Changes in Soil C and N Stocks and Their Effects on Rice Yield under Long-Term Upland-Paddy Rotations
Round 1
Reviewer 1 Report
Review
The work titled "Long-term upland-paddy rotation effect on the soil C and N stocks in the middle and lower reaches of the Yangtze River” deals with ways to increase soil organic matter. However, after examining the manuscript, I have a few comments.
- There is no information on the taxonomy of the soils on which the experiment was conducted. I propose to use the taxonomy in WRB 2023 IUSS Working Group WRB. 2022. World Reference Base for Soil Resources. International soil classification system for naming soils and creating legends for soil maps. 4th edition. International Union of Soil Sciences (IUSS), Vienna, Austria.
- No information about soil texture, which is one of the most important properties of soils. Please enter the percentage of soil fraction.
- soil reaction in what extract was analysed.
- Please include a brief description of the analysis procedure: SOM, TN and AN
- By introducing organic matter into the soil, we change the C:N ratio, please calculate and comment
- The authors in Table 1 use the term SOM, while in Table 2 they use the term SOC. Please unify.
- Table 3. The proportion of soil C and N density within 0–50 cm (%). I suggest changing to percentage share of total soil C and N content in in investigated layers in ratio total stock in 0-50 cm.
Some comments also in PDF.
Comments for author File: 
Comments.pdf
Author Response
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Author Response File: 
Author Response.docx
Reviewer 2 Report
Considering the scarcity of information on the long-term effects of upland-paddy rotation on soil carbon and nitrogen reserves, the manuscript has new and novel findings that can be used in the management of crop rotation in the experimental area. However, I have a few minor comments to improve the manuscript as below:
1) In the materials & methods section (line 94), the correct name of the statistical design is randomized complete block design (RCBD).
2) In the sub-section of 2.3 (Data analysis), the type of the mean comparison (LSD, Duncan, Tukey, ...) should be specified.
3) In the discussion section (line 287), inserting a sentence to explain the "priming effect" is needed to inform the readers.
4) Finally, critical results have been obtained in this research, but their importance has not been mentioned in the conclusion section. It is recommended that at the end of the conclusion, the importance of the research findings or at least the most important achievement of the research, and its impact on the relevant research area be mentioned, and a suggestion or a perspective of the future of the research can be given.
Author Response
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Author Response File: Author Response.docx
Reviewer 3 Report
Experimental details should be self-explainable so write in proper way about the cropping systems as well as different input application. The C and N inputs should be quantified and presented in table form. A apparent balanced sheet should be incorporated so that a picture should be clear about the accumulation of C and N in soil. Give productivity trend under different scenario of cropping system. Improve the conclusion part of the paper with a specific recommendation. Overall work is good but the information provided in paper is not sufficient for readers.
Comments for author File: Comments.pdf
Author Response
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Author Response File: Author Response.docx
Reviewer 4 Report
Dear Authors
I have reviewed your manuscripts, and here are my comments.
TiTitle
The title does not reflect the content.
Authors should consider revising it and make sure the title reflects the manuscript's content.
Abstract:
The authors should revise the abstract. State clearly the background, and objective of the study. write briefly the methods and main findings. State the implication of the study.
Introduction:
There is no clear research question (RQ), Authors should provide clear statements of RQ so that it will help readers to interpret the result.
There is no clear objective for the study. The clear, precise statement of the objective will help readers to understand the result and implication
Material and methods
Authors should re-write this section in more detail.
State the laboratory methods used to determine soil properties. Readers who need detailed explanations may read the reference.
Conclusion
Can not assess the conclusions as no clear research question and research objective.
best regards,
Author Response
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Author Response File: Author Response.docx
Round 2
Reviewer 1 Report
Comments
Point 1: There is no information on the taxonomy of the soils on which the experiment was conducted. I propose to use the taxonomy in WRB 2023 IUSS Working Group WRB. 2022. World Reference Base for Soil Resources. International soil classification system for naming soils and creating legends for soil maps. 4th edition. International Union of Soil Sciences (IUSS), Vienna, Austria.
Response 1: Thanks for your suggestion. The MS has been revised accordingly in L91.- This is not a valid taxonomy according to the WRB system. Please correct. Below is a link to the current edition of the WRB taxonomy.
https://www3.ls.tum.de/boku/wrb-working-group/documents/wrb-2022/wrb-2022-errata/
Point 2: No information about soil texture, which is one of the most important properties of soils. Please enter the percentage of soil fraction.--
Response 2: Thanks for your suggestion. The MS has been revised accordingly in Table 1-ok done
Point 3: soil reaction in what extract was analysed.
Response 3: Thanks for your suggestion. But we don't understand what “soil reaction” mean, would you mind elaborating a bit more? - soil reaction is pH-
(in what extract was it determined (water or CaCl2 or ...? what ratio..?)
Point 4: Please include a brief description of the analysis procedure: SOM, TN and AN.
Response 4: Thanks for your suggestion. The MS has been revised accordingly in L145-147. -ok done
Point 5: By introducing organic matter into the soil, we change the C:N ratio, please calculate and comment.
Response 5: Thanks for your careful reading and I have added C/N ratio to Figure 2 accordingly in L214 -ok done
Point 6: The authors in Table 1 use the term SOM, while in Table 2 they use the term SOC. Please unify.
Response 6: Thanks for your careful reading and I have revised Table 1 accordingly in L94 .-ok done
Point 7: Table S3. The proportion of soil C and N density within 0–50 cm (%). I suggest changing to percentage share of total soil C and N content in investigated layers in ratio total stock in 0-50 cm.
Response 7: Thanks for your suggestion. The title of Table S3 has been changed -ok done
Point 8: Table 2: please use stock.
Response 8: Thanks for your suggestion. The Table 2 has been revised accordingly in L188 -ok done
Point 9: Table S3: ound numbers to one place.
Response 9: Thanks for your suggestion The Table S3 has been revised -ok done
Point 10: I suggest using stocks rather than density (L221).
Response 10: Thanks for your suggestion. The MS has been revised accordingly in L221n -ok done
Author Response
Point 1: There is no information on the taxonomy of the soils on which the experiment was conducted. I propose to use the taxonomy in WRB 2023 IUSS Working Group WRB. 2022. World Reference Base for Soil Resources. International soil classification system for naming soils and creating legends for soil maps. 4th edition. International Union of Soil Sciences (IUSS), Vienna, Austria.
https://www3.ls.tum.de/boku/wrb-working-group/documents/wrb-2022/wrb-2022-errata/
Response 1: Many thanks for your suggestion and providing us with links. We think that the test soil belongs to Hydragric by reading the documents. The MS has been revised accordingly in L95-96.
Point 2: soil reaction in what extract was analysed. soil reaction is pH- (in what extract was it determined (water or CaCl2 or ...? what ratio..?)
Response 2: Many thanks for your suggestion and answer. The MS has been revised accordingly in L151.
Author Response File: Author Response.docx
Reviewer 3 Report
Paper may be accepted
Author Response
Dear reviewer,
Thank you for reviewing our manuscript. We appreciate the valuable comments made by youon the manuscript.
Reviewer 4 Report
Dear Authors
Thank you for considering parts of my comments.
Yet, I observed that you have not improved the abstract and Introduction.
-State the objective CLEARLY and PRECISELY in the abstract and in the Introduction section.
For example: "the objective of this study was...."' or "this study aimed to...."
-state research questions CLEARLY
For example, "The remaining challenges are...
Readers could have better insight into your result and discussion as well as the conclusion if only they know your objective of the study.
In addition, you may claim long-term research if you present your data from 2003 to the present. In your current study. you just present data ONLY from the 2019 observation. It means your study is only one year study. Moreover, you just compare your treatments, not temporal variation.
Best regard
Author Response
Point 1: State the objective CLEARLY and PRECISELY in the abstract and in the Introduction section.
For example: "the objective of this study was...."' or "this study aimed to...."-state research questions CLEARLY. For example, "The remaining challenges are... " Readers could have better insight into your result and discussion as well as the conclusion if only they know your objective of the study.
Response 1: Many thanks for your suggestion. The MS has been revised accordingly in L13, L77-86.
Point 2: you may claim long-term research if you present your data from 2003 to the present. In your current study. you just present data ONLY from the 2019 observation. It means your study is only one year study.
Moreover, you just compare your treatments, not temporal variation.
Response 2: Many thanks for your careful reading and valuable comments on the MS. Due to the relatively smaller variations in soil C and N contents after long-term rotations and the experimental arrangement, we do only present data from the 2019 in our study. But we will continue to carry out this experiment in the future to obtain more data and possible new findings.
In this study, we focused on the differences in C and N stocks among paddy-upland rotations rather than temporal variation.
Author Response File: Author Response.docx
