This paper can be, to my opinion, a valuable contribution to SOIL. However, the reviewers both point to some major issues, mostly related to poor and inconsistent use of terminology related to measured mineral and organic fractions. Other issues raised had to do with serious concerns over used methodology to isolate meaningful fractions. I would therefore ask you to thoroughly address the issues raised by the two reviewers in a revised manuscript and bring more clarification around methodology and resulting fractions. The text is at times confusing to read and to follow the author's reasoning, so please try to bring more logic into the data interpretations and discussion. I understand fractionation methods are operationally defined and all have their limitations, but clarification is definitely needed to justify their choice and why they are relevant for addressing the questions asked in this paper.
I look forward seeing a revised manuscript soon.

Dear Dr. Trumbore,

Thank you for your detailed and thoughtful responses to the reviewers’ comments. Both of them brought up valid concerns that required quite a bit of rewriting, convincing, and adding text to the manuscript. You significantly modified your manuscript paying close attention to their comments and suggestions. I'm pleased to see more consistent use as well as proper descriptions of used terminology to indicate the different clay and Fe and Al oxide fractions, as this created much confusion and hesitation over the correctness of interpretation of the results. The manuscript greatly improved in doing so and it is now much easier to read and follow the logic behind the interpretations of the data since fractions are better labeled with direct links to used methodology (since all fractions are operationally defined).
I would advise you to closely check the manuscript for grammatical and spelling errors. I also noticed some mislabeling in the figure axis (e.g. Fig. 5 X-axes). Otherwise, I believe this paper is acceptable for publication in SOIL.

Thank you.

As indicated by the topical editor, the manuscript needs to be checked for grammar and spelling, and then also some mislabeling.
If these things are taken care off, then I am very eager to accept your manuscript.
Thanks for choosing SOIL!

best,
jo