Although plants can accumulate chlorine foliarly and from the atmosphere, the concentration
of chlorine in plant tissue is often closely related to the supply or concentration of chloride in soil.
Testing soils for chloride is routine in laboratories involved in salinity problems, but soil testing for
chloride supply to predict crop response to fertilization is a fairly recent development. Soil test
interpretations for chloride supply are currently conducted in the North American Great Plains and
are limited to only a few crops (2)
In this large land-locked geographical region, little potassium fertilizer (KCl) is applied, and
chloride input from rainfall is low. Soil test interpretations for chloride have not been developed
outside this region because chloride inputs from various sources are often greater and because supplies
of this nutrient are generally considered adequate for most crops.