Rapid Prediction of Soil Water Retention using Mid Infrared Spectroscopy

Abstract

Soil‐water properties vary widely with soil composition and texture, but measurements are often time consuming and expensive to determine using traditional laboratory methods. Mid‐infrared (MIR) spectroscopy is sensitive to soil composition, allowing multivariate calibrations to be derived between volumetric soil water retention and MIR spectra. Mid‐infrared partial least squares (PLS) models can be derived from the spectra of soils and reference data, and can be used to predict the water retention solely from the MIR spectra of unknown samples. Regressions between laboratory‐determined volumetric water retentions, θv, at matric suctions from 1 to 1500 kPa and values predicted by MIR PLS analysis are presented for a broad variety of surface soils from southern Australia. Cross‐validation produced coefficient of determination values ranging from 0.67 to 0.87 and standard error of cross‐validation in the range 4.1 to 3.2. Prediction robustness was tested using an independent set of samples for values of θv at field capacity (10‐kPa suction) and permanent wilting point (1500‐kPa suction). The prediction standard error for the test set was higher than for cross‐validation. This was attributed to a mismatch between spectra for the test set and those of the calibration samples, resulting in a reduced ability of the calibration samples to model the test set spectra. The MIR PLS prediction method performed at least as well as some pedotransfer functions and was shown to be a rapid and inexpensive method for the prediction of volumetric soil moisture content for a range of soil types at a range of matric suctions.

Recent applications of vibrational mid-Infrared (IR) spectroscopy for studying soil components: a review

“…On the basis of a chemisorption study, it was concluded that the band at 1640-1610 cm -1 was due to physically adsorbed water while the one at 1380 cm -1 was due to coordinatively bound water (Aochi, et al, 2011). Weak bands at about 1980, 1870 and 1790 cm -1 are attributed to quartz overtone (Janik, et al, 2007b;Nguyen, et al, 1991). In addition, clay mineral spectra show an intense complex band at around 1048 cm -1 , related to the stretching vibrations of Si-O groups, while the bands at 525 and 468 (Bishop, et al, 2008;Spence and Kelleher, 2012).…”

“…In particular the FTIR spectra of clay minerals made it possible to distinguish clay minerals from each other through the bands assigned to OH and Si-O groups (Bishop, et al, 2008;Madejova, 2003). Clays or aluminosilicates show two sharp peaks at 3695 and 3622 cm -1 due to OH stretching (Janik, et al, 2007b;Madejova, 2003;Nguyen, et al, 1991). A broad band near 3400 cm -1 is due to OH stretching (H bonded water); the position and intensity of this band is affected by various exchangeable cations.…”

“…MIR spectroscopy has frequently been applied to investigate soil properties and soil organic matter (SOM) characteristics (Aguiar, et al, 2013;Bellon-Maurel and McBratney, 2011;Calderon, et al, 2011aCalderon, et al, , 2011bDemyan, et al, 2012;Du and Zhou, 2009;Francioso, et al, 2009;Haberhauer and Gerzabek, 1999;Kaiser, et al, 2011). Currently, the combination of multivariate statistical methods used for the Fourier Transform IR (FTIR) spectra analysis has provided a powerful method for the discrimination and identification and/or quantification of single components in soils (Aguiar, et al, 2013;Bellon-Maurel and McBratney, 2011;Bornemann, et al, 2010;Calderon, et al, 2011aCalderon, et al, , 2011bD'Acqui, et al, 2010;Fernandez-Getino, et al, 2013;Janik, et al, 2007aJanik, et al, , 2007bLudwig, et al, 2008;Minasny, et al, 2008;Pirie, et al, 2005;Reeves III, 2010;Stumpe, et al, 2011;Tatzber, et al, 2010;Viscarra Rossel, et al, 2006;Yang, et al, 2012). The representation of MIR spectra is not uniform in the literature.…”

Mid-infrared spectroscopy and partial least-squares regression to estimate soil arsenic at a highly variable arsenic-contaminated site

“…The spectral peaks observed at 3,695, 3,657 and 3,626 cm -1 were attributed to the presence of -OH stretching band for kaolinite (Fig. 3a) (Schroeder 2002;Cornell and Schwertmann 2003;Janik et al 2007;Song et al 2012). The bands observed at 413, 428, 470 and 522 cm -1 in the spectra of soil samples (Fig.…”

Effect of Soil Use and Coverage on the Spectral Response of an Oxisol in the VIS-NIR-MIR Region

“…On the other hand, [16] demonstrated that soil physical properties based on soil solid composition and surfaces such as clay content and contraction-swelling potential can be reasonably predicted using MIR spectroscopy; [17] calibrated MIR reflectance spectra to estimate soil water content to several matrix pressure heads. Viscarra [2] performed a very complete review of the different soil attributes measured by NIR and MIR spectroscopy.…”