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Movement and degradation of [ 14 C]atrazine in undisturbed soil columns
Author(s) -
Kruger Ellen L.,
Somasundaram L.,
Coats Joel R.,
Kanwar Ramesh S.
Publication year - 1993
Publication title -
environmental toxicology and chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.1
H-Index - 171
eISSN - 1552-8618
pISSN - 0730-7268
DOI - 10.1002/etc.5620121103
Subject(s) - atrazine , leaching (pedology) , chemistry , degradation (telecommunications) , hectare , pesticide , environmental chemistry , pesticide degradation , leachate , soil horizon , soil water , environmental science , soil science , agronomy , ecology , telecommunications , biology , computer science , agriculture
The movement and degradation of [ 14 C]‐atrazine were studied in undisturbed soil columns (15 × 60 cm) taken manually from a field with no previous pesticide history. The experiment was conducted indoors under controlled temperature conditions. Three weeks after application of [ 14 C]‐atrazine (2.2 kg a.i. per hectare) to the soil surface, the columns were leached at weekly intervals for 12 weeks. Approximately 1.2% of the applied 14 C was recovered in the leachate over the 12‐week period, which corresponds to an atrazine (plus degradation products) concentration of 7.6 μg/L. On completion of the last leaching event, the columns were cut into 10‐cm increments and analyzed for [ 14 C]‐atrazine and degradation products. Seventy‐seven percent of the 14 C applied to soil columns remained in the upper 10 cm and included primarily atrazine (9%) and soil‐bound residues (57%). Deethylatrazine was the predominant degradation product in the top 10 cm (3.6%). Other degradation products were found in the top 10 cm at relative concentrations of deisopropylatra‐zine > hydroxyatrazine > didealkylatrazine > deethylhydroxyatrazine > deisopropylhydroxyatra‐zine. Uncharacterized polar metabolites in the top 10 cm accounted for 6% of the applied 14 C. Atrazine, deethylatrazine, and deisopropylatrazine were found at all depths. In addition, didealkylatrazine was detected to the 50‐cm depth, hydroxyatrazine to the 30‐cm depth, and deethylhydroxyatrazine to the 20‐cm depth.