# Spraying Urea



## Harts (May 14, 2018)

Quick question: Can I dissolve my Urea granules in my sprayer and spray the lawn? I wanted to tank mix some Humic, Iron and Urea tonight as rain is in the forecast tomorrow. I'm going to be cutting tonight and I wanted to spray after and minimize my time.


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## g-man (Jun 15, 2017)

Yes you can. You can apply it foliar or immediately water it into the soil.


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## bosox_5 (Jun 20, 2018)

When doing this, what are the concerns? I know you can more easily burn the lawn by spraying, so should you spray less than you would spread? I've never sprayed fert before, but I am interested in doing it in the future and want to learn more.


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## MMoore (Aug 8, 2018)

what kind of rates do you need to use to apply it without burn when you go foliar @g-man


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## g-man (Jun 15, 2017)

@MMoore check this thread.

 Spraying nitrogen


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## Dkrem (Mar 16, 2019)

Yes, if the urea is just straight milky prills they will dissolve very quickly and it takes very little water to do it. Test it first in a cup of water. The reaction absorbs heat so the water will greatly drop in temperature as it dissolves. Be careful and do some research on foliar urea application rates.


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## Pete1313 (May 3, 2017)

Not sure about the compatibility with the humic, but no issues dissolving the urea granules and spraying with iron. Just make sure that since the urea isn't spray grade to use some type of strainer to avoid getting any impurities in the tank. You can see what I use here.
https://thelawnforum.com/viewtopic.php?f=27&t=8014&start=60#p148899

I have done up to .2 lbs/M of N from urea and left it on the leaf without washing it down without any burn. And explained some of the benefits of foliar here.
https://thelawnforum.com/viewtopic.php?f=27&t=8014&start=100#p163204


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## GoPre (Oct 28, 2017)

I've wanted to try this as well, just nervous about the rates and the amount of water. I am pretty consistent with spraying my 2K lawn with 2 gallons of water. If I want .5 lb N/K am I simply mixing 2 lbs of urea in my tank? It seems simple, I would just hate to screw this up.

Edit: I use a 2 gal. sprayer.


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## Pete1313 (May 3, 2017)

GoPre said:


> I've wanted to try this as well, just nervous about the rates and the amount of water. I am pretty consistent with spraying my 2K lawn with 2 gallons of water. If I want .5 lb N/K am I simply mixing 2 lbs of urea in my tank? It seems simple, I would just hate to screw this up.
> 
> Edit: I use a 2 gal. sprayer.


That is correct. 2 lbs of urea in 2 gal of water over 2000 sq ft lawn would give you .46lbs/M of N in a 1gal/M carrier. That rate would be high for foliar though, so wash it off the leaves right after or maybe use a higher carrier volume. At that high of a rate why not just put it thru a spreader?


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## GoPre (Oct 28, 2017)

Pete1313 said:


> GoPre said:
> 
> 
> > I've wanted to try this as well, just nervous about the rates and the amount of water. I am pretty consistent with spraying my 2K lawn with 2 gallons of water. If I want .5 lb N/K am I simply mixing 2 lbs of urea in my tank? It seems simple, I would just hate to screw this up.
> ...


Understood, and the basis of my concern! I have just been reading benefits of foliar applications. I will cut that rate in half just to give it a try. Thanks for the response!


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## Pete1313 (May 3, 2017)

GoPre said:


> Understood, and the basis of my concern! I have just been reading benefits of foliar applications. I will cut that rate in half just to give it a try. Thanks for the response!


Cut it down even more to start. Try .625-.75 lbs(10-12 oz) of urea in 2 gal water over that 2k lawn. That would put you at .14-.17 lbs/M of N. Leave it on the leaf and based on the response adjust up or down from there.


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## SNOWBOB11 (Aug 31, 2017)

@Pete1313 Any reason to use urea over AMS? With high PH soil I've preferred the results of AMS than urea when applying granular but would like to try spraying as well.


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## cglarsen (Dec 28, 2018)

I spray 0.2 lb N/M with 1 gal water about every 7-10 days without irrigation and it doesn't burn. Throw in some iron and it's fabulous for improving color.


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## Pete1313 (May 3, 2017)

SNOWBOB11 said:


> Pete1313 Any reason to use urea over AMS? With high PH soil I've preferred the results of AMS than urea when applying granular but would like to try spraying as well.


I use urea because it is cheaper and has a lower burn potential so a higher rate can be used without the need to wash it in.


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## SNOWBOB11 (Aug 31, 2017)

Pete1313 said:


> SNOWBOB11 said:
> 
> 
> > Pete1313 Any reason to use urea over AMS? With high PH soil I've preferred the results of AMS than urea when applying granular but would like to try spraying as well.
> ...


Thanks. I'm going to spray some urea this week.


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## Sfurunner13 (Feb 26, 2019)

Silly question but how are you guys calculating this?


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## Dkrem (Mar 16, 2019)

Sfurunner13 said:


> Silly question but how are you guys calculating this?


This is my way:
https://thelawnforum.com/viewtopic.php?f=9&t=9336&p=153948#p153948


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## Harts (May 14, 2018)

Thanks guys. I'll just use my spreader tonight - I won't have time to do a test. Appreciate the quick responses.


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## GoPre (Oct 28, 2017)

Pete1313 said:


> GoPre said:
> 
> 
> > Understood, and the basis of my concern! I have just been reading benefits of foliar applications. I will cut that rate in half just to give it a try. Thanks for the response!
> ...


I really appreciate your help!


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## jrubb42 (Jun 20, 2019)

@Harts or @SNOWBOB11, did you ever get around to spraying Urea? Curious to how it turned out if so? What rates, did you water it in after, etc?


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## jurkewycmi (Jun 3, 2018)

@Harts I sprayed all my urea apps last year for fall blitz 0.5lb/1000 N with no issues

Enough carrier for 2 passes of even coverage and watered in


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## Harts (May 14, 2018)

@jrubb42 I sprayed last week. 0.125lb N per K. I used 1 gallon per K. I sprayed with iron and pgr.

I left for Chicago two days later - flying home today. So I'm not sure what the lawn looks like. I'll report back later.

I did not water in.


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## jrubb42 (Jun 20, 2019)

Harts said:


> @jrubb42 I sprayed last week. 0.125lb N per K. I used 1 gallon per K. I sprayed with iron and pgr.
> 
> I left for Chicago two days later - flying home today. So I'm not sure what the lawn looks like. I'll report back later.
> 
> I did not water in.


I literally just finished spraying at .18lb per k. Didn't water in. There was a lot of dew on the ground though. We'll see what happens I guess..


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## g-man (Jun 15, 2017)

@jrubb42 how much carrier (water)?


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## jrubb42 (Jun 20, 2019)

@g-man 1 gallon per. Should I turn on the irrigation? Lol

It's suppose to rain all day starting at 1pm but I have to watch the kid for the rest of the day. Wouldn't have been able to do it any later


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## g-man (Jun 15, 2017)

It should be good.


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## NJ-lawn (Jun 25, 2018)

Is it risky to spray/ apply urea above 80 degrees? Even if you irrigate? I realize it's only .25 lb or so


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## MMoore (Aug 8, 2018)

is there a rule re: timing of spray Nitrogen vs cutting the lawn? can it go down at the same time?


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## Pete1313 (May 3, 2017)

NJ-lawn said:


> Is it risky to spray/ apply urea above 80 degrees? Even if you irrigate? I realize it's only .25 lb or so


I'm not sure of a high temp restriction, but I've sprayed and left it on the leaf for a couple days with high temps reaching 85°f without irrigating. No issues, but have not sprayed more than .2 lbs/M of N at a time



MMoore said:


> is there a rule re: timing of spray Nitrogen vs cutting the lawn? can it go down at the same time?


 I mowed and sprayed the same day once this year on 6/1 without issue. For foliar, mow before spraying and wait a a day or two after to mow again to let it sit on the leaf and get better uptake.


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## jrubb42 (Jun 20, 2019)

@Pete1313 I read the article you mentioned earlier in this thread about the benefits to foliar vs soil intake, but have you noticed any differences personally by using a foliar method of applying N compared to spreading granular?


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## Harts (May 14, 2018)

@jrubb42 one of the benefits to spraying N vs. spreading granular is the coverage. Because a product like Urea is such a high percentage of N, the actual lbs on the ground is very low. That's not much product in the hopper and on a smaller area (I'm doing 2,500 sf at a time), the setting on my spreader needs to be set very low. Almost to the point where hardly any Urea is coming out. This makes it hard to get even coverage across my lawn.

By dissolving your N source and spraying, it is much easier to get even coverage.

Additionally, many guys are already spraying PGR and/or Iron; adding N to that mix makes it one easy application, especially since all 3 are foliar apps.


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## Pete1313 (May 3, 2017)

@jrubb42, @Harts hit on alot of the good points! I'm already committing to a 10+ app spray program with PGR, so it is a no brainer to throw some N in the tank. Besides the better coverage, I really like being able to spoon feed small amounts of N with a very economical N source, very efficiently. Comparing with granular, if I was not spraying PGR or iron already would I spray N by itself? I dont know, as there is some time commitment to spraying so frequently. I would probably look into applying some slow release granular instead. But if you are already spraying, save yourself some time and money by not using a slow release source and throw some urea in the tank. I'm really liking it thru the summer this year as I can give it just enough N without forcing too much growth and will continue with it this fall supplementing with granular AS.


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## jrubb42 (Jun 20, 2019)

@Harts @Pete1313 thanks for the replies guys. Exactly what I was looking for. Do you know if It's recommended to mix azoxy, propiconazole, or even humic acid with N to save myself some time in the future or would you think I should spray those separate?


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## Harts (May 14, 2018)

Humic is a soil app. Keep that one separate. Not sure about Azoxy and PPZ. I use granular and water in to activate. I assume the liquid versions are soil too???


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## jrubb42 (Jun 20, 2019)

Harts said:


> Humic is a soil app. Keep that one separate. Not sure about Azoxy and PPZ. I use granular and water in to activate. I assume the liquid versions are soil too???


Nothing on the label ever mentions watering in the liquid fungicide after spraying with either the Azoxy 2sc or Propicanizole 14.3 that I'm using. So I have not watered either one into the soil. I have been applying it in the evening and watering the grass each morning after. Maybe @g-man can chime in on this?


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## g-man (Jun 15, 2017)

Going from memory, I think both are contact and systemic. Contact means that applying it to the leaves (foliar) will interact with the fungus outside the plant. Systemic is that it gets absorbed into the plant, mainly thru the roots, but it can be thru the leaves too. Therefore you can do both. Apply foliar, let it sit there to address and then water it in to get it into the soil.

Please double check with the label. Rutgers has a better explanation of systemic/contact in the first page of this report. http://www2.ca.uky.edu/agcomm/pubs/ppa/ppa1/ppa1.pdf


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## jrubb42 (Jun 20, 2019)

Thanks for all you do @g-man! I know everyone here appreciates it. I'll double check those labels.


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## 1mjbrierley (Sep 22, 2018)

jurkewycmi said:


> @Harts I sprayed all my urea apps last year for fall blitz 0.5lb/1000 N with no issues
> 
> Enough carrier for 2 passes of even coverage and watered in


Saving this post


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## MMoore (Aug 8, 2018)

Here is a thought. If I'm spraying g urea, is there any root benefits for growth, or is that limited because I'm spraying the tips?

Would granular be more benefit for root massing?


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## NJ-lawn (Jun 25, 2018)

MMoore said:


> Here is a thought. If I'm spraying g urea, is there any root benefits for growth, or is that limited because I'm spraying the tips?
> 
> Would granular be more benefit for root massing?


It's recommended after 3-4 hours to water it into the soil.


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## Harts (May 14, 2018)

@MMoore, @NJ-lawn I don't water my spray apps in afterwards.

I'm not sure how or if foliar N affects the roots. One of the benefits is the N has an immediate availability to the plant and doesn't need to interact with the urease in the soil.

Certainly washing it off after a few hours isn't going to hurt. I've just never done it.


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## g-man (Jun 15, 2017)

@MMoore it is like medicine, once it enters the body, it will be moved by the blood. It doesn't matter if it is an injection or digested.

Nitrogen that is absorbed foliar, enters thru small holes in the leaf and moves thru the plant via mass transfer of the water using the energy of the sun. The plant will use it as needed for top growth or seedhead or tillers or roots. The same happens when it enters thru the roots.


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## NJ-lawn (Jun 25, 2018)

Just regurgitating what osuturfman said......

"As I said in earlier posts in this thread, the critical window is that 3-4 hours after application. If you have applied a proper rate of N with a high enough carrier volume, there should be no ill effects within that period. After 4 hours, upwards of 80% of N that is capable of entering the leaf will have done so by that time. At that point, the best practice is to irrigate to wash the remaining fertilizer residue through the canopy and into the soil for any additional uptake"


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## Pete1313 (May 3, 2017)

g-man said:


> MMoore it is like medicine, once it enters the body, it will be moved by the blood. It doesn't matter if it is an injection or digested.
> 
> Nitrogen that is absorbed foliar, enters thru small holes in the leaf and moves thru the plant via mass transfer of the water using the energy of the sun. The plant will use it as needed for top growth or seedhead or tillers or roots. The same happens when it enters thru the roots.


Agreed. A portion of foliar N is translocated to the roots. For studies or more info you can type in a google search for "foliar urea root translocation turf" and get more reading material.



NJ-lawn said:


> Just regurgitating what osuturfman said......
> 
> "As I said in earlier posts in this thread, the critical window is that 3-4 hours after application. If you have applied a proper rate of N with a high enough carrier volume, there should be no ill effects within that period. After 4 hours, upwards of 80% of N that is capable of entering the leaf will have done so by that time. At that point, the best practice is to irrigate to wash the remaining fertilizer residue through the canopy and into the soil for any additional uptake"


This goes somewhat against some of the recommendations based on research that I have read, listened to, or watched. The recommendation I have been following is delaying irrigation/rain for 24-48 hours and making sure I don't mow the next day if possible. This only would apply to low rates of true foliar urea N applied at .25 lbs/M of N or less in a low carrier volume. Foliar applied urea has better uptake then soil applied so although washing it down into the soil isn't a bad idea, leaving it on the leaf alittle longer might be a more efficient uptake of N. I've posted these links some before but are a good listen/watch on foliar N.

This one is IMO a must listen if you are considering spraying foliar urea. Although a few years old, it has lots of good info.
The Ins and Outs of Foliar Fertilizers

Here is another one where they talked some about foliar fertilization.
Frankly Speaking: Dr. Bruce Branham on nitrogen fate, physiology & foliar uptake


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## KoopHawk (May 28, 2019)

Good stuff, Pete!


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## Babameca (Jul 29, 2019)

I am a bit confused here. Urea can NOT enter the plant in its original form. It should convert first. Not the case with AS. So without being in contact with urease (which is in the soil right?) how pure urea is being used by the plant from foliar app....Urea is not NOT nitrogen if we all agree... it is a source.


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## Harts (May 14, 2018)

@babameca I am not a chemist. In fact, I didn't even take chemistry in high school. And reading the different journals on studies is seriously like reading Greek. With that said, what I do know is that when urea is dissolved in water, it doesn't need to interact with urease to create the nitrogen source. Whatever the reaction is between urea and water creates an immediate nitrogen source to the grass.

Somebody far more intelligent will provide the scientific data, I'm sure.


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