Send me some kovachii seed and I'll tell you
How many kilos do you want?
low potassium concept is not sustained by analysis
- Thread starter Roth
- Start date
Help Support Slippertalk Orchid Forum:
Rick
Well-Known Member
Roth
Well-Known Member
- Joined
- Jun 10, 2006
- Messages
- 1,469
- Reaction score
- 390
It is well known in plant physiology circles that K and Na uptake are competitive. But what cracks me up is that as long as I've been growing orchids Na has always been considered "evil" and too be avoided at all costs. Now all of a sudden its a necessary nutrient
In the environment Na is way more common than K. The low K system, or my personal growing practices didn't add any Na to the system to address that. So if our plants were suffering from Na deficiency then once again excess K is a culprit for causing that.
So far all the analysis I have ever seen of orchids had sodium. There has been tests on sodium deficiency, but that's very difficult to 'produce', and is virtually unknown in normal conditions in fact.
Sodium is considered now for quite a lot for crops as a required micronutrient in fact... Lithium is the third one similar to sodium and potassium that can be interchanged, at least for some processes, and only in parts. In some
What the results showed was that the plant would have more sodium when it has less potassium in its tissues, which tends to show that it needed to replace some missing potassium by sodium, possibly. That's an hypothesis, and there could be many other reasons not yet understood.
A
ALToronto
Guest
This sodium-potassium balance holds for people as well. Now where does lithium come into this? And does it make the plants behave better? oke:
oke:
Roth
Well-Known Member
- Joined
- Jun 10, 2006
- Messages
- 1,469
- Reaction score
- 390
This sodium-potassium balance holds for people as well. Now where does lithium come into this? And does it make the plants behave better?
That's why we made that study too, including strange things like lead, arsenic, etc... to see if there is anything interesting outside the previous knowledge.
There are things that are, again, confirmed, like the Mn quantity being on a standard 10 times higher than the Iron. This fits most analysis of wild orchids, not only Phalaenopsis, where Mn is always much higher than Fe.
There are new things, like the Lithium being quite 'high', or the aluminium being much higher too than the iron. The aluminium is interesting, because it appeared on all the media, and the fertilizers did not contain any aluminium, so it means the plants needed it in a way or another.
But that would require another study to know if it has any significance for the lithium.
A
ALToronto
Guest
What about silicon? Did you test for it, or added it specifically?
Aluminum would be quite abundant in all media - clay is an alumino-silicate, and whether the media came from soil-growing plants or lava rock or LECA, there would be plenty of aluminum in all of them. But were the plants with high Al levels any different from plants with low levels?
Aluminum would be quite abundant in all media - clay is an alumino-silicate, and whether the media came from soil-growing plants or lava rock or LECA, there would be plenty of aluminum in all of them. But were the plants with high Al levels any different from plants with low levels?
Fascinating thread.
I thought the idea of lithium for misbehaving plants very amusing, but not as amusing as the %W/W measures for the neutrog fertilizer. Just what is organic potassium? And organic ammonia? I know what organic poo is and it is rich in both... W/W measures suggest to me that 1 kg was burn to ash and then that ash was dissolved and worked back to mass fractions. Not much organic anything in a teaspoon of ash... but that is beside the point. I was using a Neutrog product on my orchids and it worked like a charm and I could dumps loads onto Catts, Cyms and Paphs (also an insigne) without trouble. This is, I think, because the various nutrients are released slowly as the pellet decomposes.
I find the conflict between the proponents of ideas of low K/high NH3 very interesting. If the plants are using the same cation transporter for K+ and NH4+ then there is little difference between talking about low K/high NH4+ and high K/higher NH4+.
Whatever the truth of the matter, both fertilizer regimes seem to work.
As regards correlations on graphs, I don't think them much good. All they do is show correlation, not cause and effect. Even if you had looked up the corresponding p-values for the correlation coefficients/sample sizes and got "significant" correlations this wouldn't say much about what is really going on. I think the only thing we can conclude from the experimental data is that if you are growing a commercial Phalie, with the same fertilizer mix as used in the experiment as well as other conditions... then you should probably grow in NZ sphag moss. That is all we can really conclude with any certainty from the data---and it doesn't exclude the possibility that there is a better way.
I thought the idea of lithium for misbehaving plants very amusing, but not as amusing as the %W/W measures for the neutrog fertilizer. Just what is organic potassium? And organic ammonia? I know what organic poo is and it is rich in both... W/W measures suggest to me that 1 kg was burn to ash and then that ash was dissolved and worked back to mass fractions. Not much organic anything in a teaspoon of ash... but that is beside the point. I was using a Neutrog product on my orchids and it worked like a charm and I could dumps loads onto Catts, Cyms and Paphs (also an insigne) without trouble. This is, I think, because the various nutrients are released slowly as the pellet decomposes.
I find the conflict between the proponents of ideas of low K/high NH3 very interesting. If the plants are using the same cation transporter for K+ and NH4+ then there is little difference between talking about low K/high NH4+ and high K/higher NH4+.
Whatever the truth of the matter, both fertilizer regimes seem to work.
As regards correlations on graphs, I don't think them much good. All they do is show correlation, not cause and effect. Even if you had looked up the corresponding p-values for the correlation coefficients/sample sizes and got "significant" correlations this wouldn't say much about what is really going on. I think the only thing we can conclude from the experimental data is that if you are growing a commercial Phalie, with the same fertilizer mix as used in the experiment as well as other conditions... then you should probably grow in NZ sphag moss. That is all we can really conclude with any certainty from the data---and it doesn't exclude the possibility that there is a better way.
Rick
Well-Known Member
This sodium-potassium balance holds for people as well. Now where does lithium come into this? And does it make the plants behave better?
Also pretty wild is that at least one study done on plant uptake of K used rubidium since it was a strong K surrogate for the plants to uptake (and easier to trace into different functions/places in the cell. But that doesn't mean that plants also have a rubidium requirement.
Please don't say the word rubidium or our plants will start wanting it.
Do realize how hard it will be to supply both lithium and rubidium?
What is rubidium?
Rick
Well-Known Member
In my AOS article I have a table of total mineral content of leaf litter over karst geology in Sumatra.
Silicon content (8042) was 3X higher than K and Al was almost the same as K (1980 ppm Al vs 2474 ppm K). Ca and N were the most common element at 14,000ppm each.
Keeping in mind this is leaf litter and research has shown that tropical plants variably recycle minerals out of the leaves before senescence. The highest rate of recycle was for P (60% recover in Panamanian epiphytes) with about 30-40% recycle of K and N. Ca and Mg were not readily reabsorbed. I have no information about internal re-absorption of anything other than NPK Ca Mg.
Recycle rates give you an idea about what is rare and what is important to the plant to recover.
I wonder if the recycle rate is the same if the nutrient is plentiful in the media?
Will these plants not recycle if they have a ready supply to the roots?
Rick
Well-Known Member
Don't know. But I suspect it could change for different reasons.
I see lots of Phals on high N and K feeds holding on to a lot more leaves than a normal phal (some even start to look like all out Vandas).
But then under high K, Ca and Mg (and Na!) become sparse commodities, and may need to be recycled under that regime.
naoki
Well-Known Member
Oh, yes, I remember that, but I couldn't quite figure out the effect of K on PS. I'm trying to figure this out, but it seems to be pretty complicated, and algae might have some difference in plants. So I'm reading Marschner's Mineral Nutrition of Higher Plants 3rd ed. edited by Petra Marschner (MMNHP). A couple related issues from MMNHP.
- In plants, K concentration is correlated with rate of photosynthesis and RuBP carboxylase activity (an important enzyme for carbon fixation/dark reaction). MMNHP p. 182.
"Upon illumination, additional influx of K from the cytosol [into chloroplast] is required for the maintenance of a high pH in the stroma [inside of chloroplasts but outside of thylakoid, thylakoid membrane is the place where Photosystems I & II and electron transport chain is located] necessary for optimal RuBP carboxylase activity."
- Correlation between NR activity/gene expression and photosynthesis makes sense since NR requires ATP.
- So this seems to suggest synergism between NO3 and K instead of antagonism in plants.
- Also for transportation, there seems to be synergism between NO3 and K. MMNHP p.187. "The role of K in the cation-anion balance is also reflected in nitrate metabolism, in which K often is the dominant counter ion for NO3 in long-distance transport in the xylem as well as for storage in vacuoles."
Stone
Well-Known Member
naoki
Well-Known Member
Among 17 essential elements, some are phloem-"mobile" (Mg, P, K, N) and others are "immobile" (B, Fe, Ca). The other 10 elements are inbetween the two extreme groups. These mobile elements are the ones which you call "recycled", right? Isn't this phloem-mobility partly determined by functions/roles of each element rather than what elements are rare/important? For example, Ca is a component of middle lamella of cell walls, and I'm guessing that it is probably energetically costly to recycle it (even cells die, cell wall could stay there and they form dead leaves).
Is Na categorized as essential elements now? It was called a beneficial element (i.e. plant can complete life-cycle without it)? Maybe my textbook is old.
Rick
Well-Known Member
I don't get that interpretation at all. In light of this article I see nitrate reductase and pH increase by K as competitive processes.
http://link.springer.com/article/10.1007/BF00383860
Some where you need some protons to knock down all the alkalinity produced by K and nitrate reduction to generate ammonia. Given the large amounts of N (as NH3 recommended for high pH pot applications) applied to pots relative to the amount the plant actually uses, it may be another case of nitrifying bacteria to the rescue as they release protons in the process of converting NH3 to NO3.
Rick
Well-Known Member
Although lots of the Ca ends up in cell walls it also is used metabolically, and yes it is a poor intracellular transport (but obviously not 0 since it ends up in the plant to the greatest degree in wild plants). However its also odd that in the case of the Panamanian epiphytes, Mg (one of the "phloem-mobile" group) was not recycled at all, while while Ca was still recycled at the rate of 15-20%. Now from an evolutionary standpoint if Ca was limiting environmentally wouldn't it make sense to come up with an energetically feasible way to recover it (instead of wasting it with growth)?
The Na thing was postulated by Xavier. My textbook is too old too.
Rick
Well-Known Member
L
limuhead
Guest
Hello,
I have made my own fertilizing for a few months now, really improved for less than a couple months now. using 5:1 NK and P) ratio, both N03- and NH4+ (50-50), tap water and Mg++ supplement + oligos.
So far, fertilizing only 30ppm N, I have the very best growth I have ever had (I see it only in a couple months!!!!), and even better since I am using 2/3 rain water +1/3 tap water instead of tap water only (reduced total EC)
Growths are mostly double sized than before, what ever fertilizing I was applying in the past (MSU, urea fertilizer...)
This can be surprising, but the biggest improvment seems to be on the most vigourous plants (Catts, Paphs roths, phil, kolo...).
I have made my own fertilizing for a few months now, really improved for less than a couple months now. using 5:1 N
K and P) ratio, both N03- and NH4+ (50-50), tap water and Mg++ supplement + oligos.So far, fertilizing only 30ppm N, I have the very best growth I have ever had (I see it only in a couple months!!!!), and even better since I am using 2/3 rain water +1/3 tap water instead of tap water only (reduced total EC)
Growths are mostly double sized than before, what ever fertilizing I was applying in the past (MSU, urea fertilizer...)
This can be surprising, but the biggest improvment seems to be on the most vigourous plants (Catts, Paphs roths, phil, kolo...).
