Fact:  Chloride is not chlorine. 

Numerous references are made that wrongly interchange chlorine (Cl2) for chloride (Cl). Some inadvertently, some misinformed. Chemically, the two are completely not alike nor their effect on soil, plant and animals. The major negative affects many refer to with chlorides in fertilizer are assuming chlorine affects. This is not a fact.

Biologically in plants, chloride aids plant metabolism.  Specifically chloride is necessary for the first step in splitting the water molecule (H2O) in the mitochondria inside cells.  This eventually ends up producing the building blocks (CHO - carbohydrates) for producing amino acids and proteins.

It's all about concentration, ppm (parts per million), ppb (parts per billion).  Earlier discussion of 100# potash 0-0-60 per acre of about 45#/A chloride would result in about 45 ppm in the top 3" of soil per acre (about 1,000,000 pounds soil).  That's 0.001 pounds (0.47 grams) per square foot (surface area).  That's it.

This concentration of chlorides actually enhances mycorrhizal fungi growth in soil that symbiotically enhances crop growth and development along with better soil health.

Plant and soil nutrition programs that neglect application of chlorides limit the crop from full genetic expression, maximum production and optimum nutrition.