Abstract
To elucidate the exposure of pesticide in agricultural environment and to investigate distribution of pesticide in paddy fields. This experiment was carried out to clarify pesticide distribution in paddy fields applied with different formulations and growing stages. Initial dissipation rate of applied butachlor EW and oxadiazon EC before rice planting were more than 90% within 3 days in paddy fields. The distribution of a.i. in the pesticide formulations tested depended upon the elapsed time at each growing stage of rice plant after application. Most of pesticides applied within 15 days after transplanting of rice seedlings, more than 95%, were located in the surface water and soil regardless of pesticides; butachlor, thiobencarb and molinate GR. The distribution of iprobenfos GR, tricyclazole WP and phenthoate EC, after application 2 hours in middle growing stage (46 days after rice planting) were shown as 16.1, 48.9 and 38.9% in surface water, 83.6, 15.4 and 10.7% in soil, and 0.3, 35.7 and 50.4% in rice plants of paddy fields, respectively. Also tricyclazole WP and phenthoate EC, after application 2 hours in the late rice growing stage (90 days after rice planting) were distributed to 7.8 and 9.8% in surface water, and 21.7 and 5.1% in soil, and 70.5 and 85.1% in rice plants of paddy fields, respectively.
벼 재배 환경에서 농약의 분포 및 유출특성과 농업환경으로의 노출성을 구명하기 위해서 살포농약의 제형과 벼 생육단계에 따른 경시적 분포양상 실험을 수행하였다. 벼 이앙전 처리제로 제초제인 butachlor 유탁제와 oxadiazon 유제의 논물 중 잔류양상은 처리 3일 후에 초기처리량의 90%이상이 소실되는 것으로 나타났고, 벼 이앙 후 15일 이내에 처리한 butachlor, thiobencarb 및 molinate 입제의 농약성분의 95%이상이 논물과 토양에 분포되어, 비살포 지역으로 유출을 방지할 수 있는 유출안전기간은 농약살포 후 5일로 설정하였다. 벼 생육 중기에 살포된 iprobenfos 입제, tricyclazole 수화제, phenthoate 유제의 처리직후 2시간 후의 분포는 논물에서 16.1, 48.9와 38.9%, 토양에서 83.6, 15.4와 10.7%, 식물체에서 는 0.3, 35.7과 50.4%가 각각 분포되었다. 또한 벼생육 후기 농약분포는 tricyclazole 수화제와 Phenthoate 유제는 논물에서 7.8과 9.8%, 토양에서 21.7과 5.1%, 식물체에서 70.5와 85.1%가 각각 분포되어 식물체 biomass가 증가 할수록 농약 부착량이 식물체에 분포되어 논물과 토양에 적은 양이 분포되었다.
