3.4.3 SOC prediction
The results obtained in the present study for prediction of the SOC were
found poor. For both, calibration
(R2c=0.83, MBEc=1.39,
RMSEc=1.44 and RPDc=0.43) and validation
(R2c=0.52; MBEc=1.40;
RMSEc=1.54; RPDc=0.41), the SVR model
was found to have better performance (Figure 4c). In general, the
prediction results for SOC using different multivariate models revealed
that the predictive ability of these models was poor. If the organic
matter content is less than 2%, the spectral reflectance properties of
the soil are hardly affected (Baumgardner et al. , 1986; Wenget al. , 2010; Nawar et al. , 2014). In the present study,
the average SOC content was 1.11% with a CV of 56.0%. The results are
concordant with those reported by Nawar et al. (2014).