Abstract: In this study, fomesafen residue and its leaching dynamics in three types of soil were clarified by high performance liquid chromatography (HPLC). When fomesafen was applied with the active ingredient at 1350 g·hm^-2, the halflives of degradation in the meadow, albic and black soils were 25.7-26.7, 16.9-19.3, and 26.7-30.1 days, respectively, which were consistent with the firstorder reaction kinetics model. Fomesafen leached gradually with its degradation in soil during 120 days, while most of it retained in the surface soil. In the albic soil, fomesafen leached to 30 cm after 30 days of application and the concentration of fomesafen in 10-30 cm soil reached the maximum after 60 days. In the meadow and black soils, the leaching depths were up to 30 cm after 5 days, and the concentrations of fomesafen in 10-30 cm soil reached the maximum after 14 days. These results indicate that fomesafen is hard to degrade in a soil with a high organic matter content, and the soil physical and chemical properties are main factors influencing fomesafen leaching. The residue toxicity of fomesafen on following rotation crops and its potential pollution to groundwater in the meadow soil and black soils were heavier than in the albic soil.

Key words: hotspot analysis, inter-decadal variation, spatial autocorrelation, East China Sea., Trichiurus japonicus