Leachingbehaviorofthreepyrethroidpesticidesinsandysoilandloam

The leaching characteristics of three pyrethroid pesticides, cyfluthrin, bifenthrin and beta-cypermethrin in the main soil types (sandy soil and loam) in tropical areas were studied by using the soil column leaching experiment and gas chromatography. The results showed that the majority of residues of three pyrethroid pesticides were discovered in the first paragraph (0-5 cm) and the amount of residues decreased with the increase of depth. The R_i values of cyfluthrin, bifenthrin and beta-cypermethrin were 52.86%, 94.73% and 83.19% respectively in sandy soils , and 54.7%, 77.28% and 55.33% respectively in loam, which were all higher than 50%. According to the leaching grade of pesticides in the soil, three pyrethroid pesticides belong to refractory leaching pesticide, which are not easy to cause pollution to groundwater. This study can provide reference for the remediation of pesticide pollution in soils and groundwater in tropical areas.