Organic Fertilization and Biostimulant Application to Improve Yield and Quality of Eggplant While Reducing the Environmental Impact

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

The manuscript presents a study on the effect of organic fertilization and biostimulant application on the yield and quality of eggplant and their environmental impact. Considering that it is important that intensive farming in the Mediterranean basin has resulted in several negative effects and circular economy can help the reduction of the anthropogenic pressure due to synthetic fertilizers and chemicals,  as well as a comparison of organic amendments with traditional mineral fertilization and the synergistic effect of biostimulants has never been evaluated on eggplant, I think that the manuscript presents helpful conclusions from the research objectives have been achieved to an extent. Overall, the manuscript is worthy of publication to an extent. However, I have some concerns that should be addressed before the paper could be published.

1. In the Abstract part, it is better for the authors to further clarify the novelty in a clearer way.
2. In the Introduction part, it is better for the authors to further clarify the novelty in a clear way. Moreover, it is better for the authors to further emphasize the importance of combined application of organic amendments and biostimulants in helping the reduction of the anthropogenic pressure due to synthetic fertilizers and chemicals and the enhancement of the field crops.
3. In the Materials and Methods part, the related indices of the environmental impact under the conditions of combined application of organic amendments and biostimulants to the egg plants. Correspondingly, these related results and discussion should be mentioned in the Results part and the Discussion part.
4. In the Discussion part, the role of the soil type, eggplant cultivars and management practices, especially the irrigation should be also mentioned.

Comments on the Quality of English Language

The English lanuage could be improved to better show the aims, the results, and conclusion in a clearer way.

Author Response

RC: The manuscript presents a study on the effect of organic fertilization and biostimulant application on the yield and quality of eggplant and their environmental impact. Considering that it is important that intensive farming in the Mediterranean basin has resulted in several negative effects and circular economy can help the reduction of the anthropogenic pressure due to synthetic fertilizers and chemicals, as well as a comparison of organic amendments with traditional mineral fertilization and the synergistic effect of biostimulants has never been evaluated on eggplant, I think that the manuscript presents helpful conclusions from the research objectives have been achieved to an extent. Overall, the manuscript is worthy of publication to an extent. However, I have some concerns that should be addressed before the paper could be published.

OR: Thank you for your valuable revision. Below, you can find the responses point by point to your comments and, in the text, the required corrections as track changes.

 

RC: In the Abstract part, it is better for the authors to further clarify the novelty in a clearer way.

OR: We thank the reviewer, you for this suggestion; we have modified the abstract to make the novelty of our research clearer.

RC: In the Introduction part, it is better for the authors to further clarify the novelty in a clear way. Moreover, it is better for the authors to further emphasize the importance of combined application of organic amendments and biostimulants in helping the reduction of the anthropogenic pressure due to synthetic fertilizers and chemicals and the enhancement of the field crops.

OR: As for the abstract, also for Introduction we have emphasized this aspect and added a new reference.

RC: In the Materials and Methods part, the related indices of the environmental impact under the conditions of combined application of organic amendments and biostimulants to the egg plants. Correspondingly, these related results and discussion should be mentioned in the Results part and the Discussion part.

OR: This comment is not clear to us. If you refer to Figure 3 on the trend of minimum and maximum temperatures, in our opinion, it is correctly commented in Material and methods section, since temperature is not an experimental factor.

RC: In the Discussion part, the role of the soil type, eggplant cultivars and management practices, especially the irrigation should be also mentioned.

OR: W agree with you about the importance of these factors on plant growth and yield. However, since they were not our experimental factors and all plants, irrespective of treatments, were managed in the same way, we did not discuss the specific influence of these parameters.

Author Response File: Author Response.docx

Reviewer 2 Report

Comments and Suggestions for Authors

The manuscript is of good quality, although a much larger number of replicates should have been used to extract more information from the assay, especially about interaction between fertilization and use of biostimulants. Some work on the Material and Methods section should also be done to improve it and help understand the assay. Suggestions and other minor quibbles follow:

• Why are those results not shown? The article is not particularly long…
• Material and Methods should be amplified and reorganized to clarify the experimental design (two-factor with three replicates) and to provide all needed information and data, such as:
  • What fraction of soil P2O5 and K2O?
  • Solid-fraction of digestate?
  • What solid residues?
  • Why a table showing most important analytical properties of both fertilizers is not provided?
  • How N rates were calculated? (organic products do not mineralize on a single crop cycle) Also, how P and K were managed?
  • The paragraph on statistical analysis should be improved

Author Response

RC: The manuscript is of good quality, although a much larger number of replicates should have been used to extract more information from the assay, especially about interaction between fertilization and use of biostimulants. Some work on the Material and Methods section should also be done to improve it and help understand the assay. Suggestions and other minor quibbles follow:

OR: Dear reviewer, we thank you very much for your valuable revision. Below, you can find the responses point by point to your comments and, in the text, the required changes as track changes.

• RC: Why are those results not shown? The article is not particularly long…

OR: Plant height values were added to Table 1.

• RC: Material and Methods should be amplified and reorganized to clarify the experimental design (two-factor with three replicates) and to provide all needed information and data, such as:

OR: Dear reviewer, as you suggested, we modified the paragraph 4.1 Plant material, growth condition, and experimental treatments, we hope that the experimental design will be better described.

• RC: What fraction of soil P2O5 and K2O?

OR: The soil content of the main macronutrients is reported at lines 311-312 of the revised version of the manuscript.

• RC: Solid-fraction of digestate?

OR: We thank the reviewer for this comment. “A solid digestate” was specified only at line 297 of the original manuscript, and it is better specified now.

• RC: What solid residues?

OR: Sorry for the mistake, we have now specified that compost was produced by the organic fraction of urban solid residues (line 317).

• RC: Why a table showing most important analytical properties of both fertilizers is not provided?

OR: We thank the reviewer for this suggestion. We added more information in the text (please see lines 315-320).

• How N rates were calculated? (organic products do not mineralize on a single crop cycle) Also, how P and K were managed?

OR: Dear reviewer, in the original version of the manuscript we had already written that the nitrogen dose was calculated using the Fertilization Plain of Campania Region (Consulenza alla concimazione); however, we re-arranged the sentence adding new information. In addition, at lines 307-309, we specified no adding phosphorus and potassium due to their high content in the trial soil.

• RC: The paragraph on statistical analysis should be improved

OR: Thanks for the suggestion, we re-arranged this paragraph.

Author Response File: Author Response.docx

Round 2

Reviewer 1 Report

Comments and Suggestions for Authors

It is better for the authors to check all of the manuscripts carefully and make the readers  read the manuscript smoothly.

Author Response

We thank the reviewer for his last suggestion.

The paper has been read carefully and some corrections have been done to improve readability.

Best regards

Author Response File: Author Response.docx