When K soil tests are low, banding K is more efficient and will generally produce better yields than from broadcasting. Sources of Potassium Fertilizer . Other commercially important forms include potassium sulfate, potassium-magnesium sulfate, and potassium nitrate. Table 1 lists these fertilizers and their K content. Principal K fertilizer materials commercially available.
Potassium chloride is produced in four major size grades.
They include, in order of increasing fineness, granular, coarse, standard, and soluble. Granular and coarse grades cost somewhat more to produce than standard. They are more suitable for use in dry bulk blends with nitrogen and phosphate fertilizers because they reduce segregation during mixing and shipment to the farm. Soluble white is used in fertilizer solutions. Crop responses to these K fertilizers have shown no agronomic differences provided the same amount of K is applied and the same placement compared.