# 1st soil test - check my work (everything high!)



## racker15 (Feb 18, 2021)

Hi Lawn Forum, thanks for all the info - here's what I've learned applied to my lawn, would love your thoughts.

Context - Bay Area backyard, 1500sqft tall fescue, new soil + new sod 6 weeks old
Soil Test - Midwest Labs S3C package + Olsen P + texture
Results - everything is high (Worksheet: https://docs.google.com/spreadsheet...wx0X-FlzWweaoJcCx3_Rpv2qi4/edit#gid=103338547)




Organic matter high; P, K, Mg, Ca are high, especially Ca at 2000+ ppm vs. sufficiency of 500-750.

Action plan:
Based on an annual 3 lb Nitrogen per 1000 sqft for tall fescue, I plan to spoon feed (every 2-4 weeks?) an annual total of 10 lbs of urea 46-0-0 (4.6 lbs Nitrogen) on my 1,500 sqft lawn across the season, with a break during the hottest 6-8 weeks of summer.

Questions I hope the community can answer:
- Is my soil test believable? Super high Ca and CEC with such a sandy soil? I did 11 sample cores to 4inch, following recommendations to remove all plant matter, roots, etc.
- Should I do anything about the high K, Mg, Ca? Mg/K balance should be OK?
- Should I use a different fertilizer, maybe ammonium nitrate for more even spread (hand spreader)?

Thanks all!


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## g-man (Jun 15, 2017)

I believe the soil test represent the sample you sent them. How much new soil is in below the new sod?

With these results, yes focus only on nitrogen.


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## racker15 (Feb 18, 2021)

Good question. I did one deep soil core and the sod + new soil is at least 8" deep. I don't expect the tall fescue roots to get that deep


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## Ridgerunner (May 16, 2017)

First, your calculations seem correct. Add nothing but N this season.


> Questions I hope the community can answer:
> - Is my soil test believable?


 What @g-man said. It's not unusual for sod farms to over fertilize. That soil looks like a man-made mixture. Let it cook for a year before testing again.



> Super high Ca and CEC with such a sandy soil? I did 11 sample cores to 4inch, following recommendations to remove all plant matter, roots, etc.


400-700 is a sufficiency range, if you have levels in the range, the turf should get the Ca it needs. Higher Ca levels are not unusual and are not detrimental to turf health. No worries in your case. CEC is a reflection of clay and OM. You've got a lot of OM.



> - Should I do anything about the high K, Mg, Ca?


Nope. Other than don't bother adding more.



> Mg/K balance should be OK?


As long as K doesn't exceed Mg in the ratio (you're good), no issues.



> - Should I use a different fertilizer, maybe ammonium nitrate for more even spread (hand spreader)?


That's up to you. AMS can lower pH a bit, but with those nutrient levels, 6.9 isn't blocking anything. However, pH in the low 6s can help with disease.


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## racker15 (Feb 18, 2021)

Thanks for the tips, will go with ammonium sulfate as you suggested! I'm doing blueberries in another part of the garden so having spare AMS will help the acidity modification needed there too


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