REFLECTANCE SPECTROSCOPY FOR ROUTINE AGRONOMIC SOIL ANALYSES

• DOI: 10.1097/ss.0b013e31804fa202
• Publication Date: 2007-06-11T08:03:25Z
• Authors: Matthew Cohen; Rao S. Mylavarapu; Ismail Bogrekci; W.S. Lee; Mark W. Clark
• Keywords: Soil test

Near-infrared reflectance spectroscopy is a demonstrated tool for quantitative analysis of numerous soil properties. Reported advantages include analytical precision, predictive accuracy, and reduced costs processing times. A library (N = 1933) representing all major orders in Florida was assembled from samples submitted to the University Extension Soil Testing Laboratory routine testing during 2004-2005. High-resolution diffuse spectra each sample visible/near infrared were used predict observations made using standard laboratory procedures pH, Mehlich-1-extractable P, K, Ca, Mg, Cu, Mn, Zn, percentage organic matter, saturated hydraulic conductivity (Ksat). Calibrations immediately applicable matter Al, based on relative performance determinant values (RPD deviation/standard error validation > 2.0). Models Ksat showed moderate accuracy (1.5 < RPD 2.0), whereas those Fe exhibited low efficiency 1.5), indicating need further refinement before near-infrared viable alternate method procedures. Prediction fertility productivity published diagnostic categories effective discrimination P Cu (phytotoxicity), Ksat. Our study that prediction strong function mean nutrient/analyte concentration soil. We rates comparable to, some cases smaller than, rates, suggesting observed spectral may be substantially because uncertainty data.