Improved Production of Marandu Palisade Grass (Brachiaria brizantha) with Mixed Gelatin Sludge Fertilization

Round 1

Reviewer 1 Report

Dear colleagues, thank you very much for your agroecologically pronounced article with so many experimental data! I believe its principal results have obvious research interest and wide practical sense even for regions far outside of the concrete area of the investigation.

I am pleased to recommend your article for publication, waiting for further development of this topic on the pages of the journal "Grasses".

As a wish for your future manuscripts, it can be noted the expediency of presenting additional illustrative material in graph with a visual demonstration of principal advantages of the best available technologies. Plus, usually it makes sense to use more actively in your introduction and discussion the papers published during last 3-5 years.

Author Response

Comments and Suggestions for Authors

Dear colleagues, thank you very much for your agroecologically pronounced article with so many experimental data! I believe its principal results have obvious research interest and wide practical sense even for regions far outside of the concrete area of the investigation.

I am pleased to recommend your article for publication, waiting for further development of this topic on the pages of the journal "Grasses".

We thank you for taking the time to review and recommend our manuscript and for your suggestions on how to improve the manuscript.

As a wish for your future manuscripts, it can be noted the expediency of presenting additional illustrative material in graph with a visual demonstration of principal advantages of the best available technologies.

We created a new Figure 1 demonstrating the process cycle of the industrialization bovine leather, sludge generation, and the advantage of its application in livestock production.

Plus, usually it makes sense to use more actively in your introduction and discussion the papers published during last 3-5 years.

In research carried out for the main scientific basis, we did not find recent publications published between 2019 to 2024 that could be compared and used in discussions to support for the use of mixed sludge from the gelatin industry in forage production.

Submission Date

27 February 2024

Date of this review

17 Mar 2024 10:45:28

Reviewer 2 Report

Dear authors,

I want to congratulate you for the work done for this research, but I want to bring some improvements to this work.

First, the Introduction section should perhaps be slightly restructured to be more concise. At the same time, the purpose and objectives of the work of this publication and what is the novelty of this publication should come out. It is true that something was specified in the last part of the introduction, but this part should be developed along with the novelty of this study, there are quite a few studies in this field. As a result, depending on the purpose and objectives of the work, the conclusions must be drawn, and in the present work it is not clear.

Other questions/improvements:

1.      In the material and method section - a small description of the analyzed species should be entered - which species of animals prefer to graze this species, and perhaps what is the load of LU/HA when grazing??

2.      Chapter 2 - material and methods must be restructured - it is very difficult to read - maybe something like this should be done - subchapters - study site, material used, statistical programs used, other measurements, etc.

3.      Chapter 3 is called - Results - but still there are discussions based on the results obtained in this research, after which comes chapter 4 with Discussions - something like this is not indicated in a scientific work. Recommendation - either chapter 3 is called Results and discussions, or all discussions are placed in chapter 4

Author Response

Dear authors,

I want to congratulate you for the work done for this research, but I want to bring some improvements to this work.

First, the Introduction section should perhaps be slightly restructured to be more concise. At the same time, the purpose and objectives of the work of this publication and what is the novelty of this publication should come out. It is true that something was specified in the last part of the introduction, but this part should be developed along with the novelty of this study, there are quite a few studies in this field. As a result, depending on the purpose and objectives of the work, the conclusions must be drawn, and in the present work it is not clear.

We improved the final part of the introduction seeking to elucidate the importance of the study and better support the objective of the work. Thanks for the suggestion.

Other questions/improvements:

1. In the material and method section - a small description of the analyzed species should be entered - which species of animals prefer to graze this species, and perhaps what is the load of LU/HA when grazing??

We included the description of the forage species and capacity for forage production and animal support, as suggested. Thanks for the suggestion.

2. Chapter 2 - material and methods must be restructured - it is very difficult to read - maybe something like this should be done - subchapters - study site, material used, statistical programs used, other measurements, etc.

We have added four sub-sections headers as suggested for the Material and Methods section: 2.1. Study Site; 2.2. Materials Used for Experiment; 2.3. Experimental Procedures; 2.4. Statistical Methods.

3. Chapter 3 is called - Results - but still there are discussions based on the results obtained in this research, after which comes chapter 4 with Discussions - something like this is not indicated in a scientific work. Recommendation - either chapter 3 is called Results and discussions, or all discussions are placed in chapter 4

We have moved discussion related writing from the Results section (chapter 3) to the Discussion section (chapter 4) as recommended. We opted to this and not merging the Results section and the Discussion section into one Results and Discussion section.

Submission Date

27 February 2024

Date of this review

19 Mar 2024 18:44:48

Reviewer 3 Report

L 51-53: This statement seems to imply that all industrial waste are rich in organic matter and is a source of fertilizer. Please be specific.

L 76-79: Are there any other studies in a different crop or soil, please mention them. It would make your justification more compelling. Also, a few lines of justification on why Marandu grass was selected.

L 222-227: What was the experimental model? Please elaborate on the statistics part of the study such as number of replications, fixed effects, random effects etc.

Table 5: How are the means being compared here, why was regression used instead of mean separation?

Results: The result section is very lengthy, it contains interpretations of results that might be better fit for the discussion section. Please consider moving interpretations (such as L 301-306; 445-451 etc,) to discussion.

L 535-536: Does MGS leave any residue in the plants, how does the residue effects grazing livstock? Please consider adding this aspect with appropriate literature.

Author Response

Comments and Suggestions for Authors

L 51-53: This statement seems to imply that all industrial waste are rich in organic matter and is a source of fertilizer. Please be specific.

We have clarified this as human and animal wastes and not implying gelatin sludge per se.

L 76-79: Are there any other studies in a different crop or soil, please mention them. It would make your justification more compelling. Also, a few lines of justification on why Marandu grass was selected.

We described at the end of the introduction the lack of studies using gelatin sludge as fertilizers in the production of forage plants in the scientific literature, which makes it difficult to discuss the results achieved. We describe in the material and methods the justification for choosing the species. Thanks for the suggestion.

L 222-227: What was the experimental model? Please elaborate on the statistics part of the study such as number of replications, fixed effects, random effects etc.

We re-wrote and provided more detail on the experimental design used, including the fixed effects and random effects.

Table 5: How are the means being compared here, why was regression used instead of mean separation?

We have re-written the statistical methods to make the statistics used clearer. As we work with doses of mixed gelatin sludge and our objective is to discover the best dose of sludge for forage production and to improve soil fertility without risk to the environment, it was necessary to work with regression statistics instead of comparison between the effects of each dose.

Results: The result section is very lengthy, it contains interpretations of results that might be better fit for the discussion section. Please consider moving interpretations (such as L 301-306; 445-451 etc,) to discussion.

We have moved discussion related writing from the Results section to the Discussion section as recommended.

L 535-536: Does MGS leave any residue in the plants, how does the residue effects grazing livestock? Please consider adding this aspect with appropriate literature.

There is no scientific evidence of harmful substances from the use of mixed gelatin sludge that could cause harm to animal grazing. We included in the sludge analysis in Table 3 the biological analyzes of the product where we evaluated Escherischi coli and viable helminth eggs. In this sense, the absence of Escherischi coli and viable helminth eggs in the analysis of sludge can guarantee greater safety in its use as fertilizer in pasture without the risk of subsequent contamination of animals.

Submission Date

27 February 2024

Date of this review

13 Mar 2024 14:11:27

Reviewer 4 Report

As a result of the work of food industry enterprises, organic waste is always generated (for example, coffee, gelatin and others), which can be used as fertilizers in crop production to improve soil fertility and increase crop yields. Therefore, this article on gelatin is relevant and important for practice. The manuscript contains a number of questions and comments aimed at improving the presented research.

1. In Figure 2, the draft axis can remove unnecessary zeros after the decimal point.

2. It would be more clear to show the results from tables 6, 7, 8, 12 in the form of drawings.

3. The study was carried out on a local site with a certain type of soil, so in the conclusions it should be noted that the effectiveness indicators relate only to this experiment.

4. It would be useful to conduct this kind of research on soils of different mechanical composition and level of fertility.

Author Response

Comments and Suggestions for Authors

As a result of the work of food industry enterprises, organic waste is always generated (for example, coffee, gelatin and others), which can be used as fertilizers in crop production to improve soil fertility and increase crop yields. Therefore, this article on gelatin is relevant and important for practice. The manuscript contains a number of questions and comments aimed at improving the presented research.

1. In Figure 2, the draft axis can remove unnecessary zeros after the decimal point.

Suggestion accepted and we have corrected these errors.

2. It would be more clear to show the results from tables 6, 7, 8, 12 in the form of drawings.

We accepted this suggestion for the results from tables 6, 7, and 12 which were presented graphically. The soil attributes presented in tables 8 and 9 could not be adequately presented in graphic form since the text would be too long and considering that a graph would be needed for each layer and variable.

3. The study was carried out on a local site with a certain type of soil, so in the conclusions it should be noted that the effectiveness indicators relate only to this experiment.

We have clarified the results relate to a specific type of soil in the Conclusion section and that the effectiveness indicators relate only to this experiment.

4. It would be useful to conduct this kind of research on soils of different mechanical composition and level of fertility.

We have added a sentence to the Conclusion recommending this suggestion for future research.

Submission Date

27 February 2024

Date of this review

16 Mar 2024 11:01:36

Round 2

Reviewer 2 Report

Dear authors,

I commend you for your contributions to this manuscript, indeed the observations were successfully made by the authors.

The paper in my view is suitable for publication after the improvements made to this manuscript.

Congratulations and good luck further!