# Question about lime/soil test



## Dawgvet (Jul 2, 2019)

Let me start by saying that I know changing soil pH is a multi-year process but I was expecting better results from adding lime.
Background: This is for a 380 sq ft backyard area with Zeon Zoysia. I did a soil test on April 2019. I used Soil Savvy (before I found TLF) and I just repeated a soil test trying to get ready for the fall (Spectrum Analytics). I know that labs use different testing procedures, so comparing the two results may be like comparing lemons to oranges (not quite an apple :lol: ). Soil samples take 5 to 6 inches deep.

Results from 4/19:










As you can see, the pH came in extremely low at 4.64
I added Pennington Fast Acting Lime (Dolomitic d.t low Ca & Mg)on 5/5/19. Based on the recommendation on the bag I added 10 lbs lime (.38 X24 lbs)










I repeated the same 10 lb treatment on 6/29/19

Now, I just received the results from Spectrum:










The pH is 4.7. Basically , or should I say acidically, "the same" as in April (though two different labs). I also realize the June treatment may not be affecting the last soil tests yet.
Other supplements such as Fe, P, K were added hence the changes in those.

My question; can I keep adding lime at a higher rates this fall?


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## Virginiagal (Apr 24, 2017)

You can add 50 lb/1000 sq ft of regular lime at a time (for the fast acting kind, you are limited to the rate on the bag). They recommend 88 lb/1000 sq ft of dolomitic lime. You could split that into two applications, one this fall, another in the spring.


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## Dawgvet (Jul 2, 2019)

Why though was there not even the slightest increase in pH after 5 months from the first application?
Would it make sense to add smaller, monthly applications vs 1 or 2 larger ones?


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## g-man (Jun 15, 2017)

Virginiagal recommendations is on point. Lime takes time to breakdown and move into the soil.

The fast acting is pulverized more so it break down faster (hence the fast acting), but the lime effect is way lower. The bag should tell you what percent of the lb you apply are equivalent to just using lime.

Using cheap lime will work the same way and get your pH corrected.


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## Dawgvet (Jul 2, 2019)

g-man said:


> Virginiagal recommendations is on point. Lime takes time to breakdown and move into the soil.
> 
> The fast acting is pulverized more so it break down faster (hence the fast acting), but the lime effect is way lower.


@g-man Could you explain this further please. If it breaks down faster, does that mean that you get a quick effect but not a long term effect? And would I be better then applying normal dolomitic vs fast acting dolomitic lime?


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## Virginiagal (Apr 24, 2017)

It is better to do applications two or three times a year rather than monthly. The regular lime has a variety of sizes of particles. The smaller ones will act quickly and the larger ones will act slowly, even over a period of years. The fast acting lime acts quickly but you use less of it (because rates are limited) and so it only corrects so much acidity. If your soil test says you need 88 lb of lime, you need 88 lb of lime whether it is fast acting or slow. It makes sense to use regular lime, and they are recommending dolomitic lime which has magnesium as well as calcium.


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## Dawgvet (Jul 2, 2019)

Ok. Thanks for the replies. 
I think I had a misunderstanding of how fast acting lime worked. 
I knew it dissolved faster and therefore start working faster, but I though it would also have the long term effects of regular lime even though, in the case of Pennington, a 1/3 of the quantity is applied.


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## g-man (Jun 15, 2017)

I just read the whole post again.

You applied 10lb of Pennington fast acting lime to 380sqft twice? A total of 20lb into 380sqft? You grass is still looking better or worst since you apply this product?

The label recommends 6lb/ksqft.

Spectrum recommends 88lb/ksqft. This will be a total of 23lb into the 380sqft.


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## Dawgvet (Jul 2, 2019)

g-man said:


> I just read the whole post again.
> 
> You applied 10lb of Pennington fast acting lime to 380sqft twice? A total of 20lb into 380sqft? You grass is still looking better or worst since you apply this product?
> 
> ...


Correct, I did 2 applications of 10 lbs each (20 lbs total) about 2 months apart. The recommended 6lb/ksqft is if you have not done a soil test and don't know your pH.
If you look at the second picture, "How Much Lime Do You Need", that is actually from their website and on bags. At a pH of 4.64, they recommended 24 lbs/Ksqft`. so 24 X 0.380 = 9.1 lbs (I rounded up to 10 lbs for weighing convenience)

Grass looks better, but at the same time I've supplemented other things to the lawn based on initial test (P, K, micronutrients) and improved management (watering on a schedule, mowing). It would be hard for me to say if one thing or a combination of things improved it.
I just can't figure out why pH did not budge at all. 
Some am I done with adding lime for the year?


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## Virginiagal (Apr 24, 2017)

Add 17 lb this fall, 17 lb in the spring. Retest next year.


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## Ridgerunner (May 16, 2017)

> Why though was there not even the slightest increase in pH after 5 months from the first application?


A couple of things come to mind.
First, you don't have an accurate starting pH. With SS, you add an acid solution to your soil sample and send it off to them. Once they get it they test the pH which includes that acid solution.
Secondly, Depending on soil texture and CEC, it is estimated (estimates vary) that it can take as long as 2-3 years for a surface application to affect the pH at the 6" depth. You tested at the 5-6" depth, whether that was inclusive or just the soil between 5 and 6" is unclear, but if the later, that would almost certainly show no change at that level.
Third dolomitic lime reacts slower than calcitic lime. With a standard grind, estimates are about 6 months longer.
pH is a measurement of the amount of H+in soil solution. To raise pH the H+ needs be reduced/neutralized. Lime products do this through a chemical reaction whereby an oxygen atom in the lime product (common lime products: CaCoo3, CaOH and CaO) combines with H+ in the soil solution to form water H2O. By employing a Buffer pH test, labs are able to measure the the quantity of the total amount of H+ present in the soil that needs to be neutralized and calculate the amount of lime needed to result in a desired pH.


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