Fertilizer discussion

gonewild said:

Wonder why recommendations have been to use excessive amounts of nutrients?

Most fertility trials have been done or funded by chemical companies so what can we expect?.

More is better? :rollhappy:

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I brought this up initially and one should note that 99% of fertilizer trials and plant research in general is conducted on domesticated plants being grown for food. And even the bulk of that is corn, wheat, and rice. The first strong clue I found on K antagonism was actually a paper on rice physiology.

Yes dollars are a motive, but primarily at the crop (food production) end.

If you Google for info on plant nutrition and fertilizer use you get virtually nothing on orchids. The few bits and pieces you get are done for mass hybrid culture for the bloom and toss market. Virtually all the focus goes into food crops. Ex situ orchid nutrition has mostly been piggy backing on the cut flower market, which has been piggy backing on the food crop science. Granted it hasn't been a total bust by the time it filtered down to orchid culture, but it looks like the "orchids are corn" assumption has its shortcomings.

To get down to the insitu orchid data took some pretty serious digging since these are almost purely academic science articles. Getting $ for serious jungle research is a battle.

Rick and Ray - using K-Lite at 50 ppm N means a reduction in "strength" of the other nutrients as well. I also periodically monitor the effluent from watered pots and don't let it get over 0.5 (forgetting the units). There should still be enough of trace elements with this approach? Also, because Ray said that KelpMax has some potassium, I have been reducing the K-Lite to about 35 ppm N during the weeks I use the KelpMax. Does this risk trace element deficiency during this period? I grow in pure sphagnum so I suspect the answer is "no" and I am not seeing any signs of deficiency in any leaves.


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Just my two cents Terry, but I don't think we have any definitive data on what constitutes a deficiency, adequacy, or excess for orchids with most nutrients - probably less so on the trace elements.

Tissue data shows the accumulation of nutrients, but tells little, if anything, about how rapidly they must be taken up, or what the "right" level is. Likewise, sampling of the microcosm the plants live in tells us what-, and how much (or little) is there, but says nothing about the demands of the plant.

If we look at the K-Lite formula, applied at 50 pm N, this is what we're contributing:

N 50 ppm
P2O5 5
K2O 5
Ca 39
Mg 12
Fe 445 ppb
Mn 310
Zn 310
Cu 155
B 116
Mo 78

I infer that your best guess is that there is still enough of everything at 50 ppm N (and maybe even lower), meaning that we probably give an excess of everything when we feed most complete fertilizers at 100-150 ppm N.


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terryros said:

I infer that your best guess is that there is still enough of everything at 50 ppm N (and maybe even lower), meaning that we probably give an excess of everything when we feed most complete fertilizers at 100-150 ppm N.


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There is a handful of leaf litter and throughfall data from rain forests, and typically we feed at orders of magnitude higher than what orchids see in the wild.

The breakdown of your moss over time, trace metals in kelp, and trace minerals in tap water is adequate for supplying the trace goodies without the use of fertilizer input. So shifting everything down proportionately around N calculation should leave you with plenty of trace metals from K lite or MSU.

terryros said:

I infer that your best guess is that there is still enough of everything at 50 ppm N (and maybe even lower), meaning that we probably give an excess of everything when we feed most complete fertilizers at 100-150 ppm N.


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Yes, and I assure you is is only barely more than a guess. I've done some research, but there is so much conflicting information in general - and so little that pertains to epiphytes - that it's hard to know what is factual and applicable.

I think Dodiodoki's thread looking for the magic ingredient (from mycorhhizae fungus) for selenpedium is illustrative of how things go in this world.

We find some species that can't take the typical conditions we impose on them from the commercial annual cut flower trade. We assume that we are missing a rare and secret ingredient since the plant we are working with is rare and comes from a secret habitat that we have little access too.

But instead of looking for something fundamental we turn to commercial cut flower trade data to avoid trying something new and continue on with our quest for micro magic secret ingredients.

Rick said:

I think Dodiodoki's thread looking for the magic ingredient (from mycorhhizae fungus) for selenpedium is illustrative of how things go in this world.

We find some species that can't take the typical conditions we impose on them from the commercial annual cut flower trade. We assume that we are missing a rare and secret ingredient since the plant we are working with is rare and comes from a secret habitat that we have little access too.

But instead of looking for something fundamental we turn to commercial cut flower trade data to avoid trying something new and continue on with our quest for micro magic secret ingredients.

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Reading after bacterial cellular building-up I found some interesting point.
Bacteria ang fungi have very fast metabolism. The main intracellular component is K+ ions. Of course they need others, N, P, etc.
Paphs are slow organism, they have very slow metabolism, so they need only a little, but continous feedeing.
Maybe K lite works because of that but I think that based on this theory very important keeping all nutritients at low concentration ( what is enough for a paph but not enough for pathogenes). As you wrote, max. 150 ppm all in water, measuring outflow TDS to avoid higher cc. in pot.

cnycharles said:

I still think that the klite will need a little more phosphorus, or at least with some species that grow/spike very quickly these plants (not just orchids) usually do better if they have more phosphorus. I know many have been debunking the 'phosphorus is needed for flowering' thing that was promoted for years, but of course klite has a relatively tiny amount of phosphorus compared to the balanced ferts; also there is a minimal amount that is necessary, and as was mentioned earlier in the thread, more (lots more) doesn't mean better

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I keep wondering why this formulation is called K-lite when it is as low in phosphorus as it is in potassium. It would be more accurate to call it PK-lite.

gonewild said:

Wonder why recommendations have been to use excessive amounts of nutrients?

The best way to sell fertilizer is to recommend a application rate double what is needed in reality. the difference between one tsp per gallon and one half tsp per gallon does not seem like much, but to the chemical company it is double sales volume. Most fertility trials have been done or funded by chemical companies so what can we expect? Results are interpreted and skewed towards more profits.

More is better? :rollhappy:

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Yep, those farmers are a bunch of credulous simpletons.

Ray said:

I'm right there with you, Rick.

I recall hearing of a trial at a large seed producer that showed symptoms of an immense iron deficiency in corn, when in reality, it was an overdose of phosphorus!

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Heh, what a bunch of simpletons.

DavidCampen said:

I keep wondering why this formulation is called K-lite when it is as low in phosphorus as it is in potassium. It would be more accurate to call it PK-lite.

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The old MSU fert was already pretty low in P, and the shift away from standard MSU to K lite was to significantly reduce the K while increasing Ca/Mg.

K lite is just a simple shorthand for how the MSU mix is modified.

Rick said:

The old MSU fert was already pretty low in P, and the shift away from standard MSU to K lite was to significantly reduce the K while increasing Ca/Mg.

K lite is just a simple shorthand for how the MSU mix is modified.

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Yes, but the K-lite is even lower in P than the MSU is.

The MSU-RO formulaton is 13-3-15-8-2 (N-P2O5-K2O-Ca-Mg)
K-Lite is 12-1-1-10-3

So K-lite has reduced phosphorus 3 fold from the MSU-RO formulation, potassium 15 fold, and increased Ca 25% and Mg 50%.

So yes, MSU-RO is unusually high in potassium (though I don't think that it is 15 times too high) but the amount of phosphorus in MSU-RO is already low, what was the motivation for reducing phosphorus another 3 fold?

Also, neither formulation lists sulfur. Is sulfur not considered important!?

https://www.aos.org/Default.aspx?id=417
https://www.firstrays.com/cgi/cart/...product=Chemicals!Nutrition&pid=219&keywords=

DavidCampen said:

So K-lite has reduced phosphorus 3 fold from the MSU-RO formulation, potassium 15 fold, and increased Ca 25% and Mg 50%.

Also, neither formulation lists sulfur. Is sulfur not considered important!?

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I would get hand cramps if I had to write low p low K high Ca and high Mg every time I wanted to refer to the basic K-lite product (that you found and examined the NPK Ca Mg label for)

I really don't consider the drop in phosphorus as significant compared to the decrease in K. Looking at the jungle data, the amounts of total fert we apply to orchids is orders of magnitude more than they would see in the wild. The amount of P (1% or 3%) is still more than enough to get the job done.

We ain't growing corn here.


There are sulfate salts in both MSU and K lite, but I think they will only show up in the raw ingredients list. Some sulfate is important. Most surface waters have tons of it, so if you add a pinch of most household waters to you RO you'll get plenty.

Rick said:

I really don't consider the drop in phosphorus as significant compared to the decrease in K. Looking at the jungle data, the amounts of total fert we apply to orchids is orders of magnitude more than they would see in the wild. The amount of P (1% or 3%) is still more than enough to get the job done.

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But an argument that you make (and to which I somewhat agree) is that it is not so much the amount as the ratio.

There are sulfate salts in both MSU and K lite, but I think they will only show up in the raw ingredients list. Some sulfate is important. Most surface waters have tons of it, so if you add a pinch of most household waters to you RO you'll get plenty.

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Here I disagree, in my opinion sulfur ratios should be much more than for iron and possibly closer to 1:1 with the magnesium. A pinch of tap water isn't nearly sufficient.

DavidCampen said:

B
Here I disagree, in my opinion sulfur ratios should be much more than for iron and possibly closer to 1:1 with the magnesium. A pinch of tap water isn't nearly sufficient.

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it depends on where you get your water from; some places the water is pretty stinky, so 'just a little dab 'll doya'

how much sulfur do you think should be available for orchids? just politely curious. but, you also mention that you think the ratio is maybe more important than just a volume; so what ratio of sulfur to magnesium or whichever do you think would be acceptable for orchids?

I had also thought that maybe the klite had gone too far down in the amount of phosphorus, because of pot plant needs when they are quickly flowering/branching (like mums); these need to have more when flower structures will be growing quickly/large.... but some of that concern was just because standard hort/flower fertilizers often had so much phosphorus in them, that that little number 1% (in klite) just seemed too low. but, from the discussion, who really knows how much orchids need, and maybe even the 1% is more than enough if freely available

cnycharles said:

how much sulfur do you think should be available for orchids? just politely curious. but, you also mention that you think the ratio is maybe more important than just a volume; so what ratio of sulfur to magnesium or whichever do you think would be acceptable for orchids?

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15-5-10-10-2.5-2 : N-P-K-Ca-Mg-S I think is a good ratio.

I gave the values for my most recent batch in a thread here yesterday, from memory I think it was:
15-10-10-8-2-0.5

Here it is:
N-P-K-Ca-Mg-S ratio of 14.6-10.4-11.4-9.5-2.4-0.5 with a nitrate/ammonia ratio of 4.3/1.
http://www.slippertalk.com/forum/showpost.php?p=403192&postcount=16

okay, thank you. I zipped over some of the numbers too quickly before

DavidCampen said:

15-5-10-10-2.5-2 : N-P-K-Ca-Mg-S I think is a good ratio.

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Why? It's really no different from what orchid growers have been using the last 100 years, and getting nowhere. What's the advantage of the above over standard MSU?

K lite wasn't put together randomly last year as something we thought would be fun to do. It was a project spurred by obvious shortcomings in long term orchid culture. The basis of it was a comparison between what's being used presently in the agricultural community (including the ornamental flower bussiness), and what the nutrient flux is in the jungle.

Then some of us have been testing this for about 2 years now (with great results). There are over 90 users world wide now (K lite came out last November/December), and most of these users are also seeing improved results over their old balanced versions or MSU knock offs. So no point in changing the formula to something that's readily available from the local garden center. It works as is.

Rick said:

Why? It's really no different from what orchid growers have been using the last 100 years, and getting nowhere. What's the advantage of the above over standard MSU?

K lite wasn't put together randomly last year as something we thought would be fun to do. It was a project spurred by obvious shortcomings in long term orchid culture. The basis of it was a comparison between what's being used presently in the agricultural community (including the ornamental flower bussiness), and what the nutrient flux is in the jungle.

Then some of us have been testing this for about 2 years now (with great results). There are over 90 users world wide now (K lite came out last November/December), and most of these users are also seeing improved results over their old balanced versions or MSU knock offs. So no point in changing the formula to something that's readily available from the local garden center. It works as is.

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My statement stands.

"using for the last 100 years and getting no where"
You are talking like its only since klite that people have been able to keep orchids alive. That is not correct. Perhaps cypripediodeae have some special needs but with laeliinae and catasetinae and various other genera that I grow I don't see what the problems are that would be cured by klite. And really, I don't see why potassium should be so toxic to cypripediodea, the half dozen that I have seem not to have been harmed by the more conventional K ratios.