# Turf needs vs soil test results



## Grassmasterwilson (Jun 11, 2018)

Has anyone had success finding a good benchmark or target for fertility in your area to then create the best fertilizer program? Many soil test I get show a need For potsssium(60-70 ppm results) and they recommend 5ish lbs K annually from waypoint.

Read somewhere above 100 ppm for fescue was a good target

My general Fert idea is 4:1:2 N:K ratio


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## Ridgerunner (May 16, 2017)

What do you mean by "split test results"?

One method is the one that I outlined at the beginning of my soil test thread. It includes the process for adjusting the soil test level to one within sufficiency range, which wouldn't be absolutely necessary if test levels were at least above MSLN minimums. IN your case, I'd be comfortable using your current K level of 70 ppm. So with a warm season grass, a 4-1-4 fertilizer would be appropriate. If next years test is greater than + or - 20% from current test levels, adjust fertilizer ratios to account for the rise or fall. Ideally/theoretically, your K levels should remain near 70 ppm on subsequent tests when a 4-1-4 is used.

Otherwise, FYI, for every one pound of N you apply using a 4-1-2, will apply 0.5 pounds of K2O which would equate to adding 9 ppm. 4 applications at that rate would add 36 ppm to the current 70 ppm, less the amount of K used by the turf (or lost to runoff, or leaching).
I make that complicated enough?


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## Grassmasterwilson (Jun 11, 2018)

@Ridgerunner I understand it. Thanks.

So....
My average fescue K level on the soil test is 57.61. Based on a climate appraisal spreadsheet I will remove 75 ppm. So MLSN + removed = 112.

112 - 57.61 = 54.39. So I should target 55 ppm at a min? I just need to convert ppm to lbs per 1000.

Is that reading it correctly?


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## Grassmasterwilson (Jun 11, 2018)

Is it ppm x 2 = lbs per acre.

Lbs per acre x 1.2046 = lbs of actual k fert.

Correct?


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## Ridgerunner (May 16, 2017)

lbs per acre X 1.2 = lbs of K2O fertilizer.
Correct. 
I still prefer the maintenance (e.g. 4-1-4) method to hold a stable soil test level but it's basically 6 of one, half a dozen to anther.
See the turfhacker and Nebraska citations in my thread.


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## Grassmasterwilson (Jun 11, 2018)

Thanks. Ridge also confirmed that if you have a soil sample showing deficiencies then you need to add the deficit in soil to the turf usage.

I assume depending on budget the deficit can be made up in multiple years?

For potassium a lot of guys I talk to prefer sulphate of potash to murate of potash for availability and lower chlorine.


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