Visible-Near Infrared Reflectance Spectroscopy for Rapid Characterization of Salt-Affected Soil in the Indo-Gangetic Plains of Haryana, India

Determination of soil physicochemical attributes in farming sites through visible, near-infrared diffuse reflectance spectroscopy and PLSR modeling

“…The three notable absorption peaks were identified at 1417-, 1914-, and 2209-nm bands by reflectance spectra as well as FDT-SG methods along with clay concentrations at 2200-2329 nm (Ben-Dor and Banin 1994;Islam et al 2003). The absorption peaks at 1400 and 1900 nm are related to water (moisture and hydroxyl ions) and clay lattice OH features at 1400 and 2200 nm (Bilgili et al 2010;Srivastava et al 2017). The water absorption peaks were usually enhanced in the FDT with SG smoothing method ( Fig.…”

“…The FDT and SG smoothing was used to process all the spectral data to smooth the spectra and to eliminate the particle size effects and noise produced by illumination variations (Bilgili et al 2010;Tsai and Philpot 1998). It is found to be an optimal spectral pre-treatment in alike studies (Awiti et al 2008;Bilgili et al 2010;Srivastava et al 2017). The SPAs were detected by the first derivative transferred spectra which generally augment the absorption features.…”

“…is standard deviation of measured values in the validation set, and RMSEP is the root mean square error of prediction of validation dataset (Bilgili et al 2010;Srivastava et al 2017;Zornoza et al 2008).…”

“…The value of R 2 demonstrates the percentage of the variation in the dependent variable that is accounted for the independent variables. The RMSEP value estimates the variation of predicted values around measured values, and as this approaches to zero, prediction performance of the equation improves (Srivastava et al 2017). The prediction of accuracy has been improved by the RPD factor as compared to using the mean composition for all samples (Srivastava et al 2017).…”

“…The VNIR-DRS is productive, rapid, non-wasting, non-destructive, and more accurate as compared to customary ways. The in situ method provides information about the SPA without perilous compounds (Awiti et al 2008;Bilgili et al 2010;Brown et al 2006;Demattê et al 2010;Rossel et al 2006Rossel et al , 2016Srivastava et al 2017;Udelhoven et al 2003;Zornoza et al 2008). In addition, a single spectrum of soils provides information about the various SPA and the methods are adaptable for on-the-go at the field (Rossel et al 2006).…”