Ammonium Nitrate vs Urea for N source

Discussion in 'Pesticide & Herbicide Application' started by DA Quality Lawn & YS, Feb 10, 2008.

  1. DA Quality Lawn & YS

    DA Quality Lawn & YS LawnSite Fanatic
    Messages: 9,296

    You see far more Urea than A.N. as an N source in fert out there. But I have heard using A.N. is superior in the fact that you cut down on the amt of salt going on the grass with Urea. Any opinions on these two N sources and what you like?
  2. bblawncare

    bblawncare LawnSite Member
    Messages: 129

    Are you saying that AN is superior because it has a lower salt index than urea? While I am not as experienced as most on here about fertilizers, I am reading like crazy to learn all I can about them so that I may add this service to my business. It is my understanding that urea has a lower salt index(1.62) than AN(2.99), but urea does not produce as good a turfgrass response as AN. But I also believe that either is a good choice as long as they are applied at the RIGHT amount and irrigated in.

    If I misunderstood what you were saying then I apologize, and if I am wrong about my understanding, then someone please correct me. I obtained my info from the University of Florida Extension.
  3. Grandview

    Grandview LawnSite Gold Member
    from WI
    Messages: 3,251

    If you ran a side by side test you would not be able see any difference. The ammonia changes to nitrate. How fast depends on soil temps.
  4. Ric

    Ric LawnSite Fanatic
    Messages: 11,969


    NO3 or Ammonium Nitrate is already in the form that is ready for plant up take. NH4 or Urea must be converted by microbes to NO3 in order to be up taken by the plant. This being said NO3 will give quicker green up than NH4 but can also cause nitrogen burn, whereas NH4 Urea is less likely to burn.

    But Since Homeland Security moderators Ammonium Nitrate, many suppliers no long carry it. Generally you must sign for Ammonium Nitrate and may be requested to account for all usage.

    Here it a thread you might want to read.
  5. Grandview

    Grandview LawnSite Gold Member
    from WI
    Messages: 3,251

    Plants can uptake ammonia or nitrate. I have never read anything one is preferred over the other. Some plants might have a preference. This is based on my soils and plant physiology courses in college.
  6. rcreech

    rcreech Sponsor
    Male, from OHIO
    Messages: 6,163

    Are you thinking of using dry (32%) or Liquid (28%)?

    I think the salt thing is a joke and wouldn't worry about it!

    Overall, you shouldn't see any big differences in the products!

    Both products are very volatile and not very stable! I wouldn't recommend just using these products only! A lot of the NO3 in these products are volatile, especaially in hot, dry conditions! If watering then it isn't as big of a deal!

    It cost a little more, but I would go with an SCU and you will get a much better extension on your feeding!

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