Dry-Aggregate Stability and Soil Nutrients Responses to Reapplication of Biochar and Organic/Inorganic Fertilizers in Urban Vegetable Production
Round 1
Reviewer 1 Report
The manuscript can be accepted after minor revisions:
The title of the research is written in a vague and incorrect way. The author should review it carefully.
The aim of the work should be highlighted at the end of the introduction part.
It is better for the readers to combine the obtained results with their discussions with no separation.
All figures should be redrawn to enhance their resolutions and to be more readable
Figures 2, 3, 4, and 5 should be combined in one figure.
The conclusion needs to be rewritten to have more quantitative data.
Author Response
The title of the research is written in a vague and incorrect way. The author should review it carefully.
The manuscript title has been rewritten for clarity.
The aim of the work should be highlighted at the end of the introduction part.
The aim of the study precedes the study hypothesis, but the reviewer suggested otherwise. We do not agree with this suggestion as it is not specified in the review guideline. We prefer to leave it in its current arrangement because the purpose of the study gives expression and clarity to the study hypothesis.
It is better for the readers to combine the obtained results with their discussions with no separation.
According to the stipulated 'instructions for authors', the 'results' and 'discussion' sections should appear separately in all research manuscript types. Thus, we followed the guidelines in preparing our manuscript.
All figures should be redrawn to enhance their resolutions and to be more readable
We think that the resolution of the figures in its present form is adequate.
Figures 2, 3, 4, and 5 should be combined in one figure.
We appreciate your suggestion to combine figures 2, 3, 4 and 5. However, the individual representation makes each figure clearer and easier to understand.
The conclusion needs to be rewritten to have more quantitative data.
We have included some quantitative data in the conclusion section. Thank you.
Reviewer 2 Report
In my opinion the research methodology is not appropriate. The experiment was set up at the site of previously conducted research. I suppose that in 2016 the soil properties in individual fertilization objects differed significantly, which results from the previously used fertilization (in 2014-2016). This is particularly clear at the NPK object, which was established after two-year UCF application. However, in the case of CCB and UCF, the authors assess changes in soil properties not after two, but after four years of fertilization. Additionally, the experimental design does not include the control object.
Therefore, the research methodology must be completed with information on soil properties before establishing the second phase of the experiment for individual fertilization objects. Without this information, the effect of particular fertilizers on changes in soil properties cannot be evaluated. It is also impossible to compare the effect of individual fertilizers on soil properties. Therefore, in present forms, the manuscript is a report from research and not an original research paper.
Detailed comments
1. What doses of CCB and UCF were used in the combination CCB + UCF?
2. Table 1 should be changed:
second column - no need to write Fertilizer-C, Fertilizer-N etc. only element symbol is enough, ie C, N, P, K, Ca, Mg;
I propose to add one column in which the content of individual elements in fertilizers in gkg-1 DM will be given
Express phosphorus and potassium content in NPK fertilizer as P and K and not as oxides; it is necessary to add biochar (CCB) to the table - chemical composition and amount of particular elements per 1 ha
There is no need to explain the chemical symbols below the table
3. Line 170: "and cattle manure was at 12 t DM ha−1 per crop" - per crop or per year?
4. Figure 1: in the case of Mma - it is not possible to highlight the homogeneous groups "ac" and "bc", and where is the group "c"?
5. Line 284 and 324 "percentile TC concentration" and "The percentile contribution ..." - percentile? or percentage?
6. Line 365-366: "This further suggests that much of the labile and absorbable forms of P were probably not utilized effectively by the cultivated vegetables." This is not true, it indicates that the amount of phosphorus introduced into the soil with fertilizer was higher than the nutritional needs of the plants and P accumulated in the soil.
7. Line 373-375: "… and the acidifying power of accumulated PO43-, which is reflected in the highly retained available P following the two-year fertilizer application". This is not true PO43- ions and the accumulated available forms of phosphorus do not acidify the soil
8. There is no need to explain of fertilizer combinations or chemical symbols under the tables and figures
9. Figure 2-5: What do the error bars mean - standard error or standard deviation?
10. Citation:
Line 82 is Horák et al. 2020 in References is Horák et al. 2019
Line 86 and 179 is Hearing et al. 2017 – lack in References
Line 105 is Tripathi 2016 in References Tripathi et al. 2016
Line 160 and 167 is MankaAbusi et al. 2019 in References Manka’abusi et al. 2019
Line 389 Hussain et al. 2017 – lack in References
Below Table 1 is MankaAbusi et al. 2022 – lack in References
Author Response
Detailed comments
- What doses of CCB and UCF were used in the combination CCB + UCF?
The combination of their individual doses was used. The CCB was applied at 20 t ha-1 (page 4; line 170) while the application of urea fertilizer was at a rate of 107 kg ha−1 and cattle manure was at 12 t DM ha−1 per crop (page 4; line 176 and 177).
- Table 1 should be changed:
second column - no need to write Fertilizer-C, Fertilizer-N etc. only element symbol is enough, ie C, N, P, K, Ca, Mg;
The correction has been made. Thank you.
I propose to add one column in which the content of individual elements in fertilizers in gkg-1 DM will be given
Yes, the column with fertilizer element in g kg -1 has been inserted.
Express phosphorus and potassium content in NPK fertilizer as P and K and not as oxides; it is necessary to add biochar (CCB) to the table - chemical composition and amount of particular elements per 1 ha
The P and K content in NPK fertilizer have been expressed as P and K elements and the requested information for corncob biochar has been added in Table 1.
There is no need to explain the chemical symbols below the table
The chemical symbols below Table 1 have been deleted.
- Line 170: "and cattle manure was at 12 t DM ha−1 per crop" - per crop or per year?
It is per crop.
- Figure 1: in the case of Mma - it is not possible to highlight the homogeneous groups "ac" and "bc", and where is the group "c"?
Yes, you are right. We have corrected the error. Thank you.
- Line 284 and 324 "percentile TC concentration" and "The percentile contribution ..." - percentile? or percentage?
Percentage is correct. Thank you.
- Line 365-366: "This further suggests that much of the labile and absorbable forms of P were probably not utilized effectively by the cultivated vegetables." This is not true, it indicates that the amount of phosphorus introduced into the soil with fertilizer was higher than the nutritional needs of the plants and P accumulated in the soil.
Yes, we agree and have made the correction. Many thanks.
- Line 373-375: "… and the acidifying power of accumulated PO24-, which is reflected in the highly retained available P following the two-year fertilizer application". This is not true PO43- ions and the accumulated available forms of phosphorus do not acidify the soil
The assertion has been deleted. Thank you.
- There is no need to explain of fertilizer combinations or chemical symbols under the tables and figures
The chemical symbols below the tables and figures have been deleted.
- Figure 2-5: What do the error bars mean - standard error or standard deviation?
They are standard error bars.
- Citation:
Line 82 is Horák et al. 2020 in References is Horák et al. 2019
The cited reference (Horák et al. 2020) has been corrected.
Line 86 and 179 is Hearing et al. 2017 – lack in References
Hearing et al. 2017 has been corrected to Häring et al. 2017.
Line 105 is Tripathi 2016 in References Tripathi et al. 2016
The cited reference (Tripathi 2016) has been corrected.
Line 160 and 167 is MankaAbusi et al. 2019 in References Manka’abusi et al. 2019
MankaAbusi has been corrected to Manka’abusi.
Line 389 Hussain et al. 2017 – lack in References
The reference has been added. Thank you.
Below Table 1 is MankaAbusi et al. 2022 – lack in References
The reference has been deleted.
Reviewer 3 Report
The paper entitled "Responses of soil nutrients, dry-aggregate stability and aggregate carbon and nitrogen to repeated application of biochar and organic/inorganic fertilizers in urban vegetable production" focuses on the impact of biochar and organic/inorganic fertilizers on some chemical-physical indicators of the soil. Although the manuscript is clearly written and structured, authors are advised to review some aspects. First of all, the title. It is too long and unattractive.
As regards materials and methods, it is recommended to insert a bibliographic reference relating to the fractionation method. Why was sonication not considered as procedure for the determination of macro and micro aggregates as the authors of the paper "Chemical and Spectroscopic Investigation of Different Soil Fractions as Affected by Soil Management" did?
Furthermore, authors in the “treatment presentation” write that wastewater was used for irrigation. Why does this thesis not appear in the results and discussions?
Have the main pollutants (heavy metals or emerging contaminants) of these waters been determined? If so, it would be interesting to evaluate their interaction with different fertilizations.
In order to better appreciate the results obtained, it would be advisable to insert the characterization of the control soil. The absence of this data is a serious problem.
Finally, it is suggested to insert the significance letters to table 2 to make understanding more immediate.
For these reasons, the manuscript needs major revisions.
Author Response
Comments and Suggestions for Authors
The paper entitled "Responses of soil nutrients, dry-aggregate stability and aggregate carbon and nitrogen to repeated application of biochar and organic/inorganic fertilizers in urban vegetable production" focuses on the impact of biochar and organic/inorganic fertilizers on some chemical-physical indicators of the soil. Although the manuscript is clearly written and structured, authors are advised to review some aspects. First of all, the title. It is too long and unattractive.
Yes, we agree with you. The title has been shortened.
As regards materials and methods, it is recommended to insert a bibliographic reference relating to the fractionation method.
The reference has been included.
Why was sonication not considered as procedure for the determination of macro and micro aggregates as the authors of the paper "Chemical and Spectroscopic Investigation of Different Soil Fractions as Affected by Soil Management" did?
Sonication was not considered because of lack of a sonicator. So, we made use of what is available in our laboratory.
Furthermore, authors in the “treatment presentation” write that wastewater was used for irrigation. Why does this thesis not appear in the results and discussions?
The waste water analysis was not carried out by the author. More so, the elemental concentrations of the clean and waste water have been documented. This information is recorded on page 5, line 190, 191.
Have the main pollutants (heavy metals or emerging contaminants) of these waters been determined? If so, it would be interesting to evaluate their interaction with different fertilizations.
The waste water was rather dilute so that nutrient and pollutant inputs were similar to those with clean water (Manka'abusi et al. 2019)
In order to better appreciate the results obtained, it would be advisable to insert the characterization of the control soil. The absence of this data is a serious problem.
The soil characterization of the control soil (before addition of ECOSAN amendment) has been included. Thank you.
Finally, it is suggested to insert the significance letters to table 2 to make understanding more immediate.
The 'significance' letters to differentiate means have been inserted. Thank you.
Round 2
Reviewer 2 Report
The authors revised the manuscript according to the comments. The manuscript can be accepted in present form.
Author Response
Thank you.
Reviewer 3 Report
Dear Authors,
I believe there are still some minor revisions needed before publishing the article.
If wastewater is diluted, it should be written in the manuscript specifying the dilution ratio. Also I believe there are some problems with the letters of significance. I suggest doing the statistical analysis again. For example, in table 2, the TN values relating to the NPK and CCB treatment (0.05 vs 0.07) are not significantly different.
Best regards
Author Response
I believe there are still some minor revisions needed before publishing the article.
If wastewater is diluted, it should be written in the manuscript specifying the dilution ratio.
The requested information has been captured in the manuscript. (page 5, line 194-196 ). However, there is no specific dilution factor as the wastewater is discharged into a lake, which then serves as the source of the irrigation water. During dry season, the dilution is thus lower than during wet season.
Also I believe there are some problems with the letters of significance. I suggest doing the statistical analysis again. For example, in table 2, the TN values relating to the NPK and CCB treatment (0.05 vs 0.07) are not significantly different.
Yes, the narrowing down to two decimal places of the mean value for the NPK treatment was erroneously recorded. This as well as the letters of significance have been corrected. Many thanks.
Sample Biochar ECOSAN NPK NPK+Biochar
0.0530 0.0826 0.0748 0.1155
