Influence of Pig Slurry Application Techniques on Soil CO2, N2O, and NH3 Emissions
Round 1
Reviewer 1 Report
The present manuscript entitled "Pig Slurry Application Techniques Affect Soil CO2, N2O, and NH3 Emissions" by Eszter Tóth, Márton Dencső, Ágota Horel, Béla Pirkó, and Zsófia
Bakacsi (sustainability-1865709) is written correctly and has a good structure; moreover, it has all the necessary parts. The article is interesting from an environmental and sustainability point of view; therefore, it should interest the reader. The paper meets Sustainability requirements, and I recommend the article for publication in Sustainability following the common editing stage. My current decision is a minor revision. More specific comments and observations are presented below.
1. Title. I suggest a slight change in the title to "Influence / Investigation of ... on ...".
2. Introduction. A paragraph regarding the techniques used to measure CO2, N2O, and NH3 may be added.
3. Sometimes, the unit is at the value, and sometimes it is separate (page 4, line 151).
4. Section 2.4. A detailed description of the methods should be added, not just a reference.
5. Page 4, line 183. Measurement parameters related to the spectrophotometer should be added.
6. Page 10, line 367. Authors mentioned “interfere soil emissions”. What can be done in the event of such disruptions?
7. Conclusion. Please, emphasize clearly the advantages of the research carried out.
8. References. I found a lot of typos. The journals are saved once as abbreviations and once as full names. Indexes are not used for chemical formulas. Please check with journal requirements.
I hope that the comments presented will help improve the article.
Author Response
Response to Reviewer
Dear Reviewer,
Thank you for your valueable comments on „Pig Slurry Application Techniques Affect Soil CO2, N2O, and NH3 Emissions” article. Attached you can find our responses and modifications.
Comment 1: Title. I suggest a slight change in the title to "Influence / Investigation of ... on ...".
Response: Thank you for the advice, we modified the title (line 3).
Comment 2: Introduction. A paragraph regarding the techniques used to measure CO2, N2O, and NH3 may be added.
Response: We added a concise paragraph of soil chamber methods, which are the most common techniques of soil derived CO2, N2O and NH3 emissions (lines 53-60).
Comment 3: Sometimes, the unit is at the value, and sometimes it is separate (page 4, line 151).
Response: We corrected the typos (lines 197, 204).
Comment 4: Section 2.4. A detailed description of the methods should be added, not just a reference.
Response: A brief description is added to section 2.4 (lines 214-223).
Comment 5: Page 4, line 183. Measurement parameters related to the spectrophotometer should be added.
Response: We indicated the measurement details of the spectrophotometer (lines 230-232).
Comment 6: Page 10, line 367. Authors mentioned “interfere soil emissions”. What can be done in the event of such disruptions?
Response: We rephrased the sentence, so it can be clearer for the reader and consists more details (lines 429-431).
Comment 7: Conclusion. Please, emphasize clearly the advantages of the research carried out
Response: We added an additional paragraph to conclusion section (lines 492-499).
Comment 8: References. I found a lot of typos. The journals are saved once as abbreviations and once as full names. Indexes are not used for chemical formulas. Please check with journal requirements
Response: We corrected the typos in the References part.
Author Response File: 
Author Response.pdf
Reviewer 2 Report
In this paper the authors present the short-term effect of pig slurry application methods of spreading and injection on soil greenhouse gas and NH3 emissions under different irrigation amounts. It is an interesting paper, well written, but some aspects must be further detailed in order to be published.
1. You must provide supplementary details regarding the initial characteristics of the soil used – volumetric water content, porosity, etc.
2. You must specify how the injection have been performed – at which depth.
3. You didn’t used a zero-control soil column? Why?
4. Define Ts.
5. You should include the limitations of your study, why is your study important and also provide some directions/ideas for further research.
Author Response
Response to Reviewer
Dear Reviewer,
Thank you for your valueable comments on „Pig Slurry Application Techniques Affect Soil CO2, N2O, and NH3 Emissions” article. Attached you can find our responses and modifications.
Comment 1: You must provide supplementary details regarding the initial characteristics of the soil used – volumetric water content, porosity, etc.:
Response: Thank you for the suggestions. We inserted an extra table (Table 2) with description providing soil texture, bulk density and porosity and initial VWC of the applied soil (lines 153-155).
Comment 2: You must specify how the injection have been performed – at which depth.
Response: We gave a more detailed method description of injetcion and spreading pig slurry application methods in the paragraph (lines 164-167).
Comment 3: You didn’t used a zero-control soil column? Why?
Response: The main goal of our study was to compare the effect of pig slurry application methods on the different gas emissions, especially on NH3 emissions. Regarding further possible researchs, when the GHG emission change is being investigated rather than the effect of application methods on GHG emissions, we are agree with the reviewer and will consider zero controls as baseline measurements.
Comment 4: Define Ts.
Response: The definition can be seen in line 99, Ts means soil temperature.
Comment 5: You should include the limitations of your study, why is your study important and also provide some directions/ideas for further research.
Response: Thank you for the comment. We added a supplementary paragraph to the Introduction and the Conclusion section (lines 112-114 and lines 492-499).
Author Response File: Author Response.pdf
Reviewer 3 Report
This study presented valuable data to explore how the pig slurry application techniques (spreading and injection) under normal, extreme, and non-irrigated treatments affected soil CO2, N2O, and NH3 emissions.
The topic of this study is interesting. The study was well designed, the data analysis robust, the discussion to the point, and overall the paper is well written. The novel finding of pig slurry application techniques affects soil CO2, N2O, and NH3 emissions in such a way that pig slurry injection decreased NH3 Emissions under dry conditions and should not be limited in terms of CO2 and N2O emissions under normal irrigation or higher precipitation conditions.
Some comments are listed below.
1. Enhance the discussion of pig slurry application methods linked with other types of organic fertilizers application locally and globally. What are the differences in effects of methods under dry and irrigation, and the differences in effects under normal and extreme irrigation treatments?
2. Strengthen the discussion of GHG and NH3 Soil Emission mechanisms under pig slurry application techniques/irrigation strategies.
3. Line 17: I think the word "technique" and" methods” are used interchangeably here and someplace in the paper. Please would you use either of them throughout the paper?
4. Line 21: Use En dash between------ (213 and 338%, 250 and 594%).
5. Table 1. Move “Ntot refers to total nitrogen content, SOC is the soil organic carbon content, NH4-N is am-117 ammonium-, and NO3-N is nitrate-nitrogen contents” from table title to table caption. Also, use En dash between 0 and 25 cm and 25 and 60cm.
6. Table 2. I would suggest the title of this table as “Description of the study treatments (slurry application techniques and irrigation strategies)”. Then move the explanation of the abbreviations (S: surface spreading, I: soil injec-150 tion), D: dry condition with no water additions, N: 500ml and E: 151 - 1000 ml water added at given days) to the table caption. Delete the row with slurry application methods and irrigation treatments.
7. Table3. Similarly, move “S: spreading application method, I: injection application method, D: no irrigation (0 mm tap water), N: regular irrigation with 15.9 mm tap water, E: regular irrigation with 31.8 mm tap water, different small letters indicate a significant difference between treatments” to table caption. Please specify in which case (within the same row, column, or both) small letters indicate a significant difference between treatments. Also, what is the value next to each mean stands for (SE and SD?) please specify in the table caption. I think it is better to give the full name of treatment abbreviations in each table and figure.
8. Authors showed the dynamic variation of soil chemical properties due to spreading and injection techniques with different irrigation strategies under different depths in Fig.2. But the combination of factors used for symbols in the legend of the figure was confusing. So, I would suggest:
1. Organize this figure under two named columns i.e. Spreading and Injection, with only one legend for all (a to h) panels. For example, under column 1 a, c, e, and g, named “Spreading” at the top (above a panel), and column 2 b, d, f, and h naming as “Injection at the top (above b panel). Then avoid the inclusion of S and I in the legend symbols and have a single (the same) symbol for each of the treatments. For example D0-5, N0.5, E0.5 …E0-55.
2. Please could you use the measure of variability on the top of the bar for each treatment (if it was replicated) so that it will be easy to know the statistical difference among together tested treatments.
Author Response
Please see the attachment.
Author Response File: Author Response.pdf
