# Nutrient Availability Chart According to pH



## Mightyquinn

I saw this earlier and thought it would be good to have here to reference.


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## GrassDaddy

that should go in the articles section so it doesn't get lost! I started to bookmark stuff but lost all my bookmarks so that new section is Great btw


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## 2xjtn

FINALLY someone posted this chart. This should be mandatory knowledge for any turfgrass manager or homeowner serious about a high-end lawn!


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## Greendoc

X2. That chart is the reason why I will not waste fertilizer on soil with a pH over 7. pH gets corrected and now if that is the case. Likewise if pH is under 6 and I am not trying to grow Centipede. You all would be surprised at how many pros are not familiar with this chart.


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## g-man

My soil pH is 8.1. I still apply fertilizer because I need it. I use AS. Correcting my clay soil will be a big challenge (CEC 21).


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## Suburban Jungle Life

Invest in a sulfur mine?  I've never seen a CEC that high. Wow. Only in theory, not someone's lawn.


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## g-man

That's what happens when you live in a limestone state. My hardwater is 24 grains at my house.

Even with this bad soil, I'm still able to grow a lawn.
https://thelawnforum.com/viewtopic.php?f=24&t=2533


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## Suburban Jungle Life

I have no doubts you can have a great lawn without optimal ph. Just may take more inputs and attention. Also, I'm sure you're really on top of it! Optimal ph just makes it easier to look nice...


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## Kicker

pfft sulfur game is weak. You got to pump those numbers up, those are rookie numbers.


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## g-man

@Kicker That sulfur (sulfate) is needed by the plant but it is way different than the one used change your pH (via H+ ion). Ridgerunner had an excellent post about it.



Ridgerunner said:


> I respectfully disagree.
> First: Although sulfur (S) is an essential plant nutrient, plants including turf can only take up and use sulfur in the form of sulfate (SO4). However, sulfate will not lower soil pH. When elemental Sulfur is applied to soil and conditions are amenable (temp and moisture) a soil microbe will combine Sulfur (S) with water (H2O) to create sulfuric acid (H2SO4) and a lot of excess H+. The sulfuric acid is very unstable and breaks down into two H+ ions and a sulfate (SO4) molecule. It's this additional H+ that is created that will lower soil pH. The sulfate is a "waste" bi-product that happens to be beneficial to the plant. It does not acidify.
> 
> Spectrum is advising the addition of 5.8 lbs/M of elemental sulfur for the purpose of lowering the soil pH. You cannot substitute sulfate (from ammonium sulfate or potassium sulfate or any other source of sulfate) as it will not affect soil pH. The ammonium sulfate and potassium sulfate is a good source for sulfate as a plant nutrient. Keep in mind that nitrification of ammonia will also creates excess H+ ions which will have an addition acidifying affect.


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## NoslracNevok

great chart, here's a reverse image search for anyone interested.

https://www.google.com/search?q=soil+ph+nutrient+availability&hl=en&tbs=simg:CAEStQIJ-W6RQwzzl58aqQILEKjU2AQaBAgVCAQMCxCwjKcIGmIKYAgDEiiaE_1QCmRPfCK4TnBPLHZsTzB2jE483uSi8PtY_17z_1XP7s-qiilK_1A_1GjChxx6BVf1QrRuzhfD8B_1BY1GNJ8SdYWrpWeAc3Vumuu2zedFfRnEMleZQLGAJ9Qy0gBAwLEI6u_1ggaCgoICAESBP_1vFUAMCxCd7cEJGpQBChoKB2RpYWdyYW3apYj2AwsKCS9tLzAydjBtMgodCgpzY3JlZW5zaG902qWI9gMLCgkvbS8wMXpibncKGAoGbnVtYmVy2qWI9gMKCggvbS8wNWZ3YgoYCgRwbG902qWI9gMMCgovbS8wNHEzNDd5CiMKEHV0aWxpdHkgc29mdHdhcmXapYj2AwsKCS9tLzAzbmh2Ygw,isz:l&tbm=isch&source=lnt&sa=X&ved=0ahUKEwi1lvursPLbAhXEqlMKHbcmBLgQpwUIIA&biw=1920&bih=1009&dpr=1#imgrc=_


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## LowCountryCharleston

Confused. The pH on my soil test came in at 4.7 but the other recordings for N came in a bit below Target Area while P and K came in at the Target area as did Ca, Mg, S and Na but Fe came in a bit lower. Based on the chart above shouldn't the Macros come in under the Target zone? Or am I wrong on how to read that chart above?

Thanks


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## Spammage

LowCountryCharleston said:


> Confused. The pH on my soil test came in at 4.7 but the other recordings for N came in a bit below Target Area while P and K came in at the Target area as did Ca, Mg, S and Na but Fe came in a bit lower. Based on the chart above shouldn't the Macros come in under the Target zone? Or am I wrong on how to read that chart above?
> 
> Thanks


A soil test shows presence in the soil and the chart references plant availability.


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## 95mmrenegade

Ph = 7.0, should you try to lower?


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## Ridgerunner

Soil tests (established extraction methods) have been developed to determine/measure the quantities of soil nutrients that are, or are predicted during a growing season, to be available in the forms needed for plant use. The Nutrient Availability Chart According to pH is a predictor of how pH may affect nutrient availability. It is based on a compilation of numerous factors (chemical interactions, microbial activity, soil weathering, plant physiology and processes, etc.) that are pH related and tend to increase or decrease nutrient plant availability. Amending the soil can increase the reported soil test values regardless of pH. Availability can also be influenced by the nutrient content of soil parent material and that can offset the influence of pH.


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## LowCountryCharleston

Ridgerunner said:


> Soil tests (established extraction methods) have been developed to determine/measure the quantities of soil nutrients that are, or are predicted during a growing season, to be available in the forms needed for plant use. The Nutrient Availability Chart According to pH is a predictor of how pH may affect nutrient availability. It is based on a compilation of numerous factors (chemical interactions, microbial activity, soil weathering, plant physiology and processes, etc.) that are pH related and tend to increase of decrease nutrient plant availability. Amending the soil can increase the reported soil test values regardless of pH. Availability can also be influenced by the nutrient content of soil parent material and that can offset the influence of pH.


So, if the nutrient values on my test were mostly at or above the target zone yet my pH was below 5 is it fair to say that I don't need to worry too much that is was that low? Though I have put down 2 apps of Lime a few weeks ago since getting the results back. 
Thanks!


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## Ridgerunner

> So, if the nutrient values on my test were mostly at or above the target zone yet my pH was below 5 is it fair to say that I don't need to worry too much that is was that low?


Not necessarily (pH isn't the only thing that can have an impact on nutrient availability - there are factors such as nutrient ratios where imbalances between nutrients may create nutrient uptake and use problems). As I said, although the pH chart is not an determinate, it is a predictor of probability. For instance, soils with a pH below 7 tend to become even more acidic through the season. Consequently, some nutrients that are currently on the low end of sufficient, might become less available and some micro-nutrients could become excessive and detrimental. As it is relatively simple to increase pH, there is no reason to ride a razor's edge by maintaining pH below 6. Adding lime was a wise choice.


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## LowCountryCharleston

Ridgerunner said:


> So, if the nutrient values on my test were mostly at or above the target zone yet my pH was below 5 is it fair to say that I don't need to worry too much that is was that low?
> 
> 
> 
> Not necessarily (pH isn't the only thing that can have an impact on nutrient availability - there are factors such as nutrient ratios where imbalances between nutrients may create nutrient uptake and use problems). As I said, although the pH chart is not an determinate, it is a predictor of probability. For instance, soils with a pH below 7 tend to become even more acidic through the season. Consequently, some nutrients that are currently on the low end of sufficient, might become less available and some micro-nutrients could become excessive and detrimental. As it is relatively simple to increase pH, there is no reason to ride a razor's edge by maintaining pH below 6. Adding lime was a wise choice.
Click to expand...

Got it. Thanks for your help. Since I put down the Lime apps a earlier this month does it make sense to take another soil sample in the fall? Can those Lime apps make any change to the pH this quick?


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## Ridgerunner

@LowCountryCharleston 
Generally, it takes a year or more for amendment induced pH changes to occur in the root zone.


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## LowCountryCharleston

Ridgerunner said:


> @LowCountryCharleston
> Generally, it takes a year or more for amendment induced pH changes to occur in the root zone.


Thanks. Guess it'll make more sense to do another soil test in the spring.


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