# Ammonium sulfate vs Urea.



## Ranger518

What results are you guys getting with the different types of nitrogen fertilizer? We really only have 2 choices around here Ammonium sulfate or Urea I have always used urea but fertlizer guy is suggesting ammonium sulfate do to it is cheeper. I know it does not Volatilize like Urea and that it makes the soil more acidic. So my question is does or is amounium sulfate do any better or worth it. To me it is not going to be any cheeper in the long run If I will need to used more lime. I also can get and do get agratane added to the urea to help with the volatilizetion when the rain forecast is not that good. This is for hybrid bermuda grass.


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## somedevildawg

I use both....early in the season it's urea but later its AN, clumping becomes a problem with the heat and humidity later in the season. Your reasons are well founded , but for us it's just a matter of availability and speadability.


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## glasswrongsize

I have also been using both. I use 100#/acre of AMS once a year or so to get the needed sulfur.

Was just speaking with my fert guy about the urea deal. The agritain is a coating that will wash off with slight rains/heavy dews; then, the nitrogen is still free to volatilize. My joint is using nutrisphere (or something like that). It is supposed to make a molecular bond and some decent dews will bind it with the soil and not volatize. He is claiming that I can use the urea (with nutrisphere) into the heat.humidity of summer. Maybe Dr Vincent will chime in on the validity of the song and dance I was fed.

'Course all the nitrogen one can afford won't do much without rain at some point.

Mark


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## endrow

Yes prior to the first cutting we will use a blend of urea and ammonium sulfate. If we spread nitrogen between second and third cutting on grass hay we would not use ammonium sulfate. Ammonium sulfate works too slowly when you're at that time of the year you're lucky to get one or two rings between the cutting and you need something that's going to activate and give a quick shot and go to work. Ammonium sulfate is stable but it is slowly slow-release


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## rjmoses

Just due to availability, I use urea early spring, ammonium sulfate after first cutting. Urea clumps too badly so my supplier doesn't carry it much after May 1st. Ammonium sulfate also supplies my sulfur.

Due to supply this year, they ran out of AS before I was ready so I ended up putting 28% on as a trial run. We'll see.

Ralph


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## Ranger518

Ok good deal looks like I should stay with the urea with coating added to it for now. I think I may try the Ammonium sulfate next spring do to its slower release.


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## Hayman1

See if you can get anyone to provide calcium ammoniuim nitrate. The calcium takes it off the explosive list. It spreads nicely. I used it last year after 1st cutting and liked it. Spreading all of first cutting grass tomorrow with it. totally stable and soluble when you get rain.


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## big_country

I use booth of the fertilizers the 46-0-0 and the 21-0-0-24S. The fertilizer company will do a blend with the two fertilizers. It is a 33-0-0-12S. It seems to be working. The ammonium Sulfate will just sit there until a rain.

The Urea needs moisture to get it to start working in the ground. The urea is a good fertilizer it just seems to volatilize quicker than the ammonium sulfate if there is no moisture.The fertilizer company I deal with told me that the 21-0-0-24S will just sit there until it gets moisture and the 46-0-0 would volatilize if no moisture would be pressent


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## r82230

AMS to get the sulfur, also don't need much (if any) N. Cheapest way to get sulfur, they told me again this morning, when I place my fertilizer order/instructions.

Larry


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## vhaby

Ranger518 said:


> What results are you guys getting with the different types of nitrogen fertilizer? We really only have 2 choices around here Ammonium sulfate or Urea I have always used urea but fertlizer guy is suggesting ammonium sulfate do to it is cheeper. I know it does not Volatilize like Urea and that it makes the soil more acidic. So my question is does or is amounium sulfate do any better or worth it. To me it is not going to be any cheeper in the long run If I will need to used more lime. I also can get and do get agratane added to the urea to help with the volatilizetion when the rain forecast is not that good. This is for hybrid bermuda grass.


Ranger,

You have been misled by your fertilizer guy. He is correct that ammonium sulfate is cheaper per ton, but it is more expensive on a pound of nitrogen basis and that is what counts. How to compute the cost per pound of nitrogen:

Urea is 46% nitrogen and the price I was given this morning was $450 per ton. 2000 lb x .46 = 920 lb of nitrogen per ton.

$450 divided by 920 = $0.489 per pound of nitrogen.

Ammonium sulfate is 21% nitrogen and its price as of this morning was $380 per ton. 2000 lb x .21 = 420 lb of nitrogen per ton.

$380 divided by 420 = $0.905 per pound of nitrogen, or nearly double the price per pound of urea nitrogen.

Yes, you get 23 pounds of sulfur along with the 21 pounds of nitrogen in each 100 pounds of ammonium sulfate and that is worth something if your soil is deficient in sulfur.

You are correct that ammonium sulfate creates more acidity in the soil than does urea and will necessitate application of more limestone than will urea. However, contrary to what you have learned, research has shown that ammonium sulfate does lose nitrogen as ammonia by volatilization when it is left on the soil surface.

Big_Country stated, "The ammonium Sulfate will just sit there until a rain. The Urea needs moisture to get it to start working in the ground. The urea is a good fertilizer it just seems to volatilize quickly if there is no moisture."

Actually, if the surface soil is perfectly dry and there is no morning dew, both urea and ammonium sulfate will "just sit there" until a rainfall event of at least 0.2 inches occurs. Then, both nitrogen sources will be moved into the soil. However, if a significant morning dew or a slight rainfall event occurs, both nitrogen sources can lose nitrogen as volatilized ammonia.

Fertilizer dealers who are tied to ammonium sulfate companies may be required to mix urea and ammonium sulfate half and half to produce a 33.5% nitrogen blend to help get rid of their supply of by-product ammonium sulfate. If you request it, they may be able to mix less ammonium sulfate with the urea and produce a 42% nitrogen blend that still contains adequate sulfur for most crops and requires less of an increase in limestone needing to be applied over time.

I was disappointed last Thursday when I was removing round bales from the hay meadow and stopped to call the fertilizer dealer who said that it would be the middle of the next week before he could bring fertilizer for the hay meadow. Two other fertilizer dealers said the same thing. That was a blessing in disguise because predicted rains did not materialize until today, Wednesday, and he came out and spread the fertilizer in a gentle rain- the best time to have urea with a small amount of ammonium sulfate applied and get it into the soil in a situation where it cannot be incorporated by tillage into a mixed stand of Coastal and common bermudagrass. I had 400 lb of a 20-5-20 with 2.5 sulfur applied per acre for this second growth of bermudagrass and hope to receive additional rainfall to produce sufficient hay to complete filling the 50 x 100 ft hay barn with a 2-yr supply of hay incase of a drought that prevents hay production next summer.

Regards,

Vincent


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## gradyjohn

Ranger518 said:


> What results are you guys getting with the different types of nitrogen fertilizer? We really only have 2 choices around here Ammonium sulfate or Urea I have always used urea but fertlizer guy is suggesting ammonium sulfate do to it is cheeper. I know it does not Volatilize like Urea and that it makes the soil more acidic. So my question is does or is amounium sulfate do any better or worth it. To me it is not going to be any cheeper in the long run If I will need to used more lime. I also can get and do get agratane added to the urea to help with the volatilizetion when the rain forecast is not that good. This is for hybrid bermuda grass.


I was formerly in the Texas Blacklands and used Ammonium sulfate because of sulfur to help with the ph and I found out that is you put AS down you don't have to worry about chiggers. Figure the price per unit and not the price per ton. Urea is best applied in the morning just before the afternoon rain. (good luck with that) What does your soil test say you need?


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## Ranger518

vhaby said:


> Ranger,
> 
> You have been misled by your fertilizer guy. He is correct that ammonium sulfate is cheaper per ton, but it is more expensive on a pound of nitrogen basis and that is what counts. How to compute the cost per pound of nitrogen:
> 
> Urea is 46% nitrogen and the price I was given this morning was $450 per ton. 2000 lb x .46 = 920 lb of nitrogen per ton.
> $450 divided by 920 = $0.489 per pound of nitrogen.
> 
> Ammonium sulfate is 21% nitrogen and its price as of this morning was $380 per ton. 2000 lb x .21 = 420 lb of nitrogen per ton.
> $380 divided by 420 = $0.905 per pound of nitrogen, or nearly double the price per pound of urea nitrogen.
> 
> Yes, you get 23 pounds of sulfur along with the 21 pounds of nitrogen in each 100 pounds of ammonium sulfate and that is worth something if your soil is deficient in sulfur.
> 
> You are correct that ammonium sulfate creates more acidity in the soil than does urea and will necessitate application of more limestone than will urea. However, contrary to what you have learned, research has shown that ammonium sulfate does lose nitrogen as ammonia by volatilization when it is left on the soil surface.
> 
> Big_Country stated, "The ammonium Sulfate will just sit there until a rain. The Urea needs moisture to get it to start working in the ground. The urea is a good fertilizer it just seems to volatilize quickly if there is no moisture."
> 
> Actually, if the surface soil is perfectly dry and there is no morning dew, both urea and ammonium sulfate will "just sit there" until a rainfall event of at least 0.2 inches occurs. Then, both nitrogen sources will be moved into the soil. However, if a significant morning dew or a slight rainfall event occurs, both nitrogen sources can lose nitrogen as volatilized ammonia.​
> Fertilizer dealers who are tied to ammonium sulfate companies may be required to mix urea and ammonium sulfate half and half to produce a 33.5% nitrogen blend to help get rid of their supply of by-product ammonium sulfate. If you request it, they may be able to mix less ammonium sulfate with the urea and produce a 42% nitrogen blend that still contains adequate sulfur for most crops and requires less of an increase in limestone needing to be applied over time.​
> I was disappointed last Thursday when I was removing round bales from the hay meadow and stopped to call the fertilizer dealer who said that it would be the middle of the next week before he could bring fertilizer for the hay meadow. Two other fertilizer dealers said the same thing. That was a blessing in disguise because predicted rains did not materialize until today, Wednesday, and he came out and spread the fertilizer in a gentle rain- the best time to have urea with a small amount of ammonium sulfate applied and get it into the soil in a situation where it cannot be incorporated by tillage into a mixed stand of Coastal and common bermudagrass. I had 400 lb of a 20-5-20 with 2.5 sulfur applied per acre for this second growth of bermudagrass and hope to receive additional rainfall to produce sufficient hay to complete filling the 50 x 100 ft hay barn with a 2-yr supply of hay incase of a drought that prevents hay production next summer.
> 
> Regards,
> Vincent


Yea that is what I was thinking also that it was cheeper per ton but overall it was not do to the added cost of more tons and needing to use more lime in fall. I think his main thing was with our humid weather and spotty rain that it was better do to it did not volatilize as bad. But I went ahead and got my usual 22-11-22 at 450lb acre with nitrogent stabilizer. It is a mix of urea DAP and potash. I hope this is the mix that I will need but soil test will tell this fall if I need to add or take away anything.


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## Mf5612

up here in ontario guys use both. we put amonium sulphate on as early as possible in spring,like april 15 ish. right after hayseeds and barley go in. we get good results from the sulphur on our ground.boron also is good for the hay.


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## mlappin

We've actually added it to our program just for the sulfur. Was adding a liquid product to our starter fertilizer, that can turn into a huge sh*t show if it settles out and starts plugging stuff.


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