Dissipation of Fenitrothion, IBP, and Butachlor in Flooded Soil Under Outdoor Conditions

실외조건(室外條件)의 담수토양중(湛水土壤中) fenitrothion, IBP, butachlor의 소실(消失)

The dissipation of insecticide fenitrothion(O,O-dimethyl O-4-nitro-m-tolyl phosphorothioate), fungicide IBP(S-benzyl O, O-diisopropyl phosphorothioate), and herbicide butachlor(N-butozymethyl-2-chloro-2', 6'-diethylacetanilide) in flooded soil planted with rice plants was investigated in outdoor pot conditions. The half lives of IBP, butachlor and fenitrothion in the flooding water treated with IBP at 98g, butachlor at 352.8g, and fenitrothion at 100g ai/10a, were 3.6, 1.7 and within 1 day, respectively. The concentration of fenitrothion at 5 days after application was found to be less than 0.0lppm. In the case of IBP and butachlor after 20 days, the concentration was 0.025 and 0.004ppm, respectively. The concentration of fenitrothion, IBP, butachlor in a soil depth of 0-3cm was 0.07, 1.45 and 3.37ppm on the 3rd day after application, and below 0.05, 0.18, 0.39ppm after 7 days, respectively. However, 27 days after application concentration of IBP and butachlor at 0-5cm soil depth resulted in 0.04 and 0.05ppm, respectively. The disappearance of pesticides was remarkably rapid, compared to those in the some soil under the laboratory conditions. Differences in the concentration of IBP in different soil profiles were few, but amounts of butachlor were remarkably higher at 0-2cm soil depth than below 2cm soil depth.

수도(水稻)를 재배(栽培)한 실외(室外) 풋트조건(條件)의 담수토양(湛水土壤)에 살충제(殺蟲劑) fenitrothion, 살균제(殺菌劑) IBP, 제초제(除草劑) butachlor 유제(乳劑)를 각각(各各) 100g, 98g, 352.8g ai/10a수준(水準)으로 수면처리(水面處理)하고 답면수(畓面水)(담수액(湛水液)) 및 토양중(土壤中) 3농약(農藥)의 잔류성(殘留性)을 조사하였다. 답면수(畓面水) 중 fenitrothion, IBP, butachlor의 농도(濃度)는 처리(處理) 1시간후에 각각(各各) 3.7, 3.2, 9.1ppm이었다. 그러나 fenitrothion의 농도(濃度)는 처리(處理) 5일(日)후에 0.01ppm이하(以下)였고 IBP와 butachlor의 농도(濃度)는 처리(處理) 20일(日)후에 각각(各各) 0.025와 0.004ppm이었다. Fenitrothion, butachlor, IBP의 답면수(畓面水)중 반감기(半減期)는 각각(各各) 1일(日)이내, 1.7일(日), 3.6일(日)이었다. 답면수(畓面水)로부터 흡착(吸着)된 토양중(土壤中) fenitrothion, IBP, butachlor 농도(濃度)는 토양(土壤) 0-3cm 층위(層位)에서 처리(處理) 후 3일(日)에 각각(各各) 0.05ppm이하(以下), 0.18ppm, 0.39ppm이었다. 그러나 처리(處理) 27일(日)후에 IBP와 butachlor의 검출(檢出) 농도(濃度)가 0-5cm 층위(層位)에서 각각(各各) 0.04, 0.05ppm으로 동일토양(同一土壤)의 실내조건(室內條件)에서보다 월등히 빨리 분해(分解)되었다. 답면수(畓面水) 및 토양중(土壤中) 소실속도(消失速度)는fenitrothion>butachlor>IBP순이었다. 토양층위별(土壤層位別) butachlor의 잔존량(殘存量)은 2cm 이하(以下)에서보다 0-2cm 층위(層位)에서가 현저(顯著)히 많았는데 비(比)하여, IBP의 토양층위별(土壤層位別) 농도(濃度)는 큰 차이(差異)가 없이 5㎝이하(以下)까지 이동(移動)되었다.