The purpose of this study was to investigate sites contaminated by pesticides, and determine whether vegetation can have a positive effect on microbial degradation of hazardous compounds in soils as a result of the rhizosphere effect. Enhanced microbial degradation of hazardous chemicals in the rhizosphere suggests that plants could be managed at contaminated sites to facilitate microbial degradation of unwanted organics. Experiments on the influence of vegetation on microbial degradation of pesticides were conducted utilizing nonvegetated and vegetated scenarios in environmental chambers. The study tested degradation of atrazine, metolachlor, and trifluralin using the herbicide resistant plant Kochia sp. Degradation tests with sterile soil, edaphosphere soil, and rhizosphere soil collected from the root zone of Kochia sp. indicated a significantly enhanced microbial degradation of the pesticides. Degradation of the parent compounds was significantly accelerated in the rhizosphere soil. Project continuation see FY 1994.