Dear authors, 

Many thanks for submitting a very interesting paper. I enjoyed reading it and think it will be a good benchmark for future work on pedotransfer functions (PTFs) and soil hydrological properties. I did not find major flaws in terms of the review conducted by the authors or with the data analysis presented within the manuscript.

However, i felt the manuscript was very long and a bit hard to follow at times. A summary explaining/outlining the paper's structure could help the reader follow better. This should be provided at the end of the introduction section, and could replace the summary at the subsections' opening. A table or list of abbreviations after the abstract would also be very helpful, as there are too many acronyms, forcing the reader to sometimes go back and forth the text. The study aim and how this was achieved needs to be made much clearer in the abstract and introduction. Some of the key takeaways presented in the last section could also be summarised in the abstract, so the impact and relevance of the study can be highlighted.  

Some sections contained too much detail that did not help understand the key message better, or even was unclear how some of the detail/text was explicitly related to the study topic. Some ideas are presented and discussed in multiple sections (e.g., upscaling, establishment of standard methods, etc) whilst conveying the same message, creating some avoidable redundancy.  i suggest the authors trim the text down and, to the best of their ability, strive to focus on the main takeaways. For example, Fig. 9 seems to portray many (if not most) of the points the authors are making. Fig. 9 could feature much earlier in the manuscript and be used as a vehicle for presenting or better structuring the discussion.

Last but not least, provided that the authors are providing a concise and comprehensive review of PTFs, I missed some text in the introduction referring to composite soils. In particular, aspects related to how vegetation and soil microbial communities may impact soil hydrological properties and PTFs, though discussed later on in the MS (in more than one section, please condense and merge), I felt it was not given enough attention and  that it should be highlighted earlier on (and perhaps in the final declaration, too), as this can open up exciting research opportunities. Perhaps the authors tried to made this implicit when discussing the impact of soil structure on PTFs and the current lack of understanding. If so, i would encourage the authors to make the point more clear. 

I am also providing some other specific comments in the attached file. Some are related to the science but most are editorial suggestions. 

Best wishes,

Publisher’s note: a supplement was added to this comment on 9 November 2023.

See attachment