I would really need help with my fertilizer mix!

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treefrog

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Matoury - FRENCH GUIANA - FRANCE
I everyone, I think I need help to prepare my fertilizer solution. Note that, being in French Guiana, the availability of fertilizers is very limited, hence the importance of preparing my own formula for orchids.

So, what I did so far (with what I could find) is:

1 - Use a 15/5/30 + 5Mg + 10So4 already prepared water soluble fertilizers as the base (normally used for orchards).

2- Using the First Ray K-Lite Knock-Off” Calculator, I figured out that if I add 1 part of this base fertilizer + 2 parts of calcium nitrate + 2 parts of Epson Salt I would get a => 9.8/1/6+ 9.8Ca +4.9Mg (pretty close to the final 9.1 – 0.9 – 4.6 – 10.3Ca – 4.5Mg Do-It-Yourself K-Lite presented on the same page. I make and use this knock-off mix by mixing 125g of the base fertilizer + 250g of calcium nitrate + 250g Epson salt. I then mix the powder into a 25L water bucket (this should give me a 2500ppm of N) and use an injector at 1% to provide 25%ppm at each watering. Note that my mother solution remains powdery with some undissolved elements in it (if someone has a solution for me to have a perfectly dissolved mix?).

3 – Now, all is missing are the microelement (not present in the base fertilizer)! I found a product called ‘Tradecorp AZ’ which is a chelated formulation of:
Fe 7.50%
Mn 3.50%
Zn 0.70%
Cu 0.28%
B 0.65%
Mo 0.30%

And now, I begin to be lost! Could someone explain and suggest a proportion/quantity of this microelement mix I should add to my mother solution (the one at 2500ppm N)?

Thank you in advance for your help!

Math
 
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Note that, being inthat my mother solution remains powdery with some undissolved elements in it (if someone has a solution for me to have a perfectly dissolved mix?).

You can't add the calcium nitrate to the concentrate tank.
The powdery undissolved elements are actually a reaction of the calcium nitrate with the other chemicals. The reaction is dissolved calcium converting into a solid mineral that is insoluble in water.
 
Concerning the trace elements. Looking at a few labels of fertilizers that already contain them, it looks like the iron level (that's the largest component) runs about 0.7% to 0.9% of the nitrogen content.

Using the middle of that range, for your 9.8% N blend, it means you're shooting for 9.8 x 0.008 = 0.0784% Fe in the blend. At 7.5% Fe, you'd need for the trace element mixture to be about 1% of the total mass of powder blend.

Lance is right about mixing the powders in a concentrated solution, but you might try adding some citric acid to the water before adding the fertilizer.
 
I will reply a bit later to the whole thing, but:

- Calcium will precipitate for most of it with citric acid, especially in concentrates
- Citric acid in tropical conditions will promote bacterial rot....
- It would be important to know the source of the nitrogen in the compound fertilizer, ammonium, urea or nitrate. Nitrate are a no-go in tropical conditions ( and in many others after all...), that's why 100% of all the growers from Taiwan to Indonesia use urea-based fertilizers...
- You definitely need 2 tanks, with 2 injectors, one tank acidified will have just a lot of precipitate, except if the pH is adjusted to 2.5-3, in which case you need a second pump to add potassium hydroxide before watering...
- K-Lite in tropical countries would have disastrous effects, there has been many tests done, and plants do need a lot of potassium. The K-Lite fantasy came from just trials, it grows it does not... My experience, and others ccome from leaf mineral analysis, especially after the plants bloom. Tropical countries as well are much more demanding in terms of feeding (that's why 1 to 2 grams/L of fertilizer is common in Thailand, including for Paphiopedilum).... and especially potassium...
 
I will reply a bit later to the whole thing, but:

- Calcium will precipitate for most of it with citric acid, especially in concentrates
- Citric acid in tropical conditions will promote bacterial rot....
- It would be important to know the source of the nitrogen in the compound fertilizer, ammonium, urea or nitrate. Nitrate are a no-go in tropical conditions ( and in many others after all...), that's why 100% of all the growers from Taiwan to Indonesia use urea-based fertilizers...
- You definitely need 2 tanks, with 2 injectors, one tank acidified will have just a lot of precipitate, except if the pH is adjusted to 2.5-3, in which case you need a second pump to add potassium hydroxide before watering...
- K-Lite in tropical countries would have disastrous effects, there has been many tests done, and plants do need a lot of potassium. The K-Lite fantasy came from just trials, it grows it does not... My experience, and others ccome from leaf mineral analysis, especially after the plants bloom. Tropical countries as well are much more demanding in terms of feeding (that's why 1 to 2 grams/L of fertilizer is common in Thailand, including for Paphiopedilum).... and especially potassium...
Merci Xavier pour ton retour.
It appear I still have a lot to learn! Growing orchids in an amazonian climate, next to primary forest, has proved to be both challenging but also very interesting and rewarding!
I just checked my fertilizer bag and I was lucky the label hadn't disappeared yet!
Here are the infos regarding the blend of N (8.4% nitrate +1% ammonium +5.6% urea)...see image below.
20240111_075959.jpg
-If orchids in equatorial climates need more K, would it be wiser for me to use the base fertilizer 15/5/30 + 5Mg + 10So4 without adding any calcium nitrate? Another fertilizer available locally is a 7-12-39 +19SO3........would it be wiser to use this one?
-When you say 1 to 2gr/L of fertilizer, do you have an idea of the approximate N ppm of the solution?
Many thanks for all these constructive comments, I cant wait to learn even more!
Mathieu
 
I certainly do not want to restart a firestorm of crap-posting, but using tissue analysis to determine what a plant needs is not particularly valid. If that were true, my blood work indicates I need extra cholesterol! Tissue analysis tells what the plant has been getting, not what it should be getting.

That said, it does seem logical that tissue analysis of wild collected plants will tell you what they’ve been getting, and if they’ve been doing well in the wild and have evolved to be there, it must be some indication of what is adequate.

Such analyses I have seen suggest that roughly 99% of the tissue is C, O, H, & N, 0.9% is P, K, Ca, Mg, & S, and the remainder is all of the trace elements, combined.

I will not refute Xavier’s claimed expertise, but there are several growers in tropical areas whose plants are growing quite well with K-Lite, others I have spoken to who only feed calcium nitrate most of the time, supplementing with the “minor” elements quarterly and trace elements annually.

There is also the case to be made that a very important factor in fertilizer selection for large-scale growers is cost, and urea is far less expensive than are nitrate and ammonium-based formulas, so that makes me wonder if that isn’t the more important factor for “why 100% of all the growers from Taiwan to Indonesia use urea-based fertilizers...”.

By itself, I know that statement to be untrue, as I used to do business with a cymbidium nursery in Taiwan that exported about 10,000 plants weekly to Japan. Their complete nutritional package consisted of fermented milk.

To me, after doing a lot of reading and having discussions with scientists and manufacturers of fertilizers, it seems that “we tried it and it works” is fairly common in the industry, when it comes to the hobby grower, there are far more variables than just the chemical components and ratios in the feed that play a role in success or failure, and that the fertilizer component ratios are not all that important. The plants are slow-growing compared to most others, the majority of nutrient ions are stored and recycled within a plant, so fertilizers end up being very low on the plants’ “Maslow’s pyramid of needs”.
 
Well, from the package there are a few problems:

- It says it contains iron sulfate, but it is nowhere to be seen in the analysis... and it looks more like a fertilizer to sprinkle on the ground for agriculture purposes rather than something to be used to water plants with. Iron sulfate in fertilizers is usually used to put on the ground...

The labels are actually not conform to the law, as they mention 2 ingredients, where more are needed to produce the NPKMgSO3 advertised... and certainly not iron sulfate. So I would be very careful with the brand as well...

- the other one with a high Sulfate content seems to be as well for ground applications, not to dissolve in water. Weird fertilizers for both...

The best is to find out who distributes better brand of fertilizer, or use directly mineral salts from a chemical supplier company ( not agriculture ones...)...
 
I certainly do not want to restart a firestorm of crap-posting, but using tissue analysis to determine what a plant needs is not particularly valid. If that were true, my blood work indicates I need extra cholesterol! Tissue analysis tells what the plant has been getting, not what it should be getting.

That said, it does seem logical that tissue analysis of wild collected plants will tell you what they’ve been getting, and if they’ve been doing well in the wild and have evolved to be there, it must be some indication of what is adequate.

Such analyses I have seen suggest that roughly 99% of the tissue is C, O, H, & N, 0.9% is P, K, Ca, Mg, & S, and the remainder is all of the trace elements, combined.

I will not refute Xavier’s claimed expertise, but there are several growers in tropical areas whose plants are growing quite well with K-Lite, others I have spoken to who only feed calcium nitrate most of the time, supplementing with the “minor” elements quarterly and trace elements annually.

There is also the case to be made that a very important factor in fertilizer selection for large-scale growers is cost, and urea is far less expensive than are nitrate and ammonium-based formulas, so that makes me wonder if that isn’t the more important factor for “why 100% of all the growers from Taiwan to Indonesia use urea-based fertilizers...”.

By itself, I know that statement to be untrue, as I used to do business with a cymbidium nursery in Taiwan that exported about 10,000 plants weekly to Japan. Their complete nutritional package consisted of fermented milk.

To me, after doing a lot of reading and having discussions with scientists and manufacturers of fertilizers, it seems that “we tried it and it works” is fairly common in the industry, when it comes to the hobby grower, there are far more variables than just the chemical components and ratios in the feed that play a role in success or failure, and that the fertilizer component ratios are not all that important. The plants are slow-growing compared to most others, the majority of nutrient ions are stored and recycled within a plant, so fertilizers end up being very low on the plants’ “Maslow’s pyramid of needs”.

It is much more complicated than that unfortunately.

Wild plant analysis, that depends when they were sampled, and which leaves. Old ones ' not to disturb the plant' wil have typically a very low potassium content if they start to be senescent. Roots need to be sampled aside ( we do that in industrial production), because there are some huge surprises in the needs and contents of the roots vs. the leaves.

If you go to make blood samples in the refugees camps with 35kg adults in Africa, you get a result, and 'it must be what human needs', as people are still alive. It is not a reasoning. To make something that is really realistic for the analysis, one needs to sample a specimen in the wild or in sustainable culture, that is really doing very well. It must be sampled properly, which leaf, and which root. Not old leaves or just random....

Foliar analysis after using a fertilizer or new one can point to a problem, like why is the potassium going down after 3 months, is it normal or not ? Why does it crashes after blooming (low K will eventually induce a total plant crash in Phalaenopsis, chlorotic leaves, becoming reddish, and eventually plant death, that's documented, even in published research) ?

People are scared of leaf or root tissue analysis because it costs money, they have most of the time no clue as to what to do with them, and they could contradict their belief as well. As well, many do not grow enough plants to sample 100g of leaves per test x X test... so better to forget that step.

Looking at the plants is as well something that does not work. Phosphorus deficiency makes beautifully green and compact plants to start with. In fact P deficiency is used to dwarf plants in ornamental production, and give them a dark green lush color... at the beginning. The yellowing and chlorosis will happen later, once they are sold/used. Yet, with a very low P fertilizer, the plants will 'green up' at first for a few months... Where orchids need massive amounts of phosphorus, and it can be proved by analysis of certain tissues ( not the leaves...).

Urea fertilizers of quality are more expensive than nitrate or ammonium-based ones, if you want to be certain there is no phytotoxic biuret inside....

The Japanese use mostly an ammonium/nitrate or full ammonium system ( many use Nitrocote/Molcoat, that are ammonium with some nitrate, others with great plants use MagAmp-K, only ammonium nitrogen...)

sour milk/fermented milk is as well conceptually very good as a nitrogen source, because it contains both ammonium and aminoacids that can be absorbed directly by the plants. I saw some cultures like that in China, the 2 problems were that you need to mix it with streptomycin/tetracyclin every couple of months ( widely available and very cheap in China and Taiwan...), and yes I had to advise nurseries in Taiwan and China, so I saw that...

For what people consider a good culture, and how successful a fertilizer is, well that depends on the standard of culture. I could listen to people that present plants as good as mine ( see my many posts on Facebook as SelectOrchids...), I won't if the plants are yellowish or if the guy takes 7 years to flower a rothschildianum, or 2 for a Phalaenopsis, from flask.

We tried and it works does not exist in reputabled fertilizer companies or larger scale nurseries, whether in Europe, Taiwan or Japan. They have massive stockpiles of trials, metrics, tissue analysis. Even the fertilizer companies usually have a in-house department with analysis standards for specific crops, and advisor to send to their larger customers, who will do... analysis before advising anything. Been there, worked that... Fertilizer components ratios are essential, with some variations, as well as the potting mix current pH, pH when feeding, and residual pH after a couple days, etc...

Most of the obvious failures in orchids, or slow growth, can be traced down as well to a pH issues related to the fertilizers and soil composition.

K-Lite or Calcium Nitrate will be the less worse fertilizers in sphagnum moss as an example, especially Chile one. Why? Because their residual effect will be to tend to raise the pH, which can become too acid in sphagnum. They are not the best fertilizers if you correct the pH of the sphagnum with lime as an example, by far, which is what I advised the Phalaenopsis nurseries in Taiwan to do, and what most are now doing on a large scale. Otherwise they were using a high urea 20-20-20 or 30-10-10 year round in sphagnum and problems appeared after 6-8 months. Now, no more problems, and no more rots due to low pH.

There are many variables, and that's why large companies employ people like me too...
 
Oh...i tried to understand your conversation....i m just a tiny puppy and try to undertstand the "whats" and "whys". First i can tell, i tried k lite.For the first time it seemed to be good, very good. Plants started grow, with many roots. But all my good looking plants died suddenly after cca. 6 months. I stopped it....About K it has inductive effect on blooming and important for bud opening, too. Too less K can cause bud blasting. But too high k can cause too early bud forming from an immature plant. I decided to use the normal 20/20/20 formula. I think too low phosphor is not too good idea too. This is part of dna, rna and adenosin triphosphate too....Ca with S is a very difficult problem because this pair is insolubile. But S however essential, plants dont need too much, only one amino acid from twenties, thiamin contain sulphur. My thought is the best to give it separately from basic fertilizer via a solubile form, eg. mgso4. I use mg with ca as mgnitrate for this reason in my basic fertilizer mix.
I think the truth is overe there but i know , Xavier is growing his plants in rockwool, basalt, it is a fully neutral media without any usable part for plants.This kind of culture is the most appropriate way to test, what our plants need. Best reg. Istvan

p.s.. pH is very important, for plant 5,8 is seems to be right, most of essential ions are soluable at this pH.
I wonder about citric acid, Xavier, most of pathogen bacterias e.g. Erwinia can t grow under 5,5, optimal pH is for erwinia is cca 6,5-7,0. On the other hand citric acid is produced by roots itself. Any expanation?
 
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When we used citric acid to gently lower the pH in stock solution at the first annual/perennial nursery I worked at, that fertilizer line got lined with icky crud that would break free and clog the mist heads :b
 
Oh...i tried to understand your conversation....i m just a tiny puppy and try to undertstand the "whats" and "whys". First i can tell, i tried k lite.For the first time it seemed to be good, very good. Plants started grow, with many roots. But all my good looking plants died suddenly after cca. 6 months. I stopped it....About K it has inductive effect on blooming and important for bud opening, too. Too less K can cause bud blasting. But too high k can cause too early bud forming from an immature plant. I decided to use the normal 20/20/20 formula. I think too low phosphor is not too good idea too. This is part of dna, rna and adenosin triphosphate too....Ca with S is a very difficult problem because this pair is insolubile. But S however essential, plants dont need too much, only one amino acid from twenties, thiamin contain sulphur. My thought is the best to give it separately from basic fertilizer via a solubile form, eg. mgso4. I use mg with ca as mgnitrate for this reason in my basic fertilizer mix.
I think the truth is overe there but i know , Xavier is growing his plants in rockwool, basalt, it is a fully neutral media without any usable part for plants.This kind of culture is the most appropriate way to test, what our plants need. Best reg. Istvan

p.s.. pH is very important, for plant 5,8 is seems to be right, most of essential ions are soluable at this pH.
I wonder about citric acid, Xavier, most of pathogen bacterias e.g. Erwinia can t grow under 5,5, optimal pH is for erwinia is cca 6,5-7,0. On the other hand citric acid is produced by roots itself. Any expanation?
What do you think about the orchids that are supposedly calcareous, like Phrag. kovachii (I know there are some Paphs that may be calcareious)? Do you think it is mostly about wanting more Ca ion or is the higher pH important for various reasons?
 
What do you think about the orchids that are supposedly calcareous, like Phrag. kovachii (I know there are some Paphs that may be calcareious)? Do you think it is mostly about wanting more Ca ion or is the higher pH important for various reasons?
Thank you for the question. I wrote it before on another topic about pH. I think there is an optimal pH for all roots, it is around 5,8, where all of macro,mezo and micronutritients are as soluable ionic form in the solution. If you analyze the ca content of different slippers, it would be the same, so i think this word "calcerous", what is used frequently , not approriate. Imho these plants don t need more ca, but their roots are more sensitive if pH gets lower. Lime or dolomit just acts as a pH buffer in the media that keeps the pH at the optimal level. If you keep a barbata and a brachy in an inert mix, eg rockwool and give them enough ca via the fertilizer solution and always adjust the pH at the optimal level, theye will grow fine both and you wont see difference between them.I would say that there are acid sensitive and acid tolerant slippers, We talk about a narrrow range...acid sensitive roots can damage under 5,0, tolerant roots don t get hurt between 4,2-4,9. But optimal for all is 5,8. This is my just opinion, as i mentioned.
 
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What do you think about the orchids that are supposedly calcareous, like Phrag. kovachii (I know there are some Paphs that may be calcareious)? Do you think it is mostly about wanting more Ca ion or is the higher pH important for various reasons?
Just to add a slightly different perspective and observation about underlying soil strata and orchids/plants, in New England and other areas, (I’m most familiar with New York State ) often many native orchids including slippers will grow in calcareous regions. Some of the zones are very wet, and the closer you get to the arctic circle where the ground doesn’t get hot, the ground can be drier. Many rare orchids grow in the bird preserves that have plants/trees also rare, growing over the limestone. In some pocket fens you can have trees growing in the calcareous muck, but have lots of acidic moss over their roots and cyp acaule has strong acidic need, but it’s growing inches above calcium. Where you have some calcareous zones, with high calcium, it prevents many plants from growing there. But the orchids thrive because they have less competition for light. So, you can have orchids that don’t necessarily need any more calcium, but they do associate with certain plants that can grow in these zones, and they can highly benefit from the calcium reducing overhead light competition.
So, though we may want to scientifically find the need our orchids have for calcium, but it may not be what we are expecting to find. Having someone with very local knowledge of the habitat can help tremendously to unwrap the riddles
 
Looking at it from a materials science perspective, I always have to question the solubility of the minerals (or lack thereof), so wonder just how much they contribute.

Most limestone, after all, is of prehistoric marine origin, so has been around a long time without dissolving.
 
I took a screen shot of the following section from a September 2008 Orchid Digest article by Alfredo Manrique.
kovachii_foliar.jpg
His analysis seems to indicate that Phrag. kovachii takes up/needs more calcium and magnesium. The higher pH of the growing media is from the calcium (and probably magnesium) carbonates. The higher pH would seem to decrease the amount of ionized Ca and Mg. The kovachii roots are probably adapted to these conditions. Could they grow and adapt to lower pH and lower Ca ion availability – maybe. Mine has been very slowly growing with pH under 6.0 without excess Ca and Mg and I think it is time to try something different.

I think I am going to try and increase the pH, Ca, and Mg for kovachii and a few other orchids linked to these high pH conditions. I think everything else can be fine with standard complete fertilizers with a pH centering around 5.8.
 
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Looking at it from a materials science perspective, I always have to question the solubility of the minerals (or lack thereof), so wonder just how much they contribute.

Most limestone, after all, is of prehistoric marine origin, so has been around a long time without dissolving.

Greetings!
I have been lurking and learning, new to all this business of trying not to kill various orchids, and this is my first post.

Sorry, but I am really confused about this idea of insolubility and irrelevance here.
As a person with 'hard water', high amounts of dissolved minerals and alkalinity precisely because of all these age-old rocks--aka mountains--the water travels through to get to me, I am compelled to assert that there is enough of a variable solubility factor in certain geographic areas to contribute significantly as far as I'm concerned.

I recently read this '22 paper
1705268365050.png

in which P. fairrieanum is stated to thrive in 'soil' with pH 7.3 to 8.0 and soil moisture measurements were a shocking 1.4 to 2.5%!
1705267906348.png
Interesting.
Granted, I'm uncertain what this means for me in my attempt to grow this plant...if only I had more moderate temperatures I might be inclined to plant on the side of the cliff I live on in similarly alkaline substrate.
 
Mmmh just in short for the kovachii:

- When we see the photos in the habitat, there is a lot of moss, possibly growing on top of limestone or calcite... That's where the roots are, not in the rocks...
- The analysis shows that they used leaves that were very old, which is a common mistake. The N and K are very low, because they were recycled... Ca is much less mobile, Mg is partially mobile, that's why we have those results, but they have no meaning...

It is a common mistake of many 'scientific' papers. To not harm the plant, they take the oldest leaves in the wild to sample. A proper sampling would be complete adult, mature leaves from the new growth.... which most people won't take for sure. If you take these, the results are vastly different.

I am certain that Manrique, when he got his permit to collect kovachii, did not snap off the mature ready to bloom growths to make analysis...

For the fairrieanum, back to when they were coming as wild plants in the 90s, the roots were not covered in limestone as the paper could suggest. They had fern and other plant roots attached, and a lot of organic decomposing matter... Again, if you sample the rock below, you get crazy numbers. I have seen that with hangianum in Vietnam too....

The key is to know what they have around the root system, not what is below. If you grow a phalaenopsis in pot on top of a marble table, you won't assume they need very high pH and lots of calcium...

For the moisture content of the soil, it is possible during the dry cold season they experience. But it has no meaning after all... Another mistake is to dissolve the samples with acid to make the analysis, then you always get crazy high levels of calcium if you analyze that. The same as dissolving marble chips in acid, then claiminig that's what is available at the roots...

-
 
Mmmh just in short for the kovachii:

- When we see the photos in the habitat, there is a lot of moss, possibly growing on top of limestone or calcite... That's where the roots are, not in the rocks...
- The analysis shows that they used leaves that were very old, which is a common mistake. The N and K are very low, because they were recycled... Ca is much less mobile, Mg is partially mobile, that's why we have those results, but they have no meaning...

It is a common mistake of many 'scientific' papers. To not harm the plant, they take the oldest leaves in the wild to sample. A proper sampling would be complete adult, mature leaves from the new growth.... which most people won't take for sure. If you take these, the results are vastly different.

I am certain that Manrique, when he got his permit to collect kovachii, did not snap off the mature ready to bloom growths to make analysis...

For the fairrieanum, back to when they were coming as wild plants in the 90s, the roots were not covered in limestone as the paper could suggest. They had fern and other plant roots attached, and a lot of organic decomposing matter... Again, if you sample the rock below, you get crazy numbers. I have seen that with hangianum in Vietnam too....

The key is to know what they have around the root system, not what is below. If you grow a phalaenopsis in pot on top of a marble table, you won't assume they need very high pH and lots of calcium...

For the moisture content of the soil, it is possible during the dry cold season they experience. But it has no meaning after all... Another mistake is to dissolve the samples with acid to make the analysis, then you always get crazy high levels of calcium if you analyze that. The same as dissolving marble chips in acid, then claiminig that's what is available at the roots...

-
Roth, ignore the foliar analysis. How do you assess the “soil” analysis by Manrique? Do you think that indicates a higher pH/higher Ca medium for growth? Or, do you think that in pure LECA (Hydroton) receiving intermittent fertigation from the top that a pH of 5.8 solution with 80 ppm Ca would be good?
 
Roth, ignore the foliar analysis. How do you assess the “soil” analysis by Manrique? Do you think that indicates a higher pH/higher Ca medium for growth? Or, do you think that in pure LECA (Hydroton) receiving intermittent fertigation from the top that a pH of 5.8 solution with 80 ppm Ca would be good?
Well that's the problem as well... With the fragments we have of the analysis, there are a couple problems, and we cannot rely on it for certain. Actually they are kind of useless...

Organic matter at 1.7% suggests that there will be acidity around the roots that are in that, a little bit buffered by the CaCO3, which I suspect to be the rock below...

The EC of 0.4 does not match the numbers as well, and there should not be much, if at all, calcium available ( except if the roots extract it by contact), at a pH of 8 for CaCO3...

The solubility of CaCO3 at a pH of 8 would be inferior to 1mg/L, in fact in the few micrograms per liter, so, except the calcium dissolved by the organic matter, and/or the calcium dissolved by the roots organic acid, which we don't know, we can say:

The said soil has absolutely no calcium whatsoever available...

I usually base dress with dolokal regularly, as I use a feed that is heavily acidifying, and it is amply enough for kovachii. I made leaf mineral analysis of kovachii, very well grown for years, and the numbers are really off the published analysis...

The same applies for a fairrieanum growing in moss on limestone. Limestone + pH of 7 to 8 = zero calcium available, except through acidivicaation by the organic matter or extraction by the roots...
 

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