# Soil Test Results - Unlikely



## jaygrizzle (Jun 6, 2018)

I just received the results back from my soil test from my local university extension and I am a little surprised by the results. Since moving into our house in March 2016 I have not put down any fertizlier what so ever. However, results for P and K both came back in a rating of "high" and therefore there was no recommendation to apply any fertilizer (other than the blurb they put in about adding N in the fall).

Does this seem possible that my soil would rate high for P and K with no fertilizer put in the lawn in approximately 2 and half years (maybe more, I'm not sure what the previous home owner applied prior to March 2016)? I assume it is, but I was just surprised by the results and was thinking that since I've never added anything that it may be low.

The pH was at 6.9 and they didn't recommend doing anything to move the pH one way or another 
Organic matter was 4.2%


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## ken-n-nancy (Jul 25, 2017)

jaygrizzle said:


> I just received the results back from my soil test from my local university extension and I am a little surprised by the results. Since moving into our house in March 2016 I have not put down any fertizlier what so ever. However, results for P and K both came back in a rating of "high" and therefore there was no recommendation to apply any fertilizer (other than the blurb they put in about adding N in the fall).
> 
> Does this seem possible that my soil would rate high for P and K with no fertilizer put in the lawn in approximately 2 and half years (maybe more, I'm not sure what the previous home owner applied prior to March 2016)? I assume it is, but I was just surprised by the results and was thinking that since I've never added anything that it may be low.
> 
> ...


Short answer: yes, it is quite reasonably possible.

Take a pictures of the soil test results and post them here. Looking at the full test results would help folks here provide a more thorough answer to your questions.

How old is the home? It is quite possible that a previously-well-fertilized established lawn could go for a few (or even many) years (particularly if you haven't been bagging the clippings) without showing soil test deficiencies.

Also, depending upon the philosophy being used for the soil test interpretation, what is "deficient" for one interpretive approach may be "sufficient" for another style of interpretation or "excessive" for another.

However, a pH of 6.9 is indicative that you have plenty of at least one of calcium, magnesium, and potassium in your lawn.. 
These three could even all be well-balanced, so your potassium (K) level could very well be just fine.

Once soil has a sufficient level of phosphorus (P) in it, mulch mowing does a pretty good job of returning most of the phosphorus to the soil again, and phosphorus doesn't leach out of the soil as readily as nitrogen or potassium, so it is not unusual for phosphorus levels to remain pretty steady for many years in soil of established turf. If lots of leaves are being mulch mowed into the lawn, phosphorus levels can even increase over time without direct application of phosphorus fertilizer.


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## jaygrizzle (Jun 6, 2018)




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## jaygrizzle (Jun 6, 2018)

ken-n-nancy said:


> jaygrizzle said:
> 
> 
> > I just received the results back from my soil test from my local university extension and I am a little surprised by the results. Since moving into our house in March 2016 I have not put down any fertizlier what so ever. However, results for P and K both came back in a rating of "high" and therefore there was no recommendation to apply any fertilizer (other than the blurb they put in about adding N in the fall).
> ...


Thanks! I just added a screenshot of the results.


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## Ridgerunner (May 16, 2017)

> Does this seem possible that my soil would rate high for P and K with no fertilizer put in the lawn in approximately 2 and half years (maybe more, I'm not sure what the previous home owner applied prior to March 2016)?


Quite possible in fact.
First, the rating systems are somewhat subjective and vary from lab to lab. as are the labels. Another lab might use the label "Optimal" in place of "High" for the same reported values. For instance some indexes identify 100 lbs of P as the cut off between sufficient and optimal. That could change your perspective.  
Second, most rating systems are based on soil with a medium CEC. Soils with a low CEC store much less nutrients, soils with high CEC can store large amounts of nutrients and often do. So fertilization additions can accumulate in the extra storage space of high CEC soils and the excess can remain in the soil long after for years. Based on your pH and Base Cations, your soil likely has an above average CEC. Also, the parent material (rock from which it was formed) and the OM in the soil is a natural source of P and K and some can be a source of very large amounts of P and/or K.
Third, poorly maintained turf can also contribute to higher numbers, or at least a smaller depletion of nutrients than a highly maintained lawn. Less N input makes for less demand and less irrigation will result in less loss due to leaching.


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