# Ward Labs Soil Test Results - Interpretation and Suggestions



## occamsrzr (Apr 27, 2020)

Got my first test results back from Ward Labs and need some help interpreting. I believe most everything looks decent. Maybe borderline K and Ca levels from my initial research. As for history, I've only been focusing on Front Yard for most of my efforts. Back yard has gone to the dog (lots of springtime post-snowmelt digging) and not in my game plan for right now. I've been in the house for about 2 years now. Neighbors say the city had done some work on front boulevard and used cheap fill dirt. The back yard is more of the native soil.

As for previous treatments. I started last year with mostly Milo, Ringer Lawn Restore, and a bit of Carbon X. Moving away from Milo as the P levels look fine. I overseeded last fall and have been slowly spoonfeeding the new seedlings with AS, Urea, and a bit of 2020's Carbon X. Soil amendments include Anderson's Humic DG, K4L's Extreme Blend, Humic, Kelp, and a few FAS treatments. Put down preventative rate of Propiconazole after the past couple weeks of 4-5inches of rain, high humidity, and higher temps.

Any help appreciated.

Front Yard:


Back Yard:


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## g-man (Jun 15, 2017)

Did they recommend lime for the front? It should use some calcitic lime.

Both need phosphorous and can use some potassium.


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## Ridgerunner (May 16, 2017)

LRI for Modified Woodruff, pg 59:
https://www.wardlab.com/wp-content/uploads/2020/02/WardGuide_Master_02262020.pdf
74lbs/M of 100 ECC for target of 6.8
See label on Lime bag for ECC (not CCE) and divide 100 by the bag ECC to get the multiplication factor to calculate the amount of bag lime needed.


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## occamsrzr (Apr 27, 2020)

Thank you both for your input. They made no recommendations. I believe I had only got the soil analysis w/o recommendations. I'll look into these next time.

That Ward Guide is invaluable. Thank you for that. I'll digest this guide and come up with a plan to add some Calcitic Lime up front. Will look into adding some more K before summer hits and some more P nearer to my fall overseed.


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## Ridgerunner (May 16, 2017)

You may find this useful for calculating total annual P and K fertilizer amounts:

THE CONDENSED VERSION FOR USING SOIL TESTS
Quick Digest 8 Step:
Identify the Test method used by the Soil Test Laboratory.
In Most cases it will be Mehlich 3. Use the Mehlich 3 Sufficiency Ranges. If your CEC is Below 4, use the "Sand" ranges where noted.

Mehlich 3 Sufficiency Ranges for P and K:
P: 26-54
K: 75-176, 50-116 for sands

If Mehlich 3 wasn't used, Ammonium Acetate was most likely used for Potassium. Use the Ammonium Acetate Sufficiency Ranges. Bray 1 and/or Bray 2 was likely used if your pH is below 7 (*some labs will use Mehlich for P with AA testing for the cations). If your pH is above 7, Olsen was probably used. Use the appropriate (Bray 1 or 2, or Olsen or Mehlich) Sufficiency Ranges to be found in the thread that follows.

Ammonium Acetate Sufficiency Ranges for K
K: 100-235, 75-175 for sands

P Sufficiency Ranges
Bray 1 (Bray P1, Bray 1-P, Weak Bray)
Sufficiency Range (ppm): 15-30
Bray 2 (Bray P2, Bray 2-P, Strong Bray)
Sufficiency Range (ppm): 40-60
Olsen
Sufficiency Range (ppm): 12-28
Mehlich 3 
Sufficiency Range ppm: 26-54

Nitrogen is the driving force in the turf's usage of nutrients. For every unit of N the plant uses, it will use a proportionate amount of P and K. The following calculations will be based on ppm of elemental P and K with conversion to weights of P2O5 and K2O
For every pound of N applied to the lawn:
Cool season grasses will use approximately 0.3 lbs of P2O5 (or 3 ppm of P) and between .5 and .75 lbs of K2O (or 9-14 ppm of K).
Warm season grasses will use approximately .3 lbs of P2O5 (or 3 ppm of P) and .75 and 1 lbs of K2O(or 13-18 ppm of K).
1. Determine the Total pound of N you will be applying for the growing season.
2. Multiply the Total number of lbs of N by 3 to determine the total amount of P the turf will be expected to use for the season as ppm.
3. Multiply the Total number of lbs of N by 9 (for cool season turf) or 13 (for warm season turf) to determine the total amount of K the turf will be expected to use for the season as ppm.
4. Compare your soil test ppm for P and K to the appropriate sufficiency range.
5. a) If your soil test ppm value for P falls within the range, an adjustment value is 0, no adjustment.
5. b) If your soil test ppm value for P is below the sufficiency range, select a ppm value somewhere in the middle of the sufficiency range. Subtract the test report ppm value for P from your selected mid-range sufficiency range value. This value will be the P "addition" adjustment.
5. c) If your soil test ppm value for P is above the sufficiency range, select a ppm value somewhere in the middle of the sufficiency range. Subtract your selected mid-range sufficiency range value for P from the test report ppm value for P. This value will be the P "subtraction" adjustment.
6. a) If your soil test ppm value for K falls within the range, an adjustment value is 0, no adjustment.
b) If your soil test ppm value for K is below the sufficiency range, select a ppm value somewhere in the middle of the sufficiency range. Subtract the test report ppm value for K from your selected mid-range sufficiency range value. This value will be the K "addition" adjustment.
c) If your soil test ppm value for K is above the sufficiency range, select a ppm value somewhere in the middle of the sufficiency range. Subtract your selected mid-range sufficiency range value for K from the test report ppm value for K. This value will be the K "subtraction" adjustment.
7. Add the value calculated in step 2 to the value calculated in step 5 b (if applicable) or subtract the value calculated in step 5 c (if applicable) from the value calculated in step 2. If the result is zero or a negative number, the soil contains sufficient P and no P application is needed for the season. If the result is a positive number, then divide by 9. The result will be the total pounds of P2O5 fertilizer that needs to be applied for season to meet turf requirements and soil reserves. Do not apply more than 1lb/M of P2O5 within a 30 day period.
8. Add the value calculated in step 3 to the value calculated in step 6 b (if applicable) or subtract the value calculated in step 6 c (if applicable) from the value calculated in step 3. If the result is zero or a negative number, the soil contains sufficient K and no K application is needed for the season. If the result is a positive number, then divide by 18. The result will be the total pounds of K2O fertilizer that needs to be applied for the season to meet turf requirements and soil reserves. Do not apply more than 1lb/M of K20 within a 30 day period.


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