The suggested application rate for potassium is 40 to 50 pounds of K20 if needed. Plants lacking in potassium usually remain small and lack vigor. Winter hardiness is reduced, and the heads formed are small and compact. Potassium deficiencies seldom occur in small grain. Higher rates of phosphorus and potassium may be needed under an intensively managed system.
Sulfur is a constituent of several amino acids.
It is involved in electron transport, metabolism, and activities of many enzymes. Sulfur is a component of protein and very essential in small grain production. Plants cannot use nitrogen efficiently if adequate sulfur is not available. Sulfur in the form of sulfate may leach readily, and deficiencies generally occur in sandy soils. Thus, topsoils frequently test low in sulfate sulfur.