Factors in Examining Fate of Herbicides in Soil with Bioassays

A primary reason for studying the fate of a herbicide in soil is because of its potential effect, beneficial or detrimental, on plants. Herbicide concentrations in soil often can be accurately analyzed by chemical or physical procedures. But such quantitative measurements sometimes are not well correlated with plant response because of a number of interacting soil and environmental factors. If the question is not “How much herbicide residue is present in the soil?”, but rather “How much potential exists for herbicidal effects on plants?”, then the use of plants as one aspect of studies on herbicide persistence can be valuable. This paper addresses factors influencing the response of plants to herbicide residues under field conditions.