|Reeves iii, James|
Submitted to: Meeting Abstract
Publication Type: Abstract only
Publication Acceptance Date: 4/9/2008
Publication Date: 10/8/2008
Citation: Bandru, V., Hansen, D., Codling, E.E., Reeves III, J.B. 2008. Assessing Metal Contamination in Lead Arsenate Contaminated Orchard Soils Using Near and Mid-Infrared Diffuse Reflectance Spectroscopy. Meeting Abstract. Interpretive Summary:
Technical Abstract: Historic use of lead-arsenate as pesticide in apple orchards left many soils contaminated with arsenic (As) and lead (Pb). Notorious health effects and their severe soil contamination are of primary concerns for major regulatory agencies, and community at large. Wet chemistry methods for soil analyses are relatively expensive, time-consuming, and may also result in environmental pollutants. This paper explores the application of rapid and nondestructive infrared spectroscopy for assessing As and Pb along with other minerals (carbon, nitrogen, iron and phosphorus) in orchard soils. A total of 202 soil samples at the 0-15 cm depth were collected from orchard soils with history of lead arsenate use from five major apple producing states, Maryland, Michigan, New York, Virginia, Washington and West Virginia. Samples were scanned at near-infrared (400-2498 nm) and mid-infrared (2500 to 25000 mm) wavelengths regions using NIR systems. Partial least squares (PLS) with the one-out validation procedure was used to develop calibrations. Results reported various levels of soil metal content (5-220 mg kg-1 for As, 15-325 mg kg-1 for Pb, 2.5–15.0 mg kg-1 for iron) and other minerals (0.5 to 18 % for carbon, 0.2–3.5% for nitrogen, 150-1250 mg kg-1 for phosphorus). Mid-infrared spectroscopy performed better compared to near-infrared spectroscopy. The best coefficients of determination (r2) values for metals (As, Pb and iron) were 0.68, 0.76 and 0.87 respectively. With the exception of phosphorus, there were poor correlations with the other minerals. High carbonates in soil might have affected predictability of carbon. This study demonstrated that the prediction of As and Pb in lead-arsenate contaminated orchard soils is feasible.