Quantitative Estimation of Organic Matter Content in Arid Soil Using Vis-NIR Spectroscopy Preprocessed by Fractional Derivative

Table 3

Performance statistics of absorbance model for calibration set and validation set based on PLSR.

Order	Principal components	Calibration set		Validation set
			RMSEC (g kg^−1)		RMSEP (g kg^−1)	RPD
0	2	0.11	10.91	0.12	8.69	1.06
0.2	2	0.20	10.35	0.19	8.31	1.11
0.4	2	0.35	9.34	0.24	8.04	1.15
0.6	2	0.38	9.13	0.26	7.98	1.16
0.8	3	0.36	9.27	0.20	9.27	1.12
1	3	0.36	9.27	0.21	8.21	1.13
1.2	3	0.38	9.11	0.32	7.60	1.22
1.4	4	0.52	8.03	0.58	5.99	1.54
1.6	4	0.44	8.63	0.50	6.55	1.41
1.8	5	0.93	3.06	0.89	3.06	3.02
2	5	0.92	3.32	0.88	3.15	2.94