Do I need to use a sulphate free lawn fertilizer?
Washington County Oregon
Ammonium sulfate is a nitrogen source sometimes used to fertilize turf. It is a soluble for nitrogen which may not be the most appropriate for all situations. Straight ammonium sulfate often used when a soil test indicates the use of a nitrogen only fertilizer. Potassium sulfate (sulfate of potash) and potassium-magnesium sulfate are commonly added to soils low in K. All of these can end up in multi-nutrient fertilizers. All of these can effect soil pH, but with proper monitoring this isn't a major issue.
Ultimately, I would suggest using the type of fertilizer recommended by a soil test.