The comment was fully considered: the PCA and partial correlation analysis was adopted form the recommended study (e.g., Cheng et al., 2019). Correspondingly, separate subheadings (with new Table 4 and Figure 4) were added. Generally it was considered in Introduction and Materials & Methods, Results and Discussion sections. Such approach helped to analyze the underlying mechanisms.
During the discussion, the reasons behind the experimental results should be analyzed, not only from the correlation between the sample data but also cannot be explained by relying too much on the VIP score curve. In addition, partial correlation analysis (e.g., Cheng et al., 2019) could be helpful and bring more insights given the fact that soil spectra are simultaneously influenced by several soil properties (e.g., SOM and Iron oxide). This may help to analyze the underlying mechanism.