From Water Buffalo (Bubalus bubalis) Manure to Vermicompost: Testing a Sustainable Approach for Agriculture

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

This manuscript deals with the “From buffalo manure to vermicompost: testing a sustainable approach for agriculture”. The work is nice. However, the introduction should be improved. The manuscript can be accepted after considering the following points:

 

1. What are the advantages of the vermicompost method over other methods? It should be mentioned in the introduction section citing other appropriate references.
2. The introduction section is too long. It should be concise.
3. It would be nice if the authors could provide images of the plant leaves to understand their morphology, and especially the SPAD values.
4. In the conclusion, the quantitative data should be provided so that one can easily understand the summary of the work.

Comments for author File: Comments.pdf

Comments on the Quality of English Language

The English could be improved to more clearly express the research.

Author Response

We are grateful to the Reviewers for the insightful comments and helpful suggestions, which have significantly improved the quality and clarity of our work. In response, we have carefully revised the manuscript and addressed all the reviewers’ comments point-by-point as detailed below. All modifications are highlighted in the version of the manuscript with track changes, submitted with the clean, revised version (also submitted as PDF format).

Comment 1: What are the advantages of the vermicompost method over other methods? It should be mentioned in the introduction section citing other appropriate references.

Response: We have added a paragraph in the Introduction (lines 80-90) describing the main advantages of vermicomposting compared to other methods such as traditional composting and anaerobic digestion, citing appropriate literature as required.

Comment 2: The introduction section is too long. It should be concise.

Response: We revised and shortened the Introduction, while maintaining clarity and completeness. In particular, we condensed overlapping content and eliminated redundancies in the initial paragraphs.

Comment 3: It would be nice if the authors could provide images of the plant leaves to understand their morphology, and especially the SPAD values.

Response: We thank the Reviewer for the valuable suggestion. Unfortunately, we did not take close-up photographs of the plant leaves during the experiment, including those specifically related to SPAD measurements.

Comment 4: In the conclusion, the quantitative data should be provided so that one can easily understand the summary of the work.

Response: We thank the reviewer for this useful suggestion. In the revised Conclusions section, we have incorporated all key results in quantitative terms.

Reviewer 2 Report

Comments and Suggestions for Authors

The Campania region in Italy, which centers its economy on Mediterranean water buffalo farming, produces a significant amount of buffalo manure annually (with adult buffaloes generating 4–6 tons of wet manure per year). Due to the strict restrictions imposed by the EU’s Nitrates Directive (limiting nitrogen input to ≤170 kg/ha/year in sensitive areas), traditional methods of manure application are facing increasing environmental pressures. The key challenge lies in transforming organic waste into a resource while enhancing agricultural sustainability. The main issues are as follows:

1. In Fig.1d, how are the liquid and solid components of the manure separated? What methods are used? What is the moisture content of the composting material? These are key details of the experiment. The authors should provide these critical data.
2. Was the entire composting process maintained at 55-65 degrees Celsius? How was such a high temperature maintained? If external heating equipment was used, has an economic analysis been conducted?
3. The key information in vermicomposting is the performance of earthworms. What is the mass ratio of earthworms to buffalo manure? Why was this ratio chosen?

Comments on the Quality of English Language

The English language expression in this manuscript can be further improved.

Author Response

We are grateful to the Reviewers for the insightful comments and helpful suggestions, which have significantly improved the quality and clarity of our work. In response, we have carefully revised the manuscript and addressed all the reviewers’ comments point-by-point as detailed below. All modifications are highlighted in the version of the manuscript with track changes, submitted with the clean, revised version (also submitted as PDF format).

Comment 1: In Fig.1d, how are the liquid and solid components of the manure separated? What methods are used? What is the moisture content of the composting material?

Response: We have added methodological details on manure separation and moisture content in Section 2.1.

Comment 2: Was the entire composting process maintained at 55–65 °C? How was such a high temperature maintained?

Response: We thank the reviewer for the question. The thermophilic phase (55–65 °C) occurred naturally during the aerobic pre-stabilization phase, due to microbial activity. No external heating was applied. Temperature was monitored daily using thermocouple sensors placed inside the manure piles to ensure proper microbial activity and determine the transition to the cooling phase before vermicomposting.

Comment 3: What is the mass ratio of earthworms to buffalo manure? Why was this ratio chosen?

Response: The earthworm-to-substrate ratio was approximately 1:5 (w/w, fresh worm biomass to fresh manure), corresponding to 250–330 individuals per kg of substrate, based on the average weight of adult worms. This ratio has been specified in Section 2.2 of the revised manuscript. This ratio was chosen because it falls within the optimal range recommended in the literature for efficient vermicomposting by Domínguez and Edwards (2010), ensuring a good balance between decomposition rate, worm health, and process scalability under semi-controlled farm conditions.

Reviewer 3 Report

Comments and Suggestions for Authors

1. The introduction should include information on the use of vermicomposting in other animal manures.
2. In the second part Materials and Methods, details of some key parameters can be added, such as the type and number of earthworms, temperature control during composting, and specific conditions for plant cultivation.
3. It is recommended to add details related to cauliflower cultivation, such as planting density and irrigation frequency.
4. What a, b, c, etc. represent in Figure 3 should be indicated in the figure notes.
5. What PC1, PC2 represent in Fig. 4 should be labeled in the figure notes.
6. Comparisons with other similar studies in the discussion, such as the effects of vermicomposting on other crops, could be added to the discussion to enhance the generalizability of the results.
7. Some references are not formatted uniformly (e.g., journal name abbreviations) and need to be adjusted according to journal requirements.
8. A few sentences have grammatical problems.

Author Response

We are grateful to the Reviewers for the insightful comments and helpful suggestions, which have significantly improved the quality and clarity of our work. In response, we have carefully revised the manuscript and addressed all the reviewers’ comments point-by-point as detailed below. All modifications are highlighted in the version of the manuscript with track changes, submitted with the clean, revised version (also submitted as PDF format).

Comment 1: The introduction should include information on the use of vermicomposting in other animal manures.

Response: We thank the reviewer for this valuable suggestion. In response, we have specified that vermicomposting has been successfully used to process several animal manures, including cattle, pigs, poultry, and goats. We briefly summarise the main findings from recent studies, such as improved nutrient availability, enhanced microbial activity, pathogen reduction, and carbon stabilisation.

Comment 2: Add more details on the type and number of earthworms, temperature control, and cultivation conditions.

Response: We thank the reviewer for the comment. We have clarified in Section 2.2 that a mix of Eisenia fetida and Eisenia andrei was used, both species being commonly adopted in vermicomposting. Their combined use ensured efficient and adaptable organic matter decomposition. We also added details on temperature monitoring using a datalogger, and further specified cauliflower cultivation conditions, including transplant density and irrigation regime

Comment 3: Clarify what a, b, c, etc., represent in Figure 3.

Response: We have clarified the meaning of the letters in the revised caption of Figure 3. Specifically, different lowercase letters (a, b, c, etc.) placed above the bars indicate statistically significant differences among the treatments, as determined by Tukey's HSD test (p < 0.05). Treatments that share the same letter are not significantly different from each other, while treatments with different letters differ significantly.

Comment 4: Clarify what PC1 and PC2 represent in Fig. 4.

Response: We have clarified in the revised caption that PC1 and PC2 refer to the first and second principal components extracted from the multivariate dataset. PC1 and PC2 are linear combinations of the original variables and represent the directions of maximum variance in the data. PC1 accounts for 61.9% and PC2 for 16.2% of the total variability. These axes allow for dimensionality reduction while preserving the structure of the data. This information has been added to the caption of Figure 4 to improve clarity.

Comment 5: Add comparisons to other similar studies in the discussion.

Response: Thank you for your suggestion. We expanded the discussion section by adding several comparative references to relevant studies on other crops where vermicompost application led to yield, quality traits, or stress resilience improvements. These additions provide broader context and confirm the applicability of our findings. All insertions are visible in Section 4 of the revised manuscript through track changes.

Comment 6: Uniform reference formatting and minor grammar issues.

Response: We carefully revised the reference list according to journal style and corrected all identified grammar issues.

Reviewer 4 Report

Comments and Suggestions for Authors

- Include the scientific name of the buffalo (Bubalus bubalis) in the title and abstract.

- Distribute the figures into their corresponding sections; for example, place Figures 1A-E in Section 2.1 and Figures 1F-H in Section 2.2, instead of grouping them together in Section 2.3, where no reference to them is made.

- In the Materials and Methods section, at the beginning of this part, it is necessary to add a subsection on reagents, detailing each reagent used, along with its brand and purity percentage.

- Relocate Figure 3 to the section where it is referenced; currently, it is cited in the text but positioned in the Discussion section, where it is not mentioned. The same applies to Figure 4.

-It would be interesting to perform a calculation to determine how much organic fertilizer is equivalent to synthetic fertilizer.

- In the development of the study, the involvement of the two earthworm species remains unclear. Clarify their roles, such as which species was more suitable for the study, which adapted better, and which yielded better results.

- A significant restructuring of the Results Discussion section is required, contrasting the reported numerical results with those found in the scientific literature.

- Consequently, restructure the Conclusions section based on the discussion of the results.

Author Response

We are grateful to the Reviewers for the insightful comments and helpful suggestions, which have significantly improved the quality and clarity of our work. In response, we have carefully revised the manuscript and addressed all the reviewers’ comments point-by-point as detailed below. All modifications are highlighted in the version of the manuscript with track changes, submitted with the clean, revised version (also submitted as PDF format).

Comment 1: Include the scientific name of the buffalo in the title and abstract.

Response: The scientific name (Bubalus bubalis) has been added to the title and abstract.

Comment 2: Distribute Figures 1A–E in Section 2.1 and Figures 1F–H in Section 2.2.

Response: Figures and captions have been redistributed  and discussed in the corresponding sections.

Comment 3: Add a subsection on reagents with brand and purity.

Response: A new subsection (Section 2.5) has been added listing the reagents used, with brand and purity where applicable.

Comment 4: Relocate Figure 3 and 4 to the section where they are referenced.

Response: Figures 3 and 4 have been repositioned within the Results section at the appropriate location.

Comment 5: Clarify the role of the two earthworm species.

Response: We clarified it in Section 2.2.

Comment 6: Restructure the Results and Discussion section.

Response: We restructured the Discussion to align with the order of presentation in the Results more clearly and included literature-based comparisons.

Comment 7: Restructure the Conclusions.

Response: The Conclusions section has been rewritten to emphasize the practical, agronomic, and environmental implications of the findings, including quantitative data.

Round 2

Reviewer 2 Report

Comments and Suggestions for Authors

The authors solved the questions raised by the reviewers well, so the manuscript was recommended for acceptance

Reviewer 4 Report

Comments and Suggestions for Authors

ok