Early K-lite results

[gonewild]

There are a variety of reasons for this, some trees produce organic substances to inhibit things from growing on them.

Or an excess of K.

But if you want a nutrient based theory then why pick K, perhaps it is N, Ca or P.

Because K is the last letter in NPK. :rollhappy:

It was not a random choice. Rick focused on K based on his experience with it's toxicity to microbes. For decades we (growers) have tweaked the levels of nutrients and found a happy place. But as far as I know no one ever considered the drastic reduction of K since we all believed K was a major nutrient. Almost all other combinations have been tried and did not yield the results that low K is producing.

And then the amounts of the other nutrients would also be reduced proportionally. So you are saying that it is not the ratio of the nutrients but the absolute amounts available. So people should just use very dilute MSU formulation.

No not suggesting that at all. I think I have maintained it is all about the ratio between the nutrients. It appears that K needs to be low in the balance. If you apply maximum amounts it appears that orchid plants indulge on K and become obese and are subject to health problems.

For years (40) I used basically the MSU formula and tried almost every possible combo of nutrient ratios. The only real positive improvements was when I doubled the N using Calcium Nitrate. On a lot of plant types growth was better but I credited the extra N and Ca for the improvement. Now I see it was probably from the lower ratio of K. I never tried to lower the K because I based my fertilizer mix on Potassium Nitrate and I assumed K was a major nutrient that would not hurt plants if it was present in excess. I also personally ate a ton of sugar back then.....not now.

 

[gonewild]

No, that's my point - they barely moved with Dyna-Grow. I'm growing them alongside my orchids, so they're getting the same feed and growing conditions. I even planted them in lava rock, just like most of my orchids.

OK I just wanted to clarify that the growth you are seeing from K-lite is better than the growth you had before. Your observation as your opinion of this fact is what we all want to hear.

 

[Rick]

The issue I have with these nutrient flow measurements is how relevant they actually are. They are studying big trees and big trees do not account for a very big percentage of the forest coverage. Not needing very much K comes close to answering that question.

Actually that's one reason I focused on leaf litter data. Especially with regard to forest paphs. Since the amount of K available in soils (especially karst based) is very low (relative to fertilizer concentrations) the primary pool of K (and other nutrients) is in the leaf litter. As the leaves break down and rain goes through it, the trees move it back up into the tree to be recycled into biomass. The trees with deep roots can access (slowly) additional K for positive growth.

Now leaf litter data is supplied for a karst based rainforest (I believe in Sumatra) in the Orchids article. The ratios of K Ca/Mg do not match MSU. Neither do the majority of live leaf tissue data supplied from the Zotz study in Panama.

The "scientific" premise of MSU was that it was derived from leaf tissue studies. However it was not based on wild/jungle/insitu plants but on plants already being fed "balanced fertilizers" under agricultural conditions.

From other literature sources we also know that plants will pick up K in excess of need, and that it reduces the plants capability to pick up Ca and Mg.

So how do leaf litter and live leaf studies of insitu rainforest plants end up with less K than Ca when GH plants end up with more K than Ca getting fed "balanced" fert formulas?

 

[eteson]

From other literature sources we also know that plants will pick up K in excess of need, and that it reduces the plants capability to pick up Ca and Mg.

That is the main point why I decided to start testing K-lite.

I am growing Phragmipedium kovachii in a calcite+dolomite based substrate but surprisingly the plants are showing some sintoms o calcium deficiency... now I am begining to think that the excess of K of my former fertilizer was blocking the calcium...

 

[Rick]

That is the main point why I decided to start testing K-lite.

I am growing Phragmipedium kovachii in a calcite+dolomite based substrate but surprisingly the plants are showing some sintoms o calcium deficiency... now I am begining to think that the excess of K of my former fertilizer was blocking the calcium...

That's exactly what got me scratching my head in the first place doing the same thing for all the "calcareous paphs".

Actually it was K toxicity to higher life forms (not microbes) in aquatic systems that got me to look at this from a toxicity (inhibition) standpoint.

 

[gonewild]

So how do leaf litter and live leaf studies of insitu rainforest plants end up with less K than Ca when GH plants end up with more K than Ca getting fed "balanced" fert formulas?

Perhaps because in the rainforest the roots are in contact with solid Ca rich materials where in a greenhouse Ca is mainly supplied via liquid fertilizers.
Rainforest plants may be better at taking in Ca from solid sources as opposed to liquid by design where K comes to the plant in leached liquid from naturally in the rainflow.

 

[gonewild]

Actually it was K toxicity to higher life forms (not microbes) in aquatic systems that got me to look at this from a toxicity (inhibition) standpoint.

Are you saying that mussels are not microbes?

 

[Rick]

Perhaps because in the rainforest the roots are in contact with solid Ca rich materials where in a greenhouse Ca is mainly supplied via liquid fertilizers.
Rainforest plants may be better at taking in Ca from solid sources as opposed to liquid by design where K comes to the plant in leached liquid from naturally in the rainflow.

This doesn't hold up for epiphytic species, which were the point of the Zotz study (no roots attached to solid rock, and plants dependent on stem flow water).

Limestone is also impoverished in K. So leaf litter over Karst is actually overrepresented in K relative to the underlying geology.

Similar trends noted for leaf tissue over serpentine which is low in both Ca and K, but plants ended up with more Ca than K or Mg (the mineral more abundant in serpentine).

Somewhere in the pile is leaf litter data over granit. This leaf litter also isn't predominantly high in K despite the primary geologic source of K is errroded feldspars found in some granits.

Given rivers flow over the same geologies as the trees access, its very rare to find rivers/creeks/streams high in K.

 

[Rick]

Are you saying that mussels are not microbes?

Not today:wink:

 

[gonewild]

This doesn't hold up for epiphytic species, which were the point of the Zotz study (no roots attached to solid rock, and plants dependent on stem flow water).

This might depend on the Ca content of what the roots do contact. I don't think we know if tree bark might be a Ca source since Ca does form crystals in wood.

Given rivers flow over the same geologies as the trees access, its very rare to find rivers/creeks/streams high in K.

Agree, Unless the rivers are moving fresh supplies of K from the mountains above the tree zone.

 

[Rick]

This might depend on the Ca content of what the roots do contact. I don't think we know if tree bark might be a Ca source since Ca does form crystals in wood.



Agree, Unless the rivers are moving fresh supplies of K from the mountains above the tree zone.

Ca is present in tropical stem flow water, and is released from decomposing leaf matter. Another perspective to keep in mind is that the mineral component of dry leaves/bark still only acounts for a few percent of the total biomass. Most of whats there is carbon, and not Ca/Mg/K ......

Minerals in streams come in at every source (percolated through leaf litter and erroded geology). Because of high rainfall in tropics it is generally dilute anyway. I'm presently sitting on some lowland river data from Pehang, Malaysia, and the conductivity is only 30-40 uS/cm. That's a potential TDS of only 15-20 mg/L, and the Ca/Mg is about 1/3 of that. Given anion to balance, that's not leaving much for K salts.

 

[Rick]

http://ican.csme.utah.edu/wp-content/uploads/2012/02/Jordan-1980.pdf

Here's a very rare paper that actually has throughfall water concentrations.

 

[limuhead]

These are the plants I saw making the fastest improvement. Better than K-lite, MSU, or any other combination. No fert, water every other day...




Under a tree, just natural compost from Lychee leaves, Macadamia nut leaves, and some of both of them put through a shredder.

 

[Stone]

I was too tired to read all this paper but the point under ''Saturation Effect'' is interesting. It possibily expains why orchids on low K and ''normal K'' diets may very well have similar levels of K in their tissues or slightly lower in low K-fed plants? ( and I'm sure I read that somewhere) Just because we feed the plants high levels of K doesn't mean uptake will keep increasing forever. But as far as the antagonism with Mg, this may be a more important factor in the rhizosphere and at CE sites than inside the plant?
Oh yes the paper! http://plantcellbiology.masters.grk...ysiology4-Absorption_Of_Mineral_Nutrients.htm
Low K is not advised if ammonium-N is used and Ca and Mg. additions should also be increased

 

[Rick]

These are the plants I saw making the fastest improvement. Better than K-lite, MSU, or any other combination. No fert, water every other day.

I have a compot of Paph calosum seedlings doing vey well in a shredded leaf mix and no fertilization.

I wouldn't say superior to K lite plants, but doing very well. As typical for a hobby GH I don't have side by sides going of splits of the same flasking.

Right next to this compot of calosum is a compot of henryanums in a regular bark or CHC mix getting K lite. These are growing extremely fast compared to the calosums.

So is the variable species, k lite, potting mix?

The last couple times I got henry seedlings, they did crap with the same mix but MSU.???
So is that variable set genetics, or some unknown/undocumented change in growing conditions like temp/humidity?

 

[gonewild]

These are the plants I saw making the fastest improvement. Better than K-lite, MSU, or any other combination. No fert, water every other day...
Under a tree, just natural compost from Lychee leaves, Macadamia nut leaves, and some of both of them put through a shredder.

What are they?
How long have they been planted there?
They are making the fastest improvement compared to what?

 

[limuhead]

What are they?
How long have they been planted there?
They are making the fastest improvement compared to what?

These were the runts of a flask of Phrag longifolium x besseae. hardly any roots so I compotted them. About a month ago I decided to stick them in the compost at the base of a tree. They perked up almost overnight. They are doing pretty good I think. As far as comparing them to what I have some of the same seedlings in 2" pots. Some are getting K-lite, some are getting 15-5-15, some are getting a combo. Kind of a hassle but I am interested in seeing if there really is a difference between ferts. I suspect the improvement is due to high humidity.

 

[gonewild]

These were the runts of a flask of Phrag longifolium x besseae. hardly any roots so I compotted them. About a month ago I decided to stick them in the compost at the base of a tree. They perked up almost overnight. They are doing pretty good I think. As far as comparing them to what I have some of the same seedlings in 2" pots. Some are getting K-lite, some are getting 15-5-15, some are getting a combo. Kind of a hassle but I am interested in seeing if there really is a difference between ferts. I suspect the improvement is due to high humidity.

OH I thought you posted the pics to show they were growing better with no fertilizer compared to K-lite. But that is not the case.

Why is the humidity higher in the garden than in your ghse?

 

[limuhead]

Humidity is higher because the compost is constantly wet/moist because it is about 6-12 inches thick. Kind of like in any natural environment, moisture laiden air is heavier than dryer air. My greenhouse is open on all sides below the benches. The benches are all wire topped, making air movement better as opposed to solid benches. As water/moisture evaporates from the compost into the surrounding air it holds more moisture, closer to the source...

 

[gonewild]

Humidity is higher because the compost is constantly wet/moist because it is about 6-12 inches thick. Kind of like in any natural environment, moisture laiden air is heavier than dryer air. My greenhouse is open on all sides below the benches. The benches are all wire topped, making air movement better as opposed to solid benches. As water/moisture evaporates from the compost into the surrounding air it holds more moisture, closer to the source...

What is the ambient humidity in your area?