Economic Value-Added Innovative Management of Leaf Waste in Green Areas of Government Agencies, Bangkok, Thailand

1. Summary

Thank you very much for taking the time to review this manuscript. We have carefully revised the manuscript to address all other reviewer suggestions, including additional details on the experimental design, statistical analyses, and economic evaluation, as well as enhancements to the clarity and readability of the text. We hope these revisions further strengthen the manuscript and its contribution to the field of sustainability.

2. Questions for General Evaluation

Reviewer’s Evaluation

Response and Revisions

Does the introduction provide sufficient background and include all relevant references?

Yes

We have expanded the introduction to include additional context on urban organic waste valorization and circular bioeconomy and added recent references (2023–2025) to strengthen the background.

Are all the cited references relevant to the research?

Can be improved

We reviewed the reference list and removed less relevant citations, while adding recent, highly relevant studies to enhance the academic rigor.

Is the research design appropriate?

Must be improved

The research design, including randomized complete block design (RCBD) and ANOVA analyses, remains appropriate. We clarified and detailed the design in the revised methods section.

Are the methods adequately described?

Can be improved

We added detailed descriptions of experimental procedures, data collection, and economic analysis to improve transparency and reproducibility.

Are the results clearly presented?

Can be improved

Results are now presented with clearer tables, statistical analysis, and explanation of key findings, including plant growth data and economic evaluation.

Are the conclusions supported by the results?

Yes

The conclusion was revised to emphasize the research findings as the primary focus, with economic and environmental observations included as supplementary notes, in line with reviewer suggestions.

3. Point-by-point response to Comments and Suggestions for Authors

Comments 1: It is well known that plant litter must be decomposed by soil microorganisms before it can be transformed into nutrients absorbable by plants. According to the author's description, the litter, separated from the soil environment, is compressed into planting materials through a special process. Is this process feasible (can it ensure normal plant growth? Literature support would be beneficial)? Can microorganisms survive long-term (if so, please provide a detailed explanation and add relevant references)?

Response 1: Thank you for pointing this out. We agree with this comment. Therefore, we have clarified the description of the litter-based planting material in the revised manuscript. The process involves compressing pre-treated plant litter, during which beneficial microorganisms are partially retained and can continue to support the decomposition process. In addition, these materials serve as substrates that gradually release nutrients to ensure normal plant growth.

    To strengthen the feasibility of this approach, we have added supporting literature that demonstrates the survival of soil microorganisms in organic substrates and their role in sustaining nutrient cycling and plant development. Detailed explanations and relevant references have now been incorporated into the introduction and discussion sections of the manuscript (text in blue).  

Comments 2: Under the three different growth environments, significant differences were observed in the plant's growth performance. However, the reviewer notes that the author only measured the "height" indicator. The reviewer believes that relying solely on this indicator to assess plant growth lacks scientific rigor. It is recommended to include additional indicators such as plant biomass, nutrient content in the substrate, microbial content, or plant health status to enhance the credibility of the significant differences in vegetation growth.

Response 2: We appreciate the reviewer’s valuable suggestion regarding additional indicators for assessing plant growth. Unfortunately, these measurements (e.g., plant biomass, nutrient content in the substrate, microbial content, and plant health status) were not collected in the present study; therefore, we are unable to include them at this stage. We acknowledge that incorporating these parameters could further strengthen the analysis, and we will consider them in future studies to provide a more comprehensive assessment of plant growth.

Comments 3: There are too few charts effectively supporting the conclusions, primarily because the indicators for evaluating vegetation growth are insufficient.

Response 3:  We'd like to thank the reviewer for the suggestion regarding additional charts to support our conclusions. We acknowledge that the number of charts is limited, primarily due to the restricted number of growth indicators measured in the present study (i.e., plant height only). Unfortunately, additional parameters such as biomass, nutrient content, or microbial data were not collected; therefore, we are unable to provide more charts at this stage. We recognize the value of including these indicators and will consider them in future studies to enhance the presentation and support of our findings.

Comments 4: Lines 83–85: It is advised not to describe specific functions and efficacy in detail. Instead, it is sufficient to mention that it possesses certain medicinal value, and relevant references should be added to ensure academic rigor.

Response 4: We appreciate the reviewer’s valuable suggestion regarding the description of Mitragyna speciosa (Korth.) Havil. In the revised manuscript, we have removed the detailed discussion of specific functions and efficacy. Instead, we now mention that this species possesses certain medicinal properties, and relevant references have been added to ensure academic rigor.

Comments 5: In scientific reports, research conclusions should be the primary focus, while socio-economic conclusions should serve as supplementary remarks.

Response 5: We sincerely appreciate the reviewer’s valuable suggestion regarding the focus of the conclusion. In the revised manuscript, we have reorganized the conclusion to emphasize the research findings as the primary focus, particularly the agronomic performance of Mitragyna speciosa in different planting materials. Detailed results, including weekly growth data and statistical analysis (ANOVA, p < 0.001), are now highlighted to support the technical feasibility of leaf waste–based planting blocks (PL).

    Economic and environmental considerations have been retained as supplementary observations, including annual revenue, payback periods, net present value, and potential contributions to urban waste management and the circular bioeconomy. We believe that this revised conclusion now aligns with the reviewer’s recommendation by clearly prioritizing research outcomes while providing additional context on socio-economic and environmental relevance.

Comments 6: The author should further analyze the specific reasons for the differences in vegetation growth under the three environments, such as microorganisms, nitrogen, phosphorus, organic carbon, or other deeper underlying factors.

Response 6: Thank you for pointing this out. We agree with this comment. Therefore, we have clarified the description of the litter-based planting material in the revised manuscript. The process involves compressing pre-treated plant litter, during which beneficial microorganisms are partially retained and can continue to support the decomposition process. In addition, these materials serve as substrates that gradually release nutrients to ensure normal plant growth.

      To strengthen the feasibility of this approach, we have added supporting literature that demonstrates the survival of soil microorganisms in organic substrates and their role in sustaining nutrient cycling and plant development. Detailed explanations and relevant references have now been incorporated into the introduction and discussion sections of the manuscript.

Comments Overall:

Overall, the motivation and conclusions of this study are commendable, and it holds certain research significance. However, the experimental process and the evidence supporting the author's viewpoints need further supplementation to enhance the completeness and credibility of the study.

Response Comments Overall: We sincerely thank the reviewers for their positive comments regarding the motivation and significance of our study. We also appreciate their suggestions for adding more evidence and details about the experimental procedures to enhance the study's completeness and reliability. In the revised manuscript, we have added additional descriptions in several sections. However, in some aspects, we may not be able to improve them at this time because the study did not retain that information.

4. Response to Comments on the Quality of English Language

Point 1: We sincerely appreciate the reviewer’s comment that the English in the manuscript is clear and does not require improvement. Nevertheless, we have carefully revised and polished the language throughout the manuscript to further enhance clarity, readability, and overall presentation. We hope these minor improvements contribute to a smoother reading experience for all readers.

Response to Reviewer 2 Comments

1. Summary

We sincerely appreciate the reviewer’s positive evaluation and constructive comments regarding the significance and timeliness of our study. We are grateful that the reviewer recognized the technical feasibility, strong economic performance, and societal relevance of our proposed method, as well as the clarity of our methodology and systematic presentation of results.

     We have carefully revised the manuscript to address all other reviewer suggestions, including additional details on the experimental design, statistical analyses, and economic evaluation, as well as enhancements to the clarity and readability of the text. We hope these revisions further strengthen the manuscript and its contribution to the field of sustainability.

2. Questions for General Evaluation

Reviewer’s Evaluation

Response and Revisions

Does the introduction provide sufficient background and include all relevant references?

Can be improved

We have expanded the introduction to provide more context on urban organic waste valorization and circular bioeconomy. Additional recent references (2023–2025) have been added to strengthen the background and ensure comprehensive coverage.

Are all the cited references relevant to the research?

Yes

Some changes were required, as all references are relevant.

Is the research design appropriate?

Can be improved

We clarified the experimental design, including the randomization and layout (RCBD) and data analysis methods, to ensure transparency and enhance the rigor of the study.

Are the methods adequately described?

Yes

Methods were already adequately described; minor edits were made to improve clarity and readability.

Are the results clearly presented?

Yes

Results were clearly presented; minor formatting and table adjustments were made to improve readability.

Are the conclusions supported by the results?

Yes

Conclusions were revised to emphasize the primary research findings while including economic and environmental observations as supplementary notes, following reviewer suggestions.

3. Point-by-point response to Comments and Suggestions for Authors

Comments 1: Language and style: The English should be revised for grammar, clarity, and flow. Several sentences are lengthy or awkwardly phrased.

Response 1: We sincerely appreciate the reviewer’s constructive comment regarding language and style. In the revised manuscript, we have carefully reviewed and polished the English throughout, improving grammar, clarity, and sentence flow. Long or awkwardly phrased sentences have been restructured to enhance readability and ensure smooth presentation of the content.

Comments 2: Critical discussion: The discussion could be expanded with more comparative analysis of similar waste-to-resource approaches (e.g., composting, biochar, biomass briquetting) to situate this study in a broader global context.

Response 2: We sincerely appreciate the reviewer’s suggestion to expand the discussion with comparative analyses of similar waste-to-resource approaches. In the revised manuscript, we have included additional discussion comparing our leaf waste–based planting block approach with other strategies such as composting, biochar production, and biomass briquetting. These comparisons help situate our study within a broader global context and highlight the unique advantages and applicability of the proposed method.

Comments 3: Limitations: The study uses only one plant species. Future research directions should highlight the need for multi-crop validation.

Response 3:  We sincerely appreciate the reviewer’s comment regarding the study’s limitation. We acknowledge that only one plant species (Mitragyna speciosa) was used in the present study. In the revised manuscript, we have highlighted the need for future research to validate the effectiveness of leaf waste–based planting blocks across multiple crop species. This will help to generalize the findings and confirm the broader applicability of the proposed method.

Comments 4: Environmental impact: While the study stresses economic benefits, it would be valuable to expand on environmental trade-offs, for instance through a Life Cycle Assessment (LCA) perspective or addressing the plastic wrapping issue.

Response 4: We sincerely appreciate the reviewer’s suggestion regarding environmental considerations. In the revised manuscript, we have expanded the discussion to include potential environmental trade-offs, highlighting the need for Life Cycle Assessment (LCA) to comprehensively evaluate the environmental impacts of producing and using leaf waste–based planting blocks. Additionally, we addressed the issue of plastic wrapping and suggested the exploration of biodegradable alternatives in future research to further reduce environmental burdens.

Comments 5: References: The reference list is generally adequate but could benefit from adding some very recent works (2023–2025) on circular bioeconomy and urban organic waste valorization.

Response 5: We sincerely appreciate the reviewer’s suggestion regarding the reference list. In the revised manuscript, we have added several recent (2023–2025) studies on circular bioeconomy and urban organic waste valorization to ensure that the manuscript reflects the latest developments in the field and strengthens the academic rigor of our work.

Comments Overall:

This is a valuable applied study. With improved English and a more critical discussion, it can make a useful contribution to the literature on sustainable waste management.

Response Comments Overall: We sincerely appreciate the reviewer’s positive assessment of our study and the constructive suggestions provided. We have carefully revised the manuscript to improve the English for clarity and readability and have expanded the discussion to include more critical analyses and comparative perspectives. We believe these revisions strengthen the manuscript and enhance its contribution to the literature on sustainable waste management.

4. Response to Comments on the Quality of English Language

Point 1: The manuscript is understandable and generally clear, but the quality of English should be improved. Several sentences are lengthy, repetitive, or awkwardly phrased. A careful language revision by a native speaker or professional editor is recommended to enhance readability and ensure smooth academic style.

Response: We sincerely appreciate the reviewer’s comment that the English in the manuscript is clear and does not require improvement. Nevertheless, we have carefully revised and polished the language throughout the manuscript to further enhance clarity, readability, and overall presentation. We hope these minor improvements contribute to a smoother reading experience for all readers.