Indian River Research and Education Center, Institute of Food and Agricultural Sciences, University of Florida, 2199 S Rock Rd, Fort Pierce, FL, 34945, USA.
Environ Sci Pollut Res Int. 2013 Dec;20(12):8801-12. doi: 10.1007/s11356-013-1831-6. Epub 2013 Jun 6.
Soil contamination by copper (Cu) is a worldwide concern. Laboratory incubation and soil Cu characterization were conducted to examine the effects of external Cu loading and liming on Cu speciation in both bulk soil and particulates of an Alfisol and Spodosol under citrus production. Also, drainage water from the sites was evaluated for dissolved and particulate forms of Cu. Soil available Cu estimated by CaCl2, NH4OAc, or Mehlich-3 extraction significantly increased with external Cu loads and decreased with soil pH. Most increases in soil Cu occurred in the exchangeable and oxide-bound fractions. Organically bound Cu was the dominant fraction in both bulk soil and particulates, but more in particulates than bulk soil (P ≤ 0.001). Organically bound Cu was highly correlated with total recoverable Cu (P ≤ 0.01), increased significantly with external Cu loads (P ≤ 0.001), and decreased with soil pH (P ≤ 0.05). Lime addition converted part of Cu from available pools to more stable forms. Organically bound Cu complexes were found to dominate in soil solution or surface runoff. These results indicate that most Cu accumulated in the contaminated soils is highly mobile, and thus may impact citrus production and the environment.
土壤铜污染是一个全球性的问题。本研究通过实验室培养和土壤铜特征分析，考察了外源铜添加和石灰施用对柑橘种植条件下土壤（黄壤和灰壤）及颗粒态物质中铜形态的影响。同时，还评估了来自这些地点的排水中溶解态和颗粒态铜的情况。用 CaCl2、NH4OAc 和 Mehlich-3 提取的土壤有效铜含量随着外源铜负荷的增加而显著增加，随着土壤 pH 值的降低而降低。土壤铜的大部分增加发生在可交换态和氧化物结合态。有机结合态铜是土壤（包括颗粒态和非颗粒态）中占主导地位的铜形态，但在颗粒态中比非颗粒态中更多（P ≤ 0.001）。有机结合态铜与总可回收铜高度相关（P ≤ 0.01），随着外源铜负荷的增加而显著增加（P ≤ 0.001），并随着土壤 pH 值的降低而降低（P ≤ 0.05）。石灰的添加将部分铜从可利用库中转化为更稳定的形态。在土壤溶液或地表径流中发现有机结合态铜复合物占主导地位。这些结果表明，受污染土壤中积累的大部分铜具有较高的迁移性，因此可能会对柑橘生产和环境产生影响。
