Below are my referee comments on the draft report (which still needs work for completion):

Below are my comments as peer-reviewer for this draft paper:
    I believe that the contents of this paper are well worthy of publishing and contain some valuable information and learnings. While it is in need of completion, with some sections not yet written, the basic content and main results and messages from it are clear. Below are my comments as a reviewer for the paper with some general comments first, followed by specific comments.
  The paper is relatively long, since it is trying to cover a lot of information. However, I think this is okay if it is a bit more structured. Some sections could be tightened up a lot. In general the Discussion section needs tightening and clearer points defined. It is currently too much a repetition of the Results section.
  There are many aspects to the paper (probably too many to enable the main clear points to be made).   I suggest omitting the Sensitivity Analysis section (if anything, it could be argued that a sensitivity analysis on some of the key emission factors may have been more useful). I would also suggest omitting the P+S rate change component to simplify the paper. It is unclear how good the basis is for including that aspect. Is it based on survey data and is it strong? I am surprised that Irish farmers have relatively low soil P and S levels on average and that it is responsive to these elements as noted. The P and S rate data looks reasonable based on survey but are you sure that this does not simply coincide with high soil P and S levels? However, if the authors feel this is an important and real issue, for which they have good supporting data (including that it is responsive to addition of these elements) then it could be retained. However, that aspect is quite simple. In practice there will be P and S inputs in the brought-in concentrates and this will vary across the treatments and ideally this input would be taken into account in the P and S additions. This P+S effect is one aspect of the effect of treatments and is not always clear how much it contributes to the total.
Specific comments are:
1.	Title – I suggest replacing ‘expansion’ (which can imply increasing land area) with ‘intensification’.
2.	Introduction – before the middle of the 2nd page, you need to introduce that N is a critical element to target, before you get into the specific comments on N.
3.	Introduction - In last paragraph, you need to be clearer on what the 3 scenarios are. These should be more clearly defined in relation to how they reflect intensification.
4.	Section 2.1.1 – You mention the ‘default scenario’ but it has not been defined. It needs to be clear that you have a base (typical?) system and 3 scenarios.
5.	Section 2.1.1 – add ‘by animals’ after ‘Feed demand’.
6.	Section 2.1.2 – You refer to Figure 1, but this is not the correct figure. I assume that there is some other figure which has not been added in the paper.   Then in section 2.1.3.1 when you refer to Figure 2, I think this is the current Figure 1.
7.	Section 2.1.3.3 – I assume “out of” should be “or”, when referring to urine and dung.  Then after this the meaning of “type-specific tabular organic N” is unclear – expand or modify it.
8.	Section 2.1.6 – be more specific on what “Inh” includes – it appears to be a combination of several additions – this needs clarifying.
9.	Section 2.3.1 – more clarity is needed on the real basis for P and S or omit this section as noted earlier.
10.	Section 2.3.3 – more comment is needed on how the increase in milk production/cow was estimated. Likewise, in section 2.3.4, you should make the calculation process more explicit, e.g. I assume you modelled feed requirements and grass growth, and that intake was calculated; and the difference was assumed to be from concentrates?? If so, did you account for a wastage factor for feeding the concentrates (this should have been recognised).
11.	Section 3.2.1 – in the 2nd sentence, was this calculated via grass growth factors?
12.	Section 3.2.3.1 – be more clear about what N form you are referring to, e.g. use ‘total N inputs’. Otherwise wording could be interpreted as fertiliser N. On line 3 – it is unclear why the increased concentrate feeding rate would affect the fertiliser N rate.  Is the N input of 49 from concentrates? (if so, be more explicit).
13.	Section 3.3.3 – footprint is more commonly used to refer to ALL N losses, including manufacturing of fertiliser and other inputs – is that the case?
14.	Section 4.1, 2nd page – In the 4th paragraph, I think you have the N leaching values for NZ wrong (these are the same numbers as in the next section, so maybe a copy-and-past error)?   I suggest omitting the last paragraph on this page, to reduce words.
15.	Section 4.2.1 – ‘cannot be achieved” – reword this – it could be achieved by putting on more N fertiliser. This sentence needs rearranging to note that results for your treatments were lower than the target.
16.	Section 4.2.2 – merely repeat of words from Results. It should be discussion of what it means. Likewise for the end of section 4.2.3.
17.	Tables need aligning to avoid spill-over across rows – currently hard to follow some Tables.
18.	Table 6 – “TS + Inh” is in the table title but is not in the table.
19.	Figure 3 – Each figure needs a title letter. It is unclear what the middle figure is about??? In the Y-axis legend – omit “input,” since the figure does not include inputs.
20.	Figure 4 – add title numbers for each figure.
An interesting paper with some interesting messages.

 