稻茬免耕油菜除草剂在土壤中的消解动态

Degradation Dynamics of Herbicide in Soil of No-tillage Rape with Rice Stubble

为探明稻茬免耕油菜土壤中除草剂的消解动态,通过田间试验,采用NaHCO3等溶液提取,分别用液相色谱带紫外和荧光检测器测定,建立了土壤中草甘膦、百草枯的提取和检测方法。结果表明:添加量为0.5～5.0mg/kg时,草甘膦、百草枯在土壤中的添加回收率为76.4%～96.2%,变异系数为2.89%～7.22%;土壤中草甘膦、百草枯的残留消解动态符合C=AeBt的指数回归方程,其消解半衰期为5.3～11.8d。建立的提取方法准确、可靠。

For the sake of exploring the degradation dynamics of herbicide in soil of no-tillage rape with rice stubble, a field experiment was conducted, an extraction and detection method of glyphosate and paraquat in soil was constructed, taking NaHCO3 as the extraction solution and detecting by HPLC with ultraviolet and fluorescence detectors. The results showed that when the adding amount was 0. 5 5.0 mg/kg the fortified recovery rate of glyphosate and paraquat in soil ranged from 76.4% to 96.2G with the variation coefficient of 2.89 % ～7.22%3 The degradation dynamics of glyphosate and paraquat residues was in accordance with exponential regression equation C= AeBt, the half-life period was 5.3 ～ 11.8 d. The established extraction method was accurate and reliable.