Long-Term Successive Seasonal Application of Rice Straw-Derived Biochar Improves the Acidity and Fertility of Red Soil in Southern China
Round 1
Reviewer 1 Report
Dear Author,
Your article entitle of “Long-term effects of successive seasonal application of rice straw-derived biochar on the acidity and fertility of red soil in Southern China” is very interesting as you discussed on how rice straw biochar improved growth and yield of wheat/millet. However, your results look very limited, it is still insufficient to show the evident on how biochar improves crop productivity. For all figures, better quality is needed. In addition, there is no statistical indicator in each figure. Therefore, I would recommend you revise your manuscript and resubmit again.
Author Response
To Reviewer 1#,
Dear Professor,
Here we must express our deep gratitude firstly to you for spending time evaluating this manuscript (MS) and giving the related feedback to our work. In the past days, we carefully read comments from you. In particular, we redrawn related figures and added statistical indicator in each figure in the new MS. Hope our above-mentioned revisions could make it easier to understand the interpretation of the results. If you have any other comments, please kindly let me know.
Comments: Your article entitle of ‘Long-term effects of successive seasonal application of rice straw-derived biochar on the acidity and fertility of red soil in Southern China’is very interesting as you discussed on how rice straw biochar improved growth and yield of wheat/millet. However, your results look very limited, it is still insufficient to show the evident on how biochar improves crop productivity. For all figures, better quality is needed. In addition, there is no statistical indicator in each figure. Therefore, I would recommend you revise your manuscript and resubmit again.
Answer: Thanks. Soil acidity is a crop production problem of increasing concern in acid red soil. The potential of biochar as a soil amendment/soil acid management in agricultural fields is a recently recognized and yet it is un-derutilized technology. Related evidence is currently limited to short-term indoor experiments with one time BC application and no crop cultivation, yet the degree to which soil acidity may be impacted by biochar ageing process on long-time scale remains unclear. Acid soils have low pH values (<5.5 or 6) and are usually associated with the severe aluminium (Al) toxicity to plants. However, very few studies have specially focused on the impact of biochar on soil Al contents.Our study reports changes in red soil acidity, Al contents, nutrient availability, and crop growth during straw BC and amino nitrogen fertilizer application for 10 wheat/millet planting seasons over five years. Our results demonstrated rice straw-derived BC application to soil at 22.5 t ha−1 was found to be highly consistent in decreasing soil acidity and reducing soluble and ex-changeable Al3+, indicating its higher ameliorating capacity in the south of China in the long run. We have revised related sentences to understand the interpretation of the results easily. Especially, all the related Figures were redrew with statistics according to your suggestion. Please see Figures section.
Finally, we thank you again for the critical comments on this work, and do hope you would be satisfied with the explanations to your comments. please kindly let us know if you have further critical comments on this revised and resubmitted MS.
With best regards
Sincerely yours,
Xu Zhao, E-mail: zhaoxu0@issas.ac.cn
Haohao Lyu, E-mail:lvhao1026@126.com
Author Response File: 
Author Response.pdf
Reviewer 2 Report
A ANOVA deve ser adequada para o artigo ser aceito conforme comentário na linha 167 do manuscrito corrigido. Demais sugestões encontram-se no texto.
Answering the questions below:
1. What is the main question addressed by the research?
Response: Soil fertility influenced by organic fertilizer application.
2. Do you consider the topic original or relevant in the field? Does it address a specific gap in the field?
Response: Yes. It associates the use of organic material to improve soil fertility and crop response.
3. What does it add to the subject area compared with other published material?
Response: The addition is an assessment of the application of organic material on nutrient availability associated with crop production with a robust assessment of various production cycles.
4. What specific improvements should the authors consider regarding the methodology? What further controls should be considered?
Response: In the methodology, the data must be analyzed together to have a greater degree of error freedom (greater than 10) for greater reliability of the comparisons.
5. Are the conclusions consistent with the evidence and arguments presented and do they address the main question posed?
Response: Yes. With the adjustment in the statistical analysis as observed in question 04, there is no need to adjust the conclusion.
6. Are the references appropriate?
Response: Yes.
7. Please include any additional comments on the tables and figures.
Response: Figures and tables are adequate. It only needs to adjust the statistics according to the comments in question 04.
Author Response
To Reviewer 2#,
Dear Professor,
Here we must express our deep gratitude firstly to you for spending time evaluating this manuscript (MS) . In the past days, we carefully read every item of the comments from you. Especially, we redrew and adjusted the statistics according to the comments as you suggested. Now we complete the revision of this work.
Comments and Suggestions for Authors
1.What specific improvements should the authors consider regarding the methodology? What further controls should be considered?
Response: In the methodology, the data must be analyzed together to have a greater degree of error freedom (greater than 10) for greater reliability of the comparisons.
Answer: Thanks. According to your comments, all statistical analyses were conducted with the SPSS 22. Differences between the control and BC-amended soils were analyzed by two-way analysis of variance (ANOVA). The significance of difference between the treatments was assessed by least significant difference (LSD) tests at p < 0.05.Especially, all the related Figures were redrew with statistics. Please see Figures section.
- 2. Please include any additional comments on the tables and figures.
Response: Figures and tables are adequate. It only needs to adjust the statistics according to the comments in question 04.
Answer: Thanks. All the related Figures were redrew with statistics according to your suggestion. Please see Figures section.
We appreciate you again, and any valuable comments from you will be welcome.
With best regards,
Yours sincerely,
Xu Zhao, E-mail: zhaoxu0@issas.ac.cn
Haohao Lyu, E-mail:lvhao1026@126.com
Author Response File: Author Response.pdf
Reviewer 3 Report
The authors have conducted good work and demonstrated that long-term successive seasonal application of biochar that can decrease soil acidity and increase crop yields by improving soil fertility, and utilize crop straw resources in south China.
Author Response
Comments: The authors have conducted good experiment and presented long-term successive seasonal application of BC can decrease soil acidity (especially, soil exchange Al3+), and increase crop yields, which indicating that soil amendment with BC can alleviate soil acidity, improve soil fertility, and utilize crop straw resources in the south of China.
To Reviewer 3#,
Dear Professor,
Here we must express our deep gratitude firstly to you for spending time evaluating this manuscript (MS) and giving the generally positive feedback to our work. The aims of this study was to understand the effect of biochar treatment on alleviation of soil acidity, aluminium (Al) toxicity and its role in enhancing plant growth. Our five-year pot experiment showed that successive planting and fertilizer application could lead to a decreasing trend continuously with time in acidity and fertility of red soil leading to inhibition of crop growth. Repeated application of straw BC can improve soil pH and reduce exchangeable acid (exchangeable Al3+ and H+) and hydrolytic acid (HA) content, thereby avoiding Al toxicity to crops. We also demonstrated rice straw-derived BC application to soil at 22.5 t ha−1 was found to be highly consistent in decreasing soil acidity and reducing soluble and exchangeable Al3+，indicating its higher ameliorating capacity in the south of China in the long run
We appreciate you again, and any valuable comments from you will be welcome.
With best regards,
Yours sincerely,
Xu Zhao, E-mail: zhaoxu0@issas.ac.cn
Haohao Lyu, E-mail: lvhao1026@126.com
Author Response File: Author Response.pdf
Reviewer 4 Report
The authors have conducted good experiment and presented long-term suc- 28 cessive seasonal application of BC can decrease soil acidity (especially, soil exchange Al3+), and increase crop yields, which indicating that soil amendment with BC can alleviate soil acidity, improve 30 soil fertility, and utilize crop straw resources in the south of China.
Author Response
Comments: The authors have conducted good work and demonstrated that long-term successive seasonal application of biochar that can decrease soil acidity and increase crop yields by improving soil fertility, and utilize crop straw resources in south China.
To Reviewer 4#,
Dear Professor,
Here we must express our deep gratitude firstly to you for spending time evaluating this manuscript (MS) and giving the generally positive feedback to our work. The aims of this study was to understand the effect of biochar treatment on alleviation of soil acidity, aluminium (Al) toxicity and its role in enhancing plant growth. Our five-year pot experiment showed that successive planting and fertilizer application could lead to a decreasing trend continuously with time in acidity and fertility of red soil leading to inhibition of crop growth. Repeated application of straw BC can improve soil pH and reduce exchangeable acid (exchangeable Al3+ and H+) and hydrolytic acid (HA) content, thereby avoiding Al toxicity to crops. We also demonstrated rice straw-derived BC application to soil at 22.5 t ha−1 was found to be highly consistent in decreasing soil acidity and reducing soluble and exchangeable Al3+，indicating its higher ameliorating capacity in the south of China in the long run.
We appreciate you again, and any valuable comments from you will be welcome.
With best regards,
Yours sincerely,
Xu Zhao, E-mail: zhaoxu0@issas.ac.cn
Haohao Lyu, E-mail:lvhao1026@126.com
Author Response File: Author Response.pdf
Reviewer 5 Report
Dear Authors "The current study titled "Long-term effects of successive seasonal application of rice straw-derived biochar on the acidity and fertility of red soil in Southern China" presents a compelling investigation into the potential benefits of using biochar as a soil amendment. However, as with any research study, there is always room for further exploration and investigation. I believe that it would be beneficial to spend more time working on this topic in order to gain a deeper understanding of the long-term effects of biochar application on soil acidity and fertility. Additionally, the potential benefits of using biochar can only be fully realized through extensive research work that aims to explore all possible applications and implications. While the experiment outlined in the study is well-organized and conducted, I believe that there are certain deficiencies that could be addressed through a major revision. Specifically, I suggest focusing on the following areas in order to strengthen the study's conclusions and broaden its impact. List specific suggestions for revision here.
Abstract
1-The title should be a straightforward summary of your work.
2-Clearly state the problem being addressed in a single line.
3-Explain the reason for choosing the current technique and highlight any novel aspects of your research, especially if the technology has been well-studied previously.
4-Summarize your main findings in a single line.
5-Offer a brief perspective on the potential future implications of your work.
6-Avoid repeating words from the title as keywords.
Introduction
7-Include a statement about the novelty of your work at the end of the introduction, explaining what new discoveries or connections you have made in your research compared to previous studies.
8-In a single line, mention the knowledge gap that your research has addressed and provide a statement outlining your hypothesis."
M&M
It is fine
Results
It is good
Discussion
It is also fine.
Conclusion
9-Identify the intended audience who will benefit from your research.
10-Clearly state whether the aims of your study have been achieved or not.
11-Provide clear recommendations for the most effective treatment based on your findings.
Regards
Author Response
To Reviewer 5#,
Dear Professor,
Here we must express our deep gratitude firstly to you for spending time evaluating this manuscript (MS) and giving the generally positive feedback to our work. In the past days, we carefully read every item of the comments. The very detailed and constructive advice for revision potentially played an important role in enhancing the MS quality. Especially, we revised some statements as you suggested. The title, Abstract, and introduction section had been improved. In the following, we are willing to list the details to you concerned with our high respect.
Comments: Dear Authors "The current study titled "Long-term effects of successive seasonal application of rice straw-derived biochar on the acidity and fertility of red soil in Southern China" presents a compelling investigation into the potential benefits of using biochar as a soil amendment. However, as with any research study, there is always room for further exploration and investigation. I believe that it would be beneficial to spend more time working on this topic in order to gain a deeper understanding of the long-term effects of biochar application on soil acidity and fertility. Additionally, the potential benefits of using biochar can only be fully realized through extensive research work that aims to explore all possible applications and implications. While the experiment outlined in the study is well-organized and conducted, I believe that there are certain deficiencies that could be addressed through a major revision. Specifically, I suggest focusing on the following areas in order to strengthen the study's conclusions and broaden its impact. List specific suggestions for revision here.
Abstract
- The title should be a straightforward summary of your work.
Answer:Thanks. We have revised the title to “Long-term effects of successive seasonal application of rice straw-derived biochar on improves the acidity and fertility of red soil in Southern China” according to your suggestions.
- Clearly state the problem being addressed in a single line.
Answer: Thank you for the suggestion. Soil acidity is a crop production problem of increasing concern in acid red soil. The potential of biochar as a soil amendment/soil acid management in agricultural fields is a recently recognized and yet it is un-derutilized technology. Related evidence is currently limited to short-term indoor experiments with one time BC application and no crop cultivation, yet the degree to which soil acidity may be impacted by biochar ageing process on long-time scale remains unclear.To evaluate the effects of successive seasonal application of rice straw-derived biochar (BC) on acidity and fertility of soil, a five-year outdoor column trial was conducted. We had state related information in Line 15-17.
- Explain the reason for choosing the current technique and highlight any novel aspects of your research, especially if the technology has been well-studied previously.
Answer: Thank you for the suggestion. As we know, biochar is a generic term used for solid products made from forest litter, crop straw,and other biomass subjected to incomplete combustion and pyrolysis under limited oxygen or anaerobic conditions. biochar owes its physical and chemical properties, researchers have proposed the development of biochar technology as one of the potential measures to address climate change, food security, and ecological environmental problems. In recent years, application of straw BC has been found effective in eliminating red soil acidity. However, evidence is currently limited to short-term indoor experiments with one time BC application and no crop cultivation. Further, few studies have investigated the improvement effects and mechanisms of BC application during long-term cultivation. Our study reports changes in red soil acidity, nutrient availability, and crop growth during straw biochar for 10 wheat/millet planting seasons over five years. Hence, related results support popularization and application of straw carbonization technology in subtropical acid red soil areas in long run. We had state related information and novel aspects in Line 18.
4-Summarize your main findings in a single line.
Answer: Thank you for the suggestion. Our results demonstrated rice straw-derived BC application to soil at 22.5 t ha-1 was found to be highly consistent in decreasing soil acidity and reducing soluble and exchangeable Al3+, indicating its higher ameliorating capacity in the south of China in the long run. Please see Line 32-34.
5-Offer a brief perspective on the potential future implications of your work.
Answer: Thanks. Soil amendment with BC can alleviate soil acidity, improve soil fertility, and utilize crop straw resources in the south of China in the long run. Please see Line 34.
6-Avoid repeating words from the title as keywords.
Answer: Thank you for the suggestion. The keywords had been revised to: “Aluminum toxicity; Soil amendment; Five-year rotation experiment biomass yield; nutrient uptake; Five-year rotation experiment” according to your suggestion.Please see Line 35-37.
Introduction
7-Include a statement about the novelty of your work at the end of the introduction, explaining what new discoveries or connections you have made in your research compared to previous studies.
Answer: Thanks. Short-term addition of BC can result in a transient effect acidity due to changes in BC itself (i.e., the release of soluble nutrients and labile materials from BC which may have a limiting effect), suggesting that the initial results for the soil acidity improvement by biochar are of limited temporal extent. However, the impact of aging has been hypothesized as a critical factor for the interaction of biochar with the plant and soil systems. All the biochars went from an alkaline to an acidic material as a consequence of the weathering. Weathering results in acidifing the biochar through surface oxidation reactions, forming carboxylic acids,which suggesting that biochar might not be an effective agent for long-term soil liming. However, the duration of the liming potential of biochar still requires further investigations. Acid soils have low pH values (<5.5 or 6) and are usually associated with the severe aluminium (Al) toxicity to plants. However, very few studies have specially focused on the impact of biochar on soil Al contents.Our study reports changes in red soil acidity, Al contents, nutrient availability, and crop growth during straw BC and amino nitrogen fertilizer application for 10 wheat/millet planting seasons over five years. Related information please see Line 81-92.
8-In a single line, mention the knowledge gap that your research has addressed and provide a statement outlining your hypothesis."
Answer: Thanks. The duration of the liming potential of biochar still requires further investigations. We hypothesized that the contents of soil pH, Al and soil fertility would be greatly influenced by long-term BC addition. Related information please see Line 97-99.
M&M
It is fine
Results
It is good
Discussion
It is also fine.
Conclusion
- Identify the intended audience who will benefit from your research.
Answer: Thanks. Related results support popularization and application of straw carbonization technology and provide ideas and methods for more efficient utilization of straw in sub-tropical acid red soil areas.
- Clearly state whether the aims of your study have been achieved or not.
Answer: Thanks. Yes, the aims of this study was to understand the effect of biochar treatment on alleviation of soil acidity, aluminium (Al) toxicity and its role in enhancing plant growth. Our five-year pot experiment showed that successive planting and fertilizer application could lead to a decreasing trend continuously with time in acidity and fertility of red soil leading to inhibition of crop growth. Repeated application of straw BC can improve soil pH and reduce exchangeable acid (exchangeable Al3+ and H+) and hydrolytic acid (HA) content, thereby avoiding Al toxicity to crops.
- Provide clear recommendations for the most effective treatment based on your findings.
Answer: Thanks. Our results demonstrated rice straw-derived BC application to soil at 22.5 t ha-1 was found to be highly consistent in decreasing soil acidity and reducing soluble and ex-changeable Al3+, indicating its higher ameliorating capacity in the south of China in the long run.
We appreciate you again for the critical comments on this MS, and do hope you think the revision and the response are suitable. Any other valuable comments from you will be welcome.
With best regards,
Yours sincerely,
Xu Zhao, E-mail: zhaoxu0@issas.ac.cn
Haohao Lyu, E-mail:lvhao1026@126.com
Author Response File: Author Response.pdf
Round 2
Reviewer 1 Report
Thank you for your revision, I have only one small thing about Figures, could you please make it clearer i.e. the text size of X, Y A-xis name must be increased and significant letters, put it in the visible position.
Author Response
Dear Professor ,
We appreciate you very much for kindly receiving this revised manuscript (MS). we had redrawn all the figures according to your suggestion. Please see the revised MS.
We appreciate you again, and any valuable comments from you will be welcome.
With best regards,
Yours sincerely,
Xu Zhao, E-mail: zhaoxu0@issas.ac.cn
Haohao Lyu, E-mail:lvhao1026@126.com
Author Response File: Author Response.pdf
Reviewer 2 Report
Accept the manuscript for publication.
Author Response
Dear Professor ,
We appreciate you very much for kindly receiving this revised manuscript (MS). We appreciate you again.
With best regards,
Yours sincerely,
Xu Zhao, E-mail: zhaoxu0@issas.ac.cn
Haohao Lyu, E-mail:lvhao1026@126.com
Reviewer 5 Report
Dear Authors
I am satisfied with all the changes made in the manuscript.
Regards
Author Response
Dear Professor ,
We appreciate you very much for kindly receiving this revised manuscript (MS). We appreciate you again.
With best regards,
Yours sincerely,
Xu Zhao, E-mail: zhaoxu0@issas.ac.cn
Haohao Lyu, E-mail:lvhao1026@126.com
