# High Ca & Ma but extremely low pH?



## Khy (Jul 27, 2018)

Hey guys, so.. I just got my Soil Savvy report back and I'm a bit at a loss. From what I'm reading basically you should use one type of lime to raise pH if your Calcium is high and another if your Magnesium is high... what if both are high? Here's my soil sample, my pH seems pretty low at 5.02 but Ma and Ca are over the 'target area'.

Also not sure if I should be concerned/do something about the insane Phosphorous and Zinc levels or not. Everything else seems pretty solid. Just not sure what type of Limestone and how much to drop on the lawn.

I'm in NJ w/ mostly sandy/loamy soil and a TTTF/KBG mix lawn if that helps. Was planning to aerate and overseed around 1st week of September but would prefer to fix the pH balance issues first or at least begin the fixing process.


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## ken-n-nancy (Jul 25, 2017)

First off, welcome to the Lawn Forum! I hadn't originally realized this was your first post, or I might have made a much shorter reply. Hopefully this long reply doesn't scare you away!

If you haven't already, you should definitely read the Cool Season Lawn Guide: https://thelawnforum.com/viewtopic.php?f=9&t=1595



Khy said:


> Hey guys, so.. I just got my Soil Savvy report back and I'm a bit at a loss. From what I'm reading basically you should use one type of lime to raise pH if your Calcium is high and another if your Magnesium is high... what if both are high? Here's my soil sample, my pH seems pretty low at 5.02 but Ma and Ca are over the 'target area'.


OK. The problem that you have observed (that Ca and Ma are both over the target area, but the pH is still abysmally low) highlights one of the things I don't like about the Soil Savvy test report (and quite a few other soil test reports, for that matter).

In an attempt to simplify things for the lawn owner, the Soil Savvy test report leaves out a lot of the information that could be used to figure out what is going on.

I wish the Soil Savvy report included a measure of the Cation Exchange Capacity (CEC), sometimes called the Total Exchange Capacity (TEC), as that would help in understanding the issue. It would also be nice if the Soil Savvy report provided base saturation percentages of the primary cations, although one can mostly back into these from the ppm measurements for the primary cations (Calcium, Magnesium, Potassium, Sodium) and the pH.

Without going into all the details here, if all of your soil levels for the primary cations (calcium, magnesium, and potassium) were smack in the middle of the "target area" aka "optimal range," it looks like your pH would be around 5.0, while a range of about 6.5 to 6.8 is generally accepted as the target area for cool season turf. In summary, in order to have the pH be where it should be, some of the nutrient levels need to be higher than the Soil Savvy "target area" aka. "optimal range" indicated on that soil test interpretation.

Some soil test interpretation philosophies feel that ratios of primary cations to one another are practically irrelevant, as long as the absolute levels of each nutrient are high enough and the pH is in the proper range. The Soil Savvy "target areas" appear to take this approach. Other philosophies seek to bring the % of each cation in the soil to a desired level, which has the side effect of bringing the ratios of each cation to one another to a specific level, as well as bringing the pH to about that 6.7-6.8 target value. I happen to subscribe to this latter approach, but largely because if one's soil needs adjustment, the latter approach can guide the adjustment being made, rather than considering the type of adjustment to be largely irrelevant.

Basically, the former approach would conclude that you have sufficient calcium and you have sufficient magnesuim, but your pH is low, so it doesn't matter what kind of lime you add - just add lime, which will push at least one of the Ca or Mg up over the "target area" but you need to add one or the other (or both) in order to get your pH up where it belongs.

The latter approach (which is what I would do), would seek to balance the ratios of the primary nutrients that are present in the soil, rather than looking just at raw levels of nutrients in the soil, as the "balanced soil" strategy scales better to different soil types. A well-balanced soil targets a calcium % of around 68%, magnesium % of about 12%, and potassium of about 4%. Your test doesn't actually provide these "base saturation %s" but it would be possible to back into them with some calculations.

However, I'm going to take the easy way out and consider that the Ca:Mg ratio of 68% to 12% is about 5.7:1. The ratio of your Ca:Mg is 188ppm:38ppm = 4.9:1, which is a little lower than the target. In other words, to move towards a ratio of about 5.7:1 you would want to to add more calcium than magnesium. Accordingly, I would suggest applying a calcitic lime (rather than a dolomitic lime) in order to increase the Ca:Mg ratio a bit. Personally, I would not add significant additional magnesium to your lawn, or you'll shift the Ca:Mg ratio still lower.

For calcitic lime, I use Lowes Sta-Green Rapid Lime, which is a rebranded Solu-Cal product. Name brands for good calcitic limes include Solu-Cal, Mag-I-Cal, and Encap. These can be found at garden centers and occasionally (rarely?) at big box stores.



Khy said:


> Also not sure if I should be concerned/do something about the insane Phosphorous and Zinc levels or not. Everything else seems pretty solid. Just not sure what type of Limestone and how much to drop on the lawn.


I wouldn't do anything about either Phosphorus or Zinc in your soil, other than avoid application of synthetic phosphorus fertilizer (you don't need a conventional phosphurs-heavy "starter" fertilizer) and I wouldn't make any zinc-specific micronutrient applications. The high phosphorus level isn't going to harm your grass at all (it has to be absurdly high for that), it just means you really won't get much, if any, additional benefit from adding more phosphorus, so adding more synthetic phosphorus would risk phosphorus runoff without much potential benefit to the lawn. In short, don't add synthetic phosphorus to your lawn, given your soil test results. It may even be illegal in NJ to do so with your soil test results. (I live in NH, so I'm not particularly familiar with NJ regulations for phosphorus.)

Personally, if I were in your situation, I'd do the following:

1 - Your potassium is low. You should apply potassium. This will also help raise your pH a little. However, rather than use 0-0-60 (muriate of potash, aka potassium chloride), I'd use 0-0-50 (sulfate of potash, aka potassium sulfate). Sulfate of Potash is a little more difficult to find than Muriate of Potash, as it is kind of a specialty product. You can probably get it at garden centers. I get mine at Agway; I know other readers here use it too -- the folks in the "New Jersey" discussion (https://thelawnforum.com/viewtopic.php?f=23&t=2753) can surely help you find a local supplier. I would make one application now at a rate of 1#K/ksqft (which would be 2# SOP / ksqft) and another application 30 days later, but no later than Sept 15th for NJ. Late-season applications of potassium to cool season lawns have been implicated in increasing the likelihood of snow mold in some research studies.

2 - I'd make one application of a good calcitic lime at about 9#/ksqft now and then retest in the spring by sending the sample off to a better soil testing lab. Personally, I'd use Lowes' Sta-Green https://www.lowes.com/pd/Sta-Green-30-lb-Lime-Balance-Soil/50189499 as it is the least expensive source I've found. To make an application of 9#/ksqft, your ~3ksqft lawn would need ~27 pounds. The Lowes product comes in 30# bags, so I'd just get one bag and apply the whole thing, which would actually be 10#/ksqft, but that would be fine. One bag is $12.97; coupons or sales can reduce that price further.

3 - I'd apply nitrogen this fall in accordance with the Fall Nitrogen Blitz. https://thelawnforum.com/viewtopic.php?f=9&t=753

That's all I do for the remainder of this year for fertilization / lime on your lawn.

As mentioned above, I'd retest in the spring at a better lab (there's other threads on this topic) before making any spring fertilization or lime applications, in order to get a "baseline" reading that isn't affected by any recent fertilization or lime applications.


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## ken-n-nancy (Jul 25, 2017)

Oh, another thing I don't like about the Soil Savvy recommendations that I forgot about when writing the above... their recommendation for your lawn includes application of 21-0-0 for nitrogen.

21-0-0 is ammonium sulfate, which is an acidifying fertilizer. It would be *exactly *the right thing for you to use *if your pH were up above 7.2* or so, as it will help (very slowly, mind you) to lower pH over time. Alas, at your pH of 5.02, ammonium sulfate is about the worst possible nitrogen source you could apply to your lawn, as your soil is already quite acidic and you don't want to be applying an acidifying fertilizer!

Personally, if I were you in NJ, I would seek to make most of my nitrogen applications via either OceanGro (a NJ equivalent of Milorganite; the folks in the NJ discussion can help you source it) or Urea (46-0-0). I wouldn't be worried about the phosphorus in the OceanGro as long as you apply in such a way that the OceanGro is not subject to runoff from your lawn (which you should be doing anyway), as the phosphorus in OceanGro is in a non-leaching form. (See https://www.milorganite.com/using-milorganite/non-leaching-phosphorus ) If you can't apply fertilizer to your lawn in such a way that it doesn't run off into storm drains or bodies of water, then you really shouldn't be applying fertilizer to your lawn at all!


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## Khy (Jul 27, 2018)

Wow man, thanks, that was a TON of information. No worries, didn't scare me away, I've been following LCN, GCI, Connor Ward, Ryan Knorr etc. on Youtube and such all year. So I'm by no means an expect, but I'm trying to absorb as much information as humanly possible to make my yard look primo.

I actually ended up stopping at Lowes on my way home and buying that exact bag of Lime just primarily on a whim and threw it down... which was probably haphazard of me, but at least it worked out in the end? :lol:

And yes, OceanGro! I was using Milo for the year and was a tad annoyed that it was like $13.50/bag here in NJ. I was stumbling around a local garden center, saw it and damn near freaked out when the employee working there told me it was $6.99/bag for 10LBs more fert. Soooo, yeah, I stocked up on OceanGro, really glad it's a product offered here considering the insane milo cost and recent shortage.

So, sounds good. I threw down the Lime. That should help as you said. I also have some of this https://www.walmart.com/ip/Purely-Organic-Products-LLC-Lawn-Food-5-000-sq-ft-10-0-2/111367413 which is a 10-0-2 organic that I had ordered from Walmart before I discovered OceanGro (and that they prompted refunded me 100% and told me not to return it when I tried to return it... so it was free!). So maybe I'll toss some of that down tomorrow just to get a little N and K into it.

I'll definitely checkout where others are buying some Sulfate of Potash and pickup some.

Thank you again for such an amazingly detailed response. And I agree, there are definitely things Soil Savvy is lacking, I looked into Rutgers soil test but it was outlandishly expensive (unless I misunderstood the pricing?). I'll have to do a bit of research and find a better lab for the spring.


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## ken-n-nancy (Jul 25, 2017)

Khy said:


> I actually ended up stopping at Lowes on my way home and buying that exact bag of Lime just primarily on a whim and threw it down... which was probably haphazard of me, but at least it worked out in the end? :lol:


Good to hear that you can be decisive (inaction can be a problem in lawn care), but acting on whims can get you in trouble, too. Good thing that bag of lime wasn't a dolomitic lime... 



Khy said:


> Thank you again for such an amazingly detailed response. And I agree, there are definitely things Soil Savvy is lacking, I looked into Rutgers soil test but it was outlandishly expensive (unless I misunderstood the pricing?). I'll have to do a bit of research and find a better lab for the spring.


You're welcome for the detailed response. Your post seemed to indicate enough knowledge that you'd appreciate some explanation rather than just "do this" answers. I'm just here trying to help teach people "how to fish" so to speak, as I learned about good lawn care practices from online forums like this one.

There's a discussion thread here somewhere (search is your friend) about different soil test labs. Different folks have different preferences about soil testing labs. I personally like Logan Labs, but that's because I've been doing this enough to mostly do my own interpretations and/or seek help from others on the net to interpret the results -- the basic Logan Labs test doesn't include recommendations (unless you pay extra) but rather just includes the detailed results without interpretation.


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## Khy (Jul 27, 2018)

ken-n-nancy said:


> Khy said:
> 
> 
> > I actually ended up stopping at Lowes on my way home and buying that exact bag of Lime just primarily on a whim and threw it down... which was probably haphazard of me, but at least it worked out in the end? :lol:
> ...


Haha... yeah, if by decisive you mean impatient... then that's me 

Out of curiosity just for the 'educational' purposes so to speak. If I had went and grabbed dolomitic lime, what would happen? Would it be really harmful? Or would it just be in the sense of like... now the Ca/Ma ratio is further off which isn't great and should probably be adjusted to proper ratios?


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## ken-n-nancy (Jul 25, 2017)

Khy said:


> Out of curiosity just for the 'educational' purposes so to speak. If I had went and grabbed dolomitic lime, what would happen? Would it be really harmful? Or would it just be in the sense of like... now the Ca/Ma ratio is further off which isn't great and should probably be adjusted to proper ratios?


 Really harmful? No. It just means that you'd possibly be stuck with a "too high" Magnesium level.

Too much magnesium will tend to "tighten" the soil. I don't think excess magnesium directly causes any harm to plants.

Even though one can readily add more magnesium to the soil via either dolomitic lime (which contains magnesium and calcium) or epsom salt (yes, the stuff you get at the drugstore to soak your feet - aka magnesium sulfate), there isn't a good way to get magnesium out of the soil, other than to wait for it to eventually leach out, which takes a long time, as magnesium isn't particularly prone to leaching out of soil. However, you won't get to a "way too high" magnesium level from just one excess dolomitic lime application.

However, if a homeowner had heard that one needs to apply lime to their lawn every year in their area (I've read this in New England recommendations at the hardware store, in order to counter acid rain) and just blindly applied 50#/ksqft of dolomitic lime (a typical application rate for traditional dolomitic limestone) each year for a decade, they could end up with a much tighter soil under their lawn, and not much they could really do about it except wait for a few decades to pass.

There are some ares of the country, such as where dolomitic limestone is mined, that naturally have soils that are saturated with magnesium. These soils are very "tight" and need to have a lot of organic matter added to make them workable.


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## g-man (Jun 15, 2017)

@Khy @ken-n-nancy ,FYI, the top thread in the soil sub forum has some general testing steps and some of the labs with their prices.


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