Long-Term Application of an Oil Residue Organic Fertilizer Improved Soil Physical Properties in the Root Zone of Jujube Trees

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

Review of the Article:

"Long-term application of oil residue organic fertilizer improves soil physical properties in the root zone of jujube trees"

Overall Assessment:

This paper presents a comprehensive study on the impact of long-term organic fertilizer application on soil physical properties. The methodology is sound, and the results are significant. However, there are areas where the paper could be improved to strengthen the conclusions and broader implications.

Strengths:

• Novelty: The use of CT scanning to analyze soil pore structure is a novel approach that provides detailed insights into soil physical properties.
• Clear Research Question: The research question is well-defined and directly addresses a significant issue in agriculture.
• Strong Methodology: The experimental design and data analysis methods are appropriate and rigorous.
• Significant Findings: The results demonstrate a clear and positive impact of organic fertilizer on soil structure and function.

Weaknesses:

1. Limited Discussion on Soil Microbial Community: While the study focuses on physical properties, a deeper discussion on the potential impact of organic fertilizer on soil microbial communities would enhance the understanding of the overall soil health benefits.
2. Economic and Environmental Implications: A more detailed analysis of the economic costs and environmental benefits of organic fertilizer application would be valuable.
3. Long-Term Sustainability: A longer-term study could assess the long-term sustainability of organic fertilizer practices and their potential impact on soil quality and crop productivity.
4. Comparison with Chemical Fertilizers: A comparative analysis with conventional chemical fertilizers would provide a better understanding of the relative benefits of organic fertilizers.

 

 

Specific Comments and Suggestions:

Review of the Abstract

Overall, the abstract is well-written and provides a clear summary of the research. It effectively conveys the main research question, methodology, key findings, and implications.

1. Clarity and Conciseness:
• The abstract is concise and to the point. However, consider further condensing it by removing any redundant phrases or unnecessary details.
• For example, the phrase "Soil in root zone physicochemical properties influence plant root growth, solute transport and microbial activity" could be shortened to "Soil physical and chemical properties influence plant growth and soil processes."
• Some corrections here, please revise the sentences (Line 17, 20, 24 and 25)
2. Highlighting Key Findings:
• While the abstract clearly states that organic fertilizer improves soil structure, consider highlighting the most significant findings, such as the increase in specific pore sizes or the enhancement of soil aggregate stability.
• For example, you could add a sentence like, "Specifically, the application of organic fertilizer increased the proportion of pores in the 0-500 μm size range and improved soil aggregate stability."
3. Implications:
• Briefly mention the broader implications of the study, such as the potential for sustainable agriculture and soil health improvement.
• For instance, you could add a sentence like, "These findings have significant implications for sustainable agriculture in arid and semi-arid regions."

4.      Keywords:

o    Briefly mention the Keywords of the your study, you could add a sentence like, pore-size distribution, date palms, soil aggregate composition, CT scanning, pore number, and pore structure.

Review of the Introduction

The introduction is well-structured and provides a clear context for the research. It effectively outlines the problem, highlights the significance of the study, and states the research objectives. However, there are a few areas where it could be strengthened.

 

 

Specific Comments and Suggestions:

1. Research Gap:
• While the introduction effectively highlights the importance of soil structure and the use of organic fertilizers, it could be strengthened by more explicitly stating the specific research gap that this study aims to address.
• Suggestion: Consider adding a sentence like: "However, few studies have investigated the long-term effects of organic fertilizers on soil pore connectivity, particularly in arid and semi-arid regions."
2. Research Objectives:
• The research objectives could be more explicitly stated.
• Suggestion: Consider adding a specific sentence outlining the main objectives, such as: "The objectives of this study were to: (1) evaluate the impact of long-term organic fertilizer application on soil physical properties, (2) analyze the changes in soil pore structure, and (3) investigate the relationship between soil organic matter, enzyme activity, and pore connectivity."
3. Literature Review:
• The literature review is comprehensive and relevant. However, it could be further strengthened by including more recent studies on the impact of organic fertilizers on soil pore structure and connectivity.
• Suggestion: Consider incorporating recent research findings from peer-reviewed journals to provide a more up-to-date perspective on the topic.
4. Study Significance:
• The significance of the study could be emphasized further by highlighting the potential implications for sustainable agriculture and soil health.
• Suggestion: Add a sentence like: "Understanding the effects of organic fertilizers on soil pore structure is crucial for sustainable agriculture, as it can improve soil water retention, nutrient cycling, and crop productivity."

Some corrections here, please revise the sentences (Line 37, 38, 49, 50, 52 and 59)

Review of the Material and Methods Section

Overall Assessment:

The Materials and Methods section provides a clear and detailed description of the experimental design and procedures. However, there are a few areas where it could be improved.

Specific Comments and Suggestions:

• Experimental Design:
• Replication: While the authors mentioned three replicate soil columns per treatment, it would be helpful to clarify the number of replicate trees or plots for each treatment.
• Randomization: Explain how the treatments (organic fertilizer application) were randomly assigned to the different trees or plots to minimize bias.
• Control Treatment: Consider including a control treatment without any fertilizer application to isolate the effects of organic fertilizer.
• Soil Sampling:
• Provide more details on the soil sampling depth and the number of soil cores collected from each tree or plot.
• Spatial Variability: Discuss how spatial variability in soil properties was accounted for during sampling and analysis.
• Soil Analysis:
• Soil Physical Properties: Clearly describe the methods used to measure soil bulk density, electrical conductivity, and organic matter content.
• Soil Chemical Properties: Explain the methods used to determine soil enzyme activities (sucrase and urease).
• Soil Aggregate Analysis: Provide more details on the sieving procedure and the calculation of mean weight diameter (MWD).
• CT Scanning and Image Analysis:
• Image Acquisition: Specify the scanning resolution and pixel size used for CT imaging.
• Image Processing: Explain the specific image processing techniques used to segment pores and analyze pore network properties.
• Pore Network Analysis: Describe the software used for pore network modeling and the criteria for defining pores and throats.

Review of the Results and Discussion Sections

Overall Assessment:

The Results section is well-structured and clearly presents the findings of the study. However, there are a few areas where it could be improved.

Specific Comments and Suggestions:

1. Data Presentation:
• Tables: While the tables present the data clearly, consider using more concise table headings and units.
• Figures: The figures are informative, but the figure captions could be more detailed and specific. For example, Figure 2 could be captioned as "Three-dimensional reconstruction of connected pore networks in soil under different fertilizer treatments."
• Statistical Analysis: Clearly state the statistical tests used to compare the different treatments and the level of significance.
2. Discussion of Results:
• Soil Physical and Chemical Properties: Discuss the mechanisms by which organic fertilizer reduces soil bulk density and electrical conductivity.
• Soil Aggregate Stability: Explain how the increase in the proportion of larger aggregates contributes to improved soil structure and water retention.
• Soil Pore Structure: Discuss the implications of the changes in pore size distribution and connectivity for soil water infiltration, aeration, and root growth.
• Correlation Analysis: Interpret the correlations between soil organic matter, enzyme activity, and pore structure in more detail.
3. Limitations:
• Acknowledge the limitations of the study, such as the specific site conditions and the relatively short duration of the experiment.
• Discuss the potential limitations of CT scanning for analyzing soil pore structure, such as the resolution and image processing techniques.

Review of the Discussion Section

Overall Assessment:

The discussion section provides a good overview of the results and their implications. However, there are areas where it could be strengthened to provide a more comprehensive and insightful analysis.

Specific Comments and Suggestions:

1. Mechanisms of Improvement:
• While the paper discusses the impact of organic fertilizer on soil physical properties, it could delve deeper into the underlying mechanisms.
• Suggestion: Discuss how organic matter additions can enhance soil aggregation, improve soil structure, and create stable pore networks.
• Suggestion: Explore the role of soil microorganisms in decomposing organic matter and forming soil aggregates.
2. Comparison with Other Studies:
• Compare the findings of this study with previous research on the effects of organic fertilizers on soil properties.
• Suggestion: Discuss the similarities and differences in the observed effects, considering factors such as soil type, climate, and fertilizer type.
3. Limitations and Future Research:
• Acknowledge the limitations of the study, such as the specific site conditions and the relatively short duration of the experiment.
• Suggestion: Discuss potential limitations related to the CT scanning technique, such as the resolution and image processing methods.
• Propose specific future research directions, such as investigating the effects of different organic fertilizer types or the impact of climate change on soil properties.
4. Practical Implications:
• Highlight the practical implications of the findings for sustainable agriculture and soil health.
• Suggestion: Discuss the potential benefits of organic fertilizer use in terms of improved crop yields, water use efficiency, and reduced environmental impact.

Review of the Conclusion Section

Overall Assessment:

The conclusion effectively summarizes the key findings of the study. However, it could be further strengthened by highlighting the broader implications and suggesting future research directions.

Specific Comments and Suggestions:

1. Clarity and Conciseness:
• The conclusion could be more concise by removing redundant phrases and focusing on the most important findings.
• For example, the sentence "We report soil BD to decrease after prolonged application of organic fertilizers, and for soil OM, SC, and URE content, and soil 2–0.25 mm fraction and soil aggregates to both increase and for this effect to be more significant with prolonged application" could be rephrased to: "Long-term organic fertilizer application reduced soil bulk density and increased soil organic matter, enzyme activity, and aggregate stability."
2. Implications for Sustainable Agriculture:
• The conclusion should emphasize the practical implications of the findings for sustainable agriculture.
• Suggestion: Add a sentence like: "These results suggest that organic fertilizer can be a valuable tool for improving soil health and sustainable agriculture, particularly in arid and semi-arid regions."
3. Future Research Directions:
• The conclusion could propose specific future research directions to build upon the findings of this study.
• Suggestion: Consider suggesting future research on the long-term impacts of organic fertilizer on soil carbon sequestration, nutrient cycling, and crop productivity.

Review of Reference Section

Overall Assessment:

The reference list is comprehensive and includes a wide range of relevant literature. However, there are a few minor issues that could be addressed to improve its quality.

Specific Comments and Suggestions:

 

1. Consistency:
• Ensure consistent formatting for author names, journal titles, and volume/issue numbers.
• Check for any inconsistencies in capitalization, punctuation, and spacing.
2. Citation Style:
• Verify that the citation style used (e.g., APA, MLA, Chicago) is appropriate for the journal guidelines.
• Ensure that all citations in the text are correctly referenced in the reference list, and vice versa.
3. Reference Accuracy:
• Double-check the accuracy of author names, journal titles, publication years, and page numbers.
• Use a citation management software tool to help maintain accuracy and consistency in referencing.
4. Relevance:
• While the references are generally relevant, consider removing any references that are not directly cited in the text or that do not significantly contribute to the discussion.

Comments on the Quality of English Language

The English could be improved to more clearly express the research.

Author Response

Please see the attachment.

Author Response File: Author Response.docx

Reviewer 2 Report

Comments and Suggestions for Authors

1. First sentence of the summary: Organic fertilizers have been widely used in China on soil and crops. Explain which soils, which crops. I think the word agricultural is missing

2. In line 15/16, you use the abbreviations 10 y and 5 y for the first time, you should write years

3. Is it really the multi-year average of precipitation 50 mm?

4. In the materials and methods, explain how the organic fertilizer was applied to the soil, to what depth, with what tool? How did you evenly spread 150 kg of fertilizer per hectare?

5. State the soil type according to the FAO classification

6. please add state the soil texture.

7. Did the applied fertilizer have an impact on the yield/productivity of jujube trees

8. Line 167 OF5 one parenthesis is superfluous

9. Line 167 Table3 is written together, separate

10. Line 189 Table4 is written together, separate

11. Line 221 (17) and Inter-root are separated

12. Why do you use the author's last names and not numbers in the chapter from line 234 to line 242?

13. Same line 275 – Pagliai

14. Edit the reference list according to the journal's rules. In some references, use the full name of the journal (line 329) and in some cases, use abbreviations for literature sources (line 331). This must be uniform

Author Response

Please see the attachment.

Author Response File: Author Response.docx