벼 재배 Lysimeter 토양중 살균제 $^{14}C-Propiconazole$의 행방

Behaviour of Fungicide $^{14}C-Propiconazole$ in Rice Plant Grown-Lysimeter Soil

살균제 propiconazole의 벼 재배 lysimeter 토양중 행방을 조사하기 위한 실험을 수행하였다. Lysimeter의 토양은 미사질 식양토로 구성되었다. 벼 이앙 15일 후 propiconazole을 0.12kg/10a 수준으로 lysimeter 토양표면에 년 1회씩 2년에 걸쳐 2회 처리한 다음 경시적인 약제의 용탈량, 토양중 분포량 $^{14}CO_2$ 생성량, 그리고 벼에 흡수 및 이행량을 조사하였다. 약제처리 후 16주 동안 lysimeter토양에서 용탈된 방사능은 1 년차와 2 년차 실험 모두 자연 방사능 수준이었다. 시험 기간동안 lysimeter 토양에서 방출된 $^{14}CO_2$는 1 년차와 2 년차 실험에서 처리 방사능의 각각 5.7%와 7.8%였으며, 휘발성 물질의 생성율은 자연 방사능 수준으로 매우 낮아 propiconazole이 화학적으로 안정한 화학물임을 시사하였다. Propiconazole은 토양중에서 잔류방사능의 대부분이 토심 20cm 이내에 존재하여 지하수 오염의 가능성은 매우 낮았다. Lysimeter 토양중 재배된 벼에 흡수 및 이행된 propiconazole의 방사능은 1 년차 및 2 년차 실험에서 각각 처리 방사능의 3.7%와 7.6%였다.

Behaviour of a fungicide $^{14}C-propiconazole$ was investigated in a rice plant grown-lysimeter soil. The lysimeter was composed of soil cores of silty clay. $Propiconazole(Tilt\;250^R\;EC)$ plus $^{14}C-labeled$ propiconazole was applied on the surface of lysimeter soil at a rate of 0.12kg/10a after rice transplanting. The application was done consecutively for two years. The behaviours of propiconazole in the lysimeter soil were investigated by measuring the amounts of $^{14}C-leachate$, $^{14}CO_2$, the residues distributed in each soil segment and taken up by rice plants. The relative amounts of $^{14}C$ leached from the lysimeter were the background level of the applied $^{14}C$ throughout expeiment. The amounts of $^{14}CO_2$ evolved from the lysimeter were 5.7 and 7.8% of the original $^{14}C$ in the 1st and 2nd treatment, respectively. The amounts of volatile substances soil were the background level throughout experiment, which indicated that propiconazole was stable chemically in the experimental condition. The $^{14}C-activities$ absorbed and translocated into rice plants were 3.7 and 7.6% in 1st and 2nd treatment, respectively. The $^{14}C-activities$ in the soil layer of the lysimeter was distributed mainly in the depth of 0 to 20cm, which suggested propiconazole did not have the risk of groundwater contamination.