1. Missed the live Ask the Expert event?
    Catch up on the conversation about fertilization strategies for success with the experts at Koch Turf & Ornamental in the Fertilizer Application forum .

    Dismiss Notice

Ammonium Sulfate users?

Discussion in 'Fertilizer Application' started by dontsayit_sprayit, Mar 6, 2012.

  1. dontsayit_sprayit

    dontsayit_sprayit LawnSite Member
    Messages: 11

    My boss has me using ammonium sulfate as a fertilizer for a quick green up. we're only doing 3 applications in the year up here. what are your thoughts on ammonium sulfate as a whole? also in a 3 step program?
  2. Ric

    Ric LawnSite Fanatic
    Messages: 11,969

    (NH4)2SO4 Ammonium Sulfate breaks down fast to NO3 and is up taken by the plant very quickly. Therefore it helps to Green up. However it is an acid forming fertilizer because for every 1 pound of N you are applying 1 1/4 Pounds of Sulfur. BTW the Sulfur also helps in green up and is an important part of Photosynthesis. Old school chemistry was Iron Sulfate and Ammonium sulfate to create a Dark Green color. Iron Sulfate tears up your pump and stains everything.

    Take Ammonium Sulfate a step farther and note the soluble blend comes in 51 pound bag. The reason goes back the Agriculture and the days of 300 gallon Ag spray tanks. Today most farmers are using 500 tanks. 51 pound in a 300 gallon is 17 pounds per 100 or 0.17 (approx 1/5 #) per gallon as a SURFACTANT. Because Ammonium Sulfate is up taken so fast it acts as a surfactant to help up take the Pesticide being sprayed. Add that 1/5 of a pound of 21-0-0 to Roundup to get a quicker kill. etc.

    The Below Picture shows NO3 Ammonium Nitrate as the final stage of Nitrogen being broken down before being Up Taken. 34-0-0 is Ammonium Nitrate and cheaper per pound than 21-0-0 Ammonium Sulfate. Ammonium Nitrate is up taken by the plant quicker than 21-0-0 but doesn't give as quick of a green up.


  3. greendoctor

    greendoctor LawnSite Fanatic
    Messages: 9,997

    How long is your growing season and how much N are you putting down with the ammonium sulfate? Ammonium nitrogen can have a substantial residual in certain types of soil. However, I use it as part of a spoon feeding program on grass that is growing 12 months out of the year. For northern areas, the best use of ammonium sulfate seems to be as part of the winterizer that feeds the grass for the winter and preps it for a good start in spring. I use it because it supplies sulfur and does things to soil chemistry that I need. Unless your soil is based on or is on top of limestone, you need to watch for rising soil acidity. Ammonium sulfate is a very good way to acidify soil.
  4. cgaengineer

    cgaengineer LawnSite Fanatic
    Messages: 15,778

    Posted via Mobile Device
  5. RAlmaroad

    RAlmaroad LawnSite Silver Member
    from SC
    Messages: 2,253

    Northern soils are notoriously acidic except around the coast. A serious pH test would determine where Ammonium sulfate vs. Ammonium nitrate should be used. Blue grass will burn if an excess of Ammonium Nitrate is overdone. Your boss may know this and is why so insist ant to use the Sulfate. However, you'd be wasting your other fertilize should you already have a low pH. The Ammonium Sulfate will lower the pH even further and lock up the other fertilizer components and natural or added micros due ionization of root walls. This tends to show up in a fast greenup then a yellowing of the grass. We use Ammonium Sulfate on coastal area where pH tend to run closer to 7.0. Most grasses like a pH of around 6.0 or slightly acidic. Are you not using any Potassium? Potassium is needed as much or more than Nitrogen for a healthy lawn. I realize that just the use of Ammonium Sulfate would be a cheap showing of color but short lived. Potassium is root food. That soil test would indicate to need for phosphate also. Seems like you are starving the clients lawn if only using A.S....I couldn't do that just to make an easy buck and would do it professionally and correct or get out but I have very high standards for the industry and believe in being forthright with clients on cost and the health of turf and probably see more ER cases than healthy lawns. Sorry for the rant but the truth hurts.
    Last edited: Mar 8, 2012
  6. Hineline

    Hineline LawnSite Senior Member
    Messages: 535

    Big fan of A/S back off in the heat of summer but spring, fall, winter dormant there is no better.
  7. Ric

    Ric LawnSite Fanatic
    Messages: 11,969


    The reason Urea CO(NH2)2 isn't used for spring green up is soil temperature. Urea needs microbial activity to break it down to NO3 to be up taken by the plant. The Beneficial Microbes that break down urea are inactive in colder soils.

    My soil being a calcareous sandy has a natural pH of 9.5. Therefore I want all my fertilizer to be acid forming. Therefore I use Ammonium Sulfate year round and want a high percentage in any fertilizer blend I use whether I mix it myself or buy it. Being in South Florida my soil never gets cold enough to stop microbial activity and Urea can be used year round effectively unlike the North.

    Part of our Calcareous sandy soil is the lack of CEC or Chemical holding power. Therefore our fertilizer must be spoon fed or it leached out very quickly.

  8. Exact Rototilling

    Exact Rototilling LawnSite Fanatic
    Messages: 5,378

    Okay this is a question for the fert experts....specifically on issues of temperature and nitrogen release.

    Ammonium Sulfate is 20.5-0-0 and 24% sulfur. Just these last few weeks I have been using it on some accounts and some test areas. As of yet not seeing much kick from it....

    I just started using another product and the label contents are below:

    Not factoring the Sulfur content of 24% vs. the Sulfur content of 2.5% of the product I have highlighted here....which product is a faster rapid release with cooler Fall temps...?


  9. RigglePLC

    RigglePLC LawnSite Fanatic
    Messages: 13,717

    There is no slow release in Ammonium sulfate--isn't that the opposite of what most universities recommend for turfgrass?
    Urea is also fast-acting. How much faster is ammonium sulfate? Two weeks? Two days?
    How much faster does it disappear due to leaching from rain or sprinkling? How much ends up as nitrate in the ground water?

    Sulfur coated urea (blended with urea) works well in my area.
    Last edited: Oct 23, 2014
  10. Exact Rototilling

    Exact Rototilling LawnSite Fanatic
    Messages: 5,378

    Not 100% sure that's why I'm asking. :)

    We have had warmer than normal weather late September up through now in mid October.

    After pondering this more it is a matter of...which product will result in the fastest green up in cooler northern temps...?

    Slow release products are always better. Issue is a quick rapid green product is always good to have in the tool box. I have no problem with fast release use late in the season. Part of the reason is feeding weeds right before spot spraying.

    Spring time...yes it can produce mowing headaches.
    Posted via Mobile Device

Share This Page