Characterization of agricultural nonpoint pollution: Pesticide migration in a West Tennessee watershed


Pesticide migration from agricultural fields may stress receiving stream ecosystems as well as contaminate ground water. Research was conducted on an 18‐ha single‐field watershed in west Tennessee to characterize the fate of atrazine during a 12‐month period after pesticide application. Rainfall runoff and soil cores were sampled and analyzed for atrazine residues. Total loss of atrazine by runoff accounted for approximately 1.5% of the total atrazine applied. Concentrations as high as 0.25 mg/L were detected in the field discharge. By the fourth storm event after pesticide application, the atrazine concentration was below detection limits (0.1 μg/L). Atrazine loss in the upper 10 cm of soil followed a first‐order decay trend, with only 1.88% of the initial concentration remaining 238 d after pesticide application. The mean half‐life for atrazine in the upper 10 cm was approximately 21.5 d. Atrazine was detected in the 10‐ to 20‐cm soil level after the first rainfall. Atrazine was not detected below 20 cm at any sampling date during the 238 d of the study. Copyright © 1988 SETAC

Publication Title

Environmental Toxicology and Chemistry