K-Lite has been around a few years now... updates?

[Bjorn]

Bjorn, I think the hairs on paph roots are exactly where nutrients are taken up (at least some) And on the contrary, they are supremely efficient at nutrient uptake. That is why an orchid can survive with just 2 live roots where any other plant would die.

Agree on that, BUT unless they touch, or are wetted by water containing nutrients, they will not absorb it.

I'm not sure what you mean here. Obviously if the roots (of any plant) are not in contact with a substrate particle it is impossible for the root to take up anything from that particular site. (Unless water liberates the nutrient and carries it to the root - which happens constantly)

If the CEC is low, yes it happens, except for the adsorbed species. In my opinion, the whole concept of CEC gets questionable for orchids. While regular plants have lots of fine hair roots that can get to and exchange adsorbed cations by manipulating the pH in the rhizosphere, orchids do not have that fine web of hair-roots (except for the fur on the paphs) So if "the next" soil-particle has a lot of cations (nutrients) adsorbed on it, it will not be available for the orchid.
So when you fertilise, what you do is that you saturate the velamen with nutrients, and adds to any CEC-sites in the aggregates. At the next watering (without fertiliser) the surplus (not adsorbed) nutrients get flushed out of the system, perhaps some of it is adsorbed by the roots, and the roots are gradually deprived of nutrients as they are consumed by the plant, waiting for the next dose of fertiliser.
You might notice that my hypothesis is that the velamen acts as the main source of CEC for orchids. And it has to be refilled. Best is to refill with a constant but low concentration of the right nutrients. The bonding of the cations to the CEC-sites is pH dependent. At low pH the cations are more loosely bound than at higher pH. For some substrates it has previously been speculated if the CEC was so high that they adsorbed so much (notably K and CHC) that they over time actually became "poisonous" for the roots. Questionable but perhaps, at higher pH (>7?) it might?

Another thing, if it is true that the velamen is the prime source of CEC, then, once the active sites are occupied, further increase in fertiliser concentration should not give much effect, except for the detrimental effect that high salts concentration has. In my mind, most fertilisation that is going on is a waste of nutrients:evil:
I tend to agree with you Mike that the proportions are more important than we normally think of. The problem is of course that in many cases, the opimal composition for one species might not be so optimal for another one

Confused. More important than what?

than the adsorbed cations. Once you have flushed out the fertiliser solution, there is not much available for the orchids (perhaps unless you start water with slightly acid water that liberates cations from the CEC-sites)

 

[Stone]

The atmosphere.

In part yes and also a lot from the leachates from their neighbours and leaves of the tree they grow on.
So you are saying that mosses and lichens can survive and grow on that source but orchids cannot? Or are you no saying that the mosses and lichens get their nutrients from somewhere else too?

It's a really big stretch (exaggeration) to think you can remove all the micro organisms and then measure the stem flow to make this comparison.

Your contention is that orchids get their nutrients from mosses and lichens. This study proves that mosses and lichens actually remove some nutrients from the stemflow which would otherwise be available to an orchid growing on the same branch agreed?
The ONLY nutrient which can be assimilated in a gaseous form is nitrogen.
Mosses, and lichens and bacteria cannot ''create'' Calcium or copper. It all comes from the same places. Rain, dust, leaching, decomposition, insects and bacteria and fungi.
Meaurement of stemflow takes all these into account. There is no mysterious other source.

Besides stemflow is not where I said the nutrients come from.

Then where do they come from? Outer space?

The microbes are in close or direct contact with the orchid plant in my scenario.

No doubt. And they can supply nutrients as they die. Do you believe this is cannot be measured in the stemflow?
A microbe will not give up its minerals until it dies. This is measured in the stemflow readings too.
The only possible way your senario makes sense is that ENDO MYCORRHIZA is supplying the orchids needs. (mycorrhiza is NOT a microbe)That may very well be the case. In this case the orchid will have a massively enhanced ability to assimilate nutrients.
But the mycos get it's nutrients from the same places too.
The stemflow figures above are the concentration of nutrients available to all the organisms. Regardless of what they are.

How can you relate stemflow on a per hectare level?

You are missinterperating the data. These figures are for stemflow only not total nutrient to the hectare. Those numbers would probably be 10 times that number

This equates to 0.084 grams per square meter of nitrogen that is not enough nitrogen to grow a forest, so this is BS.

It doesn't need to. Forests grow on soil.

But if you insist.... The stemflow with the bryophytes contains 13% more nitrogen than without

No argument from me. Many mosses can fix atmospheric N

I wont mention that the bryophytes also remove over half of the potassium thus protecting the orchids from it's evil powers.

Silly talk. Are you saying now that K harms orchids but mosses can handle it?:rollhappy:

There is no mineral flow amount at sufficient levels to feed the orchids in what you show above. This indicates the nutrients come from something other than stemflow and the nutrients are not in a form that the research has looked for.

The nutrient form always remains the same. Its the flux that is important.
The nutrient DO NOT come from ''something other than the stemflow''!!!!!!!!
They are just gathered in a very efficient manner. Probably from the myco association I mentioned above.



How is this for a theory?

*Because for various reasons in cultivation. We destroy or inhibit
mycorrhizal inocculation of the orchid.
Be it too much P or to high an EC or Chloride in the water or pH or whatever!

*The orchid now has to rely on its own roots for nutrient assimilation....

*We give it the same concentrations we see in the habitat

*The orchid starves

*We feed more heavily (perhaps 10 times)

*The orchid thrives

*We feed very lightly

*The orchid becomes infected with mycos

*The orchid thrives.

*We feed very lightly

*The orchid DOES NOT become infected with mycos

*The orchid starves

*Conclusion....take your chance with mycos and microbes or forget them and feed enough so the orchid thrives.

Lance Birk mentioned some niveum? seedlings sponateously germinating in the pots of some imported plants. These grew very fast. (from memory) Obviously with the help of mycorrhiza.
It would be ideal if we could grow orchids this way but unless we really know what we are doing there would probably be many failures.

Further reading:http://www.researchgate.net/profile...oud_forest/links/0046351affc1b76653000000.pdf
http://www.amjbot.org/content/94/12/1944.long

 

[gonewild]

You are missinterperating the data. These figures are for stemflow only not total nutrient to the hectare. Those numbers would probably be 10 times that number

Doesn't

With: (kg/ha)

mean kilograms per hectare?

 

[ChrisFL]

So you are calling me a liar? :fight:

It's what my meter displayed. Granted it is a cheap meter and may read slightly acidic as 7.0 but that's the reading.

No, I'm simply stating a fact, that rainwater on this planet, from this atmosphere, is not neutral. Further, it is difficult for typical pH meters/electrodes to measure the pH of rainwater because it lacks enough conductive ions to work correctly. So, no, it is not likely you got an accurate reading.

 

[ChrisFL]

The atmosphere.

As in, gaseous form??

 

[myxodex]

These fertiliser threads here on ST are just great. They make me think of a form of emergent behaviour,
the chaotically repeating patterns all mixed up with an utterly unpredictable topic evolution. I'm really enjoying this one, thanks for the posts and ideas.

@ Bjorn, I'm liking your ideas, just one quibble. The CEC substrates will, as I guess you are aware, have very different H+ vs other cation affinities and hence variation of behaviour with pH, just look at the different zeolites. If you are feeding with a NH4/NO3 mixed N fert, then the pH goes through a little cycle over a few days, acidification followed by recovery back to where it started ... or not, depending on the ratio. OK this study was done on potted roses, not orchids, but I think the same mechanism is going on in our orchid pots if we use NH4 & NO3. I think CEC in the medium can be useful as a sort of cation buffer (including pH) if you "load it" with a counterion of choice before use, Antec used Mg/Ca with CHC and I simply soak my sphag in a few changes of hard water (120 ppm Ca). I'm thinking that variations in pH will be enough to cycle cations on and off CEC substrates, not to mention organic acids produced by microbes in the medium which will help mobilise cations by competitive chelation. I take your point about K, it will most likely displace most other cations except possibly NH4, but it will also depend on the heterogeneity of binding sites in the CEC that you use. Synthetic CEC materials are often fairly homogenous, natural ones not so much.

Aside from short period fluctuation in pH, sometimes there is long term drift in pH over the potting cycle, and it is this that I've measured and it caused me problems. A few years ago someone posted links to the articles by Bill Argo on pH that I found very helpful so I'll repost the links here just in the unlikely case there is anyone left here who has either not yet read them or isn't aware of the basic issues:

http://staugorchidsociety.org/PDF/IPAPlantNutrition.pdf
http://staugorchidsociety.org/PDF/IPAWaterQuality.pdf
http://staugorchidsociety.org/PDF/IPAFertilizers.pdf
http://staugorchidsociety.org/PDF/IPASubstrates.pdf
http://staugorchidsociety.org/PDF/IPAFinal.pdf

There is just one thing with the NH4/NO3 story that I'm uncomfortable with and that is the role of the microbial population. When I was going through horticultural articles on acidification by NH4, one study dismissed any significant contribution by the microbial population. They were using potted plants in loam. Agricultural studies on the uptake of SO4 and NH4 by crop plants have measured the partitioning of these ions into the microbial population and plants. The plants got most of the NH4 and SO4 unless they added some carbohydrate source to the soil, straw, molasses it didn't matter, add carbs and the microbial population got most of NH4 and SO4. When I had progressive acidification problems I was using a bark that degraded quite fast. I was also using a fertiliser that was about 50% NH4 (with rain water... yeah ... stupido !... slaps head). The pH was actually a little lower in the pot with few roots. If we are growing in an organic medium I'm convinced the microbial population can have a big effect on pH changes with NH4 ... microbes have membranes too and they also give out H+ when they take up NH4. I switched to a high NO3 fert and the bark degradation was much slower and acidification stopped being a big problem. I am cautious about agricultural studies but I think some basic mechanisms are general enough to have relevance.

Sooner or later, when I'm reading through these fert threads, my mind comes up with Paph. wentworthianum and why nobody can grow this one? Is it just impossible because of some very specific mycorrhizal association that cannot be transplanted or is there some simple fix, just so counterintuitive or unlikely that no one has thought of it or dared to try? Like Cymbidium suave for example that needs a pH of 4.5 to be happy ! http://staugorchidsociety.org/PDF/ArepHChecksNecessarybyHarryMcElroy.pdf

 

[gonewild]

*Conclusion....take your chance with mycos and microbes or forget them and feed enough so the orchid thrives.

I'm not suggesting that anyone should stop using fertilizer and depend on the living organisms. I'm simply suggesting that orchids have evolved to rely in nature on the organisms to provide nutrients in forms other than dissolved salts. That does not mean they can not use dissolved salts when available.
If what I am suggesting is correct then the known measured amounts of nutrients in the environment is not what will reveal the correct nutrients an orchid needs. That is because the organism supplied nutrient compounds may not be readily dissolved in stemflow water.

You choose to believe that science has the final answer about plant nutrition and nothing unknown can exist and nothing new can be discovered. I choose to look at new ideas and not trust in the written word.
The improved results being obtained with the use of seaweed additions to fertilizer extract just presents a reason to look past the printed text books.

Somehow the trial of using low K with K-lite has evolved into using very low levels of N by reducing the dose to extremely lower levels. The potassium level effect evaluation has been spoiled by too many people making a drastic change in the over dose of nutrients. When the K-lite formula was created it was based on applying a total dose of 100ppm N. Potassium was reduced based on 100ppm and that would still provide ample potassium at 10ppm. But now people are using 10ppm of N and that reduces the available potassium to basically nothing. In the beginning K-lite users reported fantastic growth results. THEN people started using low doses and now we see a lot of K-lite failures. That is not a test of lowering the potassium it is proof that plants need some potassium or they suffer. As far as I can see most or all of the poor results from K-lite are from low dose use at 25ppm or less then the grower switches back to their old fertilizer at 5 times the N dose and things improve. It has nothing to do with the potassium ratio but does have everything to do with lack of nutrients.

The fact that some K-lite users are having great results using low dosage amounts indicates that within their growing environment there is an additional source of nutrients the orchids are benefiting from. I suggest that this benefit is coming from living organisms. And I suggest it is this type of nutrient supply that orchids get nutrients from in Nature and not solely from dissolved salts in the stemflow. Based on this suggestion a grower that can create an environment that fosters the beneficial organisms will grow bigger and better orchids and be able to use less chemical fertilizer.
Salt based fertilizer is our only option until we learn the secrets that remain hidden.

I think this thread is about results of using K-lite? A lot of people have been disappointed with it because why? Is it the low potassium or because they have used to low of a dosage application and generally starved the plants?
To make a fair evaluation of a low potassium fertilizer (K-lite) you must supply the nitrogen at the same rate as you did with the previous fertilizer you are comparing to.

 

[gonewild]

No, I'm simply stating a fact, that rainwater on this planet, from this atmosphere, is not neutral. Further, it is difficult for typical pH meters/electrodes to measure the pH of rainwater because it lacks enough conductive ions to work correctly. So, no, it is not likely you got an accurate reading.

Just kidding about the liar part..
My pH meter does not give lab accuracy but it most likely represents the accuracy that 100% of orchids growers get on their meters. I'm talking horticulture accuracy not chemistry accuracy.

I gave you the readings I got. Now consider where I took the readings was in possibly the cleanest atmospheric place on earth. In a pristine forest far from any industry or pollution, in an area with little smoke from fires. At an elevation where I was literally in a cloud on the eastern slope of the Andes. The rain did not have far to fall to be influenced by atmospheric contaminants. Maybe the pH was not in reality 7.0 based on scientific calibration but it was pure rainwater very close to neutral pH and I was surrounded by orchids in the trees.

 

[gonewild]

As in, gaseous form??

Yes. (And/or from bacteria)
That is where discoveries with lichens is leading. Taking gases from the atmosphere and excreting unique complex chemical compounds. It's these unknown compounds that I suggest orchids have evolved to use as a nutrient source.

 

[orcoholic]

Somehow the trial of using low K with K-lite has evolved into using very low levels of N by reducing the dose to extremely lower levels.

Lance,

I think you're spot on regarding the level reported being used.

At 100ppmN K-lite is probably okay. At 10ppmN, there probably is no fertilizer that works well. At 10ppmN I think the K level is less than one ppm, as is the P. I wonder how little the micros are at that level.

I just don't get the logic of going to 10ppmN? As long as the roots don't burn, why not use more? Cost can't be factor. The cost of using 100ppmN vs. 10ppmN is probably less than a coupe cents per gallon.

 

[cnycharles]

Elements and such are also in the evaporated seawater fog that comes off of the ocean in some places. Some study a little while back showed that colliding sea currents were creating fog which was going up the mountains and on the plants. AnyWhere water evaporates other studies have shown that bacteria can be picked up from water bodies and dispersed everywhere so the same water could have nutrients carried in it. Electrical storms also release nutrients into rainwater which can be another source of food


Sent from my iPhone using Tapatalk

 

[gonewild]

Elements and such are also in the evaporated seawater fog that comes off of the ocean in some places. Some study a little while back showed that colliding sea currents were creating fog which was going up the mountains and on the plants. AnyWhere water evaporates other studies have shown that bacteria can be picked up from water bodies and dispersed everywhere so the same water could have nutrients carried in it. Electrical storms also release nutrients into rainwater which can be another source of food

Yes all those sources add up. However they still don't add up to the amount of nutrients it takes to keep orchids growing in a greenhouse. The environmental salt nutrients that show up in research just are not in high enough concentration in Nature at the points orchids grow. All the research focuses on dissolved elements flowing in. Someone needs to look at other compounds that the highly specialized orchid root may have evolved to acquire nutrients from.

In regards to nutrients coming from the sea it would not be likely here on the eastern slope of the Andes.... it's a really long way to the sea. But there is plenty of electric storms. I guess I'm just adding in a possible reason orchid roots are different from other plants and a possible reason that seaweed and it's strange compounds has such a positive effect.

 

[naoki]

ST fertilizer talk is pretty crazy (in a good way), and I learn a lot of different perspectives!

There are probably several ways to approach plant nutrients, and I think Mike's hypothesis about symbiotic (low nutrients) vs asymbiotic (high dose) culture is pretty interesting. It generally known that under high nutrient availability (especially P), plants tend to get rid of mycorrhizae (because providing carbon to the fungi becomes too costly compared to the nutrient uptake benefit). This is probably a big reason why imitating the nature doesn't mean the best for cultivated plants. I personally think that Bjorn style culture is very interesting: lots of water, low nutrients, generally bigger growing area than the traditional pot-bound method.

I used to think mycorrhizae isn't dominant in orchid culture, but there are several papers isolating the mycorrhizae from cultivated Paphs. Here is an example:
http://www.scirp.org/journal/PaperInformation.aspx?PaperID=22189#.VWZTi2DuVDc

Also, people here talk about "microbes" in speculative manners. Here is some interesting paper about orchid endophytes:
http://www.researchgate.net/profile...chid_Roots/links/0fcfd509535db6a465000000.pdf

But I don't agree that plant nutrients is just fertilizer formulation (from Ray and Mike's discussion). Mike is probably exaggerating it since the book Mike recommended has lots of information about the topic (mineral transport between root and outside, transport within plants, rhizosphere including microbes, fluctuation in root environment etc).

For myxodex's point about long-term acidification, this paper has interesting data (we talked about it frequently):
http://hortsci.ashspublications.org/content/46/7/1022.full.pdf

Their interpretation is that the root excrete (rather than decay of media) is the main cause of long-term acidification. There could be other ways to interpret the data, and it would be interesting to see what you think.

 

[Stone]

Doesn't mean kilograms per hectare?

Yes,.... running down the tree stem.

Kg/ha total yearly deposition is N 12.1, P 1.46, K 33.0

 

[gonewild]

Yes,.... running down the tree stem.

Kg/ha total yearly deposition is N 12.1, P 1.46, K 33.0

Those aren't the same numbers you gave above?
In any case 12.1 kg/ha of nitrogen is not enough nutrients to feed the forest so there has to be a different supply.

 

[paphioboy]

ST fertilizer talk is pretty crazy (in a good way)...

Can't agree more! That's why only sheep pellets for me..

 

[gonewild]

Can't agree more! That's why only sheep pellets for me..

Do you apply them as a foliar spray?

 

[Stone]

But I don't agree that plant nutrients is just fertilizer formulation (from Ray and Mike's discussion). Mike is probably exaggerating it since the book Mike recommended has lots of information about the topic (mineral transport between root and outside, transport within plants, rhizosphere including microbes, fluctuation in root environment etc).

But naoki, Why do hydroponic tomato setups out-perform grown grown?
Nutrients are determined on the optimal formulas.
I don't think it is an exaggeration to say that there must exist an optimum fertilizer formula for any plant. That does not mean we know what it is.

If you can determine the optimal formula you can allow a plant to reach it's genetic potential. (all other factors being optimum too of course) I'm not saying it is easy or even possible in some cases but when it works it really works. This is rarely achieved in nature. If you look at some of the scrawny plants hanging on for dear life in the habitat you get an idea that things are not always as good as what they could be. Take that plant off the tree and give it optimum nutrition and you will not even recognize it 2 years later. Bigger growths, more new leads - more flowers. (and no reason to die)

I have had many bush collected plants which looked like they have been really struggling to survive (short weak growths hardly capable of producing a flower) but have later exploded into vigorous growth in cultivation.

 

[Stone]

Can't agree more! That's why only sheep pellets for me..

That may not be as silly as it sounds. In the end we may discover that a plant based organic fertilizer formula is the best possible way to feed paphs.
It is what they have evolved with. But such a fertilizer could never be available commercially.

 

[Stone]

Those are not the same numbvers as above

Man! The the OLD figures are JUST for the stem flow!
The new figures are TOTAL deposition. (trees only take up a fraction of a hectare)

Again those figures DO NOT ''feed'' the forest. Trees get thir nutrients from the soil, bring up to their leaves and what leaches out is the main source of nutrients for the above ground biomass) (added to the other sources of course - rain, ocean aersols blah blah)

There has to be a different supply

I really cannot for the life of me undersand why you can't see that all above ground nutrients caome from the well known sources mentioned a million times. Apart from some N, There cannot possibly be any other source!
Maybe epiphytes ''suck'' nutrients from the tree's sap? That would make them parasites