Election Microprobe and Synchrotron X-ray Fluorescence Mapping of the Heterogeneous Distribution of Copper in High-Copper Vineyard Soils

Electron microprobe and synchrotron X-ray fluorescence mapping of the heterogeneous distribution of copper (Cu) in high-Cu vineyard soils were conducted. The spatial distribution of Cu was measured at two resolutions in thin sections of the surface of 4 cm of undistributed soil by electron microprobe and synchrotron X-ray microfluorescence spectroscopy. Bulk physicochemical analyses of Cu, pH, organic matter, texture, and mineralogy were performed. The results indicated that the Cu distribution was strongly heterogeneous at both scales of observations. The results underscored the importance of investigating the microscale spatial distribution of contaminants to ascertain their possible impact on soil microbial communities and processes. The results suggested that the current soil sampling protocols might be largely misleading in terms of the ecotoxicology of metal contaminants in soils and would need to be modified substantially.