Effects of Water Management and Rice Varieties on Greenhouse Gas Emissions in Central Japan

Round 1

Reviewer 1 Report

1)      Pls include a new Table for initial soil characteristics data of your expt.

2)      In MM section, Pls mention some important parameters (growth duration, yield potential, etc) of the tested varieties

3)      Pls use a dynamic graph (line graph) instead of a bar graph for dynamic gas emissions. It would be more scientific if you convert the bar graph (Fig 2) to a line graph.

4)      I think Table 1 and Fig.3 is similar, better to remove Table 1. Similarly, remove Tables 2 and 3.

5)      You got very low cumulative CH4 emissions, which is about 8 kg/ha in AWD and about 60-65 kg/ha in CF condition in Table 4. In contrast, you got abnormally higher N2O emissions under AWD irrigation (Table 4). Pls check the cumulative calculation formula. However, if it happens, pls try to support your low-emission data with the findings who also got similar findings.

6)      Pls check ref carefully.

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Reviewer 2 Report

Lines 37-38 : How does AWD irrigation improve soil microbial biomass carbon and nitrogen? Increase or decrease? Explain details.

Lines 39, 43 : 15%, 11% mean an average? If so, add standard deviation as reliable estimates.

Lines 45-51 : Complex and unclear; Re-write.

Line 79 : a capital letter should be used for "S"ativa  

Line 88 : "f"armyard (10 "metric ton" ha^-1)

Line 91 : add the year September 30th, 2022.

Line 105 : before an analytical intrument, use "a Gas Chromatograph"

Line 113 : T shoud be "a representative (e.g., mean)" temperature ...

Line 123 : What is the specific period (Line 119) for the GWPs of methane and nitrous oxide? Specify.

Line 132 : There are various categories in ANOVA test. What kind of ANOVA (analysis of variance) test did the authors use? Specify.

Lines 134-135 : What kind of probability is 0.05? It must be "at a 95% confidence level" or "at a 5% level of "significance".

Lines 175, 199 : at a 5% level of "significance"

Line 231 : Despite no observable signficant differences in GHG emissions and GWP, explain and discuss the known differences between the two rice varieties used in this study (e.g., genetic, morphological, etc.) with references. 

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Reviewer 3 Report

MS. Ref.: soilsystems-2589273

Title: Effects of Water Management and Rice Varieties on Green house Gas Emissions in Central Japan

Authors: Sunchai Phungern, Siti Noor Fitriah Azizan, Nurtasbiyah binti Yusof and Kosuke Noborio

The research is about Greenhouse Gas (GHG) emissions depending on water management practices and the rice varieties used from paddy fields by Lysimeter experiments.

However:

1. The abstract should state the purpose of the research, the principal results, and significant conclusions. An abstract is often presented separately from the article, so it must be able to stand alone. 

2. It is nice to have a paper structure at the end of the Introduction section.

3. Please explain more about the "lysimeter facility."

4. What is "A 2 x 2 factorial experiment"?

5. Need to include additional recent research for references.

6. Is there any related/similar study with the same dataset/method for comparison?

7. Please add an additional statement to provide insight for future work analysis, which can facilitate researchers to search and browse future works in a research area.

8. Related to "Figure 1c-d", there are other methods related to using IoT (Internet of Things) technology, which can also be included for related comparison.

Text and writing style seem easier to understand by the student with similar research area but may not be easy for other researchers that interested to read.

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Reviewer 4 Report

Overall, the paper is well-structured and thoroughly reviews existing literature on the topic. The authors present a balanced view by acknowledging AWD's potential benefits and drawbacks. While the article provides valuable insights into the effects of water management techniques and rice varieties on greenhouse gas emissions, several potential limitations could be considered:

Geographical Limitations: The study is conducted in Central Japan, and the results may not apply to other regions with different climate conditions, soil types, and rice varieties.

Potential Impact on Rice Yield: While the paper discusses studies showing that AWD can maintain or even increase rice yield, it also acknowledges that some studies suggest AWD may reduce rice yields. More research may be needed to understand under what conditions AWD might reduce yields. There are several alternative water management techniques for rice farming which may be discussed as well.

Increase in Nitrous Oxide Emissions: The paper mentions that AWD can increase nitrous oxide emissions. This is a potential drawback of AWD that needs to be further investigated.

Lack of Discussion on Practical Implications: The paper could benefit from discussing the practical implications of its findings for farmers and policymakers.

These limitations do not necessarily undermine the value of the study but highlight areas where further research could be beneficial.

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

This paper might be improved after addressing some comments. Still, it needs some improvement. Although you mentioned in the revision note that you had incorporated a dynamic line graph,  I could not get any dynamic line graph for CH4, N2O and CO2 that I mentioned in my review comments. As earlier, you presented a column graph, but it may lose the scientific content of the paper. It should be incorporated. In addition, you mentioned that CO2 emissions are negative in both irrigations (Fig 3). Most previous studies showed that CO2 emission is positive, even though it gave a higher value in AWD irrigations than CF. Pls explain all the issues scientifically.

Author Response

Please see the attachment.

Author Response File: Author Response.docx