Table 3.

The R² and RMSE values of four kinds of soils (loess, calcium soil, black soil and red soil) modeled by full wavebands (PLS, BIPLS, BPNN) and sensitive wavebands (PLS).

Soil Type	Model	Calibration Set		Prediction Set
		${\mathit{R}}_{\mathit{c}}^2$	$RMS{E}_{\mathit{c}}$(g/kg)	${\mathit{R}}_{\mathit{p}}^2$	$RMS{E}_{\mathit{p}}$(g/kg)	The Tested Range (g/kg)
Loess	PLS	0.95	0.066	0.95	0.066	0.057–0.944
	BIPLS	0.93	0.079	0.94	0.075	0.063–0.950
	BPNN	0.96	0.053	0.93	0.075	0.025–0.909
	CARS/BIPLS-PLS	0.92	0.080	0.94	0.074	0.041–0.972
Calcium Soil	PLS	0.98	0.045	0.96	0.080	0.043–1.247
	BIPLS	0.95	0.074	0.95	0.081	0.018–1.173
	BPNN	0.96	0.038	0.95	0.102	0.101–1.196
	CARS/BIPLS-PLS	0.88	0.158	0.91	0.104	0.242–1.255
Black Soil	PLS	0.98	0.086	0.79	0.285	0.079–2.149
	BIPLS	0.88	0.212	0.86	0.232	0.069–2.111
	BPNN	0.94	0.167	0.79	0.325	0.133–1.970
	CARS/BIPLS-PLS	0.85	0.249	0.83	0.270	0.240–2.112
Red Soil	PLS	0.90	0.210	0.86	0.236	0.196–2.025
	BIPLS	0.87	0.239	0.86	0.231	0.028–2.133
	BPNN	0.95	0.158	0.87	0.231	0.019–2.090
	CARS/BIPLS-PLS	0.86	0.249	0.84	0.268	0.014–2.166