increases, soil strength decreases and compressibility increases. When a farmer uses his four-wheel drive tractor to get into the field a little sooner, which is usually the time when the soil has not been allowed to dry out, either after a rain or early in the spring, the soil is most susceptible to compaction. Zones of compaction in the soil typically reduce the volume of soil tapped by the root system of the crop, making the crop stunted and less branched.