# Urea vs. Ammoniacal



## Slingblade_847 (Apr 13, 2020)

Hey fellas, and happy Father's Day to all the fellow lawn dads.

Quick question. Looking for starter fertilizer and was thinking Xstart. Contains ammoniacal N vs. Urea. Was looking for urea based product, but honestly I couldn't tell you the differences or benefits of one vs the other.

What is the main difference between these, and for starter fertilizer should I aim towards one vs. the other?


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## CarolinaCuttin (Sep 6, 2019)

@Slingblade_847 Keep in mind what goes on in the soil:

Urea >urease> Ammonia >nitrosomonas> Nitrite >nitrobacter> Nitrate

In the long run, it's all nitrate. Nitrates are highly mobile in soils so they are going to be washed through the profile quickly. They are a poor choice for starter fertilizer because after the watering cycles needed to grow the seed, most of the nitrate has washed through. Urea is very quickly converted to ammonia (ammonia takes a proton from the water in the soil to get ammonium) when it gets wet by the enzyme urease which is everywhere in your lawn. The conversion from ammonium to nitrate is a slower one, so I would prefer either a urea or ammonia source but between the two it's dealer's choice as long as soil temps are above 50° F. Below this temperature urease isn't very active and doesn't convert urea into a plant-usable form of nitrogen very efficiently.


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## Slingblade_847 (Apr 13, 2020)

@CarolinaCuttin Thanls for the insight. Took me a few reads to understand but believe I follow. Most starters I find are some sort of quicker release be it urea/ammonia based. It seems you would be suggesting something either stabilized or slow release? Any starter fert you'd recommend?


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## cldrunner (May 14, 2019)

@Slingblade_847 This 45 min video is all about nitrogen.

https://store.ewingirrigation.com/sources-of-nitrogen

This is also a great resource from Matt Martin of @thegrassfactor . I have really learned alot from this guy.






@CarolinaCuttin That was well said. You are a great source in this community!!


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## CarolinaCuttin (Sep 6, 2019)

Slingblade_847 said:


> @CarolinaCuttin Thanls for the insight. Took me a few reads to understand but believe I follow. Most starters I find are some sort of quicker release be it urea/ammonia based. It seems you would be suggesting something either stabilized or slow release? Any starter fert you'd recommend?


Quick release urea and ammonium are fine, but yes the best option is a slow release which can be a synthetic like methylene or triazone urea or an organic. It won't be flushed right through the profile like the nitrates.


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## Ohio Lawn (Mar 20, 2019)

Is amomoniacal nitrogen the same as ammonium sulfate?


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## CarolinaCuttin (Sep 6, 2019)

Ohio Lawn said:


> Is amomoniacal nitrogen the same as ammonium sulfate?


Ammonium sulfate is a source of ammoniacal nitrogen. Any salt containing the ammonium cation provides a source of ammoniacal nitrogen. It can be ammonium sulfate, ammonium nitrate, ammonium phosphate, calcium ammonium nitrate, etc.


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## Ohio Lawn (Mar 20, 2019)

CarolinaCuttin said:


> Ohio Lawn said:
> 
> 
> > Is amomoniacal nitrogen the same as ammonium sulfate?
> ...


Great. Thank you.


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