Original scientific paper
Estimation of SOC Content in Anthropogenic Soils from Flysch Deposits Using Vis-NIR Spectroscopy
Boško Miloš
orcid.org/ORCID
; Institute for Adriatic Crops and Karst Reclamation, Put Duilova 11, 21 000 Split, Croatia
Aleksandra Bensa
orcid.org/ORCID
; University of Zagreb, Faculty of Agriculture, Svetošimunska 25, 10 000 Zagreb, Croatia
Abstract
The objectives of this work were to estimate the ability of Vis-NIR diffuse reflectance spectroscopy for the prediction of soil organic carbon (SOC) content in terraced soils from Flysch deposits in Dalmatia, Croatia and to determine the significance of spectral wavelengths and regions. In a total of 159 top-soil samples (0-25 cm) SOC content was determined in the laboratory and reflectance spectra were collected using a portable Terra Spec 4 Hi-Res Mineral Spectrometer with a wavelength range 350-2500 nm. The partial last square regression (PLSR) with leave-one-out cross-validation method was used for calibrating the Vis-NIR spectra and SOC content. The SOC content varied from 2.79 to 28.66 g kg-1 with an average value of 13.47 g kg-1. The SOC model prediction parameters, the coefficient of determination (R2), the ratio of performance to deviation (RPD) and the range error ratio (RER) were 0.73, 1.76 and 8.19, respectively, indicating moderately useful calibration model which is acceptable for a rapid sample screening for SOC content determination. The wavelengths located near 1400, 1900, 2000, 2025, 2200, 2225, 2275, 2325 and 2355 nm in NIR, near 560 nm in visible and near 825 nm in the short-wave NIR (700-1100 nm) were identified as important wavelengths for PLSR SOC modelling.
Keywords
calibration; diffuse reflectance spectroscopy; PLSR; soil organic carbon
Hrčak ID:
203012
URI
Publication date:
10.6.2018.
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