| How does DICKEY-john's Soil Compaction Tester (SCT) work? |
 | Please note that soil moisture can greatly affect the readings of the DICKEY-john SCT. When moisture content is high, readings may appear misleadingly low. When soil is dry, readings may appear higher.
- Test your soil in the early spring when moisture content is relatively high and before going to the field in the fall with your tillage tools.
- Drive the fester slowly into the ground with steady even pressure.
- The gauge gives you a reading in lbs per square inch of the pressure it takes to penetrate your soil.
- Record the pressure at different levels spe-cifically noting the levels where pressure increases and again when it decreases.
- Perform several tests in the same area for best results.
- Test several areas.
- When you find evidence of compaction – areas, especially tire tracks, where you meet greater resistance – dig to the depth of the indicated compaction to find evidence of abnormal root development.
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| Why does soil compaction cost money? |
| Soil compaction is becoming a more serious problem in all parts of the world. A problem that is very expensive in several ways:
- Compacted soils are much harder to work. Research demonstrated that over 90% more power is required to plough severely compacted soil.
- Compacted soil results in poor root and plant development. Compacted soil is dense; roots cannot grow in it. That can reduce yields by 20, 30, even 50% or more.
- Compaction severely restricts the manner in which soil naturally manages water; both by holding water near the surface of the field and by limiting the ability of plants to take up water and nutrients from below. Excess surface water makes fields difficult to work in the spring and fall. And water trapped under the compacted layer reduces plant development and yields, especially during dry periods.
- A compacted zone means that the fertilizers, pesticides and herbicides you apply cannot be utilized efficiently. If they are not absorbed, they can be washed away easily. Even more serious, they can be trapped near the surface in a concentrated form resulting in crop damage and yield reductions. They can also be captured under the compaction zone, compounding the problem.
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| What causes soil compaction? |
| Soil compaction can occur in any type of soil. Typically, after years of traffic, a "plough pan" forms below the tillage zone. Traffic and tillage cause soil particles of different sizes to become clustered together, filling up all available air spaces, compacting info a hard layer that can‘t easily be penetrated by moisture or roots. Some soil types are more susceptible to compaction than others, but once a compaction problem has become established, it can only get worse. As moisture penetrates the compacted layer, and traffic continues, the compaction layer becomes denser and thicker. |
| How to detect a compaction problem? |
| Is soil compaction a problem in your fields? Now you can find out easily with a DICKEY-john SCT. Here are some numbers for the relationship be-tween compaction and root development:
- 0-200 lbs: good
- 200-300 lbs: fair
- 300-500 lbs: poor
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| Once you know exactly how compacted your soil is, and at what depth, it is relatively easy to precisely fit a solution to the problem. Your specific solution could be as simple as limiting traffic in some areas of a field, seeding a cover crop to improve water management, or avoiding wet fields. Or, you may have to rethink your tillage program by choosing a tool that will penetrate the compacted zone – not by choosing a tool that will merely change the location and extent of compaction.
However, you can‘t begin to think about a solution until you have identified the problem. And you can do that quickly and easily with a DICKEY-john SCT. |
FAQ 
How does DICKEY-john's Soil Compaction Tester (SCT) work?