Submitted to: American Chemical Society Symposium Series
Publication Type: Book / Chapter
Publication Acceptance Date: 4/3/1998
Publication Date: N/A
Technical Abstract: Volatilization of pesticides has been considered to be a large part of the loss from fields after application; however, few studies have quantified the amount lost to the atmosphere. Volatilization rates of a pre-emergent herbicide, Dual (active ingredient (a.i.) metolachlor 2.24 kg ha**-1, (2-chloro-N-(2-ethyl-6-methylphenyl) -N-(2-methoxy-1-methylethyl)acetamide)), were estimated from a 175 ha field in central Iowa over a period of 4 years. A micrometeorological approach for metolachlor was developed and refined. Flux profile concentrations of metolachlor were found to be large during the first 12-24 hours after application and quickly declined for the duration of the study. Precipitation generally contributed to large but short in duration flux peaks. In 1995, results showed that over a 10-day period, 22% of the applied metolachlor volatilized to the atmosphere.