QUANTIFYING AND MONITORING NUTRIENT CYCLING, CARBON DYNAMICS AND SOIL PRODUCTIVITY AT FIELD, WATERSHED AND REGIONAL SCALES
Location: Hydrology and Remote Sensing Laboratory
Title: Advances in spectroscopic methods for quantifying soil carbon
Submitted to: Book Chapter
Publication Type: Book / Chapter
Publication Acceptance Date: October 1, 2011
Publication Date: June 1, 2012
Citation: Reeves III, J.B., McCarty, G.W., Calderon, F., Hively, W.D. 2012. Advances in spectroscopic methods for quantifying soil carbon. In: Liebig, MA, Franzluebbers, A.J., and Follett, R. editors. Managing Agricultural Greenhouse Gases. Amsterdam, The Netherlands: Elsevier. 20:345-366.
The gold standard for soil C determination is combustion. However, this method requires expensive consumables, is limited to the determination of the total carbon and in the number of samples which can be processed (~100/d). With increased interest in soil C sequestration, faster methods are needed. Thus, interest in methods based on diffuse reflectance spectroscopy in the visible, near-infrared or mid-infrared ranges using either proximal or remote sensing. These methods have the ability to analyze more samples (2 to 3X/d) or huge areas (imagery) and do multiple analytes simultaneously, but require calibrations relating spectral and reference data and have specific problems, i.e., remote sensing is capable of scanning entire watersheds, thus reducing the sampling needed, but is limiting to the surface layer of tilled soils and by difficulty in obtaining proper calibration reference values. The objective of this discussion is the present state of spectroscopic methods for soil C determination.