Figure Legends
FIG. 1 Geographical distribution of the soil sample sites
FIG. 2 Laser shot points on a soil sample pellet
FIG. 3 Average FTIR-ATR spectra of the soil samples
FIG. 4 Average LIBS spectra of the soil samples
FIG. 5 (a) Correlations between the properties of the soil
samples. (b) Correlations between the intensities of the LIBS spectra of
six selected samples.
FIG. 6 Spatial distribution of Mg, Ca, Na, and K based on the
LIBS spectra intensity in an area of 2 × 2 mm, with the depth in
micrometers. Column C represents the distribution of elements in each
sample. C1: salt 1.08 g/kg and SOM 3.53 g/kg; C2: salt 1.09 g/kg and SOM
11.38 g/kg; C3: salt 9.49 g/kg and SOM 13.80 g/kg; C4: 9.55 g/kg and SOM
5.60 g/kg; C5: salt 10.17 g/kg and SOM 13.20 g/kg; and C6: salt 16.10
g/kg and SOM 7.52 g/kg
FIG. 7 Synchronous (a, c) and asynchronous (b, d) FTIR–ATR 2D
salt content–dependent correlation maps generated from 2500–650
cm-1 and 4000–2000 cm-1,
respectively
FIG. 8 Synchronous (a) and asynchronous (b) FTIR-ATR –LIBS
Hetero 2DCOS generated from salt content–dependent maps. Red and blue
colors represent positive and negative correlations, respectively. The
darker color indicates a stronger correlation than the lighter color