韭菜和土壤中毒死蜱的残留与降解动态

在大棚和露地栽培条件下,研究了不同浓度的毒死蜱灌根施药后土壤和韭菜中毒死蜱的残留与降解动态.结果表明:韭菜中毒死蜱的降解速度比土壤中快,平均半衰期分别为3.41 d和7.40 d;在大棚和露地栽培条件下,韭菜中毒死蜱的降解速率差异不大,平均降解半衰期分别为3.37和3.44 d.施药灌根后第21天,韭菜中毒死蜱的残留量(0.021 ～0.102mg·kg-1)基本低于GB 2763-2005规定的最大残留限量标准(≤0.1 mg·kg-1).新生韭菜中仍残留少量毒死蜱,但明显低于药后第一次刈割.土壤中残留的毒死蜱对韭菜中的农药残留量有显著影响.

Residue of chlorpyrifos and its degradation dynamics in Chinese chive (allium tuberosum) plant and soil

This paper studied the residue of chlorpyrifos and its degradation dynamics in Chinese chive (Allium tuberosum) plant and soil after irrigating different concentrations of this pesticide into A. tuberosum root zone under plastic greenhouse and open-field cultivated conditions. The chlorpyrifos in A. tuberosum plant had a faster degradation rate than that in soil, with an average half-life of the pesticide being 3.41 and 7.40 days in the plant and soil, respectively. Under the conditions of plastic greenhouse and open-field cultivation, the degradation rate of chlorpyrifos in A. tuberosum plant had less difference, with the average half-life of chlorpyrifos being 3.37 and 3.44 days, respectively. 21 days after irrigating into root zone, the chlorpyrifos (0.021-0.102 mg x kg(-1)) in A. tuberosum plant did not exceed the maximum residue limit (< or = 0.01 mg x kg(-1), GB 2763-2005). A few chlorpyrifos residue was found in the new growth parts of A. tuberosum, but the residue concentration was obviously lower than that in the first harvested plant after irrigating this pesticide. The chlorpyrifos residue in soil had significant effects on the residue of the pesticide in A. tuberosum plant.