TSM Services Research Farm, Catlin, Illinois, USA
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A cycle is defined as a series of events which repeats regularly. Nutrients run in cycles, either depleting or building up in availability in the soil. A nutrient which is building up is what TSM® calls an "up cycle", and a nutrient depleting in availability is called a "down cycle".  TSM® takes soil samples annually, so you can determine what cycle your nutrients are on after the second season or the second soil test. On the chart below, an "up cycle" is represented by the blue arrow. The "down cycle" is represented by the red arrow.

The efficiency of the fertilizer applied is greatly determined by what cycle the nutrient is on. If a nutrient is on an "up cycle" you can expect high nutrient efficiency up to 400%. If a nutrient is on a "down cycle", you can expect low nutrient efficiency down to a (minus)-400%. This is to say that if your soil is on a steep "down cycle", you could apply a fertilizer product to your soil and your soil test could go down.

Soil pH also has cycles and is the easiest to follow. For example, on a "down cycle" it is possible to make an application of ag lime or pelletized lime, then one year later the pH could have gone down. This would indicate a "down cycle" of calcium and/or magnesium in the soil.

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On the other hand, the opposite could also happen. An application of
ag lime or pelletized lime could be made and the pH could jump much more than normally expected. This would indicate an "up cycle" is taking place with the calcium and/or magnesium.

A nutrient cycle is determined by two things:
  • The amount of the material applied
  • The quality of the material used
Using high-quality, fine material in large amounts causes a very fast "up cycle", but it is very short-lived. Using poor quality, coarse material causes a very slow "up cycle", but it may last for many years.

For example, a field which received a very coarse application of ag lime many years ago may have a pH which remains fairly constant or is slowly rising and doesn't seem to go down. However, the disadvantage is not having control of your pH for the duration of the cycle.

TSM® uses nutrient cycles when making recommendations. When a major nutrient is determined to be on an "up cycle", we recommend reducing the amount of that product. When a nutrient is determined to be on a "down cycle", we recommend increasing the amount of that nutrient.

By following this pattern, the TSM® program can reduce the influence that cycles can have on fertilizer efficiency. As a grower continues in the TSM® program through the years, the result is that fertilizer can be applied in lesser amounts yet have a much higher efficiency in the soil. In other words, a soil test can be maintained or built up using less fertilizer.

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