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).