PONE-D-19-27232

Effect of conservation farming and biochar addition on SOC quality, N mineralization, and crop productivity in a light textured Acrisol in the sub-humid tropics

PLOS ONE

Dear Dr Munera-Echeverri,

Thank you for submitting your manuscript to PLOS ONE. After careful consideration, we feel that it has merit but does not fully meet PLOS ONE’s publication criteria as it currently stands. Therefore, we invite you to submit a revised version of the manuscript that addresses the points raised during the review process.

Please, address all comments by both reviewers.

We would appreciate receiving your revised manuscript by Dec 22 2019 11:59PM. When you are ready to submit your revision, log on to https://www.editorialmanager.com/pone/ and select the 'Submissions Needing Revision' folder to locate your manuscript file.

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Jorge Paz-Ferreiro, Ph.D.

Academic Editor

PLOS ONE

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Reviewers' comments:

Reviewer's Responses to Questions

Comments to the Author

1. Is the manuscript technically sound, and do the data support the conclusions?

The manuscript must describe a technically sound piece of scientific research with data that supports the conclusions. Experiments must have been conducted rigorously, with appropriate controls, replication, and sample sizes. The conclusions must be drawn appropriately based on the data presented.

Reviewer #1: Partly

Reviewer #2: Yes

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2. Has the statistical analysis been performed appropriately and rigorously?

Reviewer #1: Yes

Reviewer #2: Yes

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3. Have the authors made all data underlying the findings in their manuscript fully available?

The PLOS Data policy requires authors to make all data underlying the findings described in their manuscript fully available without restriction, with rare exception (please refer to the Data Availability Statement in the manuscript PDF file). The data should be provided as part of the manuscript or its supporting information, or deposited to a public repository. For example, in addition to summary statistics, the data points behind means, medians and variance measures should be available. If there are restrictions on publicly sharing data—e.g. participant privacy or use of data from a third party—those must be specified.

Reviewer #1: Yes

Reviewer #2: Yes

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4. Is the manuscript presented in an intelligible fashion and written in standard English?

PLOS ONE does not copyedit accepted manuscripts, so the language in submitted articles must be clear, correct, and unambiguous. Any typographical or grammatical errors should be corrected at revision, so please note any specific errors here.

Reviewer #1: Yes

Reviewer #2: Yes

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5. Review Comments to the Author

Please use the space provided to explain your answers to the questions above. You may also include additional comments for the author, including concerns about dual publication, research ethics, or publication ethics. (Please upload your review as an attachment if it exceeds 20,000 characters)

Reviewer #1: - Please include a more robust description of the experimental design. Specifically, focus on replications, sample sizes for each of the dependent variables. I had to spend time looking through supplementary materials to find this information.

- The planting arrangements in the maize varies and needs to be discussed as another potential contributing factor to the lack of yield differences in your trial.

- You might spend more time discussing the importance of the maize-groundnut system and why that was resulted in differences compared to your study.

- I would also encourage you to add more discussion regarding the 7 years prior in CF as this also likely influenced the results of your study.

Reviewer #2: Dear Authors,

I am enclosing herewith the review comments of the manuscript entitled "Effect of conservation farming and biochar addition on SOC quality, N mineralization, and crop productivity in a light textured Acrisol in the sub-humid tropics". The study presented by you is a nice representing of work on conservation farming practices along with biochar application and its effect on soil health aspects (soil organic matter, N-mineralization, etc,). This piece of work is very relevant to the present context of soil health and as a means of environmental conservation practices. Many papers are available on biochar but a combination of biochar and conservational farming, tillage, crop rotation on a long-term basis is still needed for the scientific community. Therefore, this paper would be a relevant and good resource for other researchers throughout the world. However, I do have some moderate revisions/suggestions/recommendations. I strongly recommend to go through the comments, make changes or refute with proper explanations as needed to get finally accepted to our journal. I have very general and some specific comments for this paper. I would only consider this manuscript only when these following MODERATE changes (MODERATE REVISION; I’m giving major because there is no moderate revision option for our journal) will be made or suggestions are refuted with proper explanation. My comments are intended to further improve the manuscript such that it addresses the questions as asked properly. I would reconsider the manuscript for publication if the moderate/minor major changes are made and resubmitted.

General comments

1. Suggest not to use any abbreviation in the title of the manuscript.

2. Recommend to use ‘Table’ not ‘tab’ in the entire manuscript. Please make change accordingly.

3. Materials and methods are very detailed-oriented and explanatory which is good for readers.

Specific comments

Introduction

1. In general, authors have used good reference to refer their manuscript. However, I recommend and suggest to read some articles quickly which are useful, recent and very relevant articles to cite in this manuscript not only to make the literature search up-to-date but also the paper will be more acknowledged while readers’ read it. Please see my line-wise comments.

2. Line 41-44: Please use some recent references in some reputed journal which will explain many recent facts in this manuscript such as Sihi et al., 2016, Sihi et al., 2017 (see the full reference list below). You can use those papers and may want to cite it wherever you think is relevant.

3. Line 47-49: Please use these recently published articles whichever you think is relevant: Chalise et al., 2019, Maiga et al., 2019, Sihi et al., 2017.

4. Line 54-56: You may want to include the citation from this perspective paper and research papers which are recent and very related: Nair et al., 2017 and Dari et al., 2016.

5. Line 68-69: A relevant paper area on conservation farming practices on soil organic matter and soil health in tropical/sub-tropics areas can be cited here: Sihi et al., 2017.

6. Line 82-85: Please read these papers and cite accordingly: Chalise et al., 2019, Maiga et al., 2019.

7. Line 93-98: “This study shows positive effects…climate-smart solutions for agriculture in sub-humid regions”…….this whole section should not be the part of ‘Introduction’. It should be part of your result section. Please move to the results and Discussion section or rather conclusion section.

References

1. Sihi, D., Gerber, S., Inglett, P. W., & Inglett, K. S. (2016). Comparing models of microbial–substrate interactions and their response to warming. Biogeosciences, 13(6), 1733-1752.

2. Sihi, D., Inglett, P. W., Gerber, S., & Inglett, K. S. (2018). Rate of warming affects temperature sensitivity of anaerobic peat decomposition and greenhouse gas production. Global change biology, 24(1), e259-e274.

3. Chalise, K.S., Singh, S., Wegner, B.R., Kumar, S., Pérez-Gutiérrez, J.D., Osborne, S.L., Nleya, T., Guzman, J., Rohila, J.S., 2019. Cover Crops and Returning Residue Impact on Soil Organic Carbon, Bulk Density, Penetration Resistance, Water Retention, Infiltration, and Soybean Yield. Agronomy Journal 111, 99-108.

4. Maiga, A., Alhameid, A., Singh, S., Polat, A., Singh, J., Kumar, S., Osborne, S., 2019. Responses of soil organic carbon, aggregate stability, carbon and nitrogen fractions to 15 and 24 years of no-till diversified crop rotations. Soil Research.

5. Sihi, D., Dari, B., Sharma, D. K., Pathak, H., Nain, L., & Sharma, O. P. (2017). Evaluation of soil health in organic vs. conventional farming of basmati rice in North India. Journal of Plant Nutrition and Soil Science, 180(3), 389-406.

6. Nair, V. D., Nair, P. K., Dari, B., Freitas, A. M., Chatterjee, N., & Pinheiro, F. M. (2017). Biochar in the agroecosystem–climate-change–sustainability nexus. Frontiers in plant science, 8, 2051.

7. Dari, B., Nair, V. D., Harris, W. G., Nair, P. K. R., Sollenberger, L., & Mylavarapu, R. (2016). Relative influence of soil-vs. biochar properties on soil phosphorus retention. Geoderma, 280, 82-87.

Materials and Methods

1. Line 113-114: Why biochar was applied in that particular depth, why not other depth?

2. Rest of the experimental details and all section in M&M part is well explained and nicely described. I do to have any comments.

Tables

1. Make sure the title of each tables are not bold. Be consistent and there is no need to bold any words within the table even.

2. Same comments as above for figures (no bold except the word TABLE or FIG.), make the relevant changes.

3. I do not see any reason to highlight some columns in your table (e.g. Table 2) so remove it.

Conclusions

1. Strongly recommend to make your conclusion succinct. Please re-write it having only those part which are direct results of your study.

2. Please do not include any reference or citation or others’ results in the conclusion section e.g. remove the line 387-389 from the conclusion section to your introduction part or Discussion part.

3. Suggest not to have multiple paragraphs for conclusion. Try to have one solid paragraphs with all important conclusion of your study unless it is really necessary to stretch your main results.

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Reviewer #1: No

Reviewer #2: No

[NOTE: If reviewer comments were submitted as an attachment file, they will be attached to this email and accessible via the submission site. Please log into your account, locate the manuscript record, and check for the action link "View Attachments". If this link does not appear, there are no attachment files to be viewed.]

While revising your submission, please upload your figure files to the Preflight Analysis and Conversion Engine (PACE) digital diagnostic tool, https://pacev2.apexcovantage.com/. PACE helps ensure that figures meet PLOS requirements. To use PACE, you must first register as a user. Registration is free. Then, login and navigate to the UPLOAD tab, where you will find detailed instructions on how to use the tool. If you encounter any issues or have any questions when using PACE, please email us at figures@plos.org. Please note that Supporting Information files do not need this step.

PONE-D-19-27232R1

Effect of conservation farming and biochar addition on soil organic carbon quality, nitrogen mineralization, and crop productivity in a light textured Acrisol in the sub-humid tropics

PLOS ONE

Dear Dr Munera-Echeverri,

Thank you for submitting your manuscript to PLOS ONE. After careful consideration, we feel that it has merit but does not fully meet PLOS ONE’s publication criteria as it currently stands. Therefore, we invite you to submit a revised version of the manuscript that addresses the points raised during the review process.

Manuscript is much improved. Please, see comments of the reviewer.

We would appreciate receiving your revised manuscript by Feb 29 2020 11:59PM. When you are ready to submit your revision, log on to https://www.editorialmanager.com/pone/ and select the 'Submissions Needing Revision' folder to locate your manuscript file.

If you would like to make changes to your financial disclosure, please include your updated statement in your cover letter.

To enhance the reproducibility of your results, we recommend that if applicable you deposit your laboratory protocols in protocols.io, where a protocol can be assigned its own identifier (DOI) such that it can be cited independently in the future. For instructions see: http://journals.plos.org/plosone/s/submission-guidelines#loc-laboratory-protocols

Please include the following items when submitting your revised manuscript:

• A rebuttal letter that responds to each point raised by the academic editor and reviewer(s). This letter should be uploaded as separate file and labeled 'Response to Reviewers'.
• A marked-up copy of your manuscript that highlights changes made to the original version. This file should be uploaded as separate file and labeled 'Revised Manuscript with Track Changes'.
• An unmarked version of your revised paper without tracked changes. This file should be uploaded as separate file and labeled 'Manuscript'.

Please note while forming your response, if your article is accepted, you may have the opportunity to make the peer review history publicly available. The record will include editor decision letters (with reviews) and your responses to reviewer comments. If eligible, we will contact you to opt in or out.

We look forward to receiving your revised manuscript.

Kind regards,

Jorge Paz-Ferreiro, Ph.D.

Academic Editor

PLOS ONE

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Reviewers' comments:

Reviewer's Responses to Questions

Comments to the Author

1. If the authors have adequately addressed your comments raised in a previous round of review and you feel that this manuscript is now acceptable for publication, you may indicate that here to bypass the “Comments to the Author” section, enter your conflict of interest statement in the “Confidential to Editor” section, and submit your "Accept" recommendation.

Reviewer #2: (No Response)

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2. Is the manuscript technically sound, and do the data support the conclusions?

The manuscript must describe a technically sound piece of scientific research with data that supports the conclusions. Experiments must have been conducted rigorously, with appropriate controls, replication, and sample sizes. The conclusions must be drawn appropriately based on the data presented.

Reviewer #2: Yes

**********

3. Has the statistical analysis been performed appropriately and rigorously?

Reviewer #2: Yes

**********

4. Have the authors made all data underlying the findings in their manuscript fully available?

The PLOS Data policy requires authors to make all data underlying the findings described in their manuscript fully available without restriction, with rare exception (please refer to the Data Availability Statement in the manuscript PDF file). The data should be provided as part of the manuscript or its supporting information, or deposited to a public repository. For example, in addition to summary statistics, the data points behind means, medians and variance measures should be available. If there are restrictions on publicly sharing data—e.g. participant privacy or use of data from a third party—those must be specified.

Reviewer #2: Yes

**********

5. Is the manuscript presented in an intelligible fashion and written in standard English?

PLOS ONE does not copyedit accepted manuscripts, so the language in submitted articles must be clear, correct, and unambiguous. Any typographical or grammatical errors should be corrected at revision, so please note any specific errors here.

Reviewer #2: Yes

**********

6. Review Comments to the Author

Please use the space provided to explain your answers to the questions above. You may also include additional comments for the author, including concerns about dual publication, research ethics, or publication ethics. (Please upload your review as an attachment if it exceeds 20,000 characters)

Reviewer #2: The authors have done a good job of addressing the comments suggested by both the reviewers. I have one quick comment. As per the suggestion by Reviewer 2, the authors did not include any reference from Sihi et al., 2016, 2017 or 2018 although the author has mentioned that it has been cited. In one instance they have mentioned that the study is nit relatable to Sihi et al., 2017. Please add this reference or refute it with a possible explanation. Other than that I do not have additional comments.

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7. PLOS authors have the option to publish the peer review history of their article (what does this mean?). If published, this will include your full peer review and any attached files.

If you choose “no”, your identity will remain anonymous but your review may still be made public.

Do you want your identity to be public for this peer review? For information about this choice, including consent withdrawal, please see our Privacy Policy.

Reviewer #2: No

[NOTE: If reviewer comments were submitted as an attachment file, they will be attached to this email and accessible via the submission site. Please log into your account, locate the manuscript record, and check for the action link "View Attachments". If this link does not appear, there are no attachment files to be viewed.]

While revising your submission, please upload your figure files to the Preflight Analysis and Conversion Engine (PACE) digital diagnostic tool, https://pacev2.apexcovantage.com/. PACE helps ensure that figures meet PLOS requirements. To use PACE, you must first register as a user. Registration is free. Then, login and navigate to the UPLOAD tab, where you will find detailed instructions on how to use the tool. If you encounter any issues or have any questions when using PACE, please email us at figures@plos.org. Please note that Supporting Information files do not need this step.

Effect of conservation farming and biochar addition on soil organic carbon quality, nitrogen mineralization, and crop productivity in a light textured Acrisol in the sub-humid tropics

PONE-D-19-27232R2

Dear Dr. Munera-Echeverri,

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

Within one week, you will receive an e-mail containing information on the amendments required prior to publication. When all required modifications have been addressed, you will receive a formal acceptance letter and your manuscript will proceed to our production department and be scheduled for publication.

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With kind regards,

Jorge Paz-Ferreiro, Ph.D.

Academic Editor

PLOS ONE

Additional Editor Comments (optional):

Reviewers' comments: