Characterization of Biochar Produced from Greenhouse Vegetable Waste and Its Application in Agricultural Soil Amendment

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

• Authors' affiliations please write it with English language.
• Abstract needs enhancement by adding more numerical results obtained, especially for biochar properties.
• The two paragraphs lines 154-163 please cite these methods.
• Use the rules of abbreviation writing line 181 what is BET? Apply for all.
• Please check equation 1 for part of H.
•  Adjust the numbers which in line 198 (4 months) and in line 200 (132 days)? (4months are 120 days)
• Table 1 write n.d. in the cells which don’t contain data as in the table key. And mention the table key by the star.
• Your text of the study results is insufficient and lacks clarity; please add and present all results in your tables and charts.
• As in my abstract note correct your conclusion (rewrite it) to reflect all your work.
• Line 467 figure and video, where are these?
• Please revise the journal template for author contributions and fill all template items.

With my best wishes,

Author Response

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Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

This manuscript presents biochar derived from vegetable waste and its application in agricultural soil amendment. The specific suggestion is as following.

1. In table 2, the concentration of Ca/K/Mg is very high. Why?
2. The control treatment should give fertilizer, not only soil alone.
3. The experiment design is not appropriate in table 3.
4. The content of N, P, and K in soil should be determined.
5. The role of biochar enhancing bean production should be discussed.
6. The difference of biomass (hight, weight) in bean should be detected.

Author Response

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Author Response File: Author Response.pdf

Reviewer 3 Report

Comments and Suggestions for Authors

1- Introduction section is ok.
2- Materials and methods:
- I believe Figures 1 and 2 are unnecessary.
- 2.3 Biochar production: What were the criteria adopted to perform pyrolysis at 450 degrees, with a rate of 10°C per minute and a reaction time of 30 minutes? Please justify and support this. From what I saw, the thermogravimetric analysis (TGA) was not performed at the same heating rate.
- Add a reference to Dulong's equation;
3- Results:
- I think it is extremely important to include the thermogravimetric analysis data along with its mass loss versus temperature graph. It will enhance the work.
- Tables 1 and 2 are simply presented, without any discussion or comparison. Since the focus of the work was the production of biochar for later application to soils, it is necessary to discuss the characterization in detail (Table 1).

- Why did the biochar have a high ash content and low fixed carbon? Perhaps due to the lack of an inert atmosphere during pyrolysis? Discuss
- Why did the biochar have a lower carbon content in the elemental analysis compared to the raw materials (tomato, broccoli, and zucchini)? Shouldn't it have a higher carbon content because it underwent a priolysis process? Again, I believe that perhaps the lack of inert material oxidized the process and generated a lot of ash.
- Discuss why the biochar had such a high pH (super alkaline/basic).
- Discuss the HHV values.
- Table 2: Discuss the metals in higher concentrations and why they occur in these raw materials and consequently appeared in the biochar.
- 3.2 Biochar in the soil: Why was the biochar-to-soil ratio only 0.5%? Support this choice with studies, since the fertilizer ratio was higher.

I believe that discussing the results at the end isn't very interesting. As a suggestion for evaluation, I recommend presenting one piece of data and discussing it, presenting another and discussing it, and not everything at the end.

Author Response

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Author Response File: Author Response.pdf

Reviewer 4 Report

Comments and Suggestions for Authors

Comments are provided in the attached file.

Comments for author File: Comments.pdf

Author Response

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Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

Comments and Suggestions for Authors

With my best wishes,

Reviewer 2 Report

Comments and Suggestions for Authors

The revised manuscript is much better than previous one. It may be accepted for publication.

Reviewer 3 Report

Comments and Suggestions for Authors

The authors made all the suggestions proposed in the first round of review! For me, the article is suitable for publication.