fertilizer-nutrients Diesel Exhaust Fluid, good/cheap source of Nitrogen?

DementedWelder

DementedWelder

I've been trying to find a good source of 5-0-0 or 15-0-0 nitrogen and somehow stumbled upon a youtube rabbit hole of fertilizing with DEF. Seems to make sense considering it's about 32% urea and the rest deionized water with no trace elements. A gallon of DEF is just about $4 with a discount I'm able to get, which is vastly cheaper than Alaska Fish Fert or even Ammonium Nitrate. Less tempting to magically have a fuse and some aluminum powder fall in there by accident too. lol
Go away Uncle Sam. I'm behaving.

How viable of an option does this seem to be? It's too early for maths for me so haven't confirmed if it's 15-0-0 or not, but lawn care forums seem to keep insisting.
NH3 is highly soluble in water. 46% nitrogen by weight.

Does this seem practical or just nonsense?
 
Pure agricultural urea will almost certainly be much cheaper. It is used in much higher quantities, doesn't have to be dissolved and bottled, and doesn't have to be that pure. Pure NH3 is actually 82 % pure nitrogen, you are probably talking about ammonia solutions (just multiply that percentage with its concentration). And that link sounds like a horrible AI creation.
 
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Save $ and collect your urine, which contains a few % of urea and some trace elements as a nice extra. Piss in a bucket and dilute with water, apply to your plants. Don't piss on your plants directly! Urine also contains NaCl and too much might "burn" your plants.
 
@ahayastani
Problem with that is it's an unknown quantity of nitrogen.

@Annuchin
The bulk places around here are just that, bulk. I could get it cheaper for sure, but would wind up paying more overall for a quantity I don't need. My cheap-ass would get up to no good with excess dry fertizers hanging around.


@NJChilehead
Hahaha. I hadn't even noticed the date.
The DEF is slightly cheaper, by almost exactly the mark-up value Amazon typically has. Overall cheaper too. I don't need much.

Unless it becomes the bulk of my N, $8 of DEF would last me well into multiple seasons. Part of why it caught my interest.
 
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I put this question through Google Deep Research to see what it had to say 🤷‍♂️

It confirmed the 15-0-0 match but warns about microorganism contamination, concentration burns, and long term soil impact.

docs.google.com

DEF as Nitrogen Fertilizer?

An Evaluation of Diesel Exhaust Fluid (DEF) as a Nitrogen Fertilizer The inquiry into the potential use of Diesel Exhaust Fluid (DEF) as a nitrogen fertilizer stems from its known composition, which includes a significant percentage of urea. Urea is recognized for its high nitrogen content and it...
docs.google.com docs.google.com
 
Seems good enough for me.

Edit: Not going to be too worried about buring the plants. I'd have to really mess up my maths.

So long as DEF works out, seems my final NPK will be in the 0.4-0.1-0.2 range. I'm aiming for the nitrogen in the .3 range but keeping liquid measurements simple, 0.4 is close enough.
Should be fine for feeding every other day.
 
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hmartin said:
I put this question through Google Deep Research to see what it had to say 🤷‍♂️
It confirmed the 15-0-0 match but warns about microorganism contamination, concentration burns, and long term soil impact.
https://docs.google.com/document/d/1LFlJX8GTscYTvOmkhHm5QvwhWNut36DJbFN19_QAeuI/edit?usp=sharing
Click to expand...
The correct calculation results in 46.65 % nitrogen in urea (14.01 g/mol (N) * 2 (atoms N in urea) / 60.06 g/mol (urea)) and 16.53 % N in DEF (1.09 kg/L (density DEF) * 32.5 % (urea in DEF) * 46.65 % (N in urea)). And the paragraph about the dangers of the deionized water in DEF is almost comical...
 
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