Dousset Sylvie, Jacobson Astrid R, Dessogne Jean-Baptiste, Guichard Nathalie, Baveye Philippe C, Andreux Francis
UMR 5561 Biogéosciences, UFR des Sciences de la Terre et de l'Environnement, Université de Bourgogne, 6 boulevard Gabriel, 21000 Dijon, France.
Environ Sci Technol. 2007 Dec 1;41(23):8056-61. doi: 10.1021/es071664c.
The fate of organic herbicides applied to agricultural fields may be affected by other soil amendments, such as copper applied as a fungicide. The effect of copper on the leaching of diuron and glyphosate through a granitic and a calcareous soil was studied in the laboratory using sieved-soil columns. Each soil was enriched with copper sulfate to obtain soil copper concentrations of 125, 250, 500, and 1000 mg kg(-1). Glyphosate leaching was influenced by soil pH and copper concentration, whereas diuron leaching was not. In the calcareous soil, glyphosate leaching decreased as copper levels increased from 17 mg kg(-1) (background) to 500 mg kg(-1). In the granitic soil, glyphosate leaching increased as copper levels increased from 34 mg kg(-1) (background) to 500 mg kg(-1). The shapes of the copper elution curves in presence of glyphosate were similar to shapes of the glyphosate curves, suggesting the formation of Cu-glyphosate complexes that leach through the soil. Soil copper concentration does not influence diuron leaching. In contrast, increasing copper concentrations reduces glyphosate leaching through calcareous soils, and conversely, increases glyphosate leaching through granitic soils. Our findings suggest that the risk of groundwater contamination by glyphosate increases in granitic soils with elevated copper concentrations.
施用于农田的有机除草剂的命运可能会受到其他土壤改良剂的影响，例如作为杀菌剂施用的铜。在实验室中使用过筛土柱研究了铜对敌草隆和草甘膦在花岗岩土和石灰性土壤中淋溶的影响。向每种土壤中添加硫酸铜，使土壤铜浓度达到125、250、500和1000 mg kg⁻¹。草甘膦的淋溶受土壤pH值和铜浓度的影响，而敌草隆的淋溶不受影响。在石灰性土壤中，随着铜含量从17 mg kg⁻¹（背景值）增加到500 mg kg⁻¹，草甘膦的淋溶减少。在花岗岩土中，随着铜含量从34 mg kg⁻¹（背景值）增加到500 mg kg⁻¹，草甘膦的淋溶增加。存在草甘膦时铜的洗脱曲线形状与草甘膦曲线形状相似，表明形成了可通过土壤淋溶的铜 - 草甘膦络合物。土壤铜浓度不影响敌草隆的淋溶。相反，增加铜浓度会减少草甘膦在石灰性土壤中的淋溶，反之，会增加草甘膦在花岗岩土壤中的淋溶。我们的研究结果表明，在铜浓度升高的花岗岩土壤中，草甘膦污染地下水的风险增加。
