Early K-lite results

[Ray]

I am an "equal opportunity abuser" of orchids. I treat all of them the same, so yes, the paphs got the 125 ppm N, and were fine. I think some of it is related to S/H culture, which in my case involves a lot of flushing at every watering, and maintenance of high humidity in the greenhouse, resulting in very little mineral and waste buildup.

Like you, I cut back about a year ago.

 

[naoki]

I was also using MSU (in combination with a bunch of whatever fert.) @100ppm for paphs (and others) when I first got MSU from Ray about 2-3 years ago. Roots were OK as with Ray's. But the media (bark) seemed to have deteriorated quite a bit, so I lowered the concentration to 10-30ppm after learning from Rick et al. I haven't repotted since the change, so I don't know about the root growth. I feel like the shoot growth seems to be a bit slower. I thought that this is psychological things, but it is interesting to hear Brabantia is feeling in the same way. This might mean that plants are going with higher root:shoot ratio. I hope it is leading to the long-term health, though. And I can probably stretch the repotting a bit (I'm going to keep eyes on pH and TDS of pour through as Mike Stone and Rick mentioned). I'm also using bark based media (bark:coarse perlite:sphag:sand=3:2:1:0.5), and not S/H.

You are right, lots of horticultural studies do show faster growths under much higher N than what we are using. They probably throw out their plants after 1 year or experiments, though (so degradation in root environment, or repotting isn't an issue for them).

 

[gonewild]

.

Interesting for me what you say Charles, because during many years I tried to feed my plants at 125 ppm N as Ray recommended (in former days). Of cause I have burned many time the roots of my plants (Cattleya, Dendrobium, Oncidium and there hybrids ...) and for sure when I changed the substrate of my paphio's it remained no roots. Thought when I read scientific papers on the optimization of some orchids culture I see that some researchers are able the feed at high concentration. What is the trick? Are fertilizers made with urea as nitrogen source as "agressive" than the one made with ammonium and nitrate salts? Professional producers of Phalaenopsis are also feeding at high concentration 1000 µS is usual!

It is very unlikely that you would damage (burn) the roots with a nitrogen level of 125ppm. That is assuming that you are getting the nitrogen from a commercial fertilizer formula. 125 ppm N combined with lessor amounts of P and K wont give salt levels high enough to damage roots. If your roots were damaged by the irrigation application then perhaps the salt content of your source water is/was too high.

If you apply fertilizer at levels strong enough to damage tissue you should see leaf damage before root damage.
What you perceive as burned roots are probably roots that died as a result of something other than the 125ppm N strength fertilizer.

To be clear in what I am trying to say is that 125ppm N will not burn leaves or roots. If the irrigation water is damaging root tissue it would be caused by overall salt levels being too high (too high ppm level) not the Nitrogen level.

 

[Stone]

I was also using MSU (in combination with a bunch of whatever fert.) @100ppm for paphs (and others) when I first got MSU from Ray about 2-3 years ago. Roots were OK as with Ray's. But the media (bark) seemed to have deteriorated quite a bit, so I lowered the concentration to 10-30ppm after learning from Rick et al.

Naoki,
Media is decomposed by bacteria (mainly) which use N as their major requirement. If we give adequate N to the pot, both the plant and the bacteria will be satisfied and function normally however if the N rate is reduced below the optimum level, the bacteria will win out every time and the plant will get off second best. Reducing N to reduce microbe numbers and slow decomposition of organic components will only result in the plant slowing growth as well. Therefore it is vital that we supply enough N to satisfy both plant and bacteria. There is no way around this if we use organic materials to make up our mix.
Of course different materials behave differently. Eg: if we use composted pine bark, becauase the outer layers have largely been broken down there is a much reduced requirement for N (known as nitrogen drawdown (which see)). On the other hand orchiata which is simply aged will last much longer but has a higher need for N therefore we need to up the N supply to this particular bark to keep both plant and microbe happy.
This is one of the primary reasons I've been looking into NH4NO3 as a supplimenatry N source as it is all N and you can use it to boost N without raising EC levels to high.
Urea could be used but it may be too acidifing without lime additions and I (like you) prefer more even nitrate to ammonium ratios, besides which it is impossible to gage what you are doing with an EC meter.

 

[Stone]

If you apply fertilizer at levels strong enough to damage tissue you should see leaf damage before root damage.
What you perceive as burned roots are probably roots that died as a result of something other than the 125ppm N strength fertilizer.

To be clear in what I am trying to say is that 125ppm N will not burn leaves or roots. If the irrigation water is damaging root tissue it would be caused by overall salt levels being too high (too high ppm level) not the Nitrogen level.[/

It's not direct tissue damage that's the problem, it's reverse osmosis where high media EC leads to salt concentration higher in the media than the roots which will draw water from them and kill them after which they will (possibly) get attacked by pathogens. That wont happen on a leaf surface as usually does not stay wet. Of course if you put a tablespoon of fertilizer in a glass of water and poured that on the leaves you would burn everything!

 

[Brabantia]

Naoki,
Media is decomposed by bacteria (mainly) which use N as their major requirement. If we give adequate N to the pot, both the plant and the bacteria will be satisfied and function normally however if the N rate is reduced below the optimum level, the bacteria will win out every time and the plant will get off second best. Reducing N to reduce microbe numbers and slow decomposition of organic components will only result in the plant slowing growth as well. Therefore it is vital that we supply enough N to satisfy both plant and bacteria. There is no way around this if we use organic materials to make up our mix.

So the key is: use a nearly mineral substrate if I want to feed at low level of fertilyser? If my mind is correct it is what Rick (TN) is doing ...dolomite stones and moss to hold it in the wood orchid basket. I read that 20% of organic matter was sufficient in a substrate mainly mineral (for example: 20% peat moss mixed with 80% perlite).

 

[naoki]

Thank you for the explanation, Mike. I've known N and bark media, but your explanation really points out what is going on (especially, I didn't know how composted bark could work). I'll dig around more information about this process related to media-microbe relationship. I probably need to get the book (Growing Media for Ornamental Plants) you recommended.

In old days, people recommended NPK=3:1:1 for bark, but you are trying to go more extreme ratio with ammonium nitrates, right?

I guess foliar feeding is one way to keep the microbe population small. Since the limiting resource for bacteria seems to be N, we could drench the orchid with no N fertilizer. Then foliar feeding with urea? But it is too much work.

I guess with enough inorganic, breaking down of bark isn't probably a big deal. Dr. Tanaka's brachy method uses 60-70% inorganic, and he doesn't have to repot for a long time.

 

[Brabantia]

I don't know if publications are existing on reactivity between materials used usually in horticulture and there capacity to react with ammonium and nitrate nitrogen forms. This is maybe a good subject for a student thesis.

 

[gonewild]

It's not direct tissue damage that's the problem, it's reverse osmosis where high media EC leads to salt concentration higher in the media than the roots which will draw water from them and kill them after which they will (possibly) get attacked by pathogens. That wont happen on a leaf surface as usually does not stay wet. Of course if you put a tablespoon of fertilizer in a glass of water and poured that on the leaves you would burn everything!

125ppm N levels of fertilizer is not a high EC level. MSU type fertilizers when mixed to provide 125ppm N and mixed with good pure water (rain, RO, ect) do not create high EC levels that will damage orchid roots.

When you apply fertilizer that actually have EC levels that exceed what the plants can tolerate the foliage will show stress (damage) before the roots do. I'm not talking about water applied to the foliage I am talking about water applied to the root zone.

 

[gonewild]

Since the limiting resource for bacteria seems to be N, we could drench the orchid with no N fertilizer. Then foliar feeding with urea? But it is too much work.

That won't work well. Orchids need to use their roots to take in the majority of their nutrients.
Feed the bacteria in the media and let the bacteria do their job of providing a perfect media environment.

 

[naoki]

That won't work well. Orchids need to use their roots to take in the majority of their nutrients.

Lance, yeah, it probably doesn't work, and too much troubles. But I think there are studies which used tracers to show orchids take up some types of nutrients via leaves (I can't find the citation, though). I think it was about P and N. In case of N, the N uptake is higher when NH4 and NO3 are mixed than when they were used separately. I think Ray said Urea can also get incorporated to leaves readily. Obviously it doesn't apply to all mineral nutrients. Also, roots are more efficient than leaves in uptake (this is probably obvious, but I saw a paper about it). So it probably requires lots of foliar N application, and it is wasteful (and difficult to control the dripping). Uptaking is only part of the story, so there could be other side effects. But are there data showing that orchids can't survive with just foliar N? Or did you try it? Just curious.

 

[Stone]

125ppm N levels of fertilizer is not a high EC level.

Never said it was

When you apply fertilizer that actually have EC levels that exceed what the plants can tolerate the foliage will show stress (damage) before the roots do

.

How do you know that? Excessive accumulation of salts will result in browning of the leaf tip (usually) but the leaf continues to function at a reduced rate where as irreparable damage to the roots can happen within hours.

 

[Stone]

In old days, people recommended NPK=3:1:1 for bark, but you are trying to go more extreme ratio with ammonium nitrates, right?

I don't know about extreme but I have been experimenting with adding very low concentrations of plain N (as AN, and mainly to satisfy the bacteria) to the watering in between feedings- which I have now reduced even more.

So now its regular fertilizer at 0.3 dS/m which gives me 40ppm-N and about 20 to 30 ppm-K every 3rd or so watering. And water with plain N at about 40ppm in between. The paphs (including the brachys) look pretty happy with that. Other things are getting much higher rates double or triple the above.

Perhaps the reason people are seeing improvements with Klite is not the reduction in K but the fact that they are actually giving more N ( at similar ECs to MSU for instance) therefore reducing the salinity stress at the roots while not sacrificing N. ( or more precisely, giving more N without increasing overall salinity). If that is the case there is no need for Klite....simply reduce the EC and make up the difference with more N.
Let me give an example:
If a plant growing in pure perlite had an optimum EC level of say 1.0 dS/m with N at 100ppm and K at 100ppm. You would/could achieve optimum growth. Now if you reduced the EC to 0.5 dS/m you would still have the K/N ratio the same but the growth will be reduced because of the reduced N. Then... if you brought up the N level back to 100ppm, optimum growth will resume. The K/N ratio is now 0.5 but the growth is the same. Does that make sense?
In OTHER words, as I've said before and as has been proved in many, many.....many trials. K is not the problem.

I recently read aother study on K in a bromeliad. Growth was not affected by rising K .....even AFTER Ca and Mg levels began to fall!!
I will try to find it again but it's gone walkabout.

 

[Brabantia]

Lance, yeah, it probably doesn't work, and too much troubles. But I think there are studies which used tracers to show orchids take up some types of nutrients via leaves (I can't find the citation, though). I think it was about P and N. In case of N, the N uptake is higher when NH4 and NO3 are mixed than when they were used separately. I think Ray said Urea can also get incorporated to leaves readily. Obviously it doesn't apply to all mineral nutrients. Also, roots are more efficient than leaves in uptake (this is probably obvious, but I saw a paper about it). So it probably requires lots of foliar N application, and it is wasteful (and difficult to control the dripping). Uptaking is only part of the story, so there could be other side effects. But are there data showing that orchids can't survive with just foliar N? Or did you try it? Just curious.

How are working professionals? I don't think they spray one pot at a time. The leaves and the substrate are impregnated by the fertilizing solution. Of course we do not know the proportions of elements picked up by the leaves and by the roots .

 

[gonewild]

Never said it was

Didn't say you did.

How do you know that?

I did not get my knowledge from the internet.

Excessive accumulation of salts will result in browning of the leaf tip (usually) but the leaf continues to function at a reduced rate where as irreparable damage to the roots can happen within hours.

Not talking about excessive accumulation of salts. The discussion is about application concentration and ratio. Excessive accumulation is a simple result of neglect and poor cultural practice.

 

[gonewild]

Lance, yeah, it probably doesn't work, and too much troubles. But I think there are studies which used tracers to show orchids take up some types of nutrients via leaves (I can't find the citation, though). I think it was about P and N. In case of N, the N uptake is higher when NH4 and NO3 are mixed than when they were used separately. I think Ray said Urea can also get incorporated to leaves readily. Obviously it doesn't apply to all mineral nutrients. Also, roots are more efficient than leaves in uptake (this is probably obvious, but I saw a paper about it). So it probably requires lots of foliar N application, and it is wasteful (and difficult to control the dripping). Uptaking is only part of the story, so there could be other side effects. But are there data showing that orchids can't survive with just foliar N? Or did you try it? Just curious.

We tried it years ago. Best growth is obtained by irrigation of roots.

But be clear what your question is..... Are you asking if orchids can survive with just foliar N or are you asking if they can grow well and be productive with just foliar N?

Orchids can survive without any artificial application of N. But note that no one that keeps orchids wants their plants to just survive.

We need to be careful and not make feeding orchids more complex than need be. Looking for published scientific proof is going in the wrong direction. As horticulturists and not biologists we need to learn from growing plants and not reading papers.

Most knowledge about plant nutrition has never been published in a science paper.

 

[gonewild]

If that is the case there is no need for Klite....

Why the vendetta against K-lite? Is it the name you object to?

simply reduce the EC and make up the difference with more N.

Whats the difference in the nutrient N/K ratio whether you remove K or add N? The result is still a lower ratio of K.

Let me give an example:
If a plant growing in pure perlite had an optimum EC level of say 1.0 dS/m with N at 100ppm and K at 100ppm. You would/could achieve optimum growth. Now if you reduced the EC to 0.5 dS/m you would still have the K/N ratio the same but the growth will be reduced because of the reduced N. Then... if you brought up the N level back to 100ppm, optimum growth will resume. The K/N ratio is now 0.5 but the growth is the same. Does that make sense?

You just took the long way around and arrived at a fertilizer that has lower K. But if it makes you happy you can call it "N-heavy"

In OTHER words, as I've said before and as has been proved in many, many.....many trials. K is not the problem.

Show us a trial that tested low K that was not designed to show that higher levels of K produce more growth faster?
The object of "K-lite" is to produce long term plant health not fast rapid growth that results in higher disease rates and shorter average lifespan. (But for some reason it is providing fast rapid growth as well as improved health.)

I recently read aother study on K in a bromeliad. Growth was not affected by rising K .....even AFTER Ca and Mg levels began to fall!!
I will try to find it again but it's gone walkabout.

Don't you just hate it when you don't have published proof for what you say?

 

[Stone]

Didn't say you did.



I did not get my knowledge from the internet.



Not talking about excessive accumulation of salts. The discussion is about application concentration and ratio. Excessive accumulation is a simple result of neglect and poor cultural practice.

What on earth are you on about

 

[gonewild]

What on earth are you on about

¿Qué es lo que no entiendes?

 

[Stone]

Why the vendetta against K-lite? Is it the name you object to?

I don't have a vendetta. I'm just trying to show that this concept is barking up the wrong tree. I think it would be remiss of me to just keep what I think is the truth to myself. Or should I keep quiet and not obviously irritate you so much?

Whats the difference in the nutrient N/K ratio whether you remove K or add N? The result is still a lower ratio of K.

Geez Lance I thought by know you would see my point but obviously you are still missing it. The difference is this: A high K/N ratio is not what is causing all the ''problems'' Rick and you keep talking about.
The whole point of developing K lite was to reduce the K not to raise the N. The theory is that K was the offending nutrient NOT that N was too low and that it was this that lead to reduced uptake of various which caused all sorts of unsubstantiated ills and this is simply not the case.

You just took the long way around and arrived at a fertilizer that has lower K. But if it makes you happy you can call it "N-heavy"

Once again the K ion is not causing the problem. (NOTE! if it is, it's only because it is leading to an overall increase in salinity which is higher than optimum for that particular plant. NOT because of the antagonism with other nutrients) I am happy to take reports improvements by using Klite at face value, BUT just don't tell me its the lowered K that caused an improvement by allowing increased Ca and Mg to be taken up thereby leading to a better plant which was more resistant to pathogens ect. ect.

If all other nutrients are supplied in adequate amounts, Nitrogen can be used to increase or decrease plant growth. It is this basic understanding that seems to eluding you.

The object of "K-lite" is to produce long term plant health not fast rapid growth that results in higher disease rates and shorter average lifespan.

I agree that is the object but this stuff about fast growth resulting in higher disease rates and shorter average lifespan is complete garbage and has no basis in fact whatsoever.

Don't you just hate it when you don't have published proof for what you say?

You don't seem to worry about it too much!