What soil tests does VIS-NIR relate to? Could VIS-NIR someday replace wet chemistry lab measurements?
Because of the vibrations that occur when molecules containing O-H, C-H, NH bonds are illuminated, VIS-NIR soil measurements correlate well with water, carbon, and nitrogen. Relationships to other properties such as calcium, magnesium, pH, CEC, clay content have been reported in the literature. Veris Technologies research results confirm this, however results are not as consistent as they are for C and N. Extensive research is still required in soil VIS-NIR, and as spectral libraries grow, improved calibrations to soil properties may result.
