The authors have very well accommodated referee requests. I agree with the proposed modifications to the manuscript. Only a few minor points of attention remain:

The abstract is too long: even detail is provided on specifics of the lab incubations. This part can be condensed without loss of information.
P2 2nd line of the introduction: remove . after Environment Canada
P2 L24 comma after ‘Baggs’
P3 L9-12 ‘The term “isotopomer” is used herein to indicate molecules of the same mass in which the trace isotopes are arranged differently. This differs from “isotopologue”, which is a more general term referring to molecules that differ in isotopic composition (Ostrom and Ostrom, 2012).’ Could be omitted.

It would indeed be a good idea to provide ‘the new fig 5’ as supplementary material and refer to it in the text. While your approach is plausible, like referee 1 most readers will be at first skeptic about setting SP endmembers based on these bulk measurements of soil emitted N2O. Fig. 5 clearly demonstrates that in fact using literature based SP endmembers yields unrealistic N2O source fraction calculations. This is an important point that does deserve a bit more attention in the discussion.

Fig. 4: Please clarify in the caption: are these observations from the three soils combined? I suspect so, but this is not immediately clear yet.

The first line of the conclusions section seems a bit redundant to me – belongs rather in an abstract – but the authors can decide upon this.

Soil-2019-27 is now ready for publication. Thank you for dealing with all raised comments this swiftly.

Dear Authors,

First of all, thank you very much for choosing SOIL to publish your interesting work! Second, I do appreciate how you have worked with the reviewers and Topical Editor to improve the manuscript. Hence, it is with great pleasure that I do accept your manuscript for publication in SOIL.

Best,
Jo