Figure 1.
Mean NIR spectral absorbance (Log 1 R−1, R = reflectance) of sediment samples.
Solid line mean spectra of all samples, upper dashed line mean spectra of samples with >30% organic matter, lower dashed line mean spectra of samples with <30% organic matter.
Table 1.
Statistical summary of the sample dataset.
Table 2.
Calibration and validation statistics of partial least-squares regression models.
Figure 2.
Exemplary observed vs. NIR predicted values for total concentrations of N, Fe, P, and S.
Open circles calibration data set, filled circles external validation.
Figure 3.
Exemplary observed vs. NIR predicted values for NaCl-extractable Ca and N-NH4 and oxalate-extractable Fe and P.
Open circles calibration data set, filled circles external validation.