A Comprehensive Benefit Evaluation of the Model of Salt-Tolerant Crops Irrigated by Mariculture Wastewater Based on a Field Plot Experiment

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

This study explores the reutilization of mariculture wastewater for irrigating halotolerant rice, positing its potential to ameliorate environmental degradation while enhancing agronomic output. The findings indicate a 9.01% yield augmentation and enrichment of edaphic nutrients under wastewater irrigation, alongside a remarkable 188.8% escalation in ecosystem service value relative to freshwater irrigation. While the research underscores notable synergies between aquaculture byproducts and agronomy, the constrained experimental parameters may limit extrapolation. Further empirical scrutiny is warranted to substantiate this integrative irrigation paradigm’s longitudinal viability and generalizability. Due to the relatively low-quality quality in presenting this work, a major revision has been reached before any consideration of acceptance.

1.      Please update your references and citations according to the MDPI standards. There are so many “Error! Reference source not found” throughout your manuscript.

2.      Using Grammarly or other grammar software, please filter out all typos and grammatical mistakes.

3.      Please further reduce your similarity to former publications using the iThenticate report in the attachment.

4.      Line 72: The following works could be reviewed and cited regarding the seawater intrusion-induced escalating chloride ion content (https://doi.org/10.3390/jmse12040690 and https://doi.org/10.3389/fmars.2024.1385517 ).

5.      Table 2: Please leave a space between values and units. Please fix the rest elsewhere.

6.      Lin 142: Why did you use deionised water for the freshwater experiments in comparative tests?

7.      Line 174: Please use minus signs instead of hyphens. Please fix the rest elsewhere.

8.      All figures are presented in a relatively low quality. You may intend to stretch them to cover the width of each page as you did to all tables. The resolution of them is still low.

9.      Did you have any soil tests for soil classification and fundamental soil properties?

10.  Line 232: No indentation should be ahead of “where”. Please fix the rest elsewhere.

11.  Having an abbreviation list and nomenclature is better after the conclusion chapter, as many abbreviations and equations exist.

12.  It would be good to have to measure precisions for all measurements in your methodological chapter.

13.  Lines 468-469: (11000 – 80000) = –69000? (11000 – 80000)/(6000 – 3000) = -13 RMB/(μS/cm•hm^–2), negative value? (14000 − 110000) = –96000? (14000 − 110000)/(12000 – 6000) = –16 RMB/(μS/cm•hm^–2), negative value, again? Please double-check your calculation in decimals throughout all your data calculations. Also, please update the yuan by RMB, the official representation of the Chinese yuan, for international recognition.

14.  Line 505: What is sej? Typo? Unit? Please check all your content word by word before the next submission.

15.  Table 12: You forget to superscript the minus and plus herein. Please fix the rest elsewhere.

16.  Lines 537 and 538: 28892.23 and 7,272.21. You can put a comma at a thousand or not, but the consistency of the value output must be maintained.

17.  Line 594: You can remove number (4) for this concluding part and additionally write up a reflection (reflecting your limitations) and prospects (future works) before re-highlighting your research contribution and significance.

 

18.  Please update your reference list using the MDPI Endnote style. 

Comments for author File: Comments.pdf

Comments on the Quality of English Language

Moderate edits.

Author Response

Thank you very much for taking the time to review this manuscript. Please find the detailed responses below and the corresponding revisions/corrections highlighted/in track changes in the re-submitted files.

 

Point-by-point response to Comments and Suggestions for Authors

Comments 1: Please update your references and citations according to the MDPI standards. There are so many “Error! Reference source not found” throughout your manuscript.

Response 1: We have updated all references and citations according to the MDPI standards. Please find the revision.

 

Comments 2: Using Grammarly or other grammar software, please filter out all typos and grammatical mistakes.

Response 2: We have checked the whole manuscript. The typos and grammatical mistakes have been revised.

 

Comments 3: Please further reduce your similarity to former publications using the iThenticate report in the attachment.

Response 3: We have made revisions according to the iThenticate report.

 

Comments 4: Line 72: The following works could be reviewed and cited regarding the seawater intrusion-induced escalating chloride ion content (https://doi.org/10.3390/jmse12040690 and https://doi.org/10.3389/fmars.2024.1385517 ).

Response 4: These two papers are reviewed and cited in this part. The seawater intrusion-induced escalating chloride ion content was reported in coastal regions of Southeast Queensland, Australia. 

Cao, W.; Yan, G.; Hofmann, H.; Scheuermann, A. State of the Art on Fe Precipitation in Porous Media: Hydrogeochemical Processes and Evolving Parameters. J. Mar. Sci. Eng. 2024, 12, 690. https://doi.org/10.3390/jmse12040690

Cao W, Hofmann H, Yan G and Scheuermann A (2024) Porewater exchange and iron transformation in a coastal groundwater system: a field investigation, driving mechanisms analysis, and conceptual model. Front. Mar. Sci. 11:1385517. https://doi.org/10.3389/fmars.2024.1385517

 

Comments 5: Table 2: Please leave a space between values and units. Please fix the rest elsewhere.

Response 5: Table 2 and other tables have been revised by leaving a space between values and units.

 

Comments 6: Lin 142: Why did you use deionised water for the freshwater experiments in comparative tests?

Response 6: Given that rice requires multiple irrigations during its growth process, we hope that the water source used for each irrigation can be consistent and controllable to facilitate subsequent comparative analysis.

 

Comments 7:  Line 174: Please use minus signs instead of hyphens. Please fix the rest elsewhere.

Response 7: In the revision, all the minus signs (−) are used instead of hyphens (-).

 

Comments 8: All figures are presented in a relatively low quality. You may intend to stretch them to cover the width of each page as you did to all tables. The resolution of them is still low.

Response 8: All figures are revised and stretched for the high resolution.

 

Comments 9:  Did you have any soil tests for soil classification and fundamental soil properties?

Response 9: The soil was from the coastal mudflats in Dongtai City, Yancheng, Jiangsu Province of China. We made soil test. The physical and chemical characteristics of the soil are showed in Table 1.

 

Comments 10: Line 232: No indentation should be ahead of “where”. Please fix the rest elsewhere.

Response 10: Revised. There are no indentations ahead of “where”.

 

Comments 11: Having an abbreviation list and nomenclature is better after the conclusion chapter, as many abbreviations and equations exist.

Response 11: We added an abbreviation list and nomenclature after the conclusion chapter.

 

Comments 12: It would be good to have to measure precisions for all measurements in your methodological chapter.

Response 12: We have checked and made revisions.

 

Comments 13: Lines 468-469: (11000 – 80000) = –69000? (11000 – 80000)/(6000 – 3000) = -13 RMB/(μS/cm•hm–2), negative value? (14000 − 110000) = –96000? (14000 − 110000)/(12000 – 6000) = –16 RMB/(μS/cm•hm–2), negative value, again? Please double-check your calculation in decimals throughout all your data calculations. Also, please update the yuan by RMB, the official representation of the Chinese yuan, for international recognition.

Response 13: Revised: the unit conductivity reduction benefit value of light saline soil  (110000 – 80000)/(6000 – 3000) = 10 RMB / (μS/cm•hm^-2), and the unit conductivity reduction benefit value of medium saline soil  (140000 − 110000)/(12000 – 6000) = 5   RMB/ (μS/cm•hm^-2). We have identified and corrected typographical errors within the numerical data presented. The official representations of the Chinese yuan are updated by RMB.

 

Comments 14:  Line 505: What is sej? Typo? Unit? Please check all your content word by word before the next submission.

Response 14: The units of emergy were defined as solar emjoules (abbreviated sej) for the emergy theory and methods. We added the presentation in the text.

 

Comments 15: Table 12: You forget to superscript the minus and plus herein. Please fix the rest elsewhere.

Response 15: The minus and plus herein are superscripted in the tables.

 

Comments 16: Lines 537 and 538: 28892.23 and 7,272.21. You can put a comma at a thousand or not, but the consistency of the value output must be maintained.

Response 16: Revised for the consistency of the value output.

 

Comments 17: Line 594: You can remove number (4) for this concluding part and additionally write up a reflection (reflecting your limitations) and prospects (future works) before re-highlighting your research contribution and significance.

Response 17: The conclusion chapter has been rewritten. Also, the limitations and prospects are added in the last part.

 

Comments 18: Please update your reference list using the MDPI Endnote style.

Response 18: The references are updated.

 

Response to Comments on the Quality of English Language

Point 1: Moderate edits.

Response 1: Thank you very much. We made revisions for the Quality of English Language.

 

Reviewer 2 Report

Comments and Suggestions for Authors

The paper presents the results of long-term natural application of mariculture wastewater for irrigation of seawater rice in laboratory conditions. The article also contains a large module with an economic assessment of the benefits of such use, which includes both economic and environmental aspects. The article deserves a general positive assessment; however, there are a number of minor remarks, which should be corrected to improve the paper.

1. References should be fixed throughout the text (Error! Reference source not found).
2. Although the abbreviations of some parameters are presented in the Abstract (for example, SOC, AK, etc.), in the main text of the article they should be presented at the first mention. I consider it appropriate to do this in the first column of Table 1.
3. It is advisable to adhere to uniform system units of area measurement throughout the text. I would consider it appropriate to use 1 ha instead of mu, acres (Table 5) and hm² everywhere.
4. In Table 2: 'Physical and chemical properties' in the title; names and abbreviations of parameters in the first column (as in Table 1).
5. Table 2: Please specify the type of mariculture wastewater, with salinity as low as 0.05% or 500 mg/L.
6. Subsection 2.2.1 (lines 147–161): It would be good to present the irrigation scheme over time: the water depth per irrigation and the frequency of irrigation.
7. Subsection 2.2.2 (lines 163–182): Considering that the number of replicates (N=3) is very small for bioindicative studies, it would be appropriate to present the methodology of statistical processing of the results, in order to check the significance of the differences between the obtained three series for different irrigation schemes.
8. Fig. 1 (p. 5): Small inscriptions on Fig. 1 are almost unreadable, try making them a little bigger.
9. Please, use in the text denotation pH instead of PH.
10. Subsection 2.2.3 (lines 183–343) is particularly large; I recommend that it be presented as a separate subsection 2.3, and if possible, shorten the commonly known explanations.
11. I would recommend presenting all economic calculations in US dollars or Euros.
12. Table 4: please, explain sej and sej/j; the joule should be J; UEV_w and Em_w have the same name, but different designations and units.
13. Fig. 2: add contrast in the captions for better readability.
14. Subsection 3.1:  why the theoretical rice yield of 427.8 kg/mu (line 347) does not correspond to the value given in Table 5.
15. Lines 350–353: two sentences are repeated twice in a row.
16. Fig. 3: Please add contrast to all labels, remove zeros after the decimal point, increase the font size on the legend.
17. Table 5: Irrigation mode, not Processing; Above ground biomass in g/pot? Where is 796.65 g from line 348? Is a theoretical yield in kg/Acres? Please, note what means a, b and ab.
18. Fig. 4–5: please, add contrast and increase the font size.
19. Table 5 and Table 6: It would be good to discuss in the text the result that 50/50 irrigation produced the minimum rice yield, rather than the average value between freshwater irrigation and wastewater irrigation. It is important whether this is a pattern obtained or just a scatter of results given the small number of replicates.
20. Table 6 and further: taking into account the significant deviations in experimental results, I consider it impractical to calculate economic parameters with an accuracy of 6–7 digits.
21. Table 10: The text does not explain the large difference between the organic matter accumulation in the bottom layer (BL) 61.89 g/pot vs 5.57 g/pot or 11 times, as well as the presence of a negative value in the middle layer for freshwater irrigation.
22. Conclusions: please do not number your conclusions; also try to summarize them.
23. References: All references should be presented in accordance with the requirements of the journal Agronomy.

Comments on the Quality of English Language

In general, the English language of the paper is of high quality. I have only a few minor remarks:

1. Please use the term 'respectively' when listing parameters in a sentence (e.g. lines 59, 420, etc.).

2. Table 1: not Metrics, better Parameters.

3. Lines 347–355: The same structure of simple sentences is repeated more than 10 times in a row in one paragraph. Please make the corresponding description more diverse.

Author Response

Thank you very much for taking the time to review this manuscript. Please find the detailed responses below and the corresponding revisions/corrections highlighted/in track changes in the re-submitted files.

 

Point-by-point response to Comments and Suggestions for Authors

Comments 1: References should be fixed throughout the text (Error! Reference source not found).

Response 1: Revised. All the references are fixed throughout the text.

 

Comments 2: Although the abbreviations of some parameters are presented in the Abstract (for example, SOC, AK, etc.), in the main text of the article they should be presented at the first mention. I consider it appropriate to do this in the first column of Table 1.

Response 2: We checked all the abbreviations of parameters and presented them at the first mention.

 

Comments 3: It is advisable to adhere to uniform system units of area measurement throughout the text. I would consider it appropriate to use 1 ha instead of mu, acres (Table 5) and hm2 everywhere.

Response 3: In the revision, we use Mu (1 Mu=667m²) as the main unit of area measurement for experimental data and individual benefit values calculation, except hm² for the unit of total benefit values.

 

Comments 4: In Table 2: 'Physical and chemical properties' in the title; names and abbreviations of parameters in the first column (as in Table 1).

Response 4: The title, names and abbreviations of parameters are revised in Table 2.

 

Comments 5: Table 2: Please specify the type of mariculture wastewater, with salinity as low as 0.05% or 500 mg/L.

Response 5: A salinity of 0.05% indicates that there are 0.05 grams of salt per kilogram of seawater.

 

Comments 6: Subsection 2.2.1 (lines 147–161): It would be good to present the irrigation scheme over time: the water depth per irrigation and the frequency of irrigation.

Response 6: Thank you very much for your suggestion. We added the irrigation scheme in this Subsection. The irrigation scheme in this study was an intermittent irrigation system with alternating shallow-wet-dry cycles. Except for maintaining a water level of 0−30mm during the early tillering stage, an intermittent irrigation system was adopted for the rest of the growth stages. Field drainage was implemented at the end of tillering, and water supply was cut off after the rice reaches the yellow maturity stage. ‘Shallow’ refered to maintaining a water layer of 20−30mm during each irrigation. ‘Wet and Dry’ meant allowing the field surface to naturally dry out without retaining water, with the soil's saturated water content rate at 80%−70% serving as the lower limit control indicator. The field was maintained with a thin layer of water or saturated soil moisture the day after each irrigation. Starting from the third day, the field was drained for two to three days. The next round of irrigation typically began four to six days later, and this cycle repeated until the rice reaches the yellow maturity stage and the field was dried.

 

Comments 7: Subsection 2.2.2 (lines 163–182): Considering that the number of replicates (N=3) is very small for bioindicative studies, it would be appropriate to present the methodology of statistical processing of the results, in order to check the significance of the differences between the obtained three series for different irrigation schemes.

Response 7: Thank you very much for your suggestion. We added the data analysis and statistical methods. For the experimental monitoring indicators, Excel was utilized to organize experimental data and generate charts. SPSS 16.0 was employed for analysis of variance (ANOVA) and multiple comparisons. The Least Significant Difference (LSD) method was adopted for statistical significance testing at the P<0.05 level. Additionally, a two-tailed test (T) was performed to analyze the bivariate correlation between indicators.

 

Comments 8: Fig. 1 (p. 5): Small inscriptions on Fig. 1 are almost unreadable, try making them a little bigger.

Response 8: Revised.

 

Comments 9: Please, use in the text denotation pH instead of PH.

Response 9: Revised.

 

Comments 10: Subsection 2.2.3 (lines 183–343) is particularly large; I recommend that it be presented as a separate subsection 2.3, and if possible, shorten the commonly known explanations.

Response 10: Revised. Subsection 2.2.3 is presented as a separate subsection 2.3. The contents are revised by shortening the commonly known explanations.

 

Comments 11: I would recommend presenting all economic calculations in US dollars or Euros.

Response 11: Thank you very much for your suggestion. The first Reviewer also made a similar suggestion, advocating the use of RMB, which is the official representation of the Chinese yuan, for international recognition. So, we have considered adopting RMB as the unit of measurement. For reference purposes, we have included the exchange rates of RMB against the US dollar and the euro within the text.

 

Comments 12: Table 4: please, explain sej and sej/j; the joule should be J; UEVw and Emw have the same name, but different designations and units.

Response 12: Revised. The units of emergy were defined as solar emjoules (abbreviated sej) for the emergy theory and methods. The units of transformity were sej/J, defined as the solar emergy required to provide a Joule of a product or service. UEVw: Emergy value conversion rate of water, sej/J. Emw: Environmental service emergy value of water, sej.

 

Comments 13: Fig. 2: add contrast in the captions for better readability.

Response 13: Revised.

 

Comments 14: Subsection 3.1: why the theoretical rice yield of 427.8 kg/mu (line 347) does not correspond to the value given in Table 5.

Response 14: 427.8 is the average of the rice yield for the three irrigation modes in Tale 5. That is: 427.8 = (442.37 +358.82 +482.22)/3.

 

Comments 15: Lines 350–353: two sentences are repeated twice in a row.

Response 15: Revised.

 

Comments 16: Fig. 3: Please add contrast to all labels, remove zeros after the decimal point, increase the font size on the legend.

Response 16: Revised.

 

Comments 17: Table 5: Irrigation mode, not Processing; Above ground biomass in g/pot? Where is 796.65 g from line 348? Is a theoretical yield in kg/Acres? Please, note what means a, b and ab.

Response 17: Revised. Above ground biomass is in g/pot. 796.65 g from line 348 is the average of above ground biomass for the three irrigation modes in Tale 5. The theoretical yield is in kg/Mu (667m²). To indicate statistical significance of differences (denoted as a, b, and ab), first arrange the means in descending order and label the largest mean with the letter 'a'. Compare this mean sequentially with the others; if no significant difference is found, mark the same letter 'a'. This process continues until a mean is encountered that shows a significant difference, which is then labeled with the letter 'b'. The downward comparison stops here, and subsequent means that also differ significantly from the previously labeled mean are labeled with 'b' until a new significant difference emerges, at which point the next letter, 'c', is used.

 

Comments 18: Fig. 4–5: please, add contrast and increase the font size.

Response 18: Revised.

 

Comments 19: Table 5 and Table 6: It would be good to discuss in the text the result that 50/50 irrigation produced the minimum rice yield, rather than the average value between freshwater irrigation and wastewater irrigation. It is important whether this is a pattern obtained or just a scatter of results given the small number of replicates.

Response 19: Thank you very much for your suggestion. Indeed, the result with those of 50/50 irrigation seems quite odd. Yet, we have double-checked the results and reviewed the experimental procedure, and the actual data indicates what we have seen. We analyzed that the possible reason could be the three replications of the data and potential errors in the experiment, as the sample size is indeed small, and further repetitions are needed. Your advice is invaluable, and we will take this issue into full consideration in our subsequent experiments.

 

Comments 20: Table 6 and further: taking into account the significant deviations in experimental results, I consider it impractical to calculate economic parameters with an accuracy of 6–7 digits.

Response 20: Thank you very much. These indicators involve original physical units, unit conversions, unit value amounts, currency values, etc., resulting in economic value data with many decimal places. While the data may appear precise, it can indeed be somewhat confusing. However, given the individual measurement and aggregation of various values, we have not rounded off these figures. This is because we are currently only estimating the economic value based on experimental data. Nevertheless, when it comes to decision-making references, such as implementing policies like economic subsidies and ecological compensation, appropriate rounding and simplifying the unit value amounts can make them more practical. Your suggestion is excellent, and we will consider simplifying these economic data factors in their future applications.

 

Comments 21: Table 10: The text does not explain the large difference between the organic matter accumulation in the bottom layer (BL) 61.89 g/pot vs 5.57 g/pot or 11 times, as well as the presence of a negative value in the middle layer for freshwater irrigation.

Response 21: The large difference data observed here are indeed intriguing, yet they are what the objective experimental data indicate. Possible reasons could lie in the inherent errors of the experiment itself, as well as in the averaging of discrepancies among the three replicate sets of data. The negative value means that, for the middle soil layer irrigated with freshwater, the final measured organic matter content (8.96g/kg) was slightly lower than that before the experiment (9.29g/kg), hence resulting in a negative value in terms of change.

 

Comments 22: Conclusions: please do not number your conclusions; also try to summarize them.

Response 22: The conclusion chapter has been rewritten. Also, the limitations and prospects are added in the last part.

 

Comments 23: References: All references should be presented in accordance with the requirements of the journal Agronomy.

Response 23: Revised.

 

Response to Comments on the Quality of English Language

Point 1: Please use the term 'respectively' when listing parameters in a sentence (e.g. lines 59, 420, etc.).

Response 1: Revised. The term 'respectively' is used.

 

Point 2: Table 1: not Metrics, better Parameters.

Response 2: Revised. “Metrics” is replaced by “Parameters” in Table 1.

 

Point 3: Lines 347–355: The same structure of simple sentences is repeated more than 10 times in a row in one paragraph. Please make the corresponding description more diverse.

Response 3: Revised. This paragraph has been revised to enhance the diversity of its description.

 

Round 2

Reviewer 1 Report

Comments and Suggestions for Authors

Accept as is.

Comments on the Quality of English Language

Minor edits.