'What Orchids Eat', importance of calcium

[Jayfar]

[Ray]

The basis of that certainty, David?

I was actually referring to the plant tissues, but I recall reading of the media too, as we're talking ionic radii in aqueous solutions, in which those of Mg and Ca are 2x-3x that of K.

[DavidCampen]

Originally Posted by Ray

I was actually referring to the plant tissues,

You said "Potassium binds very well and preferentially (compared to calcium and magnesium) ... with potting media"
Are you now saying that you did not intend to make that statement?

[POLKA]

Originally Posted by DavidCampen

So you are saying that your statement that "Potassium binds very well and preferentially (compared to calcium and magnesium) ... with potting media" was just speculation that is probably wrong? I would go farther and say that that statement is almost certainly wrong.

David,
I seem to be able to follow Ray. So why is it wrong?

Rex

[Ray]

Yes David. I misread your original response.

I think my last one clarified that.

[DavidCampen]

Originally Posted by Ray

Yes David. I misread your original response.

I think my last one clarified that.

So, do we agree that potassium ion does _not_ bind to potting media in preference to calcium ion or magnesium ion?

[Ray]

No, I don't agree.

While I have no references on that specific subject - it is SO difficult to find specific info relating to orchids only - my understanding of the underlying chemistry tells me that when exposed to a solution bearing equal concentrations of the three ions, the K will be more readily captured.

How's the popcorn, Jay?

[Jayfar]

Originally Posted by Ray

How's the popcorn, Jay?

Nutrition Facts and Analysis for Snacks, popcorn, oil-popped, unsalted

Foods highest in Potassium and Magnesium and Calcium, and lowest in Sodium
(based on levels per 100-gram serving)

Read More Foods highest in Potassium and Magnesium and Calcium, and lowest in Sodium in Snacks
1 Snacks, popcorn, oil-popped, unsalted
Potassium: 225mg Magnesium: 108mg Calcium: 10mg Sodium: 3mg


Read More Foods highest in Potassium and Magnesium and Calcium, and lowest in Sodium in Snacks

[isurus79]

Originally Posted by tucker85

When I read the article ‘What Orchids Eat’ by Rick Lockwood, two points I took away from it were that calcium is a very important mineral for growing healthy orchids and that potassium blocks the uptake of calcium. I realize he was talking about the possible long term toxicity of excess potassium

So does this mean you will be getting rid of your bloom boosters?

[King_of_orchid_growing:)]

Ok, I'm gonna post this video, and hopefully it will shed some light into the role of potassium and what potassium deficiency does. It does not talk about orchids specifically, but it does explain a little bit of what potassium's role in plants is.

Potassium Deficient Corn and Soybean During Drought - YouTube

I'd like to also post this video of an aquarium hobbyist because he had a massive problem with potassium deficiency in his aquarium. This guy took the time to figure out his problem and he solved it:

Potassium Deficiency - YouTube

I think these 2 videos are very pertinent to what we're talking about in order to understand the role of potassium in plants, and that at no point in time should they be deprived of potassium. Potassium deficiency causes severe long term damage. And from these 2 vids, that is extremely clear.

I also found this article from the Univ of Hawaii talking about K+, Ca2+, and Mg2+:

Soil Management

Again, while it doesn't talk about orchids specifically, it does talk about the ions to some degree. Do understand that this article might be simplified in order for many people to understand it better. However, I just feel that it gives us a better ground basis to work off of.

---------- Post added at 07:50 AM ---------- Previous post was at 07:33 AM ----------

Look guys, I can't currently find any evidence that is able to support the idea of potassium toxicity in plants.

I'm not saying that it can't happen, but as of right now, all I'm seeing is tons and tons of evidence that support plants take up a lot of K+.

I have, however, found this article, but it isn't free. It is in regards to K+, Ca2+, and Mg2+ balance. So if anyone is willing to pay for the article and explain its contents, then by all means, go for it.

https://dl.sciencesocieties.org/publ...0/AJ0390100887