The Effects of Plastic Mulching Combined with Different Fertilizer Applications on Greenhouse Gas Emissions and Intensity, and Apple Yield in Northwestern China

Round 1

Reviewer 1 Report

I have suggested some changes in the attached PDF, which are self-explanatory.

Comments for author File: Comments.pdf

Minor editing of the English language required

Author Response

Thank you for your suggestion and we attached the response letter.

Author Response File: Author Response.docx

Reviewer 2 Report

Sompouviset et al. is an interesting study that investigates the impact of plastic mulching (with conventional polyethylene films) and fertilizer treatment in apple production on fruit yield and vapor fluxes. This manuscript is ultimately publishable, but requires major revision to improve its presentation. Clarification on a few matters is also required.

1.       The Results and Discussion (not plural: “Discussions”) sections should be merged ("Results and Discussion") to reduce redundant text and simplify comprehension by the reader. For instance, there is significant overlap between Sect 4.1 and L 360-369.

2.       All abbreviations should be defined at their first mention in the main paper. Several abbreviations are not, including GHG, NM, PM, GWP, etc. Once an abbreviation is defined, there is no need to define it an additional time.

3.       Please review the significant figures for all numerical values given in the tables and the text (e.g., L 605: 162.88%; L 645: 1446.27 kg CO2/ha: Is the level of precision of the measurement sufficiently precise to support 5-6 significant figures?)

4.       Introduction: Several findings from the literature relating to plastic mulching are described. Do these results pertain specifically to low-density polyethylene films or to mulch films prepared from other materials, such as biodegradable polymers (e.g., PBAT or PBS)? It is important to clarify in the text, since vapor permeability results differ greatly between polyethylene and biodegradable mulch films.

5.       L 60-61: This sentence is awkward; difficult to understand. This statement is important, since it appears to convey the significance and impact of your study.

6.       L 68: “the result was different” is unclear

7.       Introduction, L 72 ff: The term “chemical fertilizer” is unclear; undefined. How does this term relate to “inorganic fertilizer” and “organic fertilizer”?

8.       Figure 1 is not cited in the text. I find it not to be necessary. Please move this figure to the Supporting Information (SI) and cite it in the main paper text (Fig S1).

9.       Figs 1 and 2 should include the geographical region of the study within the captions.

10.   Please describe the positioning and deployment of the LDPE mulch film more clearly. It appears that the apple trees were planted at least 8 years prior to the current study, which took place starting in 2018 (please confirm). How were the films laid: via machine-laying or hand-laying? The description in Sect 2.2 states the films were laid “on 2 sides of the trees”. Please describe whether mulch film resided on the “other” 2 sides. Perhaps a photograph can be included in the SI that shows how the films were laid relative to a tree.

11.   Sects 2.3.1 and 2.3.2: Please describe how many gas and soil samples were collected for a given mulching x fertilizer treatment at a given time point. Was the sampling randomized, in conjunction with the randomized experimental plot design?

12.   L 190-194: Please use passive verb tense rather than imperative verb tense.

13.   L 627-629: The subject of the sentence, “Who”, is unclear.

 

The technical writing quality can be improved. I found a few awkward and unclear sentences, a few of which are given in my responses to the authors.

Author Response

Thank you for your comments, they helped us to improve our manuscript and we attached the response

Author Response File: Author Response.docx

Round 2

Reviewer 2 Report

The authors have addressed most of the issues I raised satisfactorily. Yet, one issue raised previously requires further minor revision. A few additional minor corrections also need to be addressed.

1. The authors did indicate where one statement in the Introduction pertained specifically to biodegradable mulches, which is appreciated. It appears that implicitly, the abbreviation "PM" refers to plastic mulching using conventional, low-density polyethylene mulch films. The Introduction should be clarified to indicate that PM refers to the use of conventional mulch films, not biodegradable ones, unless noted otherwise throughout the paper.

2. L 148: "was covered the middle" (awkward)

3. L 304. "km" should replace "kms" since the former is the universally accepted abbreviation of kilometer(s) according to the SI units system.

4. Fig 8 caption: "hihighly" (spelling)

Proofreading for English language minor errors is recommended.

Author Response

Dear reviewer, we have revised manuscript according to your suggestions and you can find the attached file of response to reviewer.

Author Response File: Author Response.pdf