AS is better than urea on S-deficient soils, because it has

AS is better than Urea on S-deficient soils, because it has Sulphuric acid.
Urea is a source of nitrogen, an essential nutrient crucial for crop growth and development. It is a widely used nitrogenous fertilizer because of its high N content is 46%.
AS is Ammonium Sulphate is a quick-acting acidic nitrogenous fertilizer. It is used for alkaline soils. It contains 21% nitrogen and 24% Sulphur.
AS is better than Urea on Sulphur deficient soils it produces sulphuric acid and releases a good amount of Sulphur into the soil.