| In order to grasp the residues of herbicides at different dosages in the soil, based on field experiments, combined with the HYDRUS model, the transport process of soil water content, glyphosate and Haloxyfop-R-methyl(HPME) in sunflower fields in Hetao irrigation area was simulated, and the transport law of glyphosate and HPME at different dosages in soil was explored. The results showed that the residues of glyphosate and HPME were mainly distributed in the 0-5cm and 5-10cm soil layers, the degradation rate of the 0-5cm soil layer was faster. The degradation rates of glyphosate and HPME in the 0-5cm soil layer 7 days after the drug were 71%~75.8% and 94.7%~94.9%. The degradation rates of glyphosate and HPME in 5-10cm soil layer 7 days after the drug were 48%~50% and 86.2%~89.9%. No glyphosate and HPME were detected in soil and groundwater 21 days after the drug. Based on the simulation results of the HYDRYS model, it was known that the coefficients of determination between simulated and measured soil water content, glyphosate and HPME values was close to 1,the root mean square errors was generally less than 10%, and the average absolute errors less than 5.8%. The error analysis showed that the HYDRUS model could well simulate the soil water content distribution characteristics and herbicide transport law in sunflower field. The results of this study can provide a scientific basis for the rational application of herbicides and the protection of soil and groundwater environment in the Hetao irrigation area. |