# Soil pH Change from Acidic to Alkaline



## waltonereed (Aug 16, 2020)

Hi all, I've done soil tests in each of the past two years. The first year my soil pH was 5.25, so I applied lime in fall of 2020.

This past fall, I had another soil test performed (by a different lab), and my soil pH came out to 7.7, for a net change of +2.45. Is it possible to have this drastic of a change over one year, or could the difference also be driven by using different labs?


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## Grizzly Adam (May 5, 2017)

How much lime was applied per/1000?


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## waltonereed (Aug 16, 2020)

50 lbs


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## Grizzly Adam (May 5, 2017)

Well, every 9-12.5 lbs of elemental has the ability to increase pH by .5 or 1000 sq ft, so it sounds like you are right about where you should be after that large dose.


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## corneliani (Apr 2, 2019)

Different labs have different testing/extraction methods. Post the soil test results and it may shine some more light on the differences. 50#/1000 should not raise your soil pH from 5.25 to 7.7, not sure that's even possible.

EDIT: It could also be your testing depth (?). Just thought of that, as lime takes a while to work its way into the soil depth (depending on type you applied, obviously). As a BROAD reference, 50#/1000 should result in less than 1 pH change in a loamy/clay soil.


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## waltonereed (Aug 16, 2020)

Sure, here's the original:


And last fall's:


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## g-man (Jun 15, 2017)

I dont see buffer pH in the original test, and the number of exactly 1.0tons/acre makes me suspicious of the recommendation. Core depth between samples, the type of lime you used (fast acting?) and how many months ago will have an effect in the results.

Regardless, you are very deficient in phosphorous and potassium. Check the soil remediation guide on how to address those.

PS you say last fall, but the test says January 2022. Why?


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## waltonereed (Aug 16, 2020)

Thanks to you both! I put down granular dolomitic lime in Fall 2020. I've already ordered products to remediate the P and K for this upcoming season.

Test says January 2022 b/c I waited 3 months between taking the sample and actually getting around to sending it in


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## g-man (Jun 15, 2017)

How much time between lime application and taking the sample?

Fast aciting lime or agricultural lime?


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## waltonereed (Aug 16, 2020)

Agricultural lime; ~11-12 months between application and sample.


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## Ridgerunner (May 16, 2017)

Where to start?
1 The Auburn test was done on 9/14. The Waypoint was done on 1/24. Soil pH is typically at its lowest at the end of the growing Season. Once turf growth and microbe activity slows as temps get lower, the acidifying slows/stops and over the Winter, it begins to rise as the H+ leaches.
2. Most lime recommendations (especially university- Auburn is one of them) are based on changing pH to an 8" depth.
3. One ton per acre is just under 46lbs/M. You applied 8% more lime than recommended.
4. Lime recommendations are accurate to + or - 500lbs/acre or 12.5lbs/M.
5. Depending on fineness, average Ag lime takes 1 to 1.5+ years to totally dissolve. In this case that's significant as it's possible that your sample could have included some undissolved lime which would skew results. Although the Ca levels don't really support this.
6. It could be a sampling error.
7. It could be a difference in lab procedures (it's why it is strongly recommended to use the same lab for all subsequent tests.)
8 It could be a lab error.


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## Lawn Whisperer (Feb 15, 2021)

Did you level your lawn? What and how much medium did you use to level?

https://thelawnforum.com/viewtopic.php?f=2&t=22885


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## waltonereed (Aug 16, 2020)

I didn't. Unfortunately constant rainfall last summer made it unfeasible 



Lawn Whisperer said:


> Did you level your lawn? What and how much medium did you use to level?
> 
> https://thelawnforum.com/viewtopic.php?f=2&t=22885


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## Lawn Whisperer (Feb 15, 2021)

If you decide to level with sand, it can bring the average pH of your soil closer to 7.0, since most sands are neutral in pH. I wouldn't make any pH corrections, like sulfur or citric acid. Until your next soil test, just fertilize as needed.



waltonereed said:


> I didn't. Unfortunately constant rainfall last summer made it unfeasible
> 
> 
> 
> ...


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