The prediction of soil carbon fractions using mid-infrared-partial least square analysis

Publication Type:

Journal Article

Source:

Australian Journal of Soil Research, Volume 45, Number 2, p.73-81 (2007)

Accession Number:

DOI: 10.1071/SR06083

URL:

http://www.publish.csiro.au/nid/84/paper/SR06083.htm

Keywords:

carbon fractions, Charcoal, mid infrared, MIR, organic carbon, PLS, TOC

Abstract:

This paper describes the application of mid-infrared (MIR) spectroscopy and partial least-squares (PLS) analysis to predict the concentration of organic carbon fractions present in soil. The PLS calibrations were derived from a standard set of soils that had been analysed for total organic carbon (TOC), particulate organic carbon (POC), and charcoal carbon (char-C) using physical and chemical means. PLS calibration models from this standard set of soils allowed the prediction of TOC, POC, and char-C fractions with a coefficient of determination (R2) of measured v. predicted data ranging between 0.97 and 0.73. For the POC fraction, the coefficient of determination could be improved (R2 = 0.94) through the use of local calibration sets. The capacity to estimate soil fractions such as char-C rapidly and inexpensively makes this approach highly attractive for studies where large numbers of analyses are required. Inclusion of a set of soils from Kenya demonstrated the robustness of the method for total organic carbon and charcoal carbon prediction.

Notes:

CSIRO, Land and Water, and CRC for Greenhouse Accounting, PMB No. 2, Glen Osmond, SA 5064, Australia. World Agroforestry Centre (ICRAF), PO Box 30677 ? 00100, Nairobi, Kenya. Corresponding author. Email: jan.skjemstad@csiro.au