Ultra-violet, visible, near-infrared, and mid-infrared diffuse reflectance spectroscopic techniques to predict several soil properties

Abstract

Reflectance spectroscopy techniques in the ultraviolet, visible, near-infrared and mid-infrared regions are alternatives for many traditional laboratory methods for measuring soil properties. However, debate exists over whether the near-infrared (700–2500 nm) or the mid-infrared (MIR, 2500–25000 nm) region of the electromagnetic spectrum is more useful for predicting soil properties. Therefore, the aim of this study was to compare UV-VIS-NIR and MIR spectroscopic techniques to predict several soil properties. A total of 415 surface and subsurface soil samples were collected from widely spread locations within New South Wales and south-eastern Queensland of Australia to model the proposed hypothesis. Principal component regression analysis (PCR) was used to develop calibration and validation models from soil spectra and reference laboratory values. The models developed using MIR spectra achieved higher prediction accuracy (regression coefficient, r2 = 0.62–0.85) for pH, organic carbon, clay, sand, CEC, and exchangeable Ca and Mg than that obtained by UV-VIS-NIR spectra (r2 = 0.28–0.76). PCR models were also developed for the combined spectral regions (UV-VIS-NIR+MIR). The models developed using combined spectra were also found to predict pH, organic carbon, clay, sand, CEC, and exchangeable Ca and Mg with acceptable accuracy (r2 = 0.59–0.79). The results of this study indicate that MIR spectra are better than UV-VIS-NIR spectra for estimation of common soil properties.

Prediction of Soil Physical and Chemical Properties by Visible and Near-Infrared Diffuse Reflectance Spectroscopy in the Central Amazon

“…The modeling performance for clay and sand in our study are in agreement with the results found by [32,[39][40][41] which ranged from 0.51 to 0.86 (R 2 ) and 31 to 120 g·kg −1 (RMSE) for both soil fractions. However, all these studies used different soils, methodologies, prediction algorithms and soil properties were not back-transformed in some situations.…”

“…Greater predictive performance for particle size is usually observed in the MIR compared to the VIS-NIR region. It can be explained by the stronger interaction between mid-infrared reflection spectra and soil particles by fundamental vibration processes when compared to the VIS-NIR [27,39,40].…”

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

“…Three categories, based on RPD in the ranges >2, 1.4-2.0, and <1.4, were used to indicate decreasing reliability of predicting (Chang, et al, 2001). Similar results of suitable limits for RPD were also described by Dunn, et al (2002) and Pirie, et al (2005). Strong correlations were found between FTIR spectra and soil parameters: C/N ratio, C and N content, lignin, HA, soil organic carbon (SOC), inorganic carbon, metals, pH, and others.…”

“…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.…”

On-line measurement of soil properties without direct spectral response in near infrared spectral range

“…literature, sodium (Na ex ) and potassium (K ex ) are among the most difficult properties to be measured with the NIR spectroscopy (Malley et al, 1999;Chang et al, 2001;Zornoza et al, 2008;Pirie et al, 2005;Dunn et al, 2002;Shepherd & Walsh, 2002;Islam et al, 2003;Volkan et al, 2010;. For the same soil property, laboratory vis-NIR methods achieved higher accuracy as compared to measurement under field soil conditions, particularly with on-line vis-NIR sensors Kuang et al, 2012).…”