江汉平原典型土壤环境中有机磷农药的分布特征及影响因素

为了研究江汉平原土壤中有机磷农药（OPPs）的分布特征，项目组于2015年9月在地下水监测场所在区域，采集了78个剖面土和7个表层土土样，通过气相色谱-氮磷检测器（GC-NPD）分析OPPs的含量，研究江汉平原土壤中OPPs的分布特征.结果表明，研究区土壤普遍存在OPPs，其中地表土中OPPs的含量范围为89.80~193.85 ng·g^-1，平均值为140.05 ng·g^-1；剖面土中OPPs的整体含量范围为19.81~138.28 ng·g^-1，平均值为40.99 ng·g^-1.地表土和剖面土中OPPs主要检出成分均为甲胺磷、氧化乐果、二嗪农和喹硫磷等，并且根据美国土壤农药残留限量标准，研究区土壤中10种OPPs的残留量已对农产品的安全构成威胁.研究区剖面土中∑OPPs分布为：水平方向，沿河农田剖面土 > 沿河非农田剖面土 > 中部农田剖面土，即：GS1-1 > GS4 > GS2 > GS3；垂直方向，大部分剖面土随着深度的增加整体上呈先减小后增大的趋势；研究区土壤中OPPs的分布受多种因素的影响：农业生产过程中施用OPPs的量、土壤对OPPs的吸附、解吸附作用、地下水的垂直运动、研究区的地形环境、土壤有机质的含量等.

Distribution Characteristics and Influencing Factors of Organophosphorus Pesticides in Typical Soil Environment of Jianghan Plain

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.