Behavior of Bromobutide in Paddy Water and Soil After Application

Behavior of the herbicide bromobutide, (RS)-2-bromo-N-(α,α-dimethylbenzyl)-3,3-dimethylbutyramide, in paddy water and soil after application to paddy fields was investigated to evaluate the degradation to bromobutide-debromo, N-(α,α-dimethylbenzyl)-3,3-dimethylbutyramide, and runoff of the herbicide. The respective maximum concentrations of bromobutide and the metabolite were 1,640–2,230 and 11.1–15.8 μg/L in the paddy water, and 2,210–4,140 μg/kg dry and 74–119 μg/kg dry in the paddy soil, respectively. The runoff ratios of the applied bromobutide from the paddy fields were calculated as 28 ± 16%. The respective mean values of the half-lives of bromobutide in the paddy water and the soil were 2.7 ± 0.34 days and 6.9 ± 2.6 days, respectively.