Table 7.

Predictive performances for the wavelength refined models. Cal = calibration. Val = validation. Results are shown for the two different approaches used for variable selection: using the top 30% of wavelengths based on the regression coefficients from the full-spectra models and using wavelengths previously determined to be associated with nitrogen and water.

Water wavelength selection models				Nitrogen wavelength selection models
	PLSR	Cal	Val		PLSR	Cal	Val
Regression Coefficients	R2	0.81	0.69	Regression Coefficients	R2	0.74	0.66
	RMSE	2.05	2.53		RMSE	0.32	0.41
	RPD	2.31	1.78		RPD	1.89	1.66
Known Absorption Features	R2	0.71	0.64	Known Absorption Features	R2	0.54	0.52
	RMSE	2.57	2.74		RMSE	0.42	0.47
	RPD	1.85	1.76		RPD	1.45	1.39