Degradation of atrazine in two soils as a function of concentration
- Univ. of Minnesota, St. Paul, MN (United States)
- USDA-ARS, St. Paul, MN (United States); and others
Dissipation of atrazine (2-chloro-4-ethylamino-6-isopropylamino-s-triazine) in a Webster clay loam soil (fine loamy, mixed, mesic Typic Haplaquoll), and Estherville sandy loam (sandy, mixed, mesic typic Hapludoll) was determined over a concentration range of 5 to 5000 mg kg{sup -1} in field and laboratory experiments. Over the first 6 mo in the clay loam soil, the persistance of atrazine (based on percent of applied) was greater for the high-rate treatments than the low-rate treatments. However, in the laboratory, there was no effect of concentration on dissipation; the amount of atrazine degraded increased proportionally with the increase of concentration. In the sandy loam, persistance was greater at high concentration in both field and laboratory studies. Mineralization was the most important pathway for the dissipation of atrazine at all concentrations in the clay loam soil and from 5 to 500 mg kg{sup -1} may have increased soil microbial growth and activity and thus increased the degradation of atrazine based on the increase in soil respiration in the clay loam soil. Degradation pathways in both soils apparently were not influenced by concentration. Ring cleavage and hydrolysis were the major metabolic pathways in both soils, with dealkylation of less importance. Addition of a dairy manure amendment increased the rate of atrazine mineralization, while corn mean decreased and (NH{sub 4}){sub 2}HPO{sub 4} amendments prevented mineralization. 41 refs., 6 figs., 4 tabs.
- Sponsoring Organization:
- USDOE
- OSTI ID:
- 405352
- Journal Information:
- Journal of Environmental Quality, Vol. 25, Issue 5; Other Information: PBD: Sep-Oct 1996
- Country of Publication:
- United States
- Language:
- English
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