Fixen says that studies indicate any number of chloride sources can be used. Potassium chloride is the most common because it provides two essential nutrients, may cost less and is readily available. Magnesium chloride is another source and is applied as a liquid fertilizer. Other options include ammonium chloride and calcium chloride. You can apply these materials in any number of ways.
Chloride is soluble and moves like nitrates in the soil.
Under heavy rainfall conditions or in sandy soils there is a possibility it will leach out. The scientist says profits can be increased by adding Cl fertilizer, especially in low to medium testing soils. Here's how he figures it. On soils testing low in Cl, the typical application rate is 30 lbs. per acre. Where you live has an impact on Cl availability.