urea VS. ammonium nitrate

[kenojoe]

I tried to do a search, but as usual the search is not working. What is the difference between these two? My neighbor just fertilized his fields and used urea. He tells me its 46% nitrogen and cheaper than ammonium nitrate. The last time I bought a buggy of A.N. for my field I thought the FBI was going to watch me put it down. What is the difference in the two? What works better? And why.

 

[Jogeephus]

I'd prefer ammonium nitrate over urea any day of the week but the cost has skyrocketted and I now mostly use urea. Urea will volatize quicker and this is its biggest drawback as I see it. However you can treat the urea with a product that will make it more of a slow release product. I have done this several times and it seems to be helpful if rain isn't coming your way.

 

[Douglas]

urea is cheaper but more susceptible to volitization which is sort of like evaporation of the nitrogen if you don't get rain in a few days, something up to 20% loss with no rain and high temps for 5 days. If you know it is going to rain, or you are incorporating for crops or renovation urea is probably ok. My supplier stoped selling ammonium nitrate because of the terrorism paperwork. He now carries ammonium sulphate nitrate. I need the 12% sulfur and something is added to lessen volitization. Seems to be the new alternative to ammonium nitrate around here.

 

[dyates]

I used ammon. nitrate this year because it was cheaper. $399/ton vs. 427 for urea. Everybody looked at me like I was stupid because the nitrogen per pound was cheaper in the urea. Nitrate nitrogen won't drop the pH like urea, so you get a little better utilization. pH is low on new rental fields. I may use urea after I get the pH right.