# Urea as fertiliser



## Bjorn (Sep 7, 2011)

I have always used non-urea fertilisers for my orchids and have been quite content with the results. With a few exceptions. Amongst them a PEOY NFS that has been hanging there without much growth and with a rather pale appearance. I have tried several things like calcium and magnesium nitrate additions etc, but it did not green up. Then I thought: " What the h... lets try Urea, its commonly used as foliar feed so why not make a try?" Ok, I had some pure urea in a canister, dissolved 10g into a liter of water(1%) and started with a slight spray on the surface of the leaves. Not enough to moisten evenly and far from dripping. Covered the rest of the plants as well - again very slight. Voila! next day (or two days later) everything had greened up, the PEOY the most, from yellowish green to more like grass-green. The rest of the plants in my mixed collection of 500plants+(?) also seemed more shiny and darker green. It was like magic. It even seems to have accelerated growth a bit (this I am sceptical to though)?:clap:
I will definitely start to include Urea in my fertilisers from now on, possibly in the water, but definitely as additional foliar feed.
Any comments or other experiences?
P.S. unfortunately no pictures available- well "after" is possible but without "before" its hardly convincing:evil:


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## gonewild (Sep 7, 2011)

The result you saw is not from the "quality" of Urea. The result is because the plant finally got enough nitrogen and that indicates that you have not been applying enough with your regular routine. Either you have been using too weak of a solution of not applying often enough.

Urea is not a good choice to include in fertilizer for orchids.


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## Marc (Sep 7, 2011)

I don't claim to be an expert but for each and every study that states that urea isn't good for orchids there is a study that says it is.

So I personally can't judge about urea. I personally use a Peters fertilizer ( 21-7-21 + 3%MgO ) of which the N parts is partially Urea based nitrogen and I'm happy with it.


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## NYEric (Sep 7, 2011)

I'll just piss on my plants from now on! :evil:


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## Brabantia (Sep 7, 2011)

Marc said:


> I don't claim to be an expert but for each and every study that states that urea isn't good for orchids there is a study that says it is.
> 
> So I personally can't judge about urea. I personally use a Peters fertilizer ( 21-7-21 + 3%MgO ) of which the N parts is partially Urea based nitrogen and I'm happy with it.



As I have already explained, when I visited a great Vanda producer in Holland in the technical room I saw many many bags of Peters 20-20-20 and few bags of Calcium nitrate. I must add that they cultivate at high temperature (28 °C 80°F) and that urea is a cheap nitrogen source. 
I believe that temperature is the limiting factor for urea and organic fertilysers use for orchids culture in temperate countries… except in "very" heated greenhouses for commercial productions.


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## gonewild (Sep 7, 2011)

Brabantia said:


> As I have already explained, when I visited a great Vanda producer in Holland in the technical room I saw many many bags of Peters 20-20-20 and few bags of Calcium nitrate. I must add that they cultivate at high temperature (28 °C 80°F) and that urea is a cheap nitrogen source.
> I believe that temperature is the limiting factor for urea and organic fertilysers use for orchids culture in temperate countries… except in "very" heated greenhouses for commercial productions.



Probably for Vandas with their extensive dependence on atmosphere moisture Urea would work well since almost all of the Nitrogen from urea is quickly released into the air in gas form. Vandas probably suck it up but for other orchids and plants grown in media in pots it is not the best choice.

It is a good choice for the fertilizer makers because it is a cheap source of Nitrogen to put into the bag. For growers it is a poor choice because so much of the Nitrogen never reaches the plants and thus a waste of money.


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## SlipperFan (Sep 7, 2011)

I've heard that urea needs microorganisms in soil to break it down to be useful, and that's why it's not a good choice for orchids. Is that true?


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## gonewild (Sep 7, 2011)

SlipperFan said:


> I've heard that urea needs microorganisms in soil to break it down to be useful, and that's why it's not a good choice for orchids. Is that true?



Not True.

The Nitrogen in Urea rapidly turns into Ammonia gas in soil. 
Ammonia gas inhibits soil microbs. 
Ammonia gas can damage sensitive roots.

Urea is designed for use on field crops.

Why use this on orchids when there are better choices?


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## gonewild (Sep 7, 2011)

Google search found this....
http://www1.agric.gov.ab.ca/$department/deptdocs.nsf/all/faq7758


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## SlipperFan (Sep 7, 2011)

Thanks, Lance. Clears that myth up for me.


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## Rick (Sep 7, 2011)

It may also be useful that the toxicity of ammonia is pH based. It is highly toxic at pH's above 7.8. Below pH 7 toxicity (if you could call it that) goes way down. This is true even for bacteria species that "eat" ammonia.

So in Bjorn's case it may not be unlikely that pot pH had dropped lower than a good optimal to pick up N from nitrate, but able to pick it up from ammonia. 

It's also not inconceivable that a significant shot of ammonia could have altered the pot pH and released a bunch of pent up nutrients.????

So many variables!!!


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## Bjorn (Sep 8, 2011)

Obviously none of you got it right Ok lets make it more precise:
The Urea application never, never, NEVER got into the soil, just as a slight spray, drizzle, not enough to wet the leaf surface. And there it rested. Over night the changes to green appeared. Please note, there was no watering or spraying or misting going on during that time. I know what I say is contrary to common "knowledge" but if it works and there are no other variables in the experimental set-up, my scientific education has told me to believe in the observations and look for mechanistic explanations to the observations.
Ok this was not a planned and controlled experiment with double blinds etc. but there was a change in the plants, it was quick (in hours), it had nothing to do with soil and it happened after I sprayed with a 1% solution of Urea p.a. in pure water (rain).:rollhappy:
I have done some googling on the issue and it turns out that used as foliar feed urea is not dependent on urease to enter the leaf(in potatoes), and it is quick-a few hours is enough. It is further claimed that it makes absorption of other nutrients easier. Urea might not be the best nitrogen source for generalised fertilising(through soil) but it seems to be the best for leaf-application. And its not a salt and does hence not burn tissue easily. The below link should be interesting to those that are interested in this issue, it contains quite a bit of info.
http://forums2.gardenweb.com/forums/load/orchids/msg032222191547.html
Those of you that uses Peters 20-20-20 already add some urea, Personally I think that I will stay with my base fertiliser (urea free) and supply with an Urea based foliar feed that i have come over. Its rich in most necessary elements incl. micro. 
And yes Rick, I do follow you regarding potassium, I do think it is important to reduce it and increase Ca (and Mg) so I add both to my standard feed. 
One thing, as Calcium nitrate tends to react with concentrated fertilises it should not be mixed into the stock solution. It can however be mixed into the diluted water e.g. at the nozzle. I found that magnesium sulphate may be added directly to my stock solution without problems at a rate of 20% (2%Mg). Its best to make a test, take some stock solution and add epsom salt and look for precipitation/haze. If its stable for some days its ok.
In my set-up, I use a 10% fertiliser solution(with epsom salt) hooked up on a Dosmatic that dilutes 1:500. That gives a 200ppm nutrient solution. On the end of the hose I have one of those cheap injectors and here some 200ppm Calcium Nitrate is added as well. (Its actually some 40ppm Ca in the mix). The total mix coming out of the hose is around some 400ppm containing 90ppm N, 10ppm P, 40ppmK, 40ppmMg, 53ppmCa + S and micro. Numbers are approximate
This is in all water btw. and still that Urea application had such an effect.


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## gonewild (Sep 8, 2011)

I understood that you applied it as a foliar application. I still stand by my statement. The reason you saw a rapid "greening" of the foliage is because the plants were low on nitrogen. If you had been applying adequate nitrogen regularly you would not have seen a rapid response to the sudden availability of Nitrogen.

I always foliar feed my plants by drenching the plants with whatever fertilizer solution I'm using. Foliar applications are very beneficial for most nutrients not just Nitrogen.



> In my set-up, I use a 10% fertiliser solution(with epsom salt) hooked up on a Dosmatic that dilutes 1:500. That gives a 200ppm nutrient solution. On the end of the hose I have one of those cheap injectors and here some 200ppm Calcium Nitrate is added as well. (Its actually some 40ppm Ca in the mix). The total mix coming out of the hose is around some 400ppm containing 90ppm N, 10ppm P, 40ppmK, 40ppmMg, 53ppmCa + S and micro. Numbers are approximate



Have you actually measured the ppm coming out of your hose at 400ppm?

I'm having a little trouble following your math, maybe I'm getting a little old? in your 400ppm mix you account for 233ppm, what does the other 167ppm consist of?

In your nutrient ratio you have the answer as to why the Urea greened up your plants..... 90ppm Nitrogen is not enough. It it were enough then the plants would not have changed so dramatically with the Urea application. You could easily double the Nitrogen ppm's in your nutrient ratio.


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## Paul (Sep 8, 2011)

one other possibility (to study) is that urea is better assimilated by Paphs than N03- form...


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## Justin (Sep 8, 2011)

please tell more about calcium nitrate reacting with fertilizer?


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## Bjorn (Sep 9, 2011)

Lance, I do follow you in saying that somehow the plants were deficient in N if they green up by N addition. My point is how quick it is and the effect overwhelmed me. Even plants growing like weed changed significantly - over night- getting much greener and shinier.It seems to work a little like that stuff housewifes spray on plants to meke them shine "leaf-gloss" or whatever its called. Well it had that effect - and over night. And without any of the stuff getting into the soil. Truly amazing. Whether that is something to aim for is another thing, to me its a bit like putting the plants on steroids - but I like it:evil:.
About the missing ppm: Firstly a disclaimer: My numbers are approximate. Then the reason for the deviation: Over here(Norway, Europe), NPK is given as the elements Nitrogen-Phosphorous-K(potassium): in USA (could be all English-speaking countries for what I know?) and some other places its actually as the oxides: N-P2O5-K2O even if they write NPK.
So my 90-10-40 European NPK is 90-23-48 US NPK. Its confusing, right? You have to take the molar weight of the individual components into consideration doing this transformation. Accordingh to my calculation the factor becomes 0.83 to transform K to K2O and 0.43 for P to P2O5.
Then: Mineral fertilisers are mostly mechanical mixes of water soluble salts of the desired cations like potassium K+, magnesium Mg2+, and Calcium Ca2+. Since these cations are positively charged you also need a counter-charge or anions which are negatively charged. In fertilisers, primarily nitrates (NO3(-)), sulphates (SO4) and phosphorous (mostly as phosphates due to higher solubility PO4(3-).
Nitrogen can be present as ammonium NH4+ or nitrate NO3- (lets forget nitrite its poisonous)and possibly urea that is not a salt but an organic molecule
Suphur mostly as suphates SO4(2-)
Phosphor mostly as phosphate (PO4(3-)
And there are all the other ingredients that make up the fertiliser mix. like borates molybdates etc all containing oxygen.
All this oxygen is not accounted for in the NPK and that is the main reason for not getting to 100 if you start counting ppm's. Take 100g Potassium nitrate (KNO3)as an example. 100g dissolved in 100liter gives 100/100000 =1000ppm These 1000 ppm becomes : 13,9N + 38,7K (46,6 in US)+ 47,4 O
So when you sum up my ppm to 233 out of 400 (=41,8% missing), you get pretty close to the result using potassium nitrate above(47.4% Oxygen) Using other oxygen bearing substances than potassium nitrate makes things more complicated and explains the deviation.
Then Calcium: When salts are dissolved in water they are broken up to cations and anions. The cations are positively charged and are typically metals like K, Mg, Ca, the anions are negatively charged and are typically of non-metals like Nitrogen and Oxygen and Sulphur or Phosporous etc. Ok, the solubility of salts are variable and the least soluble combination tends to precipitate if two solutions are mixes. So in the case of mixing calcium nitrate that has a solubility of more than 100g/100g water (as hydrate) with Potassium sulphate that dissolves 12g/100g water, what happens if you mix equal amounts of say 10% solutions (10g salt in 100g liquid)?
the total volume gets 200ml and the individual concentrations of calciumnitrate and potassium sulphate becomes 5% each. So far so good???
NO! Since calcium sulphate has a solubility of less than 0.2g/100g water, most of the calcium together with suphate will precipitate and get lost as fertiliser. The solubility of calcium sulphate is still some 2000ppm, so it does not precipitate if it is added as calcium nitrate at the nozzle, or for that sake in the bulk volume of water. BUT you cannot mix it in a stock solution.:evil:
This treatise was a bit simplified, if any out there discovers my shortcuts then bear over with me, but its not that easy to popularise the stuff.
If you have questions regarding these things then do not hesitate to ask.


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## Ozpaph (Sep 9, 2011)

Can a paph (or any plant) absorb nutrients and make enough chlorophyll to noticeably 'green up' the leaves in 24hr?


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## Bjorn (Sep 9, 2011)

Might have been 48hours but it was an amazing effect. I would say perhaps visible after 24 hours, but after that, repeated application made a hughe difference. Makes me wonder whether the roots of my paphs get to the N i fertilize with in the regular fertiliser? The roots does look ok though?


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## Ray (Sep 9, 2011)

Bjorn said:


> Over here(Norway, Europe), NPK is given as the elements Nitrogen-Phosphorous-K(potassium): in USA (could be all English-speaking countries for what I know?) and some other places its actually as the oxides: N-P2O5-K2O even if they write NPK.
> So my 90-10-40 European NPK is 90-23-48 US NPK. Its confusing, right? You have to take the molar weight of the individual components into consideration doing this transformation. Accordingh to my calculation the factor becomes 0.83 to transform K to K2O and 0.43 for P to P2O5.


While your conversions to the oxides are right, the numbers are weight percent, not PPM, so those formulas are impossible.


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## Bjorn (Sep 9, 2011)

Ray, I might misunderstand you, as you know, English is not my native language and this time I feel uncertain.
Sure, I was inprecise, but I think most got the point. Peters 20-20-20(US) would have been labelled 20- 8.6-16.6 over here. On the other hand; people should remember that 1 ppm is the same as 0.0001%. Just saw that the Wellensteins have treated this quite extensively so I stop here(http://www.ladyslipper.com/minnut.htm) There is a lot of good things written on their pages.  The fertiliser issue is well described and I would suggest that anyone having questions lookup their pages.


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## gonewild (Sep 9, 2011)

Bjorn said:


> Lance, I do follow you in saying that somehow the plants were deficient in N if they green up by N addition. My point is how quick it is and the effect overwhelmed me. Even plants growing like weed changed significantly - over night- getting much greener and shinier.It seems to work a little like that stuff housewifes spray on plants to meke them shine "leaf-gloss" or whatever its called. Well it had that effect - and over night. And without any of the stuff getting into the soil. Truly amazing. Whether that is something to aim for is another thing, to me its a bit like putting the plants on steroids - but I like it:evil:.



:clap: If you like what you see then that is a win!

But I think it might be more like putting the plants a sugar diet rather than steroids. Excess Nitrogen makes leaves dark green, bigger and shinny. All that equals a more attractive plant, but long term effect is not good. That is unless you continue to like what you see! :evil:




> About the missing ppm: Firstly a disclaimer: My numbers are approximate. Then the reason for the deviation: Over here(Norway, Europe), NPK is given as the elements Nitrogen-Phosphorous-K(potassium): in USA (could be all English-speaking countries for what I know?) and some other places its actually as the oxides: N-P2O5-K2O even if they write NPK.
> So my 90-10-40 European NPK is 90-23-48 US NPK. Its confusing, right?



No not at all confusing. What were we talking about? oke:

Thanks for the explanation I did not know the ratios had different values with other languages. More important than the percentages or ratios is that the plants have the nutrients they need when they need them.

Regardless of the ratios It is still my opinion that the use of Urea on potted plants will likely lead to a sudden problem at some point. I'm not talking about when used in commercial mixes like Peters but rather Urea on it's own. If you want to see some beautiful foliage pile on some blood meal and see what happens. It contains the perfect balance to green up leaves but it does smell a lot on a hot day!

Keep us informed about how your plants are doing with continued Urea use, maybe I'll change my opinion if you have continued success.


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## Rick (Sep 9, 2011)

Justin said:


> please tell more about calcium nitrate reacting with fertilizer?



"reacting" may not be an accurate way to put it. Calcium nitrate is hygroscopic (it wants to absorb water) and will turn into a big gooey mess if you add a bunch of it to your fertilizer in a granular fashion.

So, like Bjorn indicated, I dissolve it separately in a cup of water and add it to the rest of the fertilizer mix. after it has been dissolved.

Actually I add in step to water:
1) the Mag sulfate (stir until dissolved). It tends to be slow but not as stupid slow as messing with calcium sulfate (gypsum).
2) the Calcium nitrate (in the same cup as the dissolved Mag sulfate), the calcium nitrate will dissolve in just seconds anyway.
3) add in the rest of whatever fertilizer in whatever form. I also add a kelp extract which acts like a chelator with the cations (keeping them soluble).


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## Rick (Sep 9, 2011)

Ozpaph said:


> Can a paph (or any plant) absorb nutrients and make enough chlorophyll to noticeably 'green up' the leaves in 24hr?




Can't vouch for 24 - 48 hours, but I've seen fast improvement of less than a week with Epsom salt addition for "greening up".

Magnesium is very labile through plant tissue, and since it is the core atom in chlorophyl it is crucial for "greenness".


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## cnycharles (Sep 10, 2011)

yes, plants can green up from applications of iron, fertilizers, other chemicals, rain... in a short period of time. plants can react to growth regulators by greening up, and b-9 applied to plants to make them stay more compact can also make them look greener and healthier

calcium nitrate does both soak up water like a huge vacuuming sponge, and if you mix it with the wrong fertilizer in high concentrations you will get an endothermic reaction (one in which energy is absorbed by the reacting chemicals so the stock tank will get cold and icy, and your calcium and a few other things will harden and precipitate to the bottom of the tank). so, feed with calcium at one time, then other things the next time, problem solved. or, mix your fertilizer to appropriate levels in your water so that you can water your plants with it, and then mix up your calcium to application levels, then mix the two together. it's only when you have high concentrations that you will have the most precipitation and ice floes in your fertilizer tank (the fog rolling off and the ice on the side of the stock tank are cool, though!


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## Bjorn (Sep 10, 2011)

Lance,we are totally in line here, I would neither have used it alone or extendedly. More like a "tonic" for unhealthy looking plants. Thats why I wrote "on steroids".
About hygroscopy of calcium nitrate: yes it is but might be better if you use the hydrate instead of the waterfree? Ca(NO3)2x4H2O
I have never noticed that endothermic effect from dissolving calciumnitrate into water but have seen it with ammonium nitrate. Perhaps you get it using calcium nitrate without crystal water?


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## Rick (Sep 10, 2011)

Bjorn said:


> Lance,we are totally in line here, I would neither have used it alone or extendedly. More like a "tonic" for unhealthy looking plants. Thats why I wrote "on steroids".
> About hygroscopy of calcium nitrate: yes it is but might be better if you use the hydrate instead of the waterfree? Ca(NO3)2x4H2O
> I have never noticed that endothermic effect from dissolving calciumnitrate into water but have seen it with ammonium nitrate. Perhaps you get it using calcium nitrate without crystal water?



I've never had a noticeable endothermic reaction with the small amounts of calcium nitrate I use either. In order to keep plants (and potting mixes) from excess loading on K then Ca and Mg should be present at the same time as K.


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## cnycharles (Sep 10, 2011)

if you are using a large stock tank and making a concentrated solution that would be drawn at 1:100 and you put calcium nitrate and certain other fertilizers together, then you can get this reaction. you would notice it after a period of time, not sure if it would happen on a tiny scale but if you were mixing everything at 'application rate' to put directly on plants, the concentrations are probably too diluted for this to happen.


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## Ray (Sep 10, 2011)

Bjorn said:


> Ray, I might misunderstand you, as you know, English is not my native language and this time I feel uncertain.
> Sure, I was inprecise, but I think most got the point. Peters 20-20-20(US) would have been labelled 20- 8.6-16.6 over here. On the other hand; people should remember that 1 ppm is the same as 0.0001%. Just saw that the Wellensteins have treated this quite extensively so I stop here(http://www.ladyslipper.com/minnut.htm) There is a lot of good things written on their pages.  The fertiliser issue is well described and I would suggest that anyone having questions lookup their pages.



Again, while your conversions to cations, rather than the oxides we see on the label is correct, the numbers in a fertilizer formula are expressed in weight percent, not ppm.

A 20-20-20 is - by weight - 20% N, 20% P2O5, 20% K2O, with the rest being other ingredients. Hence, the N, P, & K of your 90-10-40 would be 140% of the total - impossible.


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## Rick (Sep 10, 2011)

cnycharles said:


> if you are using a large stock tank and making a concentrated solution that would be drawn at 1:100 and you put calcium nitrate and certain other fertilizers together, then you can get this reaction. you would notice it after a period of time, not sure if it would happen on a tiny scale but if you were mixing everything at 'application rate' to put directly on plants, the concentrations are probably too diluted for this to happen.



Yes you wouldn't notice on a tiny scale like I do.

I'm just feeding a few hundred plants, so I dilute to final mix rates without making up a concentrated super stock for large scale application.


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## Rick (Sep 11, 2011)

http://www.google.com/url?sa=t&sour...sg=AFQjCNHFsbLHugTaQySiEte75ENtL7QpQg&cad=rja

Here's another view on the application of Urea vs Nitrate based nitrogen sources with the emphasis based on pH/alkalinity


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## gonewild (Sep 11, 2011)

Rick, That is a very good explanation article.
It defines why not to use Urea with low pH water. 
What about effects of the use of Urea with high pH water?
And what about effects of use of Nitrate fertilizers with high pH water?


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## Rick (Sep 11, 2011)

gonewild said:


> Rick, That is a very good explanation article.
> It defines why not to use Urea with low pH water.
> What about effects of the use of Urea with high pH water?
> And what about effects of use of Nitrate fertilizers with high pH water?



Lance

Check out the University of Georgia extension article in the link I added to the nitrogen - pH thread. It essentially covers David Mellards article but covers your questions too. There is a chart that optimizes % nitrate against alkalinity.


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## Bjorn (Sep 12, 2011)

*Prepare for chemistry class*

Please folks, do not mix up Ammonium with Urea. I hope that you follow me in this treatise, I might not be able to explain it properly but can at least try: 
Please enjoy:
This has all to do with weak acids and salts of weak acids and as you might remember from chemistry class: Ammonium is a weak acid that may be involved in several reactions: A weak acid is an acid that does not dissociate fully and an aqueous solution of it contains significant amounts of unreacted substance. To describe this we commonly write equilibriums like i) 
(for more details http://en.wikipedia.org/wiki/Weak_acid) 
Ammonium , NH4+; has an acidifying effect in water due to the equillibrium with Ammonia, NH3, 
i) NH4+ = NH3 + H+(acid). 
(since NH4+ is a weak acid, significant amounts of NH4+ does not get transformed to NH3 and acid, This depends on pH though)
Although Urea can be assimilated through the leaf surface, normally when its used as fertiliser it gets into the soil. There, Urea decompose to ammonia, NH3, and carbon dioxide (CO2) under the action of the enzyme urease that is quite common in soil bacteria etc. The decomposition may be quite quick. The ammonia is poisonous and reacts in an alkaline manner with water: 
ii)NH3 + H2O = NH4OH = NH4+ and OH-(base).
The two reactions i) and ii) are linked by the dissociation of water:
iii)H2O = H+ + OH-. 
In pure water the concentration of OH- is equal to the concentration of H+ and is 1x10exp-7. As pH is defined as the negative logarithm of the H+ concentration, the pH is then 7 for pure water (this is a matter of definition, if you try to measure you will get acidity due to dissolved gases etc). 
So Urea makes the soil increase in pH due to equilibrium ii). This equillibrium is also pH dependent, through reaction iii). But since our common substrates like bark and moss are generally pretty acid, the Ammonia gets converted almost quantitatively to ammonium. A part of this ammonium reacts acoording to eq i), but much less than what is produced. The net effect of urea then becomes an increase in the pH.
If the mix contain ammonium salts like ammonium-nitrate, then you get an acid reaction according to eq. i)
If pH of your substrate is really high, then ammonia becomes an issue, being poisonous (eq ii)) and in these cases urea becomes unsafe to use.:evil:


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## Bjorn (Sep 12, 2011)

I have checked up, and endothermic solution enthalpies are quite common. Personally I saw it yesterday when I was preparing a 20% solution of Epsom-salt (Magnesiumsulphate heptahydrate).


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## Bjorn (Sep 12, 2011)

> Again, while your conversions to cations, rather than the oxides we see on the label is correct, the numbers in a fertilizer formula are expressed in weight percent, not ppm.
> 
> A 20-20-20 is - by weight - 20% N, 20% P2O5, 20% K2O, with the rest being other ingredients. Hence, the N, P, & K of your 90-10-40 would be 140% of the total - impossible.


Ray I do not really get to your point, what is so bad about calculating the ppm of nutrional elements in a fertiliser solution?oke:
If we are to be picky, then I could ask why you add K2O to your fertiliser mix. Its labelled like that just by convention, we both know that its not there. As with P2O5, or for that sake N. N and P and K are there in other compounds but neiter of the above oxides for sure!:rollhappy: Anyone that has been in contact with K2O and P2O5 knows why :clap:


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## Ray (Sep 12, 2011)

Bjorn, I work with ppm all the time. My point is that when specifying a fertilizer formula on a commercial package, by law (in this country, at least) the ingredients are listed in weight percent, not ppm.

As to why the P & K are specified as oxides, it all dates back to old analytical methods that required that the compounds be "dead burned" to oxides for measurements, and is simply a holdover.


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## cnycharles (Sep 12, 2011)

Bjorn said:


> Anyone that has been in contact with K2O and P2O5 knows why :clap:



.. or had very strong h2o2 drop onto leather boots or gloves! (flames, I believe)


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## Rick (Sep 12, 2011)

cnycharles said:


> .. or had very strong h2o2 drop onto leather boots or gloves! (flames, I believe)



I was so bummed with H2O2. I wanted to test it as a hypergolic rocket fuel.

Really need to get something up >>75% maybe even 90+% to get a good reaction with simple organics as a starter slug.

I tried some 35% with oils and could barely get fizzing

So for the saftey issues with concentrated peroxide it ain't worth it as a decent rocket fuel. It will burn your hands off at concentrations long before getting some good flames going.


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## Bjorn (Sep 13, 2011)

*My MK is too vigorous!*

Stupid me, I did not account for the nitrification of the Ammonia. According to some that makes soil acid when Urea is used. Others have different views.:sob: Difficult to understand these things - so many dependencies so complex relations. Still Urea as foliar feed seems to work. As a precaution, no need to mix it with the regular fertiliser. Enough of that.
Right now I got this other worry; My Michael Koopowitz has grown from seedling of approx 4" LS to 10" LS plus two new leads in one year. (NB without urea) The problem is that the plants lacks substance, should have had more "dry matter" it gets prone to rot ++ Can you visualise the problem?
What to do except stopping feeding? My Sandie and a Roth is also displaying similar traits though not as bad.


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## cnycharles (Sep 13, 2011)

Rick said:


> I was so bummed with H2O2. I wanted to test it as a hypergolic rocket fuel.
> 
> Really need to get something up >>75% maybe even 90+% to get a good reaction with simple organics as a starter slug.
> 
> ...



darn, I like my hands... our spray gloves also weren't high-test enough for it also, so I'm glad we no longer have any

bjorn, about your plant being insubstantial(?) and more prone to rot - maybe the light is a bit too low so it stretches. this could lead to thin cell walls. the word is that too much ammonium type fertilizer can make plants grow too lushly, which can lead to possible disease. also if a plant can normally grow too quickly, it can be deficient in both calcium and phosphorus. calcium moves at one speed and sometimes if it isn't available all the time in a small amount a fast-growing plant can outpace the movement from the roots to the rest of the plant. with things like mums that can grow very quickly, have large floral structures (lots of branching and flowers), a lack can cause brittleness, less branching and flowers. not exactly sure how this would translate to orchids though I noticed when I was trying a too-low phosphorus fertilizer things that grew quickly would have problems. actually also for larger plants a breeze can help toughen up plants. movement causes some plant cells to react and toughen cell walls and slow upwards growth. air jets over the top of easter lilies have been used in lieu of growth regulators to keep them shorter. I think that you can use too much nitrate fertilizer for orchids (my opinion based on work, reading and seeing discussions here, not experimental), but I believe a balance of different types could be the most benefitial, and from Rick's experiments, one with less potassium and more calcium. 

it could be just that you are using an ammonium-high fertilizer and/or your light could be a little too low. also you might just be under-fertilizing and the plant can't get enough mass as it might normally. also a little more air movement might help


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## Rick (Sep 13, 2011)

cnycharles said:


> bjorn, about your plant being insubstantial(?) and more prone to rot - maybe the light is a bit too low so it stretches. this could lead to thin cell walls. the word is that too much ammonium type fertilizer can make plants grow too lushly, which can lead to possible disease. also if a plant can normally grow too quickly, it can be deficient in both calcium and phosphorus. calcium moves at one speed and sometimes if it isn't available all the time in a small amount a fast-growing plant can outpace the movement from the roots to the rest of the plant. with things like mums that can grow very quickly, have large floral structures (lots of branching and flowers), a lack can cause brittleness, less branching and flowers. not exactly sure how this would translate to orchids though I noticed when I was trying a too-low phosphorus fertilizer things that grew quickly would have problems. actually also for larger plants a breeze can help toughen up plants. movement causes some plant cells to react and toughen cell walls and slow upwards growth. air jets over the top of easter lilies have been used in lieu of growth regulators to keep them shorter. I think that you can use too much nitrate fertilizer for orchids (my opinion based on work, reading and seeing discussions here, not experimental), but I believe a balance of different types could be the most benefitial, and from Rick's experiments, one with less potassium and more calcium.



Lots of soft growth (often with lots of blooming), poor substance, susceptability to rots is very much in line with too much N and K with inadequate Ca/Mg. Ca (and Si) needs to get incorporated into cells walls for better substance (and disease resistance). Excess K blocks uptake of divalent cations (Ca/Mg), which in turn reduces uptake of PO4.

In general for all bio (ion pumps) and substrate ion exchange (in bark and CHC) the K will always win out for adsorption if Ca or Mg is not present at higher concentrations than K. A moderately soluble top dress of something with Ca/Mg in the potting mix will offset standard fertilizer NPK imbalances, but you get faster (and I think more controlable) results if your fertilizer and irrigation water always contains more Ca than the K present in fertilizer.

Keep in mind that unless you are using very soft water or RO water there is probably at least 5-20 ppm of Ca and 3-7 ppm of Mg present in standard surface waters. I could guestimate these values better if I at least know the hardness of the water used.

Noticing the sanderianum thread that Wendy just posted, even though she uses a heavy K fertilizer and rain water, the potting mix contains a substantial amount of "limestone screenings".

After the large multi growth multis I've lost over the years that grew and bloomed like crazy for 5 years going into slow burn demise, I'm now to scared about pushing that much K over extended periods of time with only potting mix sources of Ca/Mg for backup.


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## Sirius (Sep 13, 2011)

Rick,

I am using 13-3-15 MSU fertilizer at a rate of 3/4 teaspoon per gallon of R/O water for a concentration of 75 ppm. This fertilizer also contains 8 Ca and 2 Mg. I flush every fourth or fifth watering with pure R/O water.

Where can I buy the source of additional Ca you are adding to your water? 
How much additional Ca would you recommend that I add to bring my Ca up to a beneficial level (in tsp amounts)?
How much additional epsom salt would you recommend that I add to bring my Mg up to a beneficial level (in tsp amounts)?
I read that you also add Mg to your flushes. Is that with or without the addition of extra Ca?
Would adding extra Mg without adding extra Ca be beneficial or harmful? I don't have any Ca, but I have a huge bag of epsom salts.


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## cnycharles (Sep 13, 2011)

http://www.orchidmix.com/cat4.htm

if you have a wholesale or other plant nursery around you, you might be able to get a 25 lb bag for not much money. robert's flower supply is just one orchid place I saw that has calcium nitrate, think c.l.a.n. orchids also had it (googling orchid supplies calcium nitrate). might find cheaper from greenhouse supply catalog place, but might be 25 lb bag shipped might not be cheap anymore. robert's sells it in 1lb and up quantities


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## Rick (Sep 13, 2011)

Sirius said:


> Rick,
> 
> I am using 13-3-15 MSU fertilizer at a rate of 3/4 teaspoon per gallon of R/O water for a concentration of 75 ppm. This fertilizer also contains 8 Ca and 2 Mg. I flush every fourth or fifth watering with pure R/O water.
> 
> ...




My present method of use with MSU is 1/4 tsp/gal of MSU, 1/4 tsp of Calcium nitrate (the dihydrate is fine) and 1/4 tsp of anhydrous MgSO4 (but hydrated epsom salts is probably fine too). The MgSO4 is harder to dissolve, so I put this in first and mix until dissolved, then I add the other two items. I also add a 1/4 tsp of kelp extract.

Since my dilute well water has some calcium in it already (~12 ppm) I don't add any more calcium nitrate to it for the flushes.

Alternatively I've been flushing with my dilute well water to which I add 1/4 tsp/gal of EPSOMA peletized lime. Mix and settle for about 5 minutes, and discard the settled solids. The pH of this is still <8.0 and will add a small jolt of alkalinity with the Ca/Mg.


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## Roth (Sep 14, 2011)

Alan Moon at the Eric Young qualified urea as essential to grow their plants properly some years ago.

Rick, your schedule looks OK, but there is way not enough ammonium to my taste in your program. Ammonium is required by a number of orchid species as a prefered source of nitrogen ( there was a study by Arditti about 40 years ago about that, well a compilation, but it was right). As a matter of fact, soe genuses like dendrobium phalaenopsis and some cattleya can grow in vitro with only nitrate nitrogen, but paphs, some Blc, and phals need absolutely to have ammonium, and for some, even urea... 

MSU, I tried it and did not like it at all in terms of growth speed and color, so I went back to an ammonium/urea/some nitrate fertilizer for all of my plants. As an aside the Tokyo Orchid Nursery uses a very high ammonium/low nitrate fertilizer, loaded with P too, as a slow release. In Taiwan, they use another slow release that is very high in ammonium and ureafoam (which decomposes in ammonia with time). The Orchid Zone was using the old 30-10-10 all urea, then they used the Jerry's Grow that was a 50/50 blend of ammonium and urea. Norris Powell was using an ammonium only fertizer, and for me, I tried to use a calcium nitrate/potassium nitrate based fertilizer, but the leaf color quickly became dull ( like many photos I see on the internet, have to be honest). I like my plants to be very dark green, like in the wild or like healthy plants. They reward me by growing very fast then...

There is a large study in New Zealand under way, using many different potting mixes, and fertilizers. So far, the plants grown in a MSU type fertilizer with only nitrate as a source of nitrogen are about half size the ones grown with a fertilizer including urea and ammonium, with a marginal quantity of nitrate. The results will be published in a year or so, it is done by an university, with all the requirements, including the statistician...

What is true, however, when feeding nitrate only and low P to phalaenopsis, in the first time, they seem to become darker. 

However, after a few weeks for deflasked seedlings, and a few months for mature plants, the effects start to be opposite, the plants are stunted, so they look nice, dark green, but grow at half speed. Later, some plants collapse by a kind of chlorosis...


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## Bjorn (Sep 14, 2011)

*A speculative approach*

This thread is getting very interesting. Particularly as we now have got some new contributions. Input from Xavier is always welcome; and these things with urea - well at least I find it utterly fascinating.
Unfortunately, English is not my native language, so I have problems with the nuances of the language; but here is a proposal/idea::rollhappy:
I will try to write it in a condensed form, some of you do obviously not have time to read things carefully and we are all sometimes a bit "blocked" in our own mindset 
I have been googling the issue lately and found a lot information, sometimes contradictory - which makes me go crazy. However after sorting and perhaps "filtering" these are the outcome:
Plants can assimilate NH4+ and NO3- through the roots
Urea disintegrate to NH4+ through NH3 in soil quite easily.
Urea can be assimilated through the leaf - at least for potatoes and obviously my orchids.
Urea acidifies soil. BUT first the production of NH3/NH4+ makes the soil alkaline - at least locally. Its when the Ammonia/um is oxidised to NO3- that the acid is formed. Nitrosomas produce nitite from ammonium and nitrobacter oxidise the nitrite to useful nitrate. Not straight forward is it? This happens in soil, in the cornfields. But do we know that nitrification is actually contributing much for orchids? And particularly epiphytes? What about humus ephyphites?
Let us imagine that we are plants growing in the jungle. The availability of nutrients is rater scarce so we have become very efficient in sourcing whatever comes our way.
What is coming our way, what is the source of it?
1)In the rain comes a solution of nitreous oxides commonly known as nitric and nitreous acids. Here is a source of Nitrate - grab it:drool:
What else? 
2)droppings? Birds droppings contain uric acid. I have been unable to find how it is used by plants but it is a well known fertiliser(guano) My own experience from the days I had chicken tells me that composting Chicken droppings produce a lot of NH3 if it gets wrong. So Here is a source of NH3/NH4+
3)Decaying plant matter? Source of N in plants? probably proteins and amino-acids. 
4) Misc. blue-green algae has the ability of synthesising amines and amino-acids. Possible source?

What does 2)-4) have in common except for being available N-fertilisers? Yes, they all contain Amino-groups -NH2 or easily gets broken down to ammonia(in the case of birds droppings).
Of course the amines also break down to NH3/NH4+.

All of the sources 2)-4) have to be oxidised to get into the "useful" NO3- ion. Then I ask you: Frankly, would you recon that plants would adopt to the ammonium or the nitrate as primary N-souce based on this reasoning? Particularly the epifytes should have much easier access to nitrogen though the NH3/NH4+. 
And here we arrive at Urea: If the plants prefer ammonium over nitrate, why is urea so bad? And if the plants prefer nitrate, why should the evolution lead to a preference of the (perhaps) least available nutrient?
Of course, this is merely speculations; it could of be that all the water and Nitrogen-sources available to the orchids is so full of nitrosomas and nitrobacter that it all transform to nitrate, or at least most of it? - I do not know. Anyone having info on the chemistry of seepage water in the jungle?oke:


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## Ray (Sep 14, 2011)

It's well-established in the bedding plant industry that ammonium-based nitrogen tends to accelerate internode elongation, while nitrate does not (I think I have that correct - it's been a while), so they are utilized at different times of the growth cycle. How that pertains to orchids, I have no idea, but I can tell you that my paphs grow like weeds using the MSU RO formula (18:1 nitrate:ammonium) exclusively, and each growth is about twice the size they were when I used Dyna-Gro "Grow" formula (1.7:1 nitrate:ammonium), so I detect no stunting of growth..


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## Ray (Sep 14, 2011)

Rick - I was thinking about your blend of MSU/CaNO3/Epsom salts.

Using the septahydrate Mg source, a 1/3-each blend gives you about a 9-1-5-16Ca-0.7Mg fertilizer formula. Is that sufficient mag?


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## Rick (Sep 14, 2011)

Ray said:


> Rick - I was thinking about your blend of MSU/CaNO3/Epsom salts.
> 
> Using the septahydrate Mg source, a 1/3-each blend gives you about a 9-1-5-16Ca-0.7Mg fertilizer formula. Is that sufficient mag?



Those rotten waters of hydration!!!

Actually I use anyhydrous MgSO4 and not Epsom salts

I would like to see more like 4-5 for Mg and not 0.7

Please double check the MSU contribution for Mg (the "pure water") has a few ppm of it to start with, so I don't think you should end up with <1ppm)


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## Rick (Sep 14, 2011)

From looking at some of the published work I added to this thread or the other thread on nutrition (from the GA extension website). The alkalinity values really push the choice of nitrogen.

Roth you mentioned in another post that you were growing in hard water conditions (at a GH in Europe). Alkalinity is generally high too in hard water conditions.

According to the GA extension paper, urea/ammonium is the prefered nitrogen source as alkalinity goes up.

Conversely for those using soft or RO based waters with very low alkalinity, Nitrates appear to be the preffered choice of N.

Although closely linked, pH and alkalinity are not 100% the same. pH of hard water systems are generally under 8.0 s.u. even with alkalinity values close to the hardness levels (>200 mg/L). Also soft waters can have high alkalinity and a pH approaching 9.0 (just add baking soda, NaHCO3), and the theoretical pH of pure water (alkalinity = 0) is pH 7. 

I'm using dilute well water as my base water. Hardess 20-30 and alkalinity ~15 (very low). pH is usually around 6.5.

I use primarily nitrates for N source. I just started with MSU because it was the fad thing to do at the time. However, it looks like the alkalinity / Nitrogen discussion is pertinent to the results I've been seeing for the last couple of years. I am gettin very big luxuriant dark green leaves, and very pleased with present growth results for just about all species including paphs.

I need to post some pics of some P. mastersianum seedlings that I am presently growing. They have very good color and size for about 1 year out of flask. They are big dark and shiny with a vague pattern like the textbook description. Much better than my almost demised parent plant.


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## Rick (Sep 14, 2011)

Ray said:


> Rick - I was thinking about your blend of MSU/CaNO3/Epsom salts.
> 
> Using the septahydrate Mg source, a 1/3-each blend gives you about a 9-1-5-16Ca-0.7Mg fertilizer formula. Is that sufficient mag?



At 1/4 tsp per gal of the Robert's version of MSU pure water (12-6-13 7Ca-2Mg) that's essentially half strength

6-3-6.5 -3.5Ca-1Mg (granted the P and K are "phosphate and potash" not ion).

I'm actually using dihydrate CaNO3, and the anyhydrous MgSO4

So that should come out to a bit less N and Ca and a bit more Mg.


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## Ray (Sep 14, 2011)

Ah HAH! Thanks.


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## Rick (Sep 14, 2011)

Xaviar

Here's a couple of mastersianum 17 months out of flask. Baskets are 4" for scale.


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## SlipperFan (Sep 14, 2011)

:drool:


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## Jim Toomey (Sep 14, 2011)

Holy Crap, they are huge!


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## Roth (Sep 15, 2011)

Rick said:


> Xaviar
> 
> Here's a couple of mastersianum 17 months out of flask. Baskets are 4" for scale.



Superb plants... Three things however:

- The NZ trial includes MSU and various potting mixes, and MSU is clearly a vast disaster compared to several others fertilizers tested, and various potting mixes ( the trial is on phalaenopsis clones, few thousands plants for the trial, so it is indeed an interesting one going on, not a hobby size thing...), however you are using kelp extract, which could well make a huge difference... I used in fact something quite close to what you are using as a fertilizer, and that's the best performing fertilizer in the trial, as of today ( the trial will be completed by blooming huge phalaenopsis Japanese style, to push the trial to the end, so we don't know until they bloom hehe...). The best performer as of today was a ( per weight) 2-1-3 calcium nitrate, magnesium nitrate, and Peters 20-20-20, at about 1g total per L microsiements. Monthly use of a 10-52-10.

The EYOF used as well a product called Maxicrop every other month, and another guy (who was a conman, but very good grower) in england was doing beautiful paphs flasks, and growing a lot of orchids in rockwhool with great results, using maxicrop and calcium nitrate blended...

- You are using moss ( where I don't hehe), and apparently there is algae on it, heavily. It could well make a byproduct that feeds the plants

That would be really interesting to know what percentage of the growth comes from amino acids or NO3... My general feeling, including in-vitro, is that some genus prefer one source of nitrogen ( like many crops do anyway), and within the genus, some species, and specific populations prefer different conditions too. As an example in flask, for the last replate, the real doritaenopsis and the phalaenopsis pot-plant have a very different media, to get perfect seedlings. 

I discussed that by accident with Clone Biotech in Taiwan, who have their own lab, and massive, perfect phal nursery. He told me, well that's funny you have two different last replate media, because we use your orchiata, we use NZ sphag moss, but for the doritaenopsis, we MUST get cheap chinese sphagnum moss to get the fastest growth...

Mastersianum from Ambon has heavily mottled leaf for about 20% of all the plants, and plain/mildly tesselated leaf for the remaining. The ones from Ceram have only yellowish green leaf, and can be really huge ( I mean 80+cm leafspan). The color is different, and the former grow on leaf litter, very deep shade. The latter grow on limestone, very alkaline and mineral soil. The same applies to different colonies of volonteanum and violascens. Apparently, when plants from one type grow very well, the others don't, in the same setup and growing conditions. Violascens grows on limestone outcrops, where the 'papuanum types of violascens' grow in fern roots... 

Praestans, gardineri, and praestans red leaf have similar acid or alkaline colonies ( in fact I find the big roth-size praestans to be extremely easy to grow, the wilheliminiae/pygmy gardineri too, but the normal gardineri are less easy to grow for me...). Add to that that glanduliferum is a tree epiphyte... Same for philippinense, the very rare 'Sabah' type of philippinense, which is clearly the best type, grows in Sabah on fern roots, exceedingly acid. The philippinense in the Philippines prefer alkaline, to very alkaline growing conditions. That's clear there is clonal variation to expect...


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## NYEric (Sep 15, 2011)

Rick said:


> At 1/4 tsp per gal of the Robert's version of MSU pure water (12-6-13 7Ca-2Mg) that's essentially half strength
> 
> 6-3-6.5 -3.5Ca-1Mg (granted the P and K are "phosphate and potash" not ion).
> 
> ...



Great! You can mix me up a batch and let me know what to use it on!


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## Rick (Sep 18, 2011)

http://www.hort.purdue.edu/rhodcv/hort640c/nuptake/nu00001.htm

Link to nitrogen uptake in higher plants. The chemical and non-plant interactions in the rooting zone are connected. but here is a synopsis of what the plant is doing internally. 

pH (alkalinity) plays an important role in choice of Nitrate vs ammonia.

Here's another link (a Bill Argo article through Ray's site).

http://www.firstrays.com/PDF/Part 3 - Fertilizers.pdf

There's a table that shows % ammonia based on alkalinity


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## Rick (Sep 22, 2011)

Ray said:


> Rick - I was thinking about your blend of MSU/CaNO3/Epsom salts.
> 
> Using the septahydrate Mg source, a 1/3-each blend gives you about a 9-1-5-16Ca-0.7Mg fertilizer formula. Is that sufficient mag?



I weighed out 1/4 tsps of calnitrate 4H2O and MgSO4 anhydrous, and they were 1.44g and .888g per 1/4 tsp respectively.

This comes to 45 mg/L N, 64.5 mg/L Ca and 47.3 mg/L Mg

If 1/2tsp of MSU is ~80mg/L N

Then 1/4 tsp is
40mg/L N, 20 mg/L PO4, 43mg/L K 23mg/LCa and 6.6 mg/LMg

Adding back in the Ca, N and Mg from supplements should be:
85N - 20PO4 -43K - 87.5Ca - 54Mg

as % I think that should come out something like:

13-3-7 13Ca and 8Mg


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## Ray (Oct 11, 2011)

Sorry to resurrect this after a month, but I found some textbook info that seems to confirm some of what was shared here, so went back and reread this thread.

According to Horst Marschner, in Mineral Nutrition of Higher Plants (a real "snoozer", but contains some good explanations), the chapter on nutrient uptake by leaves describes gaseous uptake (primarily ammonia) through stomata, while solution uptake is through the leaf cuticle. However, it also shows how that uptake mechanism is only significant in cases of mineral deficiencies (as Lance stated).

Also of interest is the fact that in solutions, nonpolar urea is taken up by the leaves faster than the polar nitrate and ammonium ions. (By contrast to roots, which via several different mechanisms, take up ions almost exclusively.)

So I guess the upshot of this is that foliar feeding using urea is not a bad strategy - but only if your plants are nitrogen deficient.


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## gonewild (Oct 11, 2011)

Ray said:


> So I guess the upshot of this is that foliar feeding using urea is not a bad strategy - but only if your plants are nitrogen deficient.



I think your conclusion is spot on. It is not that Urea is a bad fertilizer to use but rather leads to waste. If you use it as a foliar feed to correct or supplement low nitrogen levels it works well. But if you use it as a main source of nitrogen in the fertilizer water you are not getting good value for money spent. Also because the nitrogen leaves the media as a gas you never really know what is available for the roots to take in.


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## Bjorn (Oct 12, 2011)

This is getting interesting! Thanks for the info. Perhaps foliar feeding is something to consider additional to regular feeding?


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## Ray (Oct 12, 2011)

Bjorn said:


> This is getting interesting! Thanks for the info. Perhaps foliar feeding is something to consider additional to regular feeding?



IF you have a deficiency, sure. Otherwise, it seems doubtful that it's worth it.


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## keithrs (Oct 12, 2011)

I foliar feed every watering and I haven't seen any promising results on healthy plants..... I have noticed that plants that are struggling via root lose or be div. have seem to have jumped back alot faster. Maybe a fluke? Not sure.....


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## Ray (Oct 12, 2011)

Actually Keith, I would think that's totally consistent. A plant with severe root loss is bound to be deficient in something, not having a good way to take up nutrients, so would be more likely to be responsive to the foliar input.


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## cnycharles (Oct 12, 2011)

phals have been shown to be grown quite well (hybrids in a test), with foliar feeding on the undersides of the leaves. so much so, that some had considered not fertilizing the pots at all and just using a fogger to get the mist under the leaves.

if you have decent nitrogen levels but don't have as much calcium in there, you can help the plants a lot by foliar feeding with calcium. at work when we still were growing poinsettias, we had to spray at least once a week with pharmaceutical grade calcium on the developing bracts (red leaves) because they were growing so fast that the calcium available couldn't move to the growing edges, and they would get leaf edge burn. coating the entire upper area of leaves prevented this from happening


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## Rick (Oct 12, 2011)

cnycharles said:


> if you have decent nitrogen levels but don't have as much calcium in there, you can help the plants a lot by foliar feeding with calcium. at work when we still were growing poinsettias, we had to spray at least once a week with pharmaceutical grade calcium on the developing bracts (red leaves) because they were growing so fast that the calcium available couldn't move to the growing edges, and they would get leaf edge burn. coating the entire upper area of leaves prevented this from happening



Calcium does not exist as a stable element, so what was the anion.

Nitrate, glutonate, chloride, EDTA, sulfate, sulfonates?


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## cnycharles (Oct 12, 2011)

doesn't matter; it's at work and I won't be there for a few months
pharmaceutical grade powdered calcium


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## Rick (Oct 12, 2011)

cnycharles said:


> doesn't matter; it's at work and I won't be there for a few months
> pharmaceutical grade powdered calcium



Could be the anion thats actually doing the work rather than the calcium?

We have lots of discusions where people want to add "just calcium" to there programs, but there is no way to do that since purified elemental calcium is explosive.


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## cnycharles (Oct 12, 2011)

lol I think that you're getting a little too technical here (smile)... someone must have pressed your professor button!

I remember the pharm formula or description on the label had 'waters' on it, but since we haven't had poinsettias for a few years and I haven't picked up the carton, I don't remember the exact state of formulaic calcium


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## keithrs (Oct 12, 2011)

I don't use urea N so maybe thats why I have not seen results from foliar feeding......


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## Rick (Oct 12, 2011)

cnycharles said:


> lol I think that you're getting a little too technical here (smile)... someone must have pressed your professor button!
> 
> I remember the pharm formula or description on the label had 'waters' on it, but since we haven't had poinsettias for a few years and I haven't picked up the carton, I don't remember the exact state of formulaic calcium



My P button:clap::clap:

Anyway on Wikipedia it sounds like "pharm grade calcium" is washed and powdered calcium carbonate.


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## cnycharles (Oct 13, 2011)

I was straining my brain last night and this morning, and don't quote me but it might be calcium chloride di-hydrate, and I think it's higher than pharmacy grade. I think I remembered pharmacy grade because there was some sort of listing on the side of the container that had 'pharm' on it. I thought it had more waters, but searching online for calcium chloride pentahydrate doesn't really work... so probably di-hydrate. very soluble, very safe to use and we used 16 ounces per 100 gallons (the most we were told that could be safely used on poinsettia bracts without burning)

now I'm wondering if there is somewhere I can buy small amounts of urea fertilizer that I can use for foliar feeding, so that I don't need to put as much fertilizer around the roots


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## keithrs (Oct 13, 2011)

Hydro stores sell 16-0-0, 16-1-1, 16-1-2 depending if you want calcium, seaweed, and other trace elements. They basically cut synthetic urea in half with water and humic acids.


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## cnycharles (Oct 13, 2011)

sounds like that would be good... are there any particular brand names for this version? I'm asking because the last time I went into a hydro store to look for humic acids, there were tons of bottles and many didn't want to be overly descriptive about what was inside of them (just a lot of fancy graphics and such)


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## gonewild (Oct 13, 2011)

http://www.amazon.com/3LBS-Nitrogen-Fertilizer-Urea-46-0-0/dp/B005IAXN2Y


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## keithrs (Oct 13, 2011)

Humboldt Nutrients has a very good product called Verde...... They also have humic and fulic acids. Humbolt is 8% humic acid and flavorful is a humic acid derivative..... its 8% fulic acid


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## cnycharles (Oct 13, 2011)

thank you lance and keith for info about the urea fertilizer. I still have fulvic acid, and believe it or not I found miracle gro 'orchid fertilizer' that is 30-10-10 and 27% is urea. the standard miracle gro there at lowes was also high urea but the orchid one was a little smaller so got that for $3 and change. definitely not three pounds though but no shipping!  I'll try it out either tonight or tomorrow morning with some fulvic acid I have to see if things 'happy up'


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## Hera (Oct 15, 2011)

Charles, what strength are you going to use??? I have some MG and my babies could use a little greening. Should it be 1/2 or 1/4 or ???????


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## Rick (Oct 15, 2011)

keithrs said:


> I don't use urea N so maybe thats why I have not seen results from foliar feeding......




I don't use urea either and grow things pretty good IMHO

Granted, using the MSU pure water I have there is a small percent of N that is from ammonia.

Did you read the Bill Argo article I linked earlier?


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## keithrs (Oct 15, 2011)

I re-read this whole thread yesterday and I bookmarked Bills article for a later read.... Interesting stuff! This board has been a great place to learn!


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## cnycharles (Oct 15, 2011)

Hera said:


> Charles, what strength are you going to use??? I have some MG and my babies could use a little greening. Should it be 1/2 or 1/4 or ???????



Hello Hera, do you mean magnesium (epsom salts) or do you mean urea? The container of miracle gro orchid version was 30 10 10 and it said to use 1/4 teaspoon per gallon for watering orchids; I used a large quarter teaspoon into two gallons, but I also dropped in a fat quarter teaspoon of calcium nitrate and a splash of fulvic acid, into a 2 gallon sprayer.

About epsom salts, I probably use too much when I do it since the box says you can use up to a tablespoon per gallon, so you should probably ask rick who uses it more often


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## Hera (Oct 16, 2011)

Wow, not being a chem major I didn't even think about the mixup between magnesium and Miracle Gro. I meant Miracle Gro. That's about how much I was going to try. I wasn't sure if the amount would be the same as I would for watering. I'm going to try 1/4 tsp per gallon for spraying and see if it helps green up the ones that are looking chlorotic.


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## cnycharles (Oct 16, 2011)

I saw the MG and since it was later at night ended up thinking 'Mg'.. lol this morning I was making some breakfast and suddenly I realized 'I bet she meant Miracle Gro!'

yes, it says quarter teaspoon for watering, but maybe for misting it might need less? that's why I used part calcium nitrate and part miracle gro, just to check it out


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