向日葵和土壤中精异丙甲草胺的残留动态研究

Residue Dynamics of S-metolachlor in Sunflower and Soil

为评价960g/L精异丙甲草胺乳油在向日葵地使用后的残留行为及环境安全性,笔者于2008—2009年,在北京和长春两地开展了消解动态和最终残留的田间试验。采集的向日葵植株、籽粒和土壤样品用GC法测定,结果表明:精异丙甲草胺在北京地区向日葵植株中的半衰期为5.10天,在土壤中的半衰期为9.83天;精异丙甲草胺在长春地区向日葵植株中的半衰期为11.89天,在土壤中的半衰期为7.21天。两年两地的最终残留结果显示:在推荐使用剂量下,施药1次,收获的向日葵中精异丙甲草胺的残留量均低于0.01mg/kg。精异丙甲草胺降解速率快,在正常使用条件下,不会造成环境的污染和累积。

This study had been carried out to investigate the residue behavior and environmental safety of 960 g/L S -metolachlor EC in sunflower and soil. The field trials included the dissipation and terminal residue experiments. It were conducted in Beijing and Changchun during 2007-2008, respectively. A GC method was described for the determination of S -metolachlor in sunflower plant, sunflower seed and soil. The results showed that dissipation of S -metolachlor in sunflower plant and soil was fast. The half-life values of S -metolachlor were 5.10 d and 9.83 d in plant and soil in Beijing. The half-life values of S -metolachlor in Jilin was 11.89 d in plant and 7.21 d in soil. Two-year and two-area results showed that the terminal residues in sunflower seed and soil were lower than 0.01 mg/kg. When 960 g/L S -metolachlor EC was applied to the sunflower field ecosystem at recommended rates, it would not lead to residue contamination in sunflower seed and residue accumulation in environment.