Riise G, Lundekvam H, Wu Q L, Haugen L E, Mulder J
Department of Plant and Environmental Sciences, Agricultural University of Norway, N-1432 As, Norway. gunnhild.riiseijvf.nlh.no
Environ Geochem Health. 2004 Jun-Sep;26(2-3):269-76. doi: 10.1023/b:egah.0000039590.84335.d6.
Loss of two pesticides with different mobility characteristics, bentazone (Koc approximately 34) and propiconazole (Koc approximately 1800), were studied at three agricultural fields (Askim, Bjørnebekk and Syverud) in SE Norway. A conservative tracer (Br) was used to follow the flow of water. The loss of pesticides varied among the fields, depending on hydrological characteristics and soil properties. The loss of pesticides was higher from two artificially levelled silty clay loam soils with poor aggregate stability (Askim and Bjørnebekk) compared to a loam/silt loam soil with increased content of organic carbon and better aggregate stability (Syverud). The total accumulated loss was <0.5% from all fields. The highest pesticide concentrations were measured at the first runoff episode after application for both the mobile (bentazone) and less mobile pesticide (propiconazole) in the surface runoff. In the drainage water, the peak for the less mobile pesticide coincided with the Br tracer, while the peak for mobile pesticide appeared earlier than the Br tracer. Rapid movement of water, particles and pesticides through soils indicate flow through macropores. Larger proportions (in percent of total applied) of both the mobile and the strongly sorbed pesticides were lost through the drainage as compared to the loss through surface runoff at Askim. Here, it is suggested that macropore flow contribute to the increased loss of pesticides through the drainage. At Syverud, high infiltration capacity reduces the amount of water available for surface runoff, and somewhat higher loss of the mobile pesticide was registered in the drainage compared to the surface runoff. For the strongly sorbed pesticide, however, propiconazole was neither detected in surface nor in drainage water at Syverud. Generally, there was a higher percentage loss of the mobile compared to the strongly sorbed pesticide in both surface and drainage water, which is in agreement with the pesticides mobility characteristics in soil. An exception was, however, the erodible soil Bjørnebekk, where a higher fraction of propiconazole was lost in the surface runoff compared to bentazone. Large amounts of sediment transport from the Bjørnebekk field probably contributed to enhanced transport of the strongly sorbed pesticide.
在挪威东南部的三个农田（阿斯金、比约讷贝克和叙韦鲁德）对两种具有不同迁移特性的农药——灭草松（分配系数Koc约为34）和丙环唑（分配系数Koc约为1800）的流失情况进行了研究。使用一种保守示踪剂（溴）来追踪水流。农药的流失在不同农田之间存在差异，这取决于水文特征和土壤性质。与有机碳含量增加且团聚体稳定性较好的壤土/粉质壤土（叙韦鲁德）相比，在两种人工平整的、团聚体稳定性差的粉质粘壤土（阿斯金和比约讷贝克）中，农药的流失量更高。所有农田的总累积流失量均小于0.5%。在地表径流中，对于迁移性强的农药（灭草松）和迁移性弱的农药（丙环唑），在施药后的首次径流事件中均测得了最高的农药浓度。在排水水中，迁移性弱的农药的峰值与溴示踪剂同时出现，而迁移性强的农药的峰值则早于溴示踪剂出现。水、颗粒和农药在土壤中的快速移动表明水流经大孔隙。与阿斯金地表径流的流失量相比，迁移性强的农药和强吸附性农药通过排水流失的比例（占总施用量的百分比）更大。在此，表明大孔隙流导致了通过排水流失的农药量增加。在叙韦鲁德，高渗透能力减少了可用于地表径流的水量，与地表径流相比，排水中迁移性强的农药流失量略高。然而，对于强吸附性农药丙环唑，在叙韦鲁德的地表和排水水中均未检测到。总体而言，地表和排水水中迁移性强的农药的流失百分比高于强吸附性农药，这与农药在土壤中的迁移特性一致。然而，一个例外是易侵蚀的比约讷贝克农田，与灭草松相比，丙环唑在地表径流中的流失比例更高。比约讷贝克农田大量的泥沙输移可能促使了强吸附性农药的迁移增强。
