# Where did I go wrong- Urea



## Agiuliano10 (Apr 21, 2020)

So I am 14 DAG on my reno and went to put down my first spoon feeding of N with urea and something had to have gone wrong in my calculations. This is what I have for numbers based off an online fertilizer calculator found here: http://agebb.missouri.edu/fertcalc/.

I split the yard into sections and weighed out the urea for each section. 
Total sq ft: 4,295
Front: 1800 (.8 lbs urea or 12.8 oz)
Left Side: 420 (.2lbs urea or 3.2 oz)
Right side: 275 (.1 pounds urea or 1.6 oz)
Back: 1800 (.8lbs urea or 12.8oz)

I loaded my Scott's mini edge guard spreader and set it to the lowest setting and planned on making multiple passes until the hopper was empty. I was skeptical because it didn't seem like a lot of urea in the hopper but I figured my math was right because that calculator seemed dummy proof. I didn't even make it halfway up and down the front before the hopper emptied. Any suggestions or alternate ways to determine how much urea to put in the spreader?


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## Sinclair (Jul 25, 2017)

Use a hand spreader on the lowest setting for such low rates of fertilizer, or dissolve in water and spray it.

Urea prills are big and the rates are low, so it's difficult to use a big spreader.


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## Harts (May 14, 2018)

Spraying is much easier.

Other thing I would do is round your numbers.

1800 = 2000
420 =400
275 = 300

Also pretend urea is 50% N not 46. Makes math so much easier.


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## Agiuliano10 (Apr 21, 2020)

Harts said:


> Spraying is much easier.
> 
> Other thing I would do is round your numbers.
> 
> ...





Sinclair said:


> Use a hand spreader on the lowest setting for such low rates of fertilizer, or dissolve in water and spray it.
> 
> Urea prills are big and the rates are low, so it's difficult to use a big spreader.


Will take both of these into consideration. Thanks guys.

Did I do any damage putting a full sq footage amount on half the yard? And should I stay off that half next application?


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## Sinclair (Jul 25, 2017)

I'm the wrong guy to ask about dangerous rates of Urea. :lol:

You're fine. Apply some to the side that didn't get any, and give it a good watering.


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## Agiuliano10 (Apr 21, 2020)

Harts said:


> Spraying is much easier.
> 
> Other thing I would do is round your numbers.
> 
> ...


@Harts how many gallons of water per pounds of urea should I be using to apply at a rate of .25lbs/1k? Just read a whole thread on it and still struggling to wrap my head around the calculations


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## BBLOCK (Jun 8, 2020)

Agiuliano10 said:


> Harts said:
> 
> 
> > Spraying is much easier.
> ...


he's going to say 1 gallon of water per k
.5lb of Urea per k

call me psychic

so for quick math if we rounded to 3k sq' you would be putting down 1.5lbs of urea total into 3 gallons of water

that would give you .25N per k if you assumed that Urea was 50% N

that's exactly what I put down last week on my new reno'd grass
and i rounded up my 2700sq feet to 3k and did exactly that.

watered in.

she's looking great.


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## BBLOCK (Jun 8, 2020)

Sinclair said:


> I'm the wrong guy to ask about dangerous rates of Urea. :lol:
> 
> You're fine. Apply some to the side that didn't get any, and give it a good watering.


yeah i wasn't here last fall, save me the research.

i heard some rumors!

what were you putting down last fall for rates


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## Zip-a-Dee-Zee (Apr 9, 2020)

Concentration shouldn't matter as long as you calibrate your sprayer. If I want to spray 2,500 sq. ft. at 0.2#/M then I would dissolve just over a pound of urea in 2.5 gallons because I know I can cover 500 sq. ft. with 0.5 gallon.


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## Biggylawns (Jul 8, 2019)

Go based on how much nitrogen you want to put down.

If you want to put down .25 lb of Nitrogen per 1000 sq ft then just multiply the amount of N by 2. You would weigh out 1/2 lb or 8 oz of urea.

For carrier in spraying, use what you feel comfortable with but, as a guideline, do not go below 1 gallon of water per 1000 sq ft. Some go lower but have experience and knowledge in doing it.

If you're going to spray, based on 4300 sq ft::

Example 1:
You want .25 lb N/1000 sq ft:

Take 4300 and divide by 1000 = 4.3
To get .25 lb N, you need .5 lb of urea...
4.3 x .5 lb(weight of urea) = 2.15 lbs or written another way:: 4.3 x 8 oz (weight of urea) = 34.4 oz urea

Therefore, 34.4 oz of urea will yield .25 lb N when applied over 4300 sq ft.

Example 2:

You want .5 lb N/1000 sq ft:
Take 4300 and divide by 1000 = 4.3
To get .5 lb N, you need 1 lb urea...
4.3 x 1 lb = 4.3 lbs urea or 68.8 oz

Once you get the hang of it you'll skip the lb to oz conversion and just use oz.

Spray application should be practiced so you can consistently put down 1 gallon of water per 1000 sq ft. That will give you a good baseline for increasing/decreasing the water/1000 sq ft.


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## Agiuliano10 (Apr 21, 2020)

Biggylawns said:


> Go based on how much nitrogen you want to put down.
> 
> If you want to put down .25 lb of Nitrogen per 1000 sq ft then just multiply the amount of N by 2. You would weigh out 1/2 lb or 8 oz of urea.
> 
> ...


@Biggylawns appreciate the breakdown. This is great!


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## Harts (May 14, 2018)

1 gallon per 1000 sq. Ft.

You can also just pretend you have 4000 sq ft. Use 4 gallons of water total. Easy.

No need for 4.3 anything.

You want half pound N? Use 1lb urea. Or 4 lbs total for your yard.

Don't over complicate it.


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## 1028mountain (Oct 1, 2019)

Harts said:


> You want half pound N? Use 1lb urea. Or 4 lbs total for your yard.
> 
> Don't over complicate it.


Wouldn't a half pound N for a 4k yard would be 2lbs total? 4lbs would be 1lb per k no?


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## BBLOCK (Jun 8, 2020)

1028mountain said:


> Harts said:
> 
> 
> > You want half pound N? Use 1lb urea. Or 4 lbs total for your yard.
> ...


only 46% of the pound of Urea is actual Nitorgen right. so 1lb is only ~.5lb N


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## 1028mountain (Oct 1, 2019)

BBLOCK said:


> 1028mountain said:
> 
> 
> > Harts said:
> ...


Ahh got it. thanks man so if so using the same math for .25/k for 4k lawn it would be 2lbs of urea?

Edit: math was wrong


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## Sinclair (Jul 25, 2017)

(0.25 lbs N/k)*4k = 1 lb N

1 lb N = 2 lb Urea.


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## 1028mountain (Oct 1, 2019)

@Sinclair

I fat fingered my reply, it should have been 2lbs of urea or half of what Hart suggested for .50.

My bad.


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## ludawg23 (Aug 10, 2020)

This is a nice tool if you don't want to do the math yourself

http://agebb.missouri.edu/fertcalc/


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## Agiuliano10 (Apr 21, 2020)

If my first app of N was kind of half assed and uneven when is the next time I can apply? I'm worried the area that got essentially a double dosage will burn.

Refer to the OP as to why the screw up happened


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## Sinclair (Jul 25, 2017)

I've done more than double your accidental dose on purpose.

Get out there and feed the other half of your lawn. As long as it spreads evenly, you won't burn anything.


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## Harts (May 14, 2018)

Too many people are afraid of urea, like you're dumping glyphosate on your lawn. It's just nitrogen. As long as it's even and watered in, you are highly unlikely to burn your grass.

I'll be putting down another 1lb N per K later today from Urea. Did the same last weekend. Just because I want to see if there's any significant difference from the small apps I did in the previous years.


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## Lawn Noob (Jul 26, 2020)

Harts said:


> Too many people are afraid of urea, like you're dumping glyphosate on your lawn. It's just nitrogen. As long as it's even and watered in, you are highly unlikely to burn your grass.
> 
> I'll be putting down another 1lb N per K later today from Urea. Did the same last weekend. Just because I want to see if there's any significant difference from the small apps I did in the previous years.


Are you spraying or going with a granular broadcast application?


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## john5246 (Jul 21, 2019)

it's not rocket science guys
calculate the rate based on the Fall Nitrogen Blitz thread
DO NOT apply to wet grass
Spread the urea in 2 passes with a hand spreader. Use the lowest setting the first time till you get the hang of it.
Water it in after or if rain is expected you can time just as the clouds come in and save yourself the trouble of watering. I do about 15mins of watering with a sprinkler.


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## ken-n-nancy (Jul 25, 2017)

john5246 said:


> Water it in after or if rain is expected you can time just as the clouds come in and save yourself the trouble of watering. I do about 15mins of watering with a sprinkler.


If one is reliant upon only rainfall for irrigation and is worried about forecasts not coming to fruition, you can even put a rain cover on your broadcast spreader and spread the fertilizer *during the rain*.


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## Harts (May 14, 2018)

Lawn Noob said:


> Harts said:
> 
> 
> > Too many people are afraid of urea, like you're dumping glyphosate on your lawn. It's just nitrogen. As long as it's even and watered in, you are highly unlikely to burn your grass.
> ...


Up to 1/4lb N I spray. Anything higher is granular.


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