Experimental investigation of atrazine transport in field soil profile

To evaluate the potential pollution risk of atrazine, a field in-situ experiment was carried out to investigate the transport characteristics of atrazine, Br- and soil water coupling. The results show as follows: The soil water contents reduce at first, and then increase with the increase of soil depth for the treatment I that 24 hours after application of atrazine the duration of simulating rain event is one hour and the rainfall is 40 mm, and the treatment II that the rainfall is 80 mm. However, the changes of soil water contents with soil profile depth are in the presentation of the "S" shape for the treatment III that prior to application of atrazine the duration of simulating rain event is one hour and the rainfall is 10 mm, 24 hours after applying atrazine the duration of simulating rain event is one hour and the rainfall is 40 mm, and the treatment IV that the rainfall is 80 mm. In field experiments, the highest residual concentrations of Br- and atrazine appear in surface layers (0～10 cm), the values of residual concentrations for four treatments (I, II, III and IV) are 1.40, 1.09, 0.62, 0.52mol/kg for Br-, and 0.82, 0.74, 0.54, 0.29 μg/g for atrazine, respectively. Compared with the treatments III and IV, the concentrations of atrazine and Br- in soil surface layers are higher, however the variability of concentration is less for the treatments of I and II. The residual concentration of atrazine in soil solution gradually reduces with the increase of soil depth. For all the treatments, the order of residual concentration of atrazine in soil solution at surface soil layers (20 cm) is I>III>II>IV.