摘要
试验采用同位素示踪技术,研究了^(14)C-氰戊菊酯(速灭菊酯,速灭杀丁)在土壤表层和玉米叶片中的消失、迁移和降解.结果表明,与其它的一些拟除虫菊酯类农药相似,氰戊菊酯在旱地土壤中不发生明显的迁移,处理后25天迁移至土表2cm以下的放射性只占原始处理量的8％,氰戊菊酯在土壤中的残留性较强,在玉米植株中则消失较快,在玉米植株中,氰戊菊酯基本上停留在处理部位,而从其它部分检测到的残留极少,植株对土壤中的残留物摄取量甚微,在试验土壤中,检出了除亲体氰戊菊酯以外的几种降解产物,籍此提出了氰戊菊酯在旱地土壤中可能存在的降解途径。
The distribution , persistence and degradation of 14C-fenvalerate were investigated in aerobic soil and corn plants under field condition. Fenvalerate residues did not more significantly in the soil column. Only as low as 8.5% of the originally applied activity was recovered in the lower part of soil (2 cm below the surface) 25 days after the application, though the precipitation was as high as 265.3 mm. Similar results were observed in the corn plants. When treated on the leaves, very little radioactivity could be recovered in the other parts of the plants, and the figure was only 3.096 of the original activity on the 25th day. Therefore, it could be concluded that fenvalerate does not transfer from site to site in soil or plants. In aerobic soil, fenvalerate was relatively persistent. The calculated half-lifefor the disappearance of extractable residues was 28 days, and 36 days for the total residues. However, it disappeared more rapidly in the corn plants, and the calculated half-lifeewas 10 days. Fenvalerate degraded in the aerobic soil giving 4' -OH-fenvalerate, CONH2-fenvalerate, COOH-fenvalerate and desphenyl fenvalerate. However, both in soil and corn plants, the parent compound fenvalerate constructed the main form of the extractable residues detected.
