Biochar-Acid Soil Interactions—A Review

Round 1

Reviewer 1 Report

The paper aims to review the management of acidic soils in tropical region via biochar application. A number of similar review articles were published in the past few years. This manuscript does not provide much critical comments on the topic. Moreover, the manuscript is not well-written and structured. Therefore, I think the paper is not good enough for publication.

The English language is poor.

Author Response

Reviewer 1 Comments:

The paper aims to review the management of acidic soils in tropical region via biochar application. A number of similar review articles were published in the past few years. This manuscript does not provide much critical comments on the topic. Moreover, the manuscript is not well-written and structured. Therefore, I think the paper is not good enough for publication.

Comments on the Quality of English Language: The English language is poor.

Authors’ Response:

Thank you for your feedback on the paper. However, the paper aims to provide an updated review of the management of acidic soils via biochar application, and thus could serve as a valuable contribution to the existing literature. This review focuses on biochar characteristics, liming properties of biochar and also comparison of different methods for reducing soil acidity. Regarding the critical comments on the topic, this paper illustrate how biochar mechanistically affects on soil acidity control.    The paper does highlight some of the limitations and challenges associated with biochar application in managing acidic soils.

As for the structure and writing quality of the paper, we appreciate your feedback and already we have thoroughly improved the content and the language of the manuscript.

Reviewer 2 Report

The title is interesting to read, but the authors did not provide important information or novelty about biochar and soil acidity for the reader.

The content needs to be more focus on biochar and soil acidity: growth, yield, types of biochar, and mechanisms of biochar, and more specific on tropical region as shown on the title.

Graphic pictures and data in table needed to be improved.

Reference style is not in the format of “Journal”.

Extensive editing of English language required.

Some brief suggestions

The title is …in the tropical region.., but in the abstract, there is no information about biochar and tropical region.

Abstract

Line 16, including nutrient deficiency few nutrients…, please clarify the definition.

Line 17, other element, please check

Line 21, bio-char, but in the title, it is biochar, please check

Line 23, what does their refer to?, please check

Line 23, can results, please check English

Line 29, a guidelines, please check English

 Introduction and Content

Lines 33-59, the content is repeated between paragraph 1 and 2, and cannot get the conclusion that soil acidity in the tropical region is important. Please revise,

Lines 49-52, what is the relationship between soil acidity and soil salinity? Why did the authors mention salinity?, please clarify

Lines 81-82, During pyrolysis the nutrient in the biochar 81 concentrates while its interaction with minerals can have liming value. What does this sentence mean? , please clarify with references.

Line 314, Table 2, pH, please check

Lines 326-354, 4. Biochar effects on nutrient availability and yield of crops in acid soil

The authors did not provide data or results between yield of crops in acidic soil.

 Conclusion

Need to be improved

Extensive editing of English language required.

Author Response

Reviewer 2 Comments:

The title is interesting to read, but the authors did not provide important information or novelty about biochar and soil acidity for the reader.The content needs to be more focus on biochar and soil acidity: growth, yield, types of biochar, and mechanisms of biochar, and more specific on tropical region as shown on the title.

Graphic pictures and data in table needed to be improved.

Reference style is not in the format of “Journal”.

Extensive editing of English language required.

Some brief suggestions

The title is …in the tropical region.., but in the abstract, there is no information about biochar and tropical region.

Abstract

Line 16, including nutrient deficiency few nutrients…, please clarify the definition.

Line 17, other element, please check

Line 21, bio-char, but in the title, it is biochar, please check

Line 23, what does their refer to?, please check

Line 23, can results, please check English

Line 29, a guidelines, please check English

 Introduction and Content

Lines 33-59, the content is repeated between paragraph 1 and 2, and cannot get the conclusion that soil acidity in the tropical region is important. Please revise,

Lines 49-52, what is the relationship between soil acidity and soil salinity? Why did the authors mention salinity?, please clarify

Lines 81-82, During pyrolysis the nutrient in the biochar 81 concentrates while its interaction with minerals can have liming value. What does this sentence mean? , please clarify with references.

Line 314, Table 2, pH, please check

Lines 326-354, 4. Biochar effects on nutrient availability and yield of crops in acid soil

The authors did not provide data or results between yield of crops in acidic soil.

 Conclusion

Need to be improved

Comments on the Quality of English Language: Extensive editing of English language required.

Authors’ Response:

Thank you for your feedback on the article. We appreciate your comments and suggestions on how to improve the manuscript. To address your concerns regarding the content, we revised the manuscript to provide more specific and detailed information about the effects of biochar on soil acidity, growth, and yield. We includeded more information on the types and mechanisms of biochar,. Regarding the graphics and tables, we worked to improve the quality and clarity of these elements in order to better convey the data and findings of our study.

With regards to the reference style, we ensured that all references are cited in the proper format of “Journal” and are consistent throughout the manuscript. Lastly, we ensured that the English language in the manuscript was extensively edited to improve clarity, grammar, and syntax.

Based on suggestions

The title already Modified as Biochar –Acid Soil Interaction- A Review

• Line 16 and 17 modified as It has a number of negative effects, including nutrient shortage, elemental toxicity, and a negative impact on the biological features of the soil, which lower crop yield and productivity.
• Line 21, bio-char modified as biochar
• Line 23 modified as The use of biochar, a type of pyrogenic carbon-containing material generated from waste biomass, is becoming increasingly popular for controlling acidity while enhancing the fertility and health of the soil
• . Line 29 modified as This comprehensive review will be helpful in providing advice to agricultural specialists on the best biochar to choose for lowering soil acidity.
•  
• Line 33-59 and Lines 49-52 modified
• Lines 81-82 already modified
• Line 314 already corrected
• Lines 326-354a already modified on the section 3.1.5. Biochar improves crop performance in acidic soil

-Conclusion modified and English language is now further refined.

Reviewer 3 Report

The paper presents a brief overview of the influence of various factors on the increase of soil acidity in tropical regions, as well as ways of overcoming soil acidity, with an emphasis on the application of biochar obtained by the pyrolysis of waste biomass. The mechanism of interaction between biochar and soil is also partially presented.
The paper is interesting and systematically shows the knowledge published on this topic.
However, I would ask the authors to supplement the existing text with additional knowledge available in the literature regarding the practical application of biochar as a soil additive. First, the degree of influence on the physicochemical properties of the soil and crop yields depends on the dosage and/or the amount of biochar added to the soil. From the point of view of the sustainability of the practical application of biochar and risk assessment, I  would ask the authors to discuss the selected results, concentrating on research in real conditions.

 Minor editing of English language required

Author Response

Reviewer 3 comments and suggestions:

The paper presents a brief overview of the influence of various factors on the increase of soil acidity in tropical regions, as well as ways of overcoming soil acidity, with an emphasis on the application of biochar obtained by the pyrolysis of waste biomass. The mechanism of interaction between biochar and soil is also partially presented. The paper is interesting and systematically shows the knowledge published on this topic. However, I would ask the authors to supplement the existing text with additional knowledge available in the literature regarding the practical application of biochar as a soil additive. First, the degree of influence on the physicochemical properties of the soil and crop yields depends on the dosage and/or the amount of biochar added to the soil. From the point of view of the sustainability of the practical application of biochar and risk assessment, I would ask the authors to discuss the selected results, concentrating on research in real conditions.

Comments on the Quality of English Language:  Minor editing of English language required

Authors’ Response:

Thank you for your review of the paper. We appreciate your feedback and suggestions for improvement. Regarding your suggestion to supplement the existing text with additional knowledge available in the literature on the practical application of biochar, we agree that this is an important aspect to be addressed. We included a mechanism of interaction on section 4. Biochar effects on soil acidity is biochar specific and figure 4

 more detailed discussion regarding practical application of biochar and its influences the physicochemical properties of the soil and crop yield also included under the section 4. Biochar effects on soil acidity is biochar specific and figure 4

Risk assessment also included under the section 3.1..1.6. Challenges of Biochar application

Furthermore, we have focused on discussing research in real conditions to provide a comprehensive and practical understanding of the effects of biochar on soil and crop production.

Reviewer 4 Report

Reviewer

MDPI – Sustainability

Manuscript Number: sustainability-2400966

Title: «Managing soil acidity with biochar in tropical region- A Review».

The article is devoted to a very important topic related to soil reclamation with a layer reaction of the environment and the introduction of biochar, which, as you know, acidifies the soil. It is provided a guideline for agricultural practitioners on making the choice of suitable biochar for their soils of interest.

Figures 1, 2, 3, 4 and 5 (line 318) are of low quality

Pattern 4 is repeated twice: line 251 and 318.

line 290 Table 1 sources total 2 need to reformat the last column to make it clear.

line 314 Table 2: you need to write pH correctly, not Рн

The article is recommended for publication after the elimination of these comments.

Author Response

Reviewer 4 comments and suggestions:

The article is devoted to a very important topic related to soil reclamation with a layer reaction of the environment and the introduction of biochar, which, as you know, acidifies the soil. It is provided a guideline for agricultural practitioners on making the choice of suitable biochar for their soils of interest.

Figures 1, 2, 3, 4 and 5 (line 318) are of low quality

Pattern 4 is repeated twice: line 251 and 318.

line 290 Table 1 sources total 2 need to reformat the last column to make it clear.

line 314 Table 2: you need to write pH correctly, not Рн

The article is recommended for publication after the elimination of these comments.

Authors’ Response:

Thank you for your feedback on the article. We appreciate your review and the time you took to provide specific recommendations for improvement. We took your comments into consideration and made the necessary changes to the manuscript, including improved the quality of the figures, reformatted Table 1, corrected the spelling of "pH" in Table 2, and addressed the repetition of Pattern 4..

Reviewer 5 Report

Some improvement and corrections to the language text, word usage and punctuation needed. See suggested changes in the annotated manuscript attached.

Comments for author File: Comments.pdf

Comments and suggested changes to the language is indicated in the document text.

Author Response

Reviewer 5 comments and suggestions:

Some improvement and corrections to the language text, word usage and punctuation needed. See suggested changes in the annotated manuscript attached.

Comments on the Quality of English Language: Comments and suggested changes to the language is indicated in the document text.

Authors’ Response:

Thank you for your feedback. We did our best to address your concerns and made the necessary improvements and corrections to the language text, word usage, and punctuation.

Round 2

Reviewer 1 Report

The authors did a great job by improving the manuscript. 

Moderate English editing is required. 

Author Response

Reviewer 1 Comments and Suggestions for Authors

The authors did a great job by improving the manuscript. 

Comments on the Quality of English Language: Moderate English editing is required. 

Authors response: Thank you very much for your kind words and positive feedback. We truly appreciate your recognition of our efforts in improving the manuscript. Your feedback serves as valuable validation of our hard work and dedication to enhancing the quality of the content. We always strive to make meaningful contributions to the field and ensure that our research is presented in the best possible way. Your encouragement motivates us to continue refining our work and pursuing excellence in our endeavors.

In response to your suggestion regarding English language editing, I would like to address the matter. I understand the importance of ensuring the clarity and correctness of the language in academic writing. I have taken meticulous care to review and revise the manuscript multiple times, utilizing available grammar and language tools to the best of my ability. I have strived to ensure that the language quality of the manuscript is of a suitable standard for effective communication of the research content.

Once again, I would like to extend my gratitude for your diligence and expertise in reviewing my manuscript. Thank you for your time and consideration.

Reviewer 2 Report

The content in a manuscript is interesting; however, there are some points needed to be improved as shown below:

1. Please define the levels of acid soils.

Figure 1 shows acid soil is pH < 3.5-6.5, but the authors wrote acid soil as pH <5.5 (Line 39). Please clarify the meaning and levels of acid soils.

2. Line 202-203, Biochar has significant liming values because of its comparatively high CaCO3, MgCO3, Mg (OH)2, and MgO contents [41]. Please provide more detail reviews of  CaCO3, MgCO3, Mg (OH)2, and MgO contents in biochar, showing as a new Table.

3. Line 214, He…??

4. Table 2, please check temperature. Are they 5,000-6,000 C??

5. Lines 264-265, Please provide more details in a paragraph related to Table 3.

6. Table 3, what is questionable?? Are all details in the table from [59]??

7. Line 271-272, biochar improve oxidative stress in plants, reduce malondialdehyde…….. (Please edit English).

8. Line 250, 3.1.1.4. Biochar mediated changes in soil properties reduce soil acidity, but Line 293, 3.1.1.5. Biochar improves crop performance in acidic soil. Please edit English.

9. Lines 294-295, as Fig.5 is unpublished. So, the authors need to provide more details of experiments and results rated to Fig. 5. What is InRR in a graph?

10. Lines 295-296, please insert references.

11. Lines 296-301, please insert references.

12. Lines 308-314, please insert references.

13. Lines 314-315, please indicate the name of crop.

14. Lines 328-329, the authors need to explain and provide details related to Fig.6, showing the correlation of fresh biochar, aged biochar, root exudate, microorganisms, and soil pH.

15. Line 341, … interactions (the symbol?)

16. Line 353, 3.1.1.6. Some Challenges of Biochar Application (please check capital letters)

17. Lines 358-360, please provide more details about effects of rapid, slow, residence duration on biochar related to acid soils in text.

18. 3.2. Others Potential Treatments for management of Soil Acidity. The authors can delete this topic as it is not the main details.

19. Please show a certificate from professional English language Editing Services.

Extensive editing of English language required.

Please show a certificate from professional English language Editing Services.

Author Response

Reviewer 2 Comments and Suggestions for Authors

Reviewer Comments: The content in a manuscript is interesting.

Authors response: Thank you very much for your kind words and positive feedback. We truly appreciate your recognition of our efforts in improving the manuscript. Your feedback serves as valuable validation of our hard work and dedication to enhancing the quality of the content. We always strive to make meaningful contributions to the field and ensure that our research is presented in the best possible way. Your encouragement motivates us to continue refining our work and pursuing excellence in our endeavors.

Reviewer Comments:  However, there are some points needed to be improved as shown below:

1. Please define the levels of acid soils.

Figure 1 shows acid soil is pH < 3.5-6.5, but the authors wrote acid soil as pH <5.5 (Line 39). Please clarify the meaning and levels of acid soils.

Authors response: Modified as The soil acidity is a major problem

2. Line 202-203, Biochar has significant liming values because of its comparatively high CaCO3, MgCO3, Mg (OH)2, and MgO contents [41]. Please provide more detail reviews of  CaCO3, MgCO3, Mg (OH)2, and MgO contents in biochar, showing as a new Table.

Authors response: Modified as When biochar is applied to acidic soils the minerals, particularly, the basic cations (CaCO₃, MgO etc.) interacts with soil reactive species including the protons and thus, reduces the soil acidity [40]. However, the contribution of biochar in changing soil pH through liming values may be short-lived since the liming materials in the biochar might be exhausted after soil application [40,41] .

3. Line 214, He…??

Authors response: Modified as The authors further inferred that

4. Table 2, please check temperature. Are they 5,000-6,000 C??

Authors response: Modified as 500-600°C

5. Lines 264-265, Please provide more details in a paragraph related to Table 3.

Authors response: Modified as In acid soils, many studies reported that biochar increases the activities of soil microorganisms (Table 3). For instance, biochar has been shown to increase biological nitrogen fixation in many acid soils [58]. Moreover, similar increases in arbuscular microrhizal fungi and soil bacteria in acid soils have also been reported [59]. An increase in miocrobial activities help to cycling of nutrients while arbuscular microrhizal fungi helps to acquire nutrients and water resulting in a greater performance of plants in biochar amended soils than their controls [60].  

6. Table 3, what is questionable?? Are all details in the table from [59]??

Authors response: Modified as no significant effect. Yes all details in the table collected from the reference 59 as mentioned on previous manuscript but this revised manuscript reference no. 61

7. Line 271-272, biochar improve oxidative stress in plants, reduce malondialdehyde…….. (Please edit English).

Authors response:The text already Deleted

8. Line 250, 3.1.1.4. Biochar mediated changes in soil properties reduce soil acidity, but Line 293, 3.1.1.5. Biochar improves crop performance in acidic soil. Please edit English.

Authors response:

Thank you for providing your valuable feedback. I truly appreciate your input. I understand your concern regarding the sentence Biochar mediated changes in soil properties reduce soil acidity and Biochar improves crop performance in acidic soil. Upon careful consideration authors believe that the sentence is indeed correct. If you believe there's still room for improvement, we'd be glad to explore alternative phrasings. Once again, thank you for your time and consideration.

9. Lines 294-295, as Fig.5 is unpublished. So, the authors need to provide more details of experiments and results rated to Fig. 5. What is InRR in a graph?

Authors response: Lines 294-295 Modified as On average, biochar enhanced crop performance with the largest increase observed in acidic soils. Several meta-analysis showed that the crop performance is the most pronounced in acidic soil (Figure 5). The average yield increase was 53% in acidic soils (pH<6.0) [62]. Application of biochar with inorganic fertilizers has shown to have more pronounced effect than biochar alone [60].Figure 5 caption modified as Change in crop yield with biochar application in different soils (Mia et al. in preparation). The data was collected from published articles in 2010 and 2017. A meta-analysis was conducted following standard procedure.  Changes in yield (lnRR) modified as changes in yield (%)

10. Lines 295-296, please insert references.

Authors response: Modified and reference inserted.

11. Lines 296-301, please insert references.

Authors response: Inserted reference no. 60 and 62

12. Lines 308-314, please insert references.

Authors response: Inserted reference no. 63

13. Lines 314-315, please indicate the name of crop.

Authors response : Modified as Xu et.al. [63] reviewed updated datasets from globally conducted 455, 131, and 95 independent experiments to identify the key factors influencing the responses of crop yield, soil organic carbon, and global warming potential to biochar (B) and biochar combined with chemical fertilizers (BF). The study's goal was to investigate the effect variation of biochar application alone (B) and biochar combined with chemical fertilizers (BF) on crop yield, soil organic carbon (SOC), and global warming potential (GWP). Overall biochar and biochar combined with chemical fertilizer increased crop yield respectively, by 15.1% and 48.4%.

14. Lines 328-329, the authors need to explain and provide details related to Fig.6, showing the correlation of fresh biochar, aged biochar, root exudate, microorganisms, and soil pH.

Authors response : Details explanation regarding figure 6 are on the section 3.1.1.7.Biochar acid soil interactions and carbon stabilization

15. Line 341, … interactions (the symbol?)

Authors response :Modified as pie-pie (π-π) interactions

16. Line 353, 3.1.1.6. Some Challenges of Biochar Application (please check capital letters)

Authors response :Modified as Some challenges of biochar application

17. Lines 358-360, please provide more details about effects of rapid, slow, residence duration on biochar related to acid soils in text.

Authors response :Modified as Biochar properties are quite variable with a number of factors including pyrolysis temperature, residence time, heating rate (fast or slow), oxygen limitation level, and feedstock properties (such as cellulose or lignin content, moisture status and particle size), for getting a targeted benefit, these factors need to be optimized. Details explanation are on section 3.1.1.6. Some challenges of biochar application

18. 3.2. Others Potential Treatments for management of Soil Acidity. The authors can delete this topic as it is not the main details.

Authors response :Modified as on section 3.2. Comparison between effects of lime and biochar

19. Please show a certificate from professional English language Editing Services.

Comments on the Quality of English Language

Extensive editing of English language required.

Please show a certificate from professional English language Editing Services.

Authors response :

I would like to express my gratitude for your valuable time and effort that you have invested in evaluating my work and providing constructive suggestions for improvement. In response to your suggestion regarding obtaining a professional English language editing certificate, I would like to address the matter. I understand the importance of ensuring the clarity and correctness of the language in academic writing, and I wholeheartedly agree that proficient language usage is crucial for effective communication of the research findings. Due to resource constraints, I regrettably was not able to enlist the services of a professional English language editing agency for this manuscript. However, I have taken meticulous care to review and revise the manuscript multiple times, utilizing available grammar and language tools to the best of my ability.

While I acknowledge that professional editing services undoubtedly provide a higher level of language refinement, I have strived to ensure that the language quality of the manuscript is of a suitable standard for effective communication of the research content.

Once again, I would like to extend my gratitude for your diligence and expertise in reviewing my manuscript. Thank you for your time and consideration.

Round 3

Reviewer 2 Report

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