Calcium magnesium soil test kit

Need a decent calcium magnesium soil test kit. Wife and I have been searching all morning and there seems to be nothing in between basic PH-NPK test kits and $600+ 'professional' kits.

Aware that lab tests are better but we have eight acres that have been divided into four different gardens, three orchards, various flower beds, lawn and a large pasture. Other than a bit in the vegetable gardens none have been limed since we bought it in 1989.

Long story, but just got three tons of calcitic lime. Possibly exactly what the gardens needs since the little they have had was dolomite lime. Possibly not what the pasture needs. No clue yet about the orchards...

Searching for "calcium magnesium soil test kit" finds idiots on Amazon selling just the color chart (no test kit!) companies with no pricing listed and tons of basic NPK kits telling you to use a lab for the calcium and magnesium.

Any help appreciated! Even a better search term, or a strategy to minimize lab tests to as few as possible.

Hi William-

It sounds to me like you want to test so you have foundation guidelines for how much lime to apply in particular areas if I'm reading your post correctly? If this is the case, may I suggest sending two or three samples representing the unlimed areas as a whole off to a lab for analysis. That will provide a general idea of what the pH is of the unlimed areas, instead of paying for a soil analysis for each particular localized area, which could add up quickly.

I'm unsure of how much you know about soils and soil testing, but I'll offer a piece if info anyway. There's no real general rule that says apply x amount of lime to one acre to raise the pH x amount. This is because different soils each have different cation exchange capacities, or CEC's. A soils CEC is its capacity to hold onto positively charged minerals (the cations). An acre with a pH of 5.2 that has a CEC of 7 needs a different amount of lime than an acre of soil with a pH of 5.2 and a CEC of 43. Knowing a soils CEC along with an analysis showing the current state of mineral quantities allows one to calculate how much of numerous kinds of minerals are in excess or are in deficit.

When people ask me about adding anything to a soil I always ask if they have done a lab soil test. I think the do-it-at-home kits offer too much room for error and aren't totally accurate and I think the money spent on a soil analysis from a reputable lab is well worth the 25 or so dollars per test. Having accurate data is important and can really help anyone know where to start. Having said this, I don't think all labs are created equal. Ten years ago before I really started getting totally geeky on soil science and didn't know any better, I sent some samples in to the University of Tennessee, and they sent me results. Looking back, I think it was an insufficient test, since they did not analyze and report the soils CEC, and they also did not test for certain micronutrients. While there are many quality and reputable independent soil testing labs in America, I like to use LoganLabs. I think their price is competitive, and they offer a quality test and print the results in an easy to read and understand chart. Here's a link to an analysis I had done by LoganLabs so you can see what it looks like and the data they provide: https://permies.com/t/67972/personal-quest-super-soil#844149

I hope this answers your questions and helps you make the right choice. If you have more questions, I'll do my best to try an answer them!

Thank you! And yes, your first sentence sums it up nicely. Need to do my homework on CEC's and get back to you... Far from an expert (obviously!) but do know enough to not lime to PH alone. Want to "micro manage" calcium to magnesium ratios as much as possible since this is a relatively large amount of calcitic lime all at once. Likely a one time deal then back to a few bags per year of dolomite lime since that is what is sold locally. Also we know very little of what soil amendments were used prior to 1989. Do know it was all in corn in 87 or 88 and that at least some fertilizer was used since the empty bags were still here. Still remember all the dead corn stalks covered in millions of morning glory's.

Your other thread is interesting and I intend to read the rest. Do wonder why you picked Logan Labs? More thorough? Doubt they are cheaper than a local county extension agent.

Oh, mostly silt here. Some sand near the creek and some clay at the edges of the woods, but silt percentages are going to be very high based on jar tests.

William Bagwell wrote:

Your other thread is interesting and I intend to read the rest. Do wonder why you picked Logan Labs? More thorough? Doubt they are cheaper than a local county extension agent.

Oh, mostly silt here. Some sand near the creek and some clay at the edges of the woods, but silt percentages are going to be very high based on jar tests.

I picked Logan Labs after reading about them in a book. You are correct on pricing, the county extension is usually cheaper. I recall my test from UT extension was like $15 or $16, but it had missing information, which I didn't know at the time. I realized that years later when reading books on soil and I had saved that soil analysis. In my opinion, not having a soils CEC on a soil analysis renders it useless; there's no way to know how much of anything to apply. I'd rather apply the $15 for an incomplete test towards a test that provides more data. You can always call your extension and ask if they report that information on their soil tests. May I even suggest asking the extension office to list exactly what they do test for and report so you know what you're getting if you choose that route. I personally consider Logan Labs standard soil test a complete analysis. It contains everything I need to know to provide a foundation of where I need to go from there. I need to clarify that the soil analysis in my other thread that's linked above is two different tests. The lab analysis is the first document and I had them do a separate physical test reporting the percentage of sand, clay and silt. I did that simply because I was curious.

There are a lot of other minerals which play an important role in soil biota life and also in plant life/metabolism which are not reported in Logan Labs test, or is reported from any lab soil test that I am aware of. Elements like cobalt, silicon, selenium, iodine, yttrium to mention a few, all play a role. Not much of these and the other unreported elements are needed, but they do indeed benefit soil and plant life, and I consider them important. I am not paying for some lab mass spectrometer test to report these elements in soil or plant tissue samples; I don't need that for my uses and don't want to pay for it. What I am doing, and I recommend to anyone, is to add these minerals to any soil via either unrefined sea salt or kelp or both. For the sea salt, I use Sea-90, and for the kelp, I use an organic kelp purchased by the 50lb bag where I get my chicken feed. They are both great sources of minerals and can really give a soil a kick-in-the-pants boost micronutrients and "forgotten" minerals.

William Bagwell wrote: Want to "micro manage" calcium to magnesium ratios as much as possible since this is a relatively large amount of calcitic lime all at once.

Forgot to comment on this part! Yes, I do the same thing, and I aim for a minimum of 7:1 Ca/Mg ratio, and try not to go over 10:1, but I find 10:1 perfectly acceptable. Since you mentioned this ratio, it makes me think you are aware that magnesium makes soil colloids stick together and calcium makes them not stick together. It's amazing what happens to a stiff clay like soil that gets enough calcium bound to the soil colloids as it will begin to loosen up almost like magic.

One more thing to note, it's likely that not all the calcium that is applied will have an affect. Some calcium may wash through the soil, run off the surface in a heavy rain, or may not bond to a soil colloid.

James Freyr wrote: it makes me think you are aware that magnesium makes soil colloids stick together and calcium makes them not stick together. It's amazing what happens to a stiff clay like soil that gets enough calcium bound to the soil colloids as it will begin to loosen up almost like magic.

Silly question: can you look at how sticky your clay soil is as a quick and dirty test then?

Pearl Sutton wrote:
Silly question: can you look at how sticky your clay soil is as a quick and dirty test then?

Not such a silly question I think the answer is "kind of". I think if anyone has a clay soil, and its physical attributes are very clay like, then it is a good indicator that something is not balanced, and I will hazard a guess that it's likely going to be a lack of calcium, as opposed to having plenty of calcium with too much magnesium. I think an exception to this is a soil that has been limed with dolomite lime, over and over again, year after year - that can cause an excess of magnesium along with lots of calcium and can result in a soil that won't loosen up.

If someone has a clay like soil and the pH happens to be in their desired target range, adding gypsum to the soil is a great way to get the calcium into the soil without adjusting the pH to help loosen it up.

If we strike out on a home test kit perhaps at least a couple of samples
to Logan Labs and use a cheaper local lab to watch the calcium to magnesium
ratios in more areas. As for getting the calcium into the soil, plan to plow
it in to the gardens. Pasture will have to wait until  the ground is not
saturated and 4 inches of rain are predicted.

Interesting you mention selenium. Supposedly in a deficient area here though
a neighbor claims it showed up as a trace in his well water. Used to have
llamas which require more selenium than most other critters. Always tried
to make sure that either their feed or trace minerals had selenium. Not both
at the same time since there was controversy about just how much they did
need... Bet the areas that used to be their pasture still have much more
selenium than other parts of our land.

The Sea-90 looks good. Less actual salt so more micro-nutrients than Redmond.
No real close dealer, but two at least in north Georgia.

CEC Homework: Looks like there are two ways of measuring this. Determined and
effective, so will need to know which method is used.

William Bagwell wrote:

Interesting you mention selenium. Supposedly in a deficient area here though
a neighbor claims it showed up as a trace in his well water. Used to have
llamas which require more selenium than most other critters. Always tried
to make sure that either their feed or trace minerals had selenium. Not both
at the same time since there was controversy about just how much they did
need... Bet the areas that used to be their pasture still have much more
selenium than other parts of our land.

Oh cool, my place had llamas before I got it, hope they left selenium in the soil, that's a nutrient I take in pills because my health issues require it.

I'm going to send up the hawksignal and hope that fellow permie Dr. Redhawk will chime in and offer some thoughts on the subject.

Uh Oh, I see the hawk signal has been activated.

The  first thing I have to do is give James a big round of applause for being spot on with his assessments and recommendations.  Way to go Kola !

With a first horizon of mostly silt, I would wet the soil and then lay on that calcitic lime rather sparingly and don't turn it in (if you aren't going to be able to also add about 4 inches of compost at the same time, turning just lime in will decimate your microbiome).

When it comes to do it your self testing I have two very important questions you need to answer to your self.
1. do you have any chemistry training at all, and have a space you can dedicate as a laboratory?
2. do you have the ability to handle strong acids without spilling any or anyone or anything?
If you answer yes to both, then you would be ok to do your own dirt testing.

Note that I said dirt testing, That is what you are going to get results on (there isn't anything wrong with that, just be aware that is what you will be looking at, not soil results).

If you want good, dependable testing results you first need to take good quality, non-contaminated samples that will be representative of the land mass your sample represents. (not hard to do, just a bit time consuming)
If you use any lab other than the local extension service, ask for pricing on "Complete soil profile testing" that way you will get everything the lab can do including cec, soil particle makeup, the works.
If you can, see if they also do biological testing, that will become the end focus when you start building your soil instead of building your dirt. (remember dirt is the mineral base made up of finely ground up rocks, pebbles, etc., that support the microbiome life forms that turn dirt into soil.)

Following are some links to test kits I can recommend.

Lamotte agricultural soil test kit

Lamotte complete soil test kit


Does that cover it for you William? if not just ask what you want to know.

Redhawk

Bryant RedHawk wrote:
The  first thing I have to do is give James a big round of applause for being spot on with his assessments and recommendations.  Way to go Kola !

Redhawk, thank you for the compliment. That really means a lot to me.

Minimal training and no lab so outdoors for stuff like this. Place I worked at long ago did in house anodizing of aluminum and electroforming (not plating) copper. So have worked with moderately strong acids / caustics in the past.

Work day so please give me a day or two to explore links and fully digest your post.

Funny the tiny ad that showed up after you were summoned like Batman is, "Die Fledermaus does not fear such a tiny ad" Coincidence?

I'll be watching this thread so when ever you come up with a question I should see it fairly soon and respond.

Giving up on a home test kit for now. $449 is better than $600 but still shocking at the huge jump from basic PH-NPK kits to one that adds Calcium & magnesium. Well and humus which is nice to know. The ~$600 kits add 7 more tests for 14 total.

Rain has finally let up so can hopefully start getting some samples up next week. Will post back when I get some results back.

William Bagwell wrote:Giving up on a home test kit for now. $449 is better than $600 but still shocking at the huge jump from basic PH-NPK kits to one that adds Calcium & magnesium. Well and humus which is nice to know. The ~$600 kits add 7 more tests for 14 total.

Rain has finally let up so can hopefully start getting some samples up next week. Will post back when I get some results back.

Wow, that’s got to give you a bit of sticker shock! Our ag extension office does not do any soil testing. They just tell you to send it to a lab. I am a bit jealous of people in states where the ag extension offices actually do soil tests. Did you decide to go with Logan Labs? Or another? I really should do some testing on our soil, so I am watching this thread with interest.

At least one to Logan Labs, possibly more depending on the price deferential. Local extension office still shows they do soil testing just no price listed. Need to call or drive by there on the way to work this week. Also confirm just what it includes.

Now fighting a wet weather spring in our driveway! Shortly after we bought our land in 1989 a spring popped up and ran about a year. This was before we built and moved here in 93. Dried up and we forgot about it. Wife's parents moved out in 2000 when her dad retired. Subdivided the 16 acres and built a new driveway and bridge on the line... Out there yesterday hand digging a drain pipe. Last 50 feet just before it splits to the two housed is still a muddy mess. Needs way more gravel than the thin layer we got by with all these years.

William Bagwell wrote:
....
The Sea-90 looks good. Less actual salt so more micro-nutrients than Redmond.
No real close dealer, but two at least in Georgia.

I just ordered a 50 lb bag from New Country Organics for $27 plus $24 shipping.  Half of what Amazon Prime would have cost.  They have a location in Texas and Virginia so your shipping should be about the same.

Sincerely,

Ralph