APPLICATIONS OF PXRF FOR PEDOLOGY, AGRONOMY, AND ENVIRONMENTAL QUALITY ASSESSMENT (Invited Presentation)

Portable X-ray fluorescence (PXRF) spectrometry is a proximal sensing technology that allows for elemental determination in soils and other matrices in-situ, in seconds. Originally used primarily in mining and metallurgy industries, PXRF has rapidly gained acceptance for agronomic, pedological, and environmental quality assessment applications. Using elemental data a proxy, linear regression is commonly used to predict an unknown parameter of interest. To date, PXRF has been successfully used to quantify soil cation exchange capacity, horizons, pH, salinity, and establish the presence of lithologic discontinuities. Direct measurement of toxic elements in soil (e.g., Pb, Cr, As, Cd) is easily accomplished via PXRF, with spatial variability modelling accomplished via the use of geographic information system software. Newer lines of investigation are assessing vegetation and water samples with PXRF. Linkage of PXRF elemental data with other proximally sensed data (e.g., visible near infrared diffuse reflectance spectroscopy), has enhanced the predictive capabilities relative to either sensor in isolation. Multiple reference methods now exist worldwide to appropriately sanction the use of PXRF. Summarily, the alacrity and accuracy of data acquisition afforded by PXRF offer formidable advantages over traditional laboratory based techniques.