Urea vs Nitrate in soil

Hello,

I've been wondering for plants in soil, if there is any negatives from feeding them nutrients that have no Urea based Nitrogen?

It seems like many nutrient profiles that aren't strictly hydroponic have a combo of urea and nitrate.

From researching it seems like using only nitrate based nitrogen nutrients in differing soil conditions and plants, that it is *very slightly* better.

- Jiji

Urea, for soil potted plants is rather salty, so to speak.
Nitrates are not.

Urea based products are always avoided by me and others with the same view.
I think I remember Ed Rosenthal commenting that way in one of his books also.

The guy who wrote hydrobuddy actually has a blog post on urea, although not in soil.

http://scienceinhydroponics.com/2010/05/urea-in-hydroponics-positive-or-negative.html

I fail to see how urea, a molecule, is too salty while nitrate, an ion, is not.

https://en.wikipedia.org/wiki/Salt_(chemistry)

"In chemistry, salts are ionic compounds that result from the neutralization reaction of an acid and a base. They are composed of related numbers of cations (positively charged ions) and anions (negative ions) so that the product is electrically neutral (without a net charge)."


http://www.diffen.com/difference/Covalent_Bonds_vs_Ionic_Bonds

jijiandfarmgang said:

Hello,

I've been wondering for plants in soil, if there is any negatives from feeding them nutrients that have no Urea based Nitrogen?

It seems like many nutrient profiles that aren't strictly hydroponic have a combo of urea and nitrate.

From researching it seems like using only nitrate based nitrogen nutrients in differing soil conditions and plants, that it is *very slightly* better.

- Jiji

Click to expand...

In my opinion, if you're going to use soil, urea is more intuitive than using only nitrate sources of N. Ammonia (from breaking down urea) is used to feed the nitrifying bacteria so they can ultimately create nitrate. The bacteria in this system regulate the nitrate level of the soil.

If you're going to use only nitrates, why not use a hydroponic medium?

I'd like to go back to coco coir, but its hard to find for a reasonable price. I looked for bulk purchases but didn't come up with much.

I might end up doing a batch of hydro and soil, I guess I could do a different soiless medium.

The only thing I like about soil is that its more forgiving. Sometimes shit happens (internally, pests,pythium, power outage) or (externally, medical issues, family emergencies).

Unfortunately when you have quite a few patients who need their medicine, and you give the shit happens line, they don't like that.

- Jiji

Coco is more than I'm willing to pay as well. That's why I like DWC with 3inch netcups and for outdoor gardening stuff, peat moss based medium.

I do like soil, it's just that you lose a lot of the benefits of using a hydroponic solution using nitrate salts in soil. Using a soiless medium allows you to fine tune the metal ion ratios whereas in soil, a lot of that is locked into the soil composition.

I guess it's really more of a philosophy than a hard science (considering nitrates in soil will grow a plant perfectly fine), but i feel like it makes more sense to feed the soil (ammonium/urea) and to let bacteria regulate the level of nitrates in a soil based media. I wouldn't worry, however, about "killing off" the nitrifying bacteria with nitrates, like a lot of organic growers warn of. They'll come back as you need them without having to buy bacteria.... hehe.