PONE-D-20-11469

Cover crop mixture expression is influenced by nitrogen availability and growing degree days

PLOS ONE

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Academic Editor

PLOS ONE

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Reviewers' comments:

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Comments to the Author

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Reviewer #1: Yes

Reviewer #2: Yes

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Reviewer #1: Yes

Reviewer #2: Yes

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Reviewer #1: No

Reviewer #2: Yes

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Reviewer #1: Yes

Reviewer #2: Yes

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Reviewer #1: Dear authors,

It was a pleasure to read your original manuscript and excellent that your research results are very practical for real farms. I have only minor suggestions:

1. Please use the WRB soil classification, or if you keep the soil classification as it is written now, please add in parenthesis what classification are you using

2. In tableA appendix 2 please add more information about the farms: approximate coordinates, min/max temperature of growing season, accumulated rainfall, and soil type

3. Please check the font size of the x axis and resolution of figures, in the .pdf the resolution is rather low

4. Figures 3 and 5 would benefit from adding S.E. bars

5. The text says that the interaction of soil inorganic Nitrogen and spring GDD affected the mixture composition but this data is not shown. Please justify why did you took this approach? wouldn't it be possible to make the data available for supplementary information?

Reviewer #2: The manuscript “Cover crop mixture expression is influenced by nitrogen availability and growing degree days” is a research paper investigating the effect of nitrogen availability and length of growing season (expressed as growing degree days, GDD) on the composition of cover crop mixtures seeded in 9 locations (research station and on-farm fields) in two consecutive years. Cover crop species composition was determined by sampling aboveground biomass in fall and spring. Overall, the results show that seeding rates of different species did not determine the biomass composition of the cover crop mixture per se, but nitrogen availability and GDD influenced the expression. This is an important and timely finding, which contributes to advancing the current understanding of cover crop mixtures for the provision of multiple ecosystem services, which depend on the actual expression of the mixture. The manuscript is very well developed, and I did not find any major flaws in the presented study. Therefore, I would recommend publication after few minor revisions, which I have listed below.

Consider using keywords that are not already in the title, to increase the chances of your manuscript to be found.

Line 125: You write that you used a split-split plot design, but I can only see two factors (GDD as main and N availability as nested). Should it be split-plot?

Line 182: Based on the current phrasing, it is not clear if the research station trial is the same as the one described in the previous section or another one. Could you clarify it in the text?

Line 195: Here you write that there are four replicates in each farm, but in Figures 3 and 5 you show data from only one plot per farm. I don´t follow the reasoning for this choice, which seems counter-productive to me. Could you explain?

Line 302: In the text, could you briefly explain the interaction, as you did in lines 342-344?

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Reviewer #1: No

Reviewer #2: No

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Attachments

Attachment

Submitted filename: PONE-D-20-11469_reviewer (1).pdf

Cover crop mixture expression is influenced by nitrogen availability and growing degree days

PONE-D-20-11469R1

Dear Dr. Baraibar,

We’re pleased to inform you that your manuscript has been judged scientifically suitable for publication and will be formally accepted for publication once it meets all outstanding technical requirements.

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Kind regards,

Pirjo Mäkelä, DSc

Academic Editor

PLOS ONE

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