Potassium sulfate is an excellent source of nutrition for plants. The K portion of the K2SO4 is no different than other common potash fertilizers. However, it also supplies a valuable source of S, which is sometimes deficient for plant growth. Sulfur is required for protein synthesis and enzyme function. There are certain soils and crops where the addition of Cl- should be avoided. In these cases, K2SO4 makes a very suitable K source. Potassium sulfate is only one-third as soluble as KCl, so it is not as commonly dissolved for addition through irrigation water unless there is a need for additional S.
