Dairy Effluent-Saturated Biochar Alters Microbial Communities and Enhances Bermudagrass Growth and Soil Fertility

Round 1

Reviewer 1 Report

Thank you for submitting the manuscript. The experiment was conducted in an appropriate manner, well described, and analysed.

• The authors mention economic aspect of BC application. It would be beneficial to mention prices with this regard, and to estimate economics of BC loading with diary effluent.
• I find the article title rather complicated. I would recommend to simplify it, and to avoid using a verb.
• Automatic references to some figures should be obviously corrected.
• In Figure 5A and Figure S 4, the captions “NP-I” and “NP-F” mean “no plants – initial” etc. I would find beneficial for readers to mention it.

Author Response

Responses to Reviewer #1’s comments

Thank you for submitting the manuscript. The experiment was conducted in an appropriate manner, well described, and analyzed.

[Response]                                                                                                                            

Thank you so much for your comments on our manuscript. Based on your suggestions, we thoroughly revised our manuscript for enhancing the quality of this manuscript. Our revision in the revised manuscript was made with track-changes.

1) The authors mention economic aspect of BC application. It would be beneficial to mention prices with this regard, and to estimate economics of BC loading with diary effluent.

[Response & Action]

• Currently commercial wood biochar has been used for agronomic applications, and the price of commercial wood biochar ranges $300-$600/ton of biochar ($400/ton of biochar as an average price).

• It is not easy to evaluate possible price of dairy effluent-saturated wood biochar at this moment. However, since the dairy effluent-saturated biochar contained additional nutrients (particularly N, P, K and micronutrients such as Ca, Cu and Mn) compared with the pristine wood biochar, possible price of dairy effluent-saturated wood biochar would be higher than the pristine wood biochar.

• The revision is made in red/track-change on line 354-358:

However, accurate economic assessment for agronomic applications of SBC and UBC will be made after  large scale use on farms. Nonetheless, since SBC contained greater concentration of nutrients than UBC, possible price of SBC would be higher than that of UBC ($300-600/ton of biochar, average price of $400/ton of biochar).

2) I find the article title rather complicated. I would recommend to simplify it, and to avoid using a verb.

[Response]

Upon the reviewer’s suggestion, we change current title to the below:

Dairy effluent-nutrient loading and application rates of wood-derived biochar for Bermudagrass growth, soil fertility and microbial communities

3) Automatic references to some figures should be obviously corrected.

[Response]

We removed automatic references from the manuscript.

4) In Figure 5A and Figure S 4, the captions “NP-I” and “NP-F” mean “no plants – initial” etc. I would find beneficial for readers to mention it.

[Response]

We added the abbreviations for these terms in Figure 5.

Author Response File: Author Response.docx

Reviewer 2 Report

I think that the presented work is attractive and the manuscript has enough scientific content. However, it requires some editorial work (for example removing double spaces, adding missing information about the authors) and minor English corrections. I have found some mistakes in the text like “(Error! Reference source not found.).”

 I would suggest it be published after revisions as below:

1. The information from lines 141-142 (used Bermudagrass (Cynodon ) to evaluate the effects of BC on plant growth because it is widely cultivated around dairies in north Texas as a forage) should be included in the Introduction as a reason for choosing this particular plant. .
2. Line 145 – You do not need to make an abbreviation "RO" for “reverse osmosis” because those words were used only once in this paper.
3. Line 233 – “saturation of BC” – it has been already as abbreviated to "SBC" and I would suggest that it is kept consistent throughout the manuscript
4. Line 247 – Please change to “increased as follows:” In the table there is a lack of information about the measurement parameters in SBC. Please add this information or confirm why the data is not shown.
5. Table 1. – There is a missing word– “Water holding capacity (mL water/100g dry material).
6. Is there no difference in the content of N (SBC) compared to the control? There are missing units in Figure 2: Percent increase (%), Biochar ratio (%).
7. Lines 271-274 The sentences require editing.
8. Line 282 – “saturated BCs” have been already as abbreviated to SBC, the same for “unsaturated BCs” – just to ensure consistency throughout the manuscript
9. Lines 283-287 – These sentences are better fitted for the Discussion section or the Conclusion
10. Labels in Figure 5A are not well visible.
11. The caption 4.1. requires corrections

• 346 – BC instead WBC
• Concentrations of macro and micronutrients are the chemical properties of soil (not physicochemical properties of soil).
• Both UBC and SBC increased the content of N and P in the soils
• There is a lack of discussion about change of pH/EC in soils.

Author Response

Please see the attachment.

Author Response File: Author Response.docx