In order to study the distribution characteristics of organophosphorus pesticides (OPPs)in the soil of Jianghan plain,78 profile-soil samples from various depth and 7 surface-soil samples were collected in September,2015 in established groundwater monitoring field site, Jianghan plain. The OPPs concentrations were determined by gas chromatography with nitrogen-phosphorus detector(GC-NPD). The results showed that OPPs were widespread in our studied area. The OPPs concentrations of suface-soil samples ranged from 89.80 ng·g-1 to 193.85 ng·g-1,with an average of 140.05 ng·g-1, whereas the OPPs concentrations of profile-soil samples ranged from 19.81 ng·g-1 to 138.28 ng·g-1,with an average of 40.99 ng·g-1. The main ingredients of OPPs in surface and profile soil samples were methamidophos, omethoate, diazinon and quinalphos,and the residual amount of 10 kinds of OPPs had posed a threat to agricultural products according to the America soil pesticide residue limits standards. The horizontal distribution of OPPs concentration in profile soil followed the order of nearby river farm area > nearby river area > farm area, namely GS1-1 > GS4 > GS2 > GS3. while the vertical distribution mostly decreased at first and then increased with increasing depth. The distribution characteristics of OPPs were also influenced by many factors, such as application amount of OPPs, the adsorption and desorption actions of soil, vertical movement of groundwater, the terrain environment in the study area, and the concentration of soil organic matters.
Keywords: Jianghan Plain; distribution characteristics; influencing factors; organophosphorus pesticides; typical soil environment.