How much kaolinite could contain my soil sample?

Now that we have our reference kaolinite near infrared spectrum stored  and studied, we can acquire a we spectrum (unknown) and compare it with the reference material trying to have a clear idea od how much kaolinite could contain. Soils high or very high in kaolinite have disadvantages for agriculture, so looking to the comparison we can take some actions.

We are going to use one spectrum (the first one) from the soilspec package, where we have a data set called:  "rutherglenNIR" which is a subset of soil spectra samples from the Rutherglen Area.

First, we compare the kaolinite reference material spetrum with the spectrum of the unknown sample:

And we have a look to the kaolinite featured spectra region, so we can trimm the spectrum and start to make some comparissons after the normalization processes:

Normalization Step 1 :

Normalization Step 2:

Now we can compare the areas, and  get the conclussion that the unknown soil sample has a relative low content of kaolinite compared to the reference spactrum.

Of course we can confirm this with numbers such as Area, Relative Depth,....