Feed your Phals and watch them grow!

[Rick]

Trying to work it out mathematically will lead to confusion and probably substandard results.

This is what farmers and county extension agents do all the time, and they don't seem confused.

 

[gonewild]

That is not the way to look at it. If you tried to supply exactly what the plant ''needs'' you end up starving it.

If the plant gets exactly what it needs it won't be starved nor will it be overfed.

The way to feed (assuming everything else is right), is to increase the EC up to just before the point where any higher increase begins to reduce growth. (over the hill in the graph) Anything before that point is good not bad. That's the was trials are carried out and that's really the only way. This can only be done with close observation of the plants' response to treatment.

The problem with relying on the results of published trials is the time period is always too short. Running the nutrients to the maximum point just before damage occurs may give fast growth results in a short time but a trial with that result does not look at the plants long term response.
I've always ran my nutrient levels to the max just as you suggest but now I am believing that is a mistake.

Trying to work it out mathematically will lead to confusion and probably substandard results.

Don't all trials base their procedures on mathematical guesses?
How else would you work out the amount of nutrients to apply?

 

[Stone]

The sufficiency standards are very broad and flat between "deficiency" and "excess". There's a huge span of minimal need and over the top for the sufficiency standard curves I've reviewed, and I have yet to see a trial for species orchids.

Also I have yet to see a sufficiency curve for parameters outside of a single growth or crop production cycle.

Show me evidence that demonstrates a downward trend in plant response after an initial high performance. And you cannot use your own often quoted examples as there is not enough historical information to go by.

Since I'm feeding at less than 1/50th your rate N and 1/200th your rate of K, how are my plants even surviving (let alone thriving)

But are thriving? In comparison to what? If you are comparing your results now to your early ''boom and bust'' results, then obviously you were doing something very wrong then.

 

[Stone]

If the plant gets exactly what it needs it won't be starved nor will it be overfed.

You can't work out what the plant needs on paper. There are way too many variables. For a start every species is different. You can only do it by observation. Im' afraid that just takes years not calculators.

The problem with relying on the results of published trials is the time period is always too short. Running the nutrients to the maximum point just before damage occurs may give fast growth results in a short time but a trial with that result does not look at the plants long term response.

Well if you want to go by theory, theoretically, the long term response should be more of the same. Unless you can point to a reason why it wouldn't.

I've always ran my nutrient levels to the max just as you suggest but now I am believing that is a mistake.

Why? Show me evidence that optimum (maximum) nutrition is wrong or somehow causes a downturn.
Also don't presuppose that I or anyone else knows what the optimum is. Again there are so many variables it is probably impossible to determine. However in some cases you can get pretty close.

Don't all trials base their procedures on mathematical guesses?

No. That's why they call them trials. And what is a mathematical ''guess'' anyway? I thought maths was absolute.