Macroelements/microelements must be a costant ratio?

[DarioU]

Dear Orchid friends,
The ratio of macro and microelements in a nutrient solution must be costant? In other words a solution with 100 ppm of N must have more microelements of a solution with 60 ppm of N? Or should be better if microelements were in the same amount in both solutions? Our hobby is wonderful and interesting but very diffucult. Is not so?
Thank you

 

[PaphMadMan]

Nature doesn't supply nutrients in a fixed ratio, and there are many successful fertilizer and nutrient solutions with very different ratios. It may depend on your purposes, but in general I would keep micronutrients constant when trying out different macronutrient levels.

 

[gonewild]

I think the ratio between micro and macro nutrients is very important.
I don't thing anyone knows what the correct ratio is or even how much to apply.

 

[DarioU]

Is there something written about the range suggested for each microelement in solution? A minimum and a maximum level?
Irrigation water without any fertilizer should have the same amount of microelements?

 

[gonewild]

Is there something written about the range suggested for each microelement in solution? A minimum and a maximum level?

Yes there is a lot of research and written documents about micro nutrients.
What I'm saying is that no one really knows the correct answer.
If you look on most complete fertilizer labels it will list the micro nutrients and those ratios are based on what is assumed to be the best.
You can copy those ratios or change them based on your on environment.
You need to know what micro nutrients are already in your water supply and media so you don't add too much of any of them.

Irrigation water without any fertilizer should have the same amount of microelements?

No.
In my opinion the micro nutrients should be applied at the same time as the base fertilizer. And in my opinion that should be every time you water.

 

[DarioU]

Thank you Gonewild but the problem is that on complete fertilizer label there are the micronutrients ratios but the their ppm in the final solution depend by how much fertlizer I have used.... For 100 ppm of N I have x ppm of Boron (for istance) and for 200 ppm of N I have 2X ppm of Boron ... but 2x ppm of Boron are already in a toxic amount?

 

[ALToronto]

Given that commercially available complete fertilizers are meant to be used at 200+ ppm N, and the micros are added accordingly, you will probably not overdose the micros if you keep the N at orchid-friendly levels.

 

[DarioU]

But if I use the same commercially available complete fertilizer at 50 ppm N I underdose micros?

 

[ALToronto]

Probably not - otherwise we wouldn't be using RO and rain water for our plants; they'd be doing great in tap water.

My plants in pots get K-lite at about 10-15 ppm N in RO water (10-12 ppm TDS), total TDS reading is about 70. They're doing fine and are not showing any signs of nutrient deficiencies. Each new growth is bigger than the previous one, whether it's cattleyas, oncidiums or phrags. Everything is in balance, although at very low concentrations.

The plants on my living walls get ammonia-based 25-10-10 also at 10-15 ppm N, with added Epsom salts, for a total TDS reading of about 90-100. Since the walls are concrete based, the plants get plenty of Ca, and I need to add some Mg to balance it out. The actual amount of Ca is not nearly as important as the Ca/Mg ratio, which should be in the 2-4 range. The runoff water has a TDS reading of about 300, so it picks up a lot of calcium. It also picks up silicate, iron, aluminum, sulphate and a whole host of metals from the flyash component of my concrete.

Flyash is the leftover minerals after the organic components of coal are burned off. It's about 1% of the weight of coal, so the trace minerals in coal are concentrated 100 times. Still, they're in the same perfect balance as they were in the ancient vegetation that created the coal deposits.

I'm growing phrags in the catch basin of my newest living wall, in semi-hydro conditions in lava rock, and they seem to be ok with the 300 ppm TDS water that they get. I do flush them once in a while, though.

 

[gonewild]

But if I use the same commercially available complete fertilizer at 50 ppm N I underdose micros?

This is the part that i said no one really knows the positive answer.

The concept of using certain ratios between all the nutrients keeps things in balance.
Think like this...
If you apply 100ppm Nitrogen as a macro nutrient and at the same time you apply 2ppm Iron as a micro nutrient the nitrogen and iron have a ratio of 100:2 or 50:1 (same ratio)

Now if you apply the same fertilizer at half strength you have 50 ppm of nitrogen and 1 ppm of iron and that ratio is 50:1 which as you can see is the same ratio as above even though you applied only half as much.

This illustrates what is meant by a balance fertilizer, the ratios between nutrients are constant within the formula regardless of the strength it is mixed.

The ratio between nutrients is probably more important than the strength.... and no one knows positively what ratios are the best. However if you compare the ratios between macros and micros of different fertilizer brands you will see they are all mostly very similar.

 

[ALToronto]

Actually, Lance, a 'balanced' fertilizer has the macro nutrients in equal proportions, e.g. 20-20-20 or 10-10-10. I never saw the point of making a 10-10-10 fert by the same company that makes a 20-20-20, but PlantProd does. I haven't looked at the micros closely enough to see if they were in the same amounts.

 

[gonewild]

Actually, Lance, a 'balanced' fertilizer has the macro nutrients in equal proportions, e.g. 20-20-20 or 10-10-10. I never saw the point of making a 10-10-10 fert by the same company that makes a 20-20-20, but PlantProd does. I haven't looked at the micros closely enough to see if they were in the same amounts.

I think the term "balanced" when applied to fertilizer is just a sales prop.

I've never considered balanced as being equal numbers but rather the correct balanced ratios of nutrients for a given type of plant.

20-20-20 may be balanced for grass but it not balanced for petunias.
When 30-10-20 was created it was touted as the perfect balance for orchids.
To me a balanced fertilizer is like a balanced diet for humans, nutrients in varying quantities that when consumed together provide ideal health.

Usually the difference between 20-20-20 and 10-10-10 would be different source chemicals...... I think!

 

[limuhead]

Lately I hardly ever have time to fertilize. I fertilized last week for the first time in a month or so. I did notice some of my plants 'greened up' a bit, but after experimenting with different fertilizers, k-lite, MSU, organic, Miracle Grow, Peters, and countless others I have come to a conclusion.
OF ALL OF THE FACTORS CONCERNING ORCHIDS FERTILIZER IS THE LEAST SIGNIFICANT FACTOR. End of story...

 

[Ozpaph]

I might suggest if the other factors (light etc etc) arent optimal then the mythical 'optimal' fertilizer application is not going to compensate.
I think fertilizer is the proverbial 'icing on the cake'.

 

[Bjorn]

No, disagree. I firmly believe that good growing is absolutely dependent on a constant and regular supply of micronutrients. Many people have sufficient of the most important in their water already, others not. That is why we add fertilisers. For some reason there seems to be a common misunderstanding that 100ppm N is good for orchids and fertilisers are often composed with this concentration in mind. Reality is of course that this is the equal of "megasize me" , remember that bloke that lived on mega sized burger meals? That was not good for him and is not for the plants either.
I and several others use far less fertiliser, around 10ppm N seems more appropriate. But then we face another challenge, the micros in the readymade fertilisers get too low.
Realising this, some of us make up their own fertilisers and for some species and growers, with great success at very low macronutirent levels.
But where the "sweet spot" is, that is another story. Suggest you read the theads by Roth regarding this, perhaps this one
http://www.slippertalk.com/forum/showthread.php?t=23210&page=13
is the most precise additional to the culture document below
http://eurobodalla.org.au/fileadmin...012/Paphiopedilum_culture_and_propagation.pdf

 

[Ray]

Let us not forget that we are talking MICROnutrients here, suggesting that while they may be essential, they are not needed in great supply.

Secondly, most of them are easily translocated within plant tissues - boron being an exception - so unless the plants have been getting none of a particular nutrient, it is likely there will be sufficient amounts available.

Then we also have to consider that in some cases, the micronutrients aren't really permanently incorporated into plant tissues, but act more like "catalysts" or "transfer agents" that facilitate processes, therefore they are not consumed, but remain available for future activity.

To me, the bottom line is "yes", they are important, but knowing there are "some" being provided in my fertilizer is sufficient, even at very low application rates.


Ray Barkalow
firstrays.com

 

[orcoholic]

Lately I hardly ever have time to fertilize. I fertilized last week for the first time in a month or so. I did notice some of my plants 'greened up' a bit, but after experimenting with different fertilizers, k-lite, MSU, organic, Miracle Grow, Peters, and countless others I have come to a conclusion.
OF ALL OF THE FACTORS CONCERNING ORCHIDS, FERTILIZER IS THE LEAST SIGNIFICANT FACTOR. End of story...

I'm with you. Least important but most time wasted discussing.

 

[Rick]

Here's the actual in-situ concentrations (not ratios) of macros in water around the roots of Phrag kovachii:

Ca = 45.6ppm
K = 0.39ppm
Mg = 4.0ppm
Na = 1.2ppm
Cl = 14.2ppm
SO4 = 7.7ppm
HCO3 = 126.8ppm

NO3 = 0.39
No P listed but don't expect it to be greater than N or K.

Only micro listed (Boron) = 0.02ppm

These are very similar to the local surface water, and really not far from averages across the world (although the range is high).


So if you want to "feed" your plants like mother nature, applying N at 200ppm is totally un-natural.

Most N going into plants is fixed on the spot via nitrogen fixing microorganisms.

As a toxicologist I know that the micros (particularly the heavy metals) are toxic at low concentrations and only found in the wild at "micro" concentrations, not the "milli" concentrations we dump on our plants in fertilizer applications.

Ratios are only half the understanding of applying nutrients to plants. Need to understand the total dosing regime of concentration/amount/duration.

 

[gonewild]

Ratios are only half the understanding of applying nutrients to plants. Need to understand the total dosing regime of concentration/amount/duration.

That's the part I'm talking about that no one really knows the positive answer for.
But we are starting to learn more now that we are not just assuming the labels on fertilizer are what is correct for plants. And it's starting to look like fertilizer companies are overselling nutrients.
More is not always better. But then sometimes it is! :rollhappy:

 

[PaphMadMan]

Lately I hardly ever have time to fertilize. I fertilized last week for the first time in a month or so. I did notice some of my plants 'greened up' a bit, but after experimenting with different fertilizers, k-lite, MSU, organic, Miracle Grow, Peters, and countless others I have come to a conclusion.
OF ALL OF THE FACTORS CONCERNING ORCHIDS FERTILIZER IS THE LEAST SIGNIFICANT FACTOR. End of story...

I'm with you. Least important but most time wasted discussing.

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