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.
We all are merely gleaners from the masters who were here before us.
Last edited by RAlmaroad; 03-08-2012 at 04:55 AM.