Slownickel lounge, pull up a chair. CEC interpretation

Slipnot said:

Oh boy oh boy this can be misleading not all soils are the same so adding gyp should be used wisely .
AGVISE recently conducted a laboratory project looking at the affect gypsum has on soil test levels of calcium, soluble salts, cation ratios, soil pH and CEC. The results of the laboratory project are shown in figures 2 & 3. Some people who sell gypsum claim that it lowers the soil pH dramatically. It is apparent that this is not true, even at rates as high as 36000 lb/a gypsum the soil pH is about the same as the check.

It is most important to know the level of each nutrient in the soil. If a nutrient tests in the deficient range, it needs to be applied. The concept of balancing cations is not supported by the facts of the real world.

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We went through this Agvice stuff once already. Not sure where you posted it and I answered....

Why not check out real results by real growers, done with gypsum as presented above.

Which by the way show a dramatic lowering of pH by 0.3 (which is three times more acid in the soil) And the CEC was lowered.

Recently, we have received a number of calls asking if gypsum can be used to increase yields on high pH, salty soils in the Midwest. It has also been suggested that the base saturation ratio of many soils in the Midwest is “out of wack”, and this “problem” can be fixed by adding a few hundred pounds of gypsum. To understand this situation better, you have to first understand how the level of potassium, calcium, magnesium and sodium are determined in the laboratory. The ammonium acetate method of extraction is used by all laboratories in the Midwest to determine these nutrients. This method works very well to determine the level of potassium, calcium, magnesium and sodium held on the soil particles when the soil pH is 7.0 or lower, and the salt value less than 0.5. The level of potassium, calcium, magnesium and sodium from this test is used to calculate the cation exchange capacity and the base saturation value of a soil. If a soil has a pH higher than 7.0, and a salt level higher than 0.5 the normal testing procedure has some problems. Most soils with a pH higher than 7.0, have calcium and magnesium carbonate in the soil. Some of this carbonate is dissolved in the testing procedure and is included as part of the calcium and magnesium held on the soil. The problem is the calcium and magnesium dissolved from carbonate is not held by the soil, it comes from dissolving part of a rock in the soil (carbonate). Because of the carbonate, the calcium and magnesium test results on these soils is inflated on the high side.

Soils with a salt level higher than 0.5 also cause problems for determining the correct level of calcium and magnesium. Many salts in the soil solution contain calcium and magnesium. The calcium and magnesium contained in these soluble salts is already dissolved in the soil solution, and is not held on the soil particles. Any calcium and magnesium contained in the soil solution will be included in the test results for calcium and magnesium. The test values for calcium and magnesium on soils with a salt level higher than 0.5 will be inflated on the high side because of the error caused by calcium and magnesium from the salts being included in the test results.

Since the test values for calcium and magnesium are inflated due to problems caused by carbonates and salts, it is not possible to accurately determine the ratio of calcium or magnesium to any other nutrient using the ammonium acetate method. The whole concept of balancing nutrient levels to get to some perfect ratio is not supported by research. There is a lot of University research that shows making fertilizer decisions based on a ratio of calcium or magnesium to other nutrients does not increase yields. The approach that works is making sure you supply enough of each nutrient to supply the crops’s needs (forget the ratios).

So what does it mean when you have a soil that has a high or very high level of calcium and magnesium on the report? If the soil has a pH higher than 7.0, and the salt is higher than 0.5, it means there are carbonates and salts in the soil. The high salt level is the result of poor drainage. Improving the open drainage and tiling will fix the salt problem in the long term. The high level of carbonate in the soil means that you will want to place your phosphorus fertilizer in a band for efficiency and choose your soybean variety carefully. It does not mean that applying a few hundred pounds of gypsum will increase yields. Some of the most productive soils in the world (The Red River Valley) have a high pH with a low salt level. That should tell you that a high soil pH alone does not limit yields. Gypsum is a recognized amendment for sodium affected soils around the world. It will not lower soil pH or increase yields if sodium is not a problem. If you are considering applying gypsum to your fields, just to see if we know what we are talking about, you may want to test for gypsum first. Many soils already contain gypsum in this region. We are currently working on a routine soil test for gypsum

Gypsum alone will not raise yields, there are still several other variables.

I am not recommending to anyone to only apply gypsum, if they have high salts, wash first with gypsum so there is space to fertilize

Ask Foothill and several others there response so far. This is the real world. There is more than 1 variable.

Applying only gypsum on a normal conductivity only works if you finish the recipe.... sorry

And AA@ pH 7 breaks carbonates. Read some real research, look at that PGA article talking about soil analysis methods and WRONG conclusions, resulting in bad experiments with no results.

Last point, what is happening in a soil in Wisconsin somewhere has little to do with these mixes these guys are mixing up. Creating pH's in environments with carbonates that will have nothing to do with Wisconsin. The EC's these guys are hitting don't happen naturally except maybe here in Peru... haha

Slip,

Let's try it your way. What would you have recommended that Foothill do with that first AOG sample?

slownickel said:

Ask Foothill and several others there response so far. This is the real world. There is more than 1 variable.

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Yup, the response is undeniable. Not only on paper, but in the fields.

Paying it forward...

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Not sure if this was or not but it sounds like a jab at jidoka. He has shared/continues to share a lot. I've learned a lot from him and just didn't feel like it was right to characterize him like that. Unless there's something I don't know about. Maybe he doesn't want to share his bread and butter woo woo project but otherwise he has been very generous with his time in helping people with their soil and growing in general.

And we all give and take. You get a lot out of this too. It's an exchange.

plantingplants said:

Not sure if this was or not but it sounds like a jab at jidoka. He has shared and continues to share a lot. I've learned a lot from him and just didn't feel like it was right to characterize him like that. Unless there's something I don't know about. Maybe he doesn't want to share his bread and butter woo woo project but otherwise he has been very generous with his time in helping people with their soil and growing in general.

And we all give and take. You get a lot out of this too. It's an exchange.

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Jab, nah I wouldn't call it that. Hope it didn't come off as a jab.

You all ask and I have answered willingly, that was the point.

On my worst day I could not imagine ever telling a grower that they need to learn their lessons on their own. But that is just me. I have ALWAYS answered any question that I am able to answer to the best of my ability and in the best means possible. Sometimes I am not the best at making folks understand, but that is different. Having worked in overseas development, I just have a different attitude about growers.

I am paying it forward. Treat others as you would like to be treated, golden rule kind of thing. Take it at that.

I want people to help me as well. I think the world would be a much better place if we could all work that way. That was what my Mom and Religion taught me.

What do I know...

Slipnot,

That Agrovise page cherry pick data.

Most everyone in Wisconsin seems to use lime as their soils tend to be acidic due to the quantity of rain. goo.gl/75DyKD

Here you can see that Wisconsin folks lime and why applying gypsum doesn't make sense for where they are.

The Agrovise guys are in northdakota. Again, washed out soils.

Grow some cannabis in those soils and tell me how you do....

plantingplants said:

Not sure if this was or not but it sounds like a jab at jidoka. He has shared/continues to share a lot. I've learned a lot from him and just didn't feel like it was right to characterize him like that. Unless there's something I don't know about. Maybe he doesn't want to share his bread and butter woo woo project but otherwise he has been very generous with his time in helping people with their soil and growing in general.

And we all give and take. You get a lot out of this too. It's an exchange.

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Did not come off as a jab to me. Slow can pay it forward also. He is looking to get data for when Peru makes it legal...basically the exact same thing i did. Makes perfect sense to me

Probably a fair trade for some for sure

Ok glad we're all happy

I can't open that pdf on my phone :x

I'm thinking corn and alfalfa with the cannabis next year. Alfalfa would indicate if al and fe is becoming a problem? And also Ca. Tiedjens:

Even though corn grows at pH 5.5 to 6.0, it will do much better if grown at pH 6.8, or where the available calcium is adequate because the physical condition of the soil is better. We want to get the soil colloids practically saturated with calcium—as high as 87 per cent, according to some authorities. Alfalfa does not tolerate soluble aluminum and iron in any appreciable amounts, when present in the soil, while corn can tolerate some. Furthermore, alfalfa requires more calcium than corn does."

article with Ca and THC contents

article with Ca and THC contents

For those that would like to discuss the reality of whether Ca/Mg ratios exist or not and if they will or will they not have a difference on your production and quality, I refer back to this ancient yet extremely convincing article.

Pencil in the THC levels on the soil and leaf analysis and tell me what you see regarding Ca/Mg relationships and the brutally visual numbers.

I will run the numbers and post them since they aren't calculated.

Nice being in a thread where somebody is giving advice you can trust. Thanks Slow.

Base distributions of Cannabinoid Profile and Elemental Uptake Article

Base distributions of Cannabinoid Profile and Elemental Uptake Article

Here are the base distribution calculations along with a calculated Ca/Mg ratio. Ratios are done with Meq not PPMs.

Note the base distributions and Ca/Mg ratios of the highest THC content.

My garden experienced a big increase in plant health and vigor after applying gypsum to shoot for a higher calcium saturation.

My super silver haze wouldn't perk or pray at all and struggled until I started applying the gypsum slowly. Well, about a lb at a time.

My starting point was 72% calcium saturation based on m3 from logan labs. That gave me like a 50% saturation using AA. Last soil test I was at about 72% with AA.

This entire time the duration of "perk" after calcium foliar increased. The SSH would barely pick up for a day in the beginning. It actually grows all week now.

At one point I got my wires crossed and applied a LITTLE Mg and K to the soil and went backwards, the little canary SSH got necrotic leaf edges and some interveinal necrosis.

If balancing nutrients did not affect yields or plant health would it be safe to say you could apply whatever you like and see no results?

Where I live different plants grow in different soils. There are serpentine soils that are home to endemic species. The main reason that other plants do not grow here is attributed to a low Ca:Mg ratio.

I say throw some mgsO4 under your plants and see how they like it if you think those ratios don't matter.

Wow it really did knock off Na and Mg. So how did Ca go down in the AOG gyp pot? Saturation went up under nh4ac I guess due to the cec changing. And why did nitrates go up?


Thanks for doing those calculations. I added dry weight and its rank. I don't know how much stock we can put into a paper that only grew them until they were two feet tall and finished at most at 2.77g.


Highest dry weight has lowest Mg in leaf tissue.
Second lowest dry weight has third lowest Mg and the highest Ca.
Lowest dry weight has the lowest tissue Ca.


Copper seems positively correlated to yield not only in tissue but soil, as well.

The three highest yields had the three highest Cu values with highest yielder having the most Cu. Highest yielder was in the highest Cu containing soil. They also had lower Mg.

Great job Planting.

We know the importance of metals in flowering.

They were grown for 45 days in 4 inch pots under 12/12 from start. No wonder hahah.

So how did Ca go down in the AOG gyp pot? I don't get it.

Planting.... you are excelling. Keep it up.

plantingplants said:

They were grown for 45 days in 4 inch pots under 12/12 from start. No wonder hahah.

So how did Ca go down in the AOG gyp pot? I don't get it.

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That amount of sulfur washes a lot of stuff away. As I mentioned earlier, with the low correctives that I use, calcium and sulfur will open up the soil allowing elements that are "stuck" due to the lack of pore space to flow out.

This reaction of lowering everything is normal. This is why the pH went down so much as well. What is critical is the relationships, which got better.

Obviously there are floor levels, which is what the guys at the Agvise where trying to push, but that is another extreme, in washed out clays.

With these hybrid mixes, the last problem that folks have is a washed out medium... the problems are consistently excesses.

Planting,

I think this exercise demonstrates the need to push Ca early and keep your K reasonable all through the grow. Keeping Mg at reasonably low levels and pumping K at the right times. Pretty much what I wrote about earlier.

This crop is no different than any other annual.

I have run thousands of hectares of melons this way and gotten bumper yields and super high brix with great shelf life.