Some notes on the use of fertilisers and in particular micronutrients

[Bjorn]

I will not cover fertilisers som much here, just mention my curent fertiliser regime:
All water has fertiliser added. I use a foliar feed with the following composition, N based on urea; added at a level of approximately 40ppm, (1/33tsp/gal) to my water which is mostly coming from rain. Additional, approximately the same amount of Calcium nitrate is added.
N:20%
P:3.5%
K:11.6%
Mg:1.2%
S:5%
B:0.04%
Cu:0.2%
Fe:0.02%
Mn:0.26%
Mo:0.006%
Zn:0.14%
+ Ca(No3)2 at 40ppm.
This should make my fertigation contain approximately
15ppm N total
8ppm N from urea
7ppm N from nitrate
1.4ppm P
4.6ppm K
10ppm Ca
0.5ppm Mg
2ppm S
0.016ppm B
0.08ppm Cu
0.008ppm Fe
0.104ppm Mn
0.00024ppm Mo
0.056ppm Zn
And probably quite a bit of traces already in the water...
So, this is not a mixture of pure urea, more a 50:50mix of N from ammonium and nitrate. If we look at the micros however, we find that the Fe:Mn:Zn:Cu is close to 1:10:6:8 i.e. quite different from standard and with much less iron than commonly found. E.g K-lite has approximately 3:2:2:1 which means much more iron relatively to the others (and my mix).
In his extensive thread "Mineral nutrition" http://www.slippertalk.com/forum/showthread.php?t=7692
Xavier writes that he found Fe:Mn:Zn ratios of 1:8:4 to 1:8:8 in leaves of freshly collected wild plants. "In the fertilizer industry, that ratio is usually from 4:2:1 to 4:4:1" he also writes. So, there is no chance that "normal fertilisers" would be capable of supplying those micronutrients I though. That was the reason for starting with the foliar feed which comes quite a bit closer to Xaviers recommendations. Xavier also mentions the greening effect of mancozeb (contains Zn and Mn) and also comments on the use of copper.
After using the fertiliser mix above (corrected pH to +-6 with citric acid) i told myself that there was too much fungii going on and that I should start to spray against it. So, I brewed up a mix of mancozeb(Dithane) with copper oxychloride and some other fungizides and started spraying. I use a low pressure high airflow Paint gun for the operation, very effective. The spraying was repeated a couple of times at two weeks interval and now I am down to once a month. Quicly I experienced the greening effect on some of my plants, and furthermore, a few of them suddely started to grow like crazy.
Ok, start with randsii seedlings in beginning of February 2014. These seedlings are here Close to 2 years out of flask. Relatively pale in appearance

Here, the same seedlings in endof May 2014, after fertigation for half a year and some weeks of extra Mancozeb etc. The spraying leave a rather ugly deposit on the leaves but it does wither away. Bad Picture, but you can see the fungal reasoning plus change in size and color.

Yesterday August 6th 2014

Compare with the first Picture, same plants in the same position, BUT the SIZE!

Not only randsii, here are some roths:
End of May 2014, plants deflasked 13months earlier (April 2013)

And now in beginning of August 2014:

 

[Dido]

Oh Bjorn you have to send me some of your mix so I can try it.

 

[Bjorn]

Would if I could Dido, but its not that easy, there are two injectors hooked up on the water line, one with the foliar feed pH adjusted with citric acid and one with the Calcium nitrate. This ihas to be done in order to prevent precipitation of Calcium salts.

 

[Dido]

I was meaning the citric is not the problem I have enough
As you know.
The trace elements will be a problem at present not in future.
I will change job and will start to work for a big trace element producer soon
I come closer to your business I have the feeling

And by the way I fertilize by hand.

A friend just told me that his randsii I got him, did not move for nearly 1 year now..... So maybe he should try something like that too.

 

[Bjorn]

Good Luck to you and your friend, think the trick is to spray with dithane and copper, supplies manganese, zink and copper. I could send you some of that fertiliser though.

 

[NYEric]

Hmmm. Gives the plants that "wild-collected" look!

 

[Justin]

very, very impressive growing!

 

[AdamD]

Beautiful plants and unbelievable growth! Now, help me understand, is this just your foliar feed or are you also watering with this mix?

 

[eggshells]

Thanks for the updates Bjorn. Looking good. Has the fungal infection stopped completely. It does looks like it as the new leaves looks fresh.

 

[Bjorn]

Beautiful plants and unbelievable growth! Now, help me understand, is this just your foliar feed or are you also watering with this mix?

Basically the mancozeb etc is given for the micronutrients, but when I spray there is the added bonus of protecting against deceases as well. The drawback is of course that it looks ugly. I am now at a rate of once a month, think that should suffice.

btw: the fertilizer is given in all the water and I am using a hose to distribute it. The sprayed stuff ends up in the pot eventually.

 

[Bjorn]

Thanks for the updates Bjorn. Looking good. Has the fungal infection stopped completely. It does looks like it as the new leaves looks fresh.

It has become much better. Still some incidents, but definitely improving.

 

[gonewild]

Basically the mancozeb etc is given for the micronutrients, but when I spray there is the added bonus of protecting against deceases as well. The drawback is of course that it looks ugly. I am now at a rate of once a month, think that should suffice.

Another drawback is that the pathogens may develop a resistance to the fungicide with prolonged use. I have also used the mancozeb (and still do) to see how well it works as a nutrient and it does work. But I wonder if the improved appearance of the foliage is a result of removing pathogens rather than a benefit from the minerals as nutrients?

[/QUOTE]btw: the fertilizer is given in all the water and I am using a hose to distribute it. The sprayed stuff ends up in the pot eventually.[/QUOTE]

I'm a little confused, are you applying separate mixtures as foliar feed or is you irrigation water the same mix as the foliar fertilizer?

 

[Bjorn]

Another drawback is that the pathogens may develop a resistance to the fungicide with prolonged use. I have also used the mancozeb (and still do) to see how well it works as a nutrient and it does work. But I wonder if the improved appearance of the foliage is a result of removing pathogens rather than a benefit from the minerals as nutrients?

btw: the fertilizer is given in all the water and I am using a hose to distribute it. The sprayed stuff ends up in the pot eventually.[/QUOTE]

I'm a little confused, are you applying separate mixtures as foliar feed or is you irrigation water the same mix as the foliar fertilizer?[/QUOTE]

Clumsy written, I fertigate at a rate of approximately 80ppm TDS (foliar feed in irrigation + Ca-nitrate pH adjusted ) as described in the beginning. This is in all water by use of two dosatrons in series, one for the fertiliser and one for the Ca-nitrate.
Additionally I do this spraying with dithane etc.
Appearance is one thing, another is the growth of the randsii. That might have been coincidential, but it was so.....how to put it --- impressing.

 

[troy]

What is the ph of your foliar feeding mix

 

[Bjorn]

Unadjusted it gets to pH=8 or so, but I adjust with citric acid so that the result is approx 6.

 

[Brabantia]

@Bjorn
In your preparation are the oligo-elements chelated? Is this necessary or pure marketing? Some fertilisers producers claims they put 1% in their salts mix (dry base). If I feed at 0.5 gr/L this make 5 ppm EDTA if this is the chelate used. What about the toxicity of EDTA?

 

[Bjorn]

@Bjorn
In your preparation are the oligo-elements chelated? Is this necessary or pure marketing? Some fertilisers producers claims they put 1% in their salts mix (dry base). If I feed at 0.5 gr/L this make 5 ppm EDTA if this is the chelate used. What about the toxicity of EDTA?

I have not found anything on that, but expect that the Fe is chelated. By adding the quite large amounts of citric acid that I do to lower the pH, there is a lot of chelating going on as well. Could the citric acid be one of the key factors here?

 

[DavidCampen]

I make my own nutrient concentrates consisting of: calcium nitrate, magnesium nitrate, ammonium nitrate, potassium nitrate, ammonium citrate, potassium phosphate, ammonium sulfate, boric acid, ferric ammonium citrate, manganese nitrate, aspartic acid, zinc nitrate, copper nitrate, sodium molybdate, sodium chloride, cobalt nitrate and nickel nitrate. I don't use any chelating agents other than citric and aspartic acid which are not anywhere near as strong as EDTA and its variants. I make this as a 2 component concentrate since phosphate, sulfate and molybdate need to be segregated from calcium and magnesium in a concentrate. My most recent formulation used 25 grams of ammonium citrate and 1 gram of aspartic acid to about 650 grams of the remaining ingredients.

 

[troy]

Doesn't calcium and magnesium nitrate bond and precipitate out?

 

[troy]

I was told calcium nitrate is best used with magnesium sulfate