Maintain the Best Soil for Your Crops by Avoiding Compaction

Posted: April 2, 2013

It is that time of year again when homeowners and farmers are getting ready to plant their gardens or numerous acres of crop land. Even though planting is still a couple of weeks away, it is important to keep in mind that what you do to the soil now could affect your entire growing season. This is why it is important to maintain your soil’s fertility, which is its health or quality.

Many people might think that a soil’s health can be maintained by merely having a recent soil test done and making sure that that the pH and major nutrients, such as nitrogen, phosphorus and potassium, are well-balanced. While this is definitely an important part of maintaining soil fertility, if you ignore all the other factors that contribute to soil health, you could be setting your crops up for a lackluster growing season.

One of the factors of soil health that gets overlooked is soil compaction, especially if there has been some wet weather in the spring and people are trying to get everything planted on time. Soil compaction can reduce your soil’s productivity by affecting nutrient uptake, soil organisms (especially earthworms) and infiltration rates, whether it is in a home garden or a large farm field. It is fairly obvious if there is standing water on the soil or if the soil is extremely muddy that you should not be out there planting anything. However, even though that is the easiest time to put ruts in the soil with any type of equipment, you may not realize that compaction is most likely to occur when the soil begins to dry out a little bit (approximately 24 hours after a soaking rain) and enters into its “plastic limit (state).”

As stated in the Penn State Agronomy Guide, the plastic state is when the soil is at a moisture content level that makes it possible for you to form a “wire” of soil, approximately one quarter inch in diameter, by rolling it between your hands. In order to help you determine whether or not your soil is in the plastic state without taking time to form a “wire”, the Penn State Agronomy Guide explains how to do a simple test called the ball test. In order to complete this test, you would take a handful of soil and shape it into a ball. If the soil molds together, it is still in the plastic state, which means it is probably too wet for planting, tilling and field traffic.

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Jennifer Bratthauar is the Penn State Cooperative Extension Agronomy Nutrient Management Educator serving Adams County.  Penn State Extension in Adams County is located at 670 Old Harrisburg Road, Suite 204, Gettysburg PA  17325-3404.  Phone 334-6271 or e-mail