Figures
Figure 1 . Sampling locations in the present study (Geographic
Coordinate System: GCS_WGS_1984).
Figure 2 . Average spectral signature of calibration and
validation dataset of the salt-affected soils
Figure 3 . Soil salinity class-wise (a) raw reflectance spectra
and (b) continuum-removed spectra
Figure 4 . Relationship between observed and predicted (a) soil
pH, (b) electrical conductivity (EC), (c) Soil organic carbon (SOC), (d)
Bulk density(BD), (e) Soil available nitrogen (N), (f) Soil available
phosphorus (P), (g) Ammonium extractable potassium (K), (h) Ammonium
extractable sodium (Na) (i) Ammonium extractable calcium (Ca), (j)
Ammonium extractable magnesium (Mg), (k) Soil available sulphur (S), (l)
Soil available iron (Fe), (m) Soil available manganese (Mn), (n) Soil
available copper (Cu), (o) Soil available zinc (Zn), (p) Soil available
boron (B); R2, coefficient of regression; MBE, Mean
bias error; RMSE, Root mean square error; RPD, ratio of performance to
deviation; SVR, Support vector regression; PLSR, Partial least square
regression; PCR, Principal component regression; RF, Random forest;
Multivariate adaptive regression splines MARS