Characterization of pesticide degradation in soil is an important component in determining the environmental impact of agriculturally-applied pesticides. Several techniques currently are being used to generate these data, but small-scale laboratory studies remain one of the most effective, cost-efficient mechanisms of evaluating pesticide behavior in soil. With small-scale studies, many different environmental factors can be incorporated into the experimental design, and with the use of 14C-labeled material, these studies (often referred to as soil degradation or soil metabolism studies) provide information on test substance persistence, degradation, volatilization, and mineralization. Care must be exercised, however, in selecting the experimental parameters to be used because of the potential adverse or artificial effects on the soil system.