Originally Posted by ProMo
Looks like your math is off a bit. At rate assuming your rate is 1 lb N you would be getting 1.14 lb of sulfate. The sulfate form of sulfer does not lower Ph of soil so that is a mute point anyway. Sulfur needs to be in the elemental form to effectively lower Ph. The acid forming process of fertilizer occurs when the ammonium converts to nitrate. Since ammonium sulfate is 100% ammonium it is about 2x more acidifying than other forms of nitrogen.
I noticed the incorrect assumption and math when it was first posted. I don't correct every Mis-information I see on Lawnsite. But before this gets out of hand with BS, I will post the correct information.
Sulfur compound fertilizer are ACID FORMING FERTILIZERS. While they do little to lower pH they are more available to plants in Alkaline soils.
Ammonium Sulfate Number are actually 21-0-0-24 where the 24 stands for 24% of the first minor Element which is sulfur. If you do the Chemistry of atomic weights then Ammonium Sulfate has 1 1/4 pounds of Sulfur for ever one pound of Nitrogen. Of course you have to have a real education in Chemistry to calculate the actual atomic weight of various composts. TG/Lesco training doesn't cover real chemistry and Self study doesn't seem to work either. I can only suggest the Western Fertilizer Handbook by the California Fertilizer Association.
BTW 10 pound of 0-0-0-90 Sulfur applied to 1000 sq ft of turf will lower pH times 10 or one point of pH in 30 days time. This is only a short fix because the pH will raise to it's original or normal pH.