The Usefulness of Ozone-Stabilized Municipal Sewage Sludge for Fertilization of Maize (Zea mays L.)

Round 1

Reviewer 1 Report

the work is well written, easy to follow and gives the necessary details. The results are consistent and well discussed, with updated literature. The points to improve are related to the methodology, where extra information should be added (see attached file) and the discussion should add a paragraph referring to the limitations of the work (see attached file). Thank you very much for the good work presented and contribution to the scientific community. If possible, it would be ideal if a photo of the essay could be added.

Comments for author File: Comments.pdf

Author Response

Dear Reviewer,

we are thankful for your reasonable opinion and valuable comments. Our responses to all comments are presented in the attachment.

Best regards

Authors

Author Response File: Author Response.pdf

Reviewer 2 Report

This manuscript “The usefulness of ozone-stabilized municipal sewage sludge for fertilization of maize (Zea mays L.)” by Szostek et al. reports important findings of the use of ozonated-sludge as fertilizer for maize crop growth improvement. The authors observed improvement in soil fertility and plant growth parameters. The findings of this study are important for the valorization of sewage sludge and its use as soil amendment material. However, the manuscript requires extensive English revision. It is recommended for the authors to consider the following points carefully during their revision.

 

1. Carefully revise the entire manuscript for language and grammatical errors. See the PDF file.
2. Avoid using long sentences. The tendency is that you may end up using a word more than the required number of times in a sentence. For example, you over abused the use of “the”. Check the edited manuscript for more examples.
3. Stick to the use of either the symbol of an element or the full name. For example, nitrogen or N.
4. In the result section, the authors failed to indicate how the basic properties of the soil were determined.
5. The authors are encouraged to report their results such that each subsection is supporting the preceding one. For example, after analyzing the micro-and macronutrient contents of sludge in 3.1, subsection 3.2 should analyze/report plant growth parameters and show a direct link with the properties of sludge. The same analogy applies to 3.3, 3.4, etc. This will help readers to understand and make a link between the observed growth, photosynthetic, and other parameters with properties of sludge (since soil properties were not analyzed after harvest).
6. The discussion section is not coherent. The authors should discuss and relate their results with previous literature such that; (i) improved nutrient content by sludge is seen as a reason for improved plant growth parameters, (ii) a relationship is observed between specific nutrients such as N, P, and Mg and plant photosynthesis (chlorophyll content), (iii) the importance of the organic matter in soil properties and plant water use efficiency is observed and should be discussed in relation to recorded growth parameters, (iv) variations in heavy metal uptake (as discussed in lines 560-595).
7. These suggestions are meant to stimulate the authors’ ability in revising their manuscript for better readability and understanding. Most of what is required are within the manuscript but not well connected.

Comments for author File: Comments.pdf

Author Response

Dear Reviewer,

we are thankful for your reasonable opinion and valuable comments. Our responses to all comments are presented in the attachment.

Best regards

Authors

Author Response File: Author Response.pdf

Round 2

Reviewer 2 Report

The authors have carefully addressed all the concerns and suggestions. The manuscript is recommended for publication.