PONE-D-20-11578

Potential short-term negative versus positive effects of olive mill-derived biochar on nutrient availability in a calcareous loamy sandy soil

PLOS ONE

Dear Dr. Al-wabel,

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 submit your revised manuscript by Jul 16 2020 11:59PM. If you will need more time than this to complete your revisions, please reply to this message or contact the journal office at plosone@plos.org. When you're 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.

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). You should upload this letter as a separate file labeled 'Response to Reviewers'.
• A marked-up copy of your manuscript that highlights changes made to the original version. You should upload this as a separate file labeled 'Revised Manuscript with Track Changes'.
• An unmarked version of your revised paper without tracked changes. You should upload this as a separate file labeled 'Manuscript'.

If you would like to make changes to your financial disclosure, please include your updated statement in your cover letter. Guidelines for resubmitting your figure files are available below the reviewer comments at the end of this letter.

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

We look forward to receiving your revised manuscript.

Kind regards,

Andrés Rodríguez-Seijo, PhD

Academic Editor

PLOS ONE

Journal Requirements:

When submitting your revision, we need you to address these additional requirements.

1. Please ensure that your manuscript meets PLOS ONE's style requirements, including those for file naming. The PLOS ONE style templates can be found at

https://journals.plos.org/plosone/s/file?id=wjVg/PLOSOne_formatting_sample_main_body.pdf and

https://journals.plos.org/plosone/s/file?id=ba62/PLOSOne_formatting_sample_title_authors_affiliations.pdf

2. In your Methods section, please provide additional information regarding the permits you obtained to collect samples for the present study. Please ensure you have included the full name of the authority that approved the field site access and, if no permits were required, a brief statement explaining why.

3. Please amend the manuscript submission data (via Edit Submission) to include author Hesham Ibrahim.

[Note: HTML markup is below. Please do not edit.]

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: Yes

Reviewer #2: Yes

**********

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

Reviewer #1: Yes

Reviewer #2: No

**********

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

**********

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

**********

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: This manuscript does 2 things: First it chemically characterized biochars produced by the pyrolysis of olive mill waste and second, it compares zea mays growth in soils with biochar (and controls). The title and abstract stress the greenhouse experiment, yet the results and discussion focus on the chemical analysis of biochar. It is overly long, but also seems lacking a lot of details. It is very repetitive. For it to be acceptable for publications the authors need to re-envision the paper and make it much more clear.

The introduction spends a lot of space talking about what biochar can do for the soil in a really general way. There is so many papers out there on this already you only need to reference them briefly and move on. Instead use the introduction to educate people about what specifically you are actually doing- . What do we already know about how different production temperatures effect biochar – its nutrients, mass, etc? Then lay out predictions for how you would expect your materials to act. Similarly, this needs to be done for plants and soil nutrients – there are so many studies (and meta-analyses) that describe how biochar effects these things.

Yes, this paper is in alkaline soils and that is an interesting aspect, but you need to lay out what we know and then how do we expect that to change in alkaline soils.

THEN your results should only focus on those things laid out in the introduction. Did it do what you expected? Why or why not?. For instance there is no need to reiterate your design or anything in the discussion, implications and conclusions. This should be simply laid out in the introduction (which is just a page or two away)

Minor things

I cannot speak to the chemical analysis of the biochar (XRD etc) I assume this was performed well.

The statistics section requires much more detail

Please indicate in the tables which values are different from each other

Recommendations and conclusions are redundant. The paper is not that long and the conclusions are just not needed.

Line 63 – mitigate climate– add change

Lines 72-75 These sentences are contradictory as one says there has not been many studies in alkaline soils and then the next sentence sites three. I would just delete the last sentence

Line 77 – delete “on the other hand” (there is no first hand)

Lines 82-87 should be tacked on to the paragraph above it. The last paragraph of the sentence should start “Previous studies…”

Line 93 - Replace “the aims of this study were to investigate” to “We investigated”. -this gets rid of redundant words and is in an active voice.

Delete line 143-144 – one can just put “Table 1” at the end of the next sentence

All tables need to be formatted similarly and to the journal’s standards.

Line 152- what is basicity (do you mean pH?)

Line 209 –This paragraph is very confusing and overly wordy – please simplify

Reviewer #2: The production of BC from OMSW is an important area of research

In the section of Material and methods it is not clear if the BC was washed before being mixed with the soil, otherwise some of contaminants were introduced into the soil

From the beginning you selected alkaline soil and the BC is going to increase that. Did you try some acidic soil which is more suitable for your BC?? Why not from the beginning you selected to compare acidic vs alkaline soil?? Your BC is better suit acidic soil

The Zeta potential was not measured and data should be supplied, otherwise it is difficult to explain why for example the nutrients such as Ca, Mg and P and others were limited to the plants and the BC was unable to adsorb them

The Tables 1 and 2 no mention how many replicates, SD and statistical analysis such as LSD are available. You are talking about significance, but I can't see that.

I don't see data concerning N content in all soils especially you used NPK in the INF treatment.

You see from the results (for example Table 5) that when you have increased the soil amendment from 1% to 3% you see increase in the negative effects on plant parameters which means you have contamination in your BC which means you should wash it!!!

Might be that your supplied BC have affected your soil properties and plant growth as well. Accordingly, your results are indicating that BC supplementation didn't improve plant growth parameters.

**********

6. 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 #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.]

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 PLOS at figures@plos.org. Please note that Supporting Information files do not need this step.

Potential short-term negative versus positive effects of olive mill-derived biochar on nutrient availability in a calcareous loamy sand soil

PONE-D-20-11578R1

Dear Dr. Al-wabel,

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.

Within one week, you’ll receive an e-mail detailing the required amendments. When these have been addressed, you’ll receive a formal acceptance letter and your manuscript will be scheduled for publication.

An invoice for payment will follow shortly after the formal acceptance. To ensure an efficient process, please log into Editorial Manager at http://www.editorialmanager.com/pone/, click the 'Update My Information' link at the top of the page, and double check that your user information is up-to-date. If you have any billing related questions, please contact our Author Billing department directly at authorbilling@plos.org.

If your institution or institutions have a press office, please notify them about your upcoming paper to help maximize its impact. If they’ll be preparing press materials, please inform our press team as soon as possible -- no later than 48 hours after receiving the formal acceptance. Your manuscript will remain under strict press embargo until 2 pm Eastern Time on the date of publication. For more information, please contact onepress@plos.org.

Kind regards,

Andrés Rodríguez-Seijo, PhD

Academic Editor

PLOS ONE

Additional Editor Comments (optional):

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 #1: All comments have been addressed

Reviewer #2: All comments have been addressed

**********

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 #1: Yes

Reviewer #2: Yes

**********

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

Reviewer #1: Yes

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 #1: Yes

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 #1: Yes

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 #1: They did a great job revising the manuscript. I am require to write 100 characters so I am just typing something.

Reviewer #2: AS I mentioned in my comments, it is important to wash the BC before being used to cultivate plants. I understood that you didn't wash the BC before planting in the pots which may cause negative effects on plants. The main points/comments I have raised were corrected which make the paper more suitable for publications.

**********

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 #1: No

Reviewer #2: Yes: Prof. Hassan Azaizeh, Tel Hai Academic College, Upper Galilee 12210, Israel