Review Reports - Soil Aggregate Dynamics and Stability: Natural and Anthropogenic Drivers

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

This review consolidates current knowledge on the mechanisms underlying soil aggregate formation and stabilization. The topic is potentially interesting for the readers of Agriculture; however, I believe the manuscript would benefit from a more rational and straightforward organization. Below, I provide several suggestions to improve its structure and clarity.

It would be advisable for the authors to consider a language revision to enhance the fluency and clarity of the writing.
In this review, there is only one summary table, which is insufficient. Tables are essential as they provide a clear, concise presentation of key information, allowing readers to quickly grasp complex data and compare findings. Including additional tables would enhance the clarity and comprehensiveness of the review, making it easier for the readers to synthesize the presented information.
23-25: Do not include this information in the abstract; instead, replace it with a more concise summary of the existing knowledge.
Please write the full term the first time it is mentioned, followed by its abbreviation in parentheses, and then use the abbreviation throughout the rest of the text, e.g., Organic matter (OM). Abbreviations should only be provided at the end of the text.
The need for this review should be more clearly articulated in the introduction.
85: Are the studies meeting the selected criteria 236 or 198, as stated in L.24 of the abstract? In the references, 198 studies are listed. Could you clarify if this discrepancy?
Please provide numerical indications regarding the sizes of 'macroaggregates’, 'microaggregates’, ‘macropores’, ‘micropores’. What are the specific size ranges? Is this referring to a classification system?
133-135: ‘Macro-aggregates' and 'large soil aggregates' – what is the difference? Please clarify this distinction in the text.
191-193. Although biochar is discussed, the effects of other amendments on soil aggregate stability are not addressed. There is a considerable body of literature on this topic, which should be incorporated into the review (Annabi et al., 2007; Rivier et al., 2022; Sharma et al., 2021). This aspect is not sufficiently explored in section 6.3.3.
Table 1: There are few bibliographic references to support the content for a review. For instance, only reference [17] specifically address water infiltration and retention?
247: ‘Inorganic materials’ exactly which ones are being referred to? Please strive to be as specific and detailed as possible when using such terms.
322-324: Some sentences within the text are redundant; in this case, the sentence is even identical to the one found in L.309-311. Please review the entire text and aim to eliminate unnecessary repetitive phrases, as they only make the work cumbersome to read.
326-327: The sentence appears disconnected from both the preceding and the following ones. Please revise accordingly.
461-478: The sentences appear overly repetitive. I suggest condensing and grouping the bibliographic references.
Section 6.2.2: I find this section somewhat unclear. In lines 629-632, it is not explicitly stated whether the effects are presented as positive or negative. The inclusion of a table could further clarify this matter.
Section 6.3.3: This section could benefit from greater specificity and clarity, as some parts appear overly general and lack a clear logical flow. For instance, there is no mention of other amendments such as compost, peat, or vermicompost, which are important when discussing the effects on soil aggregate stability. Additionally, soil texture, a fundamental factor in evaluating the impact of amendments on aggregate stability, is not addressed. I suggest incorporating these elements and supporting them with relevant scientific references to enhance the completeness of the section.

Other minor suggestions:

L.51: Add space between "6]" and ".As".

L.107: The period is missing after [17].

119-120: L. 119-120: The sentence is incomplete; there is nothing written after the “:”.

L.167: “Which CAN”. Please correct.

L.241: Remove one of the two 'in'.

L.252: Kindly revise this sentence to improve clarity and ensure grammatical accuracy.

L.267,302: Please remove any excessive spacing.

L.358-360: Kindly revise this sentence for improved clarity and structure.

Cited references

Annabi M, Houot S, Francou C, Poitrenaud M, Bissonnais YL (2007) Soil Aggregate Stability Improvement with Urban Composts of Different Maturities. Soil Sci Soc Am J 71:413–423.
Rivier, P.-A.; Jamniczky, D.; Nemes, A.; Makó, A.; Barna, G.; Uzinger, N.; Rékási, M.; Farkas, C. Short-term effects of compost amendments to soil-on-soil structure, hydraulic properties, and water regime. J. Hydrol. Hydromech. 2022, 70, 74–88.
Sharma, V. Abrol, V. Sharma, S. Chadda, C.S. Rao, A.Q. Gaine, D.I. Hefft, M.A. El-Sheikh, S. Mansoor, Effectiveness of biochar and compost on improving soil hydro-physical properties, crop yield and monetary returns in inceptisol subtropics, Saudi J. Biol. Sci. 28 (12) (2021).

Comments for author File: Comments.pdf

Author Response

This review consolidates current knowledge on the mechanisms underlying soil aggregate formation and stabilization. The topic is potentially interesting for the readers of Agriculture; however, I believe the manuscript would benefit from a more rational and straightforward organization. Below, I provide several suggestions to improve its structure and clarity.

We sincerely thank Reviewer 1 for their constructive comments and valuable recommendations. We have carefully revised the manuscript in accordance with these suggestions and hope that the changes meet the journal’s standards.

Comment 1. It would be advisable for the authors to consider a language revision to enhance the fluency and clarity of the writing.

Response 1: We thank the reviewer for this suggestion. We have carefully revised the manuscript to improve language clarity, fluency, and readability throughout, ensuring that the text communicates the scientific content more effectively.

In this review, there is only one summary table, which is insufficient. Tables are essential as they provide a clear, concise presentation of key information, allowing readers to quickly grasp complex data and compare findings. Including additional tables would enhance the clarity and comprehensiveness of the review, making it easier for the readers to synthesize the presented information.

Response 2. As suggested table has been added.

Comment 3. L.23-25: Do not include this information in the abstract; instead, replace it with a more concise summary of the existing knowledge.

Response 3: We appreciate the reviewer’s observation. The sentence describing the number of articles searched and selected has been removed from the abstract. It has been replaced with a concise summary highlighting the current state of knowledge on soil aggregation and stability, as suggested.

Comment 4. Please write the full term the first time it is mentioned, followed by its abbreviation in parentheses, and then use the abbreviation throughout the rest of the text, e.g., Organic matter (OM). Abbreviations should only be provided at the end of the text.

Response 4: We thank the reviewer for pointing this out. The manuscript has been carefully revised to ensure that all abbreviations are defined in full at their first mention, followed by their abbreviations in parentheses, and subsequently used consistently throughout the text. The list of abbreviations has been retained at the end of the manuscript for reference, in accordance with MDPI style guidelines.

Comment 5. The need for this review should be more clearly articulated in the introduction.

Response 5: We thank the reviewer for this valuable suggestion. The introduction has been revised to explicitly highlight the knowledge gaps in the current literature and to justify the importance of this review. We have clarified why a comprehensive synthesis on soil aggregate dynamics and stability is timely and necessary, particularly in the context of soil health, climate change, and sustainable agriculture.

Comment 6. L.85: Are the studies meeting the selected criteria 236 or 198, as stated in L.24 of the abstract? In the references, 198 studies are listed. Could you clarify if this discrepancy?

Response 6: We appreciate the reviewer for identifying this inconsistency. The correct number of studies that met the inclusion criteria is 211, as stated in Section 2 (Data Analysis). Accordingly, the Abstract has been revised to state 211 studies to ensure accuracy and alignment with the main text and references.

Comment 7. Please provide numerical indications regarding the sizes of 'macroaggregates’, 'microaggregates’, ‘macropores’, ‘micropores’. What are the specific size ranges? Is this referring to a classification system?

Response 7: We thank the reviewer for highlighting this point. Numerical size ranges for macro- and microaggregates, as well as for macropores and micropores, have now been provided in Sections 3 and 6.1.7, respectively. The definitions follow the widely accepted classifications of Six et al. (2000) for soil aggregates and Dexter (1988) for soil pore size.

Comment 8. L.133-135: ‘Macro-aggregates' and 'large soil aggregates' – what is the difference? Please clarify this distinction in the text.

Response 8: We thank the reviewer for this observation. The terminology has been clarified in the manuscript. The phrase “large soil aggregates” is now defined as synonymous with “macroaggregates” (> 250 µm). This correction ensures consistency throughout the text.

Comment 9. L.191-193. Although biochar is discussed, the effects of other amendments on soil aggregate stability are not addressed. There is a considerable body of literature on this topic, which should be incorporated into the review (Annabi et al., 2007; Rivier et al., 2022; Sharma et al., 2021). This aspect is not sufficiently explored in section 6.3.3.

Response 9. As suggested by the reviewer, the information pertaining to organic matter amendments has been added and the suggested references have been included to enrich the section 6.2.3. However, due to extensive editing, the EndNote library has not been updated. Once we receive the clean copy from the journal at next round, we will update again the references and citations, including all those suggested by the reviewers.

Table 1: There are few bibliographic references to support the content for a review. For instance, only reference [17] specifically address water infiltration and retention?

Response 10. More references regarding water infiltration have been added

L.247: ‘Inorganic materials’ exactly which ones are being referred to? Please strive to be as specific and detailed as possible when using such terms.

Response 11: We thank the reviewer for this observation. The term “inorganic materials” has been removed from L 247 revised like The formation of soil aggregates involves a wide range of biotic and abiotic processes. Biotic mechanisms include root growth, fungal hyphae, microbial exudates, and SOM. Abiotic mechanisms include cation bridging, organo-mineral complexation, and physical drivers such as wetting-drying, swelling-shrinkage and freezing-thaw cycle.

Comment 12. L. 322-324: Some sentences within the text are redundant; in this case, the sentence is even identical to the one found in L.309-311. Please review the entire text and aim to eliminate unnecessary repetitive phrases, as they only make the work cumbersome to read.

Response 12: We appreciate the reviewer’s careful reading. The redundant sentences in lines 309–324 have been revised to, concise statement to avoid repetition and improve readability.

Comment 13. L. 326-327: The sentence appears disconnected from both the preceding and the following ones. Please revise accordingly.

Response 13: The sentence in lines 326–327 has been revised to ensure a clearer connection with the surrounding text.

Comments 14. L.461-478: The sentences appear overly repetitive. I suggest condensing and grouping the bibliographic references.

Response 14: The sentences in lines 461–478 have been condensed to eliminate repetition. The main ideas are now presented in a single coherent paragraph, and the bibliographic references have been grouped to improve readability and flow while maintaining full scientific support.

Section 6.2.2: I find this section somewhat unclear. In lines 629-632, it is not explicitly stated whether the effects are presented as positive or negative. The inclusion of a table could further clarify this matter.

Response 15: The section has been modified and a table has been added to explain the text further

Section 6.3.3: This section could benefit from greater specificity and clarity, as some parts appear overly general and lack a clear logical flow. For instance, there is no mention of other amendments such as compost, peat, or vermicompost, which are important when discussing the effects on soil aggregate stability. Additionally, soil texture, a fundamental factor in evaluating the impact of amendments on aggregate stability, is not addressed. I suggest incorporating these elements and supporting them with relevant scientific references to enhance the completeness of the section.

Response 16: The information pertaining to organic matter amendments, including vermicompost and peat, etc., has been added. Studies referring to the use of these amendments have been added to add to the information in the section.

Other minor suggestions:

L.51: Add space between "6]" and ".As".

L.107: The period is missing after [17].

119-120: L. 119-120: The sentence is incomplete; there is nothing written after the “:”. L.167: “Which CAN”. Please correct.

L.241: Remove one of the two 'in'.

L.252: Kindly revise this sentence to improve clarity and ensure grammatical accuracy. L.267,302: Please remove any excessive spacing.

L.358-360: Kindly revise this sentence for improved clarity and structure.

Response: We are thankful to the reviewer for highlighting the minor edits. All minor edits are incorporated in the revised manuscript as per the suggestion

Cited references 1) Annabi M, Houot S, Francou C, Poitrenaud M, Bissonnais YL (2007) Soil Aggregate Stability Improvement with Urban Composts of Different Maturities. Soil Sci Soc Am J 71:413–423. 2) Rivier, P.-A.; Jamniczky, D.; Nemes, A.; Makó, A.; Barna, G.; Uzinger, N.; Rékási, M.; Farkas, C. Short term effects of compost amendments to soil-on-soil structure, hydraulic properties, and water regime. J. Hydrol. Hydromech. 2022, 70, 74–88. 3) P. Sharma, V. Abrol, V. Sharma, S. Chadda, C.S. Rao, A.Q. Gaine, D.I. Hefft, M.A. El-Sheikh, S. Mansoor, Effectiveness of biochar and compost on improving soil hydro-physical properties, crop yield and monetary returns in inceptisol subtropics, Saudi J. Biol. Sci. 28 (12) (2021).

Response: Thank you for helping us by recommending relevant studies. We have edited the text accordingly; however, due to major revisions, the EndNote library is currently causing issues. Once we receive the journal’s clean copy, we will update again and sure all references have been cited correctly.

Reviewer 2 Report

Comments and Suggestions for Authors

Reviewer #

agriculture-3984630

Agriculture

“Soil Aggregate Dynamics and Stability: A Central Mechanism for Enhancing Soil Health”

By Hamza et al.

Summary

The manuscript agriculture-3984630 (Agriculture) “Soil Aggregate Dynamics and Stability: A Central Mechanism for Enhancing Soil Health” by Hamza et al. is a review manuscript focusing on summarising recent developments in the study of aggregation and architectural organization of sand, silt and clay in soils. Formation of aggregates and their potential hierarchical organization (Totsche et al., 2018; Amelung et al., 2023; Bai et al., 2025) is of great importance when considering key soil functions (e.g. climate regulation, cycling of water and nutrients, erosion control) of relevance for a number of environmental issues. The present review is then a timely contribution to the body of knowledge within this topic; within this general context, the review could, potentially, (1) provide a coherent, but succinct, descriptive account of a relevant research area, and (2) be used as introduction to the topic to a wider audience. Currently, the manuscript provides a certain amount of novel information, and it is, a priori, potentially suitable for publication because the authors have extracted some insight from their survey of the literature. The work fits the scope of the Journal and, in general, the idea is worthy of investigation. After a thorough inspection, issues needing explanation/clarification were detected, as commented in detail in the text following.

General comments

The abstract is succinct description of content, somehow disconnected from what is shown later in the manuscript (e.g. L 20-23 vs most of the manuscript).
Major caveats of the study to consider: (i) Introduction should be reassessed, to stress the novelty of the manuscript, and hence how key progress against the most recent state-of-the-art similar reviews can be achieved; (ii) other issues as (a) the text is long and unnecessary repetitive, wordy (see details below); (b) the authors are encouraged to substantially condense the writing style, focusing on the summary of main trends regarding research on the dynamic formation of aggregates, also (c), encourage a frequent linkage between text and information in Tables and Figures; and finally consider carefully that (d) in a review paper, as interesting as this one is, it is important to evaluate different studies and synthesize new information, thus including critical comments, rather than simply presenting previously published data; currently, novel insights are in general absent.
Because of the general comments detailed in previous paragraphs plus remarks included below the current version of the Manuscript as well the overall section 9 “Conclusion and future perspectives” is not fully supported by the qualitative information available through the text. This fact constrains the relevance of the study, as it may be considered just a long summary of previous research on nitrification inhibitors instead of offering a novel, critical insight. These potential shortcomings/limitations must be somehow recognised and addressed in the text.
The manuscript will benefit from careful proofreading.

Comments (per line; not exhaustive, only relevant comments added)

L 70-86. Authors should clarify unequivocally the terms (e. g. L 74 “other related terms”; which ones?) used for searching the databases. Moreover, there is some misunderstanding in using key concepts of the discipline (L 79-82); factors, drivers and/or key properties (e.g. soil texture, root traits) are referred as mechanisms of aggregate formation, which is inconsistent and misleading. Clarify.

L 104-105. Sentence is repeated. Delete.

L 117-120. The sentence is left unfinished, why? Please review.

L 139-142. Suggestion or evidence-based output? Clarify, refer to a proper source as needed.

L 142-144. Sentence partially repeats that from L 131-133. Avoid redundancy.

L 145-148. What do you mean by "complicated"? Stick to the vocabulary of the discipline. Could this review offer a new insight on such "complicated" issue? Explain.

L 185-208. This section of text is somehow confusing by implying that C in macroaggregates is very relevant for sequestering C somehow ignoring that this fact is probably because macroaggregates contain microaggregages and the C in microaggregates is the soil C showing long residence times in soils. So, the apparent contradiction from L 198-200 may be less so. Clarify. Also, comment and discuss on recent advances on the formation pathways of microaggregates and on how the processes responsible for aggregate stabilization and turnover occur along temporal time scales.

L 230-244. The reader is confused when authors discuss soil health independently of functions. Indeed, if soils’ functions (L 237-238) are optimal, the quality/heath of the soil is maintained, correct? The text would benefit from presenting a more structured and integrative summary of these topics. Otherwise, large chunks of text read as redundant. Reconsider.

L 327-338. This paragraph is most confusing, even misleading. The text implies that particles of silt and sand size does not participate in aggregate formation (only clay size particles), but this is untrue. What do you mean here? Explain, clarify.

L 354-377. Oddly, the focus is put in some "fractions" as POM and DOM, disregarding the role of microbial OM or even fractions such as mineral-associated OM - MAOM, why? The review is less thorough than claimed. Reconsider.

L 459-460. Indeed, but this has been explained before (e.g. L 378-412), so, what is new? Avoid redundancy.

L 476-479. Yes, indeed, but there is no clue on what processes are invoked. This sentence reads as generic when left at the end of a paragraph, somehow isolated from the main context of the paragraph, thus confusing. Review.

L 495-497. This text is generic. How specifically does this section aligns with information provided earlier (e.g. L 414-439) is unclear. There is a general lack of critical analysis considering the literature surveyed. Review.

L 518-522. Provide a suitable caption for Figure 3.

L 559-590. Please note: most of these drivers have been discussed in previous text. What is the point of continuous repetition? Review.

L 587-590. A cryptic sentence closing this paragraph. What do you mean? What are, exactly, the main mechanisms/processes related to the dynamics of aggregates (a hot topic, as suggested in L 20-22)? What novel insight can be offered about the formation-destruction of aggregates based on the critical analysis of the literature? Clarify.

L 625-638. Note how "circular" is the writing within the paragraph: sentence in L 627-627 and sentence 637-638 are very similar, repetitive. Improve writing, avoid redundancy.

L 629. Vocabulary must adjust to that of the discipline. What is a "resistant" top layer? Resistant to what? What do you mean? Review.

L 640-641. Reconsider this sentence. What is exactly the "arrangement of the soil". How does the soil as entity shows different size distributions?

L 658-677. This paragraph encapsulates many drawbacks of this manuscript. Indeed, the information provided is correct: as it is well-known, rotation of crops may provide advantages. However, the text repeats this idea again and again by describing individual studies showing the same output. However, what is novel on that? Moreover, what are the processes/mechanisms explaining such outcome? How the scientific understanding about these processes has advanced recently? The manuscript is descriptive when it should present an exhaustive summary and synthesis of the information in a comprehensive way, highlighting how the understanding on the topic expanded in view of new research development. A coherent, critical, synthesis overview is usually missing.

L 694-719. This entire section comes out of the blue within the context of the study, and hence it is far from justified. As presented, is just a list of some methodologies; what is the point, exactly? Are there any key methodological gaps to be filled (e. g. L 328-353)? If so, how do authors suggest this can be tackled? Clarify, discuss.

L 720-761. As written, the section reads as independent from the (incomplete) information presented earlier, i.e., disconnected from the main body of the manuscript. Writing should favour a good internal linkage among the different sections of the text; in the current manuscript, this linkage is mainly absent. Reconsider, review.

L 788-789. Are these materials relevant to the manuscript? So far, there were not referred. Reconsider, clarify.

Assessment

As consequence of all the comments detailed above, the general assessment is that the manuscript needs review and reassessment.

References considered

Amelung, W., Meyer, N., Rodionov, A., Knief, C., Aehnelt, M., Bauke, S.L., Biesgen, D., Dultz, S., Guggenberger, G., Jaber, M., Klumpp, E., Kögel-Knabner, I., Nischwitz, V., Schweizer, S.A., Wu, B., Totsche, K.U., Lehndorff, E., 2023. Process sequence of soil aggregate formation disentangled through multi-isotope labelling. Geoderma 429, 116226.

Bai, L., Shi, P., Xiao, J., Li, Z., Li, P., Liu, X., Xu, D., Wang, B., 2025. Driving mechanisms of the soil aggregate breakdown-formation on soil organic carbon mineralization under splash erosion. Soil and Tillage Research 254, 106761.

Totsche, K.U., Amelung, W., Gerzabek, M.H., Guggenberger, G., Klumpp, E., Knief, C., Lehndorff, E., Mikutta, R., Peth, S., Prechtel, A., Ray, N., Kögel-Knabner, I., 2018. Microaggregates in soils. Journal of Plant Nutrition and Soil Science 181, 104-136.

Author Response

Reviewer # 2

Agriculture-3984630

By Hamza et al.

Summary

We sincerely thank Reviewer 2 for their time, effort, and thoughtful comments and suggestions in reviewing our manuscript. Your insights have been invaluable in improving the quality and clarity of our work.

General comments

The abstract is succinct description of content, somehow disconnected from what is shown later in the manuscript (e.g. L 20-23 vs most of the manuscript).

Response 1: Thank you for the comment. The abstract has been revised to better reflect the content and scope of the manuscript. The new version includes the mechanistic focus of the review, on discussion of aggregate erosion processes, and management factors such as tillage. This resolves the previous disconnect between the abstract and the detailed content of the manuscript.

Major caveats of the study to consider: (i) Introduction should be reassessed, to stress the novelty of the manuscript, and hence how key progress against the most recent state-of-the-art similar reviews can be achieved; (ii) other issues as (a) the text is long and unnecessary repetitive, wordy (see details below); (b) the authors are encouraged to substantially condense the writing style, focusing on the summary of main trends regarding research on the dynamic formation of aggregates, also (c), encourage a frequent linkage between text and information in Tables and Figures; and finally consider carefully that (d) in a review paper, as interesting as this one is, it is important to evaluate different studies and synthesize new information, thus including critical comments, rather than simply presenting previously published data; currently, novel insights are in general absent.

Response: We appreciate the reviewer’s constructive suggestions. The Introduction has been revised to more clearly articulate the novelty of this review and to position it in relation to the most recent state-of-the-art literature. Several sections have been condensed to remove repetition and improve clarity. We strengthened the synthesis by linking descriptive content with critical evaluation, highlighting differences among studies, uncertainties, and emerging trends. Additional cross-references to the tables and figures have been inserted to support the narrative. These revisions enhance the focus, readability, and originality of the review.

Because of the general comments detailed in previous paragraphs plus remarks included below the current version of the Manuscript as well the overall section 9 “Conclusion and future perspectives” is not fully supported by the qualitative information available through the text. This fact constrains the relevance of the study, as it may be considered just a long summary of previous research on nitrification inhibitors instead of offering a novel, critical insight. These potential shortcomings/limitations must be somehow recognised and addressed in the text.

In light of the above comment, the conclusions and future perspectives section has been revamped and necessary changes have been made. We have also removed some information not directly relevant to the topic under review to make it concise and to the point. The basic purpose of the study was to integrate natural and anthropogenic factors that affect soil aggregate formation and also bring to light interactions of these factors in light of the fact that soil aggregate stability not only is immensely important for maintain soil health but also considerably affects soil C sequestration.

The manuscript will benefit from careful proofreading.

Comments (per line; not exhaustive, only relevant comments added)

Response: Thank you for pointing out the ambiguity in the search terminology and the inconsistent use of the term “mechanisms”, “factors”, and “drivers”. We have revised Lines 70–86 to clearly list all keywords used in the database search and removed the vague phrase “other related terms”.

L 104-105. Sentence is repeated. Delete.

Response: Thank you for pointing out this repetition. Repeated sentence is removed as per the suggestion from lines 104-105

L 117-120. The sentence is left unfinished, why? Please review.

Response: We thank the reviewer for noting this. Upon review, we found that the sentence in lines 117–120 did not convey meaningful information and have therefore removed it from the manuscript.

L 139-142. Suggestion or evidence-based output? Clarify, refer to a proper source as needed.

Response: Thank you for the critical review our manuscript. Proper citation has been incorporated into L 139-142

L 142-144. Sentence partially repeats that from L 131-133. Avoid redundancy.

Response: We thank the reviewer for pointing this out. We have revised lines to avoid redundancy with lines 131–133. The sentence now focuses on the overall effect of these processes on soil structure and aggregate stability, rather than repeating the specific mechanisms.

L 145-148. What do you mean by "complicated"? Stick to the vocabulary of the discipline. Could this review offer a new insight on such "complicated" issue? Explain.

Response: "We thank the reviewer for this comment. The term 'complicated' has been replaced with 'complex,' and the sentence now clearly specifies the factors influencing nutrient cycling within soil aggregates.

Response: We have now clarified the text to explain that the high carbon content in macroaggregates is largely due to the presence of meso and microaggregates within them, where carbon is more stabilized and exhibits long residence times. The apparent contradiction in lines 198–200 has been addressed accordingly

Response: We agree that discussing soil health independently of soil functions can be confusing. We have revised lines 230–244 to present a more structured and integrative summary, linking soil health directly to the performance of soil functions. Redundant text has been removed, and the section now emphasizes that optimal soil functions are fundamental to maintaining soil quality and health.

Response: We agree that the original text could be misleading. To clarify, all particle sizes, including sand, silt, and clay, contribute to aggregate formation, but the mechanisms differ. Clay particles are primarily responsible for binding smaller particles through physicochemical interactions. We have revised lines 327–338 to clearly explain the roles of different particle sizes in aggregate formation and to avoid any misunderstanding.

Response: We thank for this insightful comment. We agree that the discussion on soil organic matter (SOM) fractions should be more comprehensive. The original text focused on particulate organic matter (POM) and dissolved organic matter (DOM), but we have now expanded the section to include microbial-derived organic matter and mineral-associated organic matter (MAOM), which play critical roles in long-term carbon stabilization and soil function. This revision makes the discussion more thorough and balanced, in line with the stated scope of the review.

L 459-460. Indeed, but this has been explained before (e.g. L 378-412), so, what is new? Avoid redundancy.

Response: We agree that the content in lines 459–460 overlaps with the discussion in lines 378–412. To avoid redundancy, we have removed the repeated text and ensured that only new or complementary information is presented in this section.

Response: We agree that the original sentence was too generic and disconnected from the paragraph context. We have revised lines 476–479 to specify the processes involved.

Response: We thank the reviewer for this observation and agree that the original text was too generic. We have revised lines 495–497 to explicitly link microbial activity under varying temperature and moisture regimes to the formation, stabilization, and breakdown of aggregate.

L 518-522. Provide a suitable caption for Figure 3.

Response: Revised

L 559-590. Please note: most of these drivers have been discussed in previous text. What is the point of continuous repetition? Review.

Response: We thank the reviewer for this comment. Although lines 559–590 cover drivers already mentioned earlier, this section (6.1.8) specifically focuses on soil physicochemical properties. We have revised the text to avoid repetition by summarizing previously discussed points concisely and emphasizing the distinct role of these physicochemical factors in aggregate formation and stability.

Response: The original sentence has been revised to specify the mechanisms through which external factors influence aggregate formation and breakdown.

L 625-638. Note how "circular" is the writing within the paragraph: sentence in L 627-627 and sentence 637-638 are very similar, repetitive. Improve writing, avoid redundancy.

Response: The paragraph has been revised by removing one of the repetitive sentences to avoid redundancy and improve the clarity of the section.

L 629. Vocabulary must adjust to that of the discipline. What is a "resistant" top layer? Resistant to what? What do you mean? Review.

Response: We appreciate the reviewer’s comment. We replaced the ambiguous phrase “resistant top layer” with “surface soil layer” to use discipline-appropriate terminology and improve scientific clarity.

L 640-641. Reconsider this sentence. What is exactly the "arrangement of the soil". How does the soil as entity shows different size distributions?

Response: The sentence has been revised to replace the vague expression “arrangement of the soil” with “arrangement of soil aggregates,” which more accurately reflects the structural elements that influence water movement and stability.

Response: We appreciate the reviewer’s comment. The paragraph on crop rotation has been completely revised to remove repetitive descriptions of individual studies. The revised version now provides a concise synthesis that highlights the underlying mechanisms, recent advances and integrated biological and physicochemical processes through which crop rotation improves aggregate stability.

Response: This section has been revamped and information to maintain relevance and continuity.

Response: The authors have attempted to address the genuine concerns of the reviewer. We have reorganized the structure to link various parts of the text in a logical manner. We, initially discuss why and how soil aggregate stability is important and then we tend to identify which factors natural/anthropogenic are important for aggregate formation.

L 788-789. Are these materials relevant to the manuscript? So far, there were not referred. Reconsider, clarify.

Assessment

As consequence of all the comments detailed above, the general assessment is that the manuscript needs review and reassessment.

Response: We sincerely thank you for your valuable suggestions and comments. We have revised the entire manuscript based on the feedback and have incorporated the suggested references. Due to the major revisions, the EndNote library has not been fully updated; however, we have noted all references and will update the citations again in the clean copy from the journal, including both new and existing references.

References considered

Reviewer 3 Report

Comments and Suggestions for Authors

The manuscript is fragmentary in nature, with a list of unrelated effects that reduces aggregates to a self-sufficient "cornerstone" of "soil health" and substitutes causality between structural elements and functional properties of soil. in the introductory theses, aggregates are attributed with a direct impact on almost all soil functions and even "overall soil structure," which is logically impossible, since it is the balance of aggregation/disaggregation that forms the structure, and it is the structure that determines infiltration, porosity, gas exchange, microbial processes, and erosion resistance. The general context of a three-phase polydisperse soil body is missing, which eliminates the key idea of the coexistence of aerobic and anaerobic microenvironments: the inter-aggregate space provides air, while the intra-aggregate space provides a water reservoir; it is the ratio of these domains that governs the transformation of organic matter and carbon sequestration. The terminology fluctuates between "soil aggregates," "soil structure," and the vague "soil aggregate structure," which confuses the levels of organisation and complicates the interpretation of hydrophysical conclusions; in some places, aggregates are credited with controlling permeability and air exchange, even though these properties belong to the structure as a whole system of pore space. The sections on hydrophobicity, hydraulic conductivity, and erosion contain generalisations that do not take into account the competition of pore scales and the opposite consequences for different fractions: the assertion about the positive role of large, "less stable" macroaggregates for saturated conductivity ignores the possibility of blocking cracks with small aggregates; similarly, erosion prevention is presented without distinguishing between critical size classes for wind and water erosion, although the text itself further acknowledges the role of secondary lumps in forming surface roughness. Finally, the material on mineralogical and cationic effects is presented in an overly generalised manner: the influence of clays and cationic composition of the solution on flocculation/dispersion, as well as the participation of Fe/Al oxides and humic substances, are mentioned without the necessary detail, which ignores the significant contrasts in the mechanisms of aggregate stabilisation in different pedo-ecological environments.

Abstract

Lines 38–41, 60–68: the introduction creates a false impression of soil aggregates as a self-sufficient object responsible for "maintaining soil health" and key physical, chemical and biological properties, while the general context of soil as a three-phase polydisperse natural body is absent; polydispersity is not a specific feature of soil; it is also characteristic of mountain rocks with hypergenesis products, whereas the specificity of soil determines the synthesis of aggregates from elementary mechanical grains within the structural hierarchy.

Lines 18–20: the phrase "Soil particle aggregation and stability" creates terminological inconsistency and ambiguity, since "stability" is used in the rest of the text in relation to aggregates, while individual soil particles are relatively stable by nature; thus mixing the levels of process description (aggregate stability vs. particle properties), which distorts the meaning of the introductory sentence and requires a clear distinction between concepts.

Lines 27–29: The generalisation "Biotic factors ... improve soil aggregate stability while ... abiotic factors ... negatively affect it" is incorrect because it ignores biotic processes that disintegrate soil aggregates (in particular, the burrowing activity of mammals, bioturbation by roots during growth and death), and abiotic factors that increase their stability (inorganic adhesives and secondary minerals, in particular carbonates, Fe/Al oxides, montmorillonite, kaolinite, hydromica; the stabilising role of salts in soil aggregation in arid soils is also well known). The wording contradicts the content of the manuscript, which explicitly mentions the contribution of salts to the formation of microaggregates and the stabilisation of structure in arid climates.

Lines 29–31: reducing the effect of "management practices" to the generalised "aggregate stability ... increasing ecosystem resilience" is reductionist and does not reflect the economic significance of the indicator that is actually used in field diagnostics — the proportion of water-stable aggregates measuring 0.25–10 mm; the text does not verify the target fraction and its water stability as a separate object of assessment, nor does it define the critical conditions for the formation of this fraction, in particular soil moisture during mechanical tillage (a benchmark of about 0.8 of field moisture capacity), which determine the result after ploughing; this presentation contradicts the manuscript itself, which separately mentions "water-stable aggregates" as an indicator of the effectiveness of techniques (organic inputs, mulching) and emphasises the importance of fractions >0.25 mm, but these provisions are not integrated into the abstract and the general statement.

Introduction

Lines 38–40: the definition reduces the origin of soil aggregates to "formed after the interaction of biotic and abiotic factors during the aggregation process," which ignores the opposite process of disaggregation, without which it is impossible to describe the dynamic equilibrium of the aggregate state; such a reduction contradicts the further text of the manuscript, which explicitly mentions "turnover and disintegration" as a component of the life cycle of aggregates.

Lines 40–41: The statement “Soil aggregates are fundamental for maintaining soil health. These define soil structure…” combines different levels of description and creates a false cause-and-effect chain: aggregates are elements of structure, so they do not “ensure” soil health directly, but mediate it through the properties of the structure itself. in the formula given, the link between "aggregates → structure → functions" disappears, and "maintaining soil health" is incorrectly attributed to aggregates, while in the text below, the authors themselves attribute the influence to the soil structure.

Lines 49–51: the statement "well-aggregated soils are less prone to ... salinisation" is incorrect because it confuses cause and effect: salinisation is a factor that changes and often reduces the stability of aggregates due to ionic composition and osmotic effects, rather than a process that is "counteracted" by good aggregation; the manuscript itself provides examples where saline/saline conditions and the associated cation effects and mineral binding phases directly determine the state of aggregates (in particular, the specific influence of Na⁺/K⁺, the role of clays and organo-mineral associations, as well as changes in aggregate composition on saline-sodic soils).

Lines 53–56: the first mention uses the abbreviations OM, POM, EPS and AMF without explanation, which undermines the terminological clarity of the introduction and makes it difficult for non-specialists in the relevant fields of soil science to read.

Lines 53–56: the presentation is eclectic in nature, with a list of incompatible examples (OM/POM, EPS, AMF, "entanglement", "rhizodeposits", "glomalin") without a consistent framework of processes and levels of organisation, which obscures the systematic logic of soil structure formation; there is no distinction between the opposing processes that determine the aggregate state (aggregation vs. disaggregation) and the corresponding physicochemical and biotic mechanisms, as well as the " " there is no symmetrical consideration of destructive processes, despite the mention in the manuscript of "turnover and disintegration" as a component of the life cycle of aggregates.

Lines 60–68: the stated "physical (water retention), chemical (nutrient cycling), and biological (microbial activity) properties of soil" are presented as the sphere of "the role of soil aggregates," which shifts causality: the functions mentioned are determined by the parameters of soil structure as an integral system of pore space and particle contact, while aggregates are its elementary units and reflect the dynamic balance of aggregation and disaggregation. In this formulation, aggregates are effectively equated with the processes of water retention, gas and mass exchange, and microbial activity, which is methodologically incorrect and duplicates the previous vague statements about the "cornerstone".

Data analysis

Lines 73–74: the phrase "and other related terms" is vague and non-operational, making it impossible to reproduce the search strategy; at the same time, the list of keywords does not include the basic term "soil structure," although in the previous statement, it is precisely structure that is declared as the central category of analysis and the subject of discussion.

Soil Structural Stability: Theoretical Foundations

Line 89 (also context 88–91): the phrase "Good soil structure" is an undefined evaluative label with no operational content or criteria for attribution, which contradicts the scientific accuracy of the section "Soil Structural Stability: Theoretical Foundations"; the absence of a definition of "good" makes it impossible to verify the statement about its impact on "gas and water transport, root penetration ..." and also creates a terminological gap between the description of "soil structure" and the subsequent mention of "erosion resistance" without linking it to specific structural parameters.

Lines 91–92: the phrase “Formation of the structural units of soil (soil aggregates)” contains the arbitrary term “structural units of soil”, which does not correspond to the established nomenclature of soil morphological organisation; such wording blurs the boundaries between concepts and creates terminological ambiguity in the presentation

Lines 100–105: double repetition of the same content regarding the definition/measurement of aggregate stability — first, "It is usually expressed as the percentage of aggregates that remain after being exposed to destabilising stress", then almost verbatim, "The percentage of aggregates that remain after being exposed to destabilising stress is typically used to quantify aggregate stability.

The size classes of aggregates used by the authors should be defined. Usually, a distinction is made between microaggregates (< 0.25 mm), mesoaggregates (0.25–10 mm) and macroaggregates (> 10 mm). Aggregates are also distinguished as true (having internal porosity) and false (solid), as well as water-stable and water-unstable. It is true water-stable mesoaggregates that are considered to be of agronomic value (providing the same value and soil health).

Lines 133–136: The statement "macroaggregates and larger soil aggregates are closely related to higher microbial activities... due to ... stable environments" is questionable, since macroaggregates usually form a more porous environment with increased aeration and rapid gas exchange, which does not ensure the "stability" of microenvironments and may limit the activity of moisture-loving microbial taxa; the above generalisation does not take into account the opposite effects of hyperaeration and higher moisture variability in the interporous space of large aggregates.

Lines 149–153: The ambiguous phrase "soil aggregate structure" is used, which confuses at least three different concepts: 1) soil aggregates (individual aggregates as elements), 2) soil structure (spatial organisation of the soil body and pore space), 3) internal structure of the aggregate (intra-aggregate structure). In the given sentence, it is unclear whether it refers to the internal organisation of aggregates that affects wetting and destruction, or to the structure of the soil as a whole system that determines infiltration and permeability.

Lines 168–170: The statement that "larger but less stable macroaggregates enhance the hydraulic properties ... by increasing the saturated hydraulic conductivity" is an overgeneralisation; aggregate size is not a reliable predictor of hydraulic properties, and the mere presence of macroaggregates does not guarantee an increase in conductivity. The coexistence of fractions of different sizes significantly modifies flows: even a small proportion of microaggregates, when macroaggregates dominate, can clog cracks and interaggregate channels, sharply reducing saturated hydraulic conductivity and infiltration; The wording given in the manuscript ignores this well-known competition between pore scales.

Lines 187–189: the statement "Macro-aggregates with a size larger than 0.25 mm are essential for SOC storage..." is presented without reference to the accepted size classification and contains a terminological inconsistency: in many schemes, the fraction >0.25 mm to 10 mm is referred to as meso-aggregates, not macro-aggregates; therefore, there is no verification of the boundary and category used.

Lines 46–48: the statement about "protection of OM from rapid mineralisation" is presented without a mechanistic explanation of the ways in which such protection occurs, creating a gap between the declaration of the impact of aggregation and the actual cause-and-effect scheme; the role of physical occlusion of POM in microaggregates, diffusion limitations and organo-mineral associations is not disclosed here, despite the fact that further on in the manuscript there is a description of the mineral matrix that "protects the POM from further microbial decomposition" and dense domains with low porosity and porous mineral domains are contrasted as different microenvironments of decomposition.

Lines 209–216, 219–226: the text does not differentiate the role of aggregate fractions for different types of erosion. For water erosion, the decisive factor is the proportion of water-resistant lumps >10 mm, which increase the micro- and macro-roughness of the surface; effectiveness is limited by the durability of these lumps. For wind erosion, the presence of fine particles and aggregates <0.25 mm, which are prone to blowing away, is critical. Generalisations about "aggregate stability" without reference to size classes distort the causality of the processes described.

Lines 246–249: the list of "biotic (plant roots, fungi, SOM) and abiotic (inorganic materials) binding agents and processes" is overly narrow and does not represent the diversity of both aggregation and disaggregation processes; key abiotic mechanisms are missing (moisture-induced swelling/shrinking cycles, wetting-drying, freezing-thawing, droplet impact, delamination and slaking), as well as biotic processes of pedo- and bioturbation, particle transit through the intestines of macrofauna, and fragmentation of plant residues; at the same time, the statement about SOM as a "primary factor" is generalising and does not take into account that in the hierarchical model, part of the aggregates are formed due to mineral-cation bridges and organo-mineral complexes without the dominance of SOM. Such a reduction contradicts later sections of the manuscript, which already recognise the role of various biotic agents and processes of destruction/turnover.

Lines 281–292: the presentation overly generalises "clay minerals" and does not reflect the known contrasts between clay types and the cation composition of the soil solution. The influence of montmorillonite, illite, and kaolinite on aggregation and stability varies significantly; the difference between the effects of Na⁺ and Ca²⁺/Mg²⁺ (dispersion/flocculation) is critical, as is the role of Fe/Al oxides and humic substances in organo-mineral binding — these aspects are not articulated in the paragraph. The formula about "specific cation effects (e.g., potassium and sodium) ... through non-classical polarisation" is presented without sufficient context of the mechanism and limits of applicability, despite the presence of a relevant reference; also, the statement about "intense attraction ... constructive distance ... due to compression" leaves unclear the conditions under which such compression is realised.

Lines 625–638: Tillage's consideration is too formal and does not take into account the decisive dependence of the aggregate structure on soil moisture during tillage; there is no mention of the narrow "window" of optimal moisture content, which narrows sharply in arid conditions to a few days, while it is precisely this that determines the proportion of water-resistant aggregates after mechanical impact. It is also not specified that the effects of tillage on infiltration/compaction and erosion sensitivity are contrasting at different moisture and structural conditions, despite the statements about the destruction of aggregates, changes in density and microbial activity.

Author Response

Reviewer # 3

Comments and Suggestions for Authors

Response: We would like to appreciate and thank Reviewer 3 for their thorough evaluation and insightful recommendations. Their thoughtful guidance has greatly enhanced both the rigor and clarity of our manuscript. We have carefully revised the paper to address all of the comments provided and have incorporated the suggested improvements, and we hope that the revised version now meets the standards of the journal.

Abstract

Comment 1: Lines 38–41, 60–68: the introduction creates a false impression of soil aggregates as a self-sufficient object responsible for "maintaining soil health" and key physical, chemical and biological properties, while the general context of soil as a three-phase polydisperse natural body is absent; polydispersity is not a specific feature of soil; it is also characteristic of mountain rocks with hypergenesis products, whereas the specificity of soil determines the synthesis of aggregates from elementary mechanical grains within the structural hierarchy.

Response 1: We thank the reviewer for this detailed comment. We have revised the text to situate aggregates within the broader context of soil as a three-phase, structurally hierarchical natural body. The revision clarifies that soil aggregates are formed from primary mineral particles and organic matter through physical, chemical, and biological interactions, and that their functions depend on the integrated properties of the soil matrix rather than acting as isolated entities.

Comment 2: Lines 18–20: the phrase "Soil particle aggregation and stability" creates terminological inconsistency and ambiguity, since "stability" is used in the rest of the text in relation to aggregates, while individual soil particles are relatively stable by nature; thus mixing the levels of process description (aggregate stability vs. particle properties), which distorts the meaning of the introductory sentence and requires a clear distinction between concepts.

Response 2: We have revised the sentence to clearly distinguish between soil particles and aggregates, emphasizing that 'aggregate stability' refers to the persistence of aggregates under physical, chemical, and biological influences, while individual soil particles are inherently stable. This change ensures terminological consistency throughout the manuscript.

Comment 3: Lines 27–29: The generalisation "Biotic factors ... improve soil aggregate stability while ... abiotic factors ... negatively affect it" is incorrect because it ignores biotic processes that disintegrate soil aggregates (in particular, the burrowing activity of mammals, bioturbation by roots during growth and death), and abiotic factors that increase their stability (inorganic adhesives and secondary minerals, in particular carbonates, Fe/Al oxides, montmorillonite, kaolinite, hydromica; the stabilising role of salts in soil aggregation in arid soils is also well known). The wording contradicts the content of the manuscript, which explicitly mentions the contribution of salts to the formation of microaggregates and the stabilisation of structure in arid climates.

Response 3: Agree and have revised the sentence to reflect that biotic factors can both promote and disrupt aggregate stability, depending on processes involved.

Comment 4: Lines 29–31: reducing the effect of "management practices" to the generalised "aggregate stability ... increasing ecosystem resilience" is reductionist and does not reflect the economic significance of the indicator that is actually used in field diagnostics — the proportion of water-stable aggregates measuring 0.25–10 mm; the text does not verify the target fraction and its water stability as a separate object of assessment, nor does it define the critical conditions for the formation of this fraction, in particular soil moisture during mechanical tillage (a benchmark of about 0.8 of field moisture capacity), which determine the result after ploughing; this presentation contradicts the manuscript itself, which separately mentions "water-stable aggregates" as an indicator of the effectiveness of techniques (organic inputs, mulching) and emphasises the importance of fractions >0.25 mm, but these provisions are not integrated into the abstract and the general statement.

Response 4: We thank the reviewer for this insightful comment. We have revised the text to clarify that the proportion of water-stable aggregates (0.25–10 mm) is a key field indicator of aggregate stability and soil structural quality. These changes ensure consistency with the detailed discussion presented later in the manuscript and emphasize both the ecological and practical relevance of aggregate stability.

Introduction

Comment 5: Lines 38–40: the definition reduces the origin of soil aggregates to "formed after the interaction of biotic and abiotic factors during the aggregation process," which ignores the opposite process of disaggregation, without which it is impossible to describe the dynamic equilibrium of the aggregate state; such a reduction contradicts the further text of the manuscript, which explicitly mentions "turnover and disintegration" as a component of the life cycle of aggregates.

Response 5: The definition of soil aggregates in lines 38–40 has been revised to reflect the dynamic nature of soil aggregation. The new wording explicitly incorporates both aggregation and disaggregation processes and acknowledges the dynamic equilibrium that governs aggregate turnover. This correction aligns the definition with the subsequent discussion on aggregate formation, turnover, and disintegration.

Comment 6: Lines 40–41: The statement “Soil aggregates are fundamental for maintaining soil health. These define soil structure…” combines different levels of description and creates a false cause-and-effect chain: aggregates are elements of structure, so they do not “ensure” soil health directly, but mediate it through the properties of the structure itself. in the formula given, the link between "aggregates → structure → functions" disappears, and "maintaining soil health" is incorrectly attributed to aggregates, while in the text below, the authors themselves attribute the influence to the soil structure.

Response 6: The sentences in lines 40–41 have been revised to eliminate the incorrect cause-and-effect chain. The new text clarifies that aggregates are fundamental units of soil structure and that their effects on soil health are mediated through structural properties such as porosity, stability, and connectivity. This revision restores the correct conceptual sequence of aggregates- structure- functions, and aligns the introduction with the mechanisms described in later sections.

Comment 7: Lines 46–48: the statement about "protection of OM from rapid mineralisation" is presented without a mechanistic explanation of the ways in which such protection occurs, creating a gap between the declaration of the impact of aggregation and the actual cause-and-effect scheme; the role of physical occlusion of POM in microaggregates, diffusion limitations and organo-mineral associations is not disclosed here, despite the fact that further on in the manuscript there is a description of the mineral matrix that "protects the POM from further microbial decomposition" and dense domains with low porosity and porous mineral domains are contrasted as different microenvironments of decomposition.

Response 7: We have revised the sentence to include mechanistic explanations for how soil aggregation protects OM, incorporating physical occlusion within microaggregates, diffusion limitations, and organo-mineral associations, thereby aligning the introductory statement with the detailed discussion later in the manuscript

Comment 8: Lines 49–51: the statement "well-aggregated soils are less prone to ... salinisation" is incorrect because it confuses cause and effect: salinisation is a factor that changes and often reduces the stability of aggregates due to ionic composition and osmotic effects, rather than a process that is "counteracted" by good aggregation; the manuscript itself provides examples where saline/saline conditions and the associated cation effects and mineral binding phases directly determine the state of aggregates (in particular, the specific influence of Na⁺/K⁺, the role of clays and organo-mineral associations, as well as changes in aggregate composition on saline-sodic soils).

Response 8: We thank the reviewer for highlighting this conceptual issue. The statement in lines 49–51 has been revised to correctly reflect the relationship between salinisation and aggregate stability. The revised text clarifies that salinisation is a driver of aggregate degradation due to ionic effects, particularly the dispersive role of exchangeable sodium and changes in electrolyte concentration, rather than a process that is counteracted by aggregation. This change corrects the cause–effect interpretation and aligns the introduction with the mechanisms discussed in later sections of the manuscript.

Comment 9: Lines 53–56: the first mention uses the abbreviations OM, POM, EPS and AMF without explanation, which undermines the terminological clarity of the introduction and makes it difficult for non-specialists in the relevant fields of soil science to read.

Response: We thank the reviewer for this comment. We have revised lines 53–56 to define all abbreviations at their first occurrence: OM (organic matter), POM (particulate organic matter), EPS (extracellular polymeric substances), and AMF (arbuscular mycorrhizal fungi). This ensures terminological clarity and improves readability for non-specialist readers.

Comment 10: Lines 53–56: the presentation is eclectic in nature, with a list of incompatible examples (OM/POM, EPS, AMF, "entanglement", "rhizodeposits", "glomalin") without a consistent framework of processes and levels of organisation, which obscures the systematic logic of soil structure formation; there is no distinction between the opposing processes that determine the aggregate state (aggregation vs. disaggregation) and the corresponding physicochemical and biotic mechanisms, as well as the " " there is no symmetrical consideration of destructive processes, despite the mention in the manuscript of "turnover and disintegration" as a component of the life cycle of aggregates.

Response 10: We thank the reviewer for this detailed and constructive comment. The section in lines 53–56 has been fully rewritten to provide a coherent conceptual framework. The revised text organizes the mechanisms of aggregation into physicochemical and biotic processes and introduces the corresponding disaggregation mechanisms such as mechanical disturbance, wetting–drying cycles, osmotic stresses, and chemical dispersion. This revision clarifies the balance between aggregation and disaggregation and aligns with the life-cycle perspective on aggregate turnover presented later in the manuscript.

Comment 11: Lines 60–68: the stated "physical (water retention), chemical (nutrient cycling), and biological (microbial activity) properties of soil" are presented as the sphere of "the role of soil aggregates," which shifts causality: the functions mentioned are determined by the parameters of soil structure as an integral system of pore space and particle contact, while aggregates are its elementary units and reflect the dynamic balance of aggregation and disaggregation. In this formulation, aggregates are effectively equated with the processes of water retention, gas and mass exchange, and microbial activity, which is methodologically incorrect and duplicates the previous vague statements about the "cornerstone".

Response 11: We appreciate the reviewer’s clarification. The text in lines 60–68 has been revised to restore the correct causal sequence linking aggregates, soil structure, and soil functions. The revised wording explains that aggregates act as the fundamental units of soil structure, while water retention, gas exchange, and microbial activity are regulated by structural properties such as pore size distribution and connectivity. This change removes the methodological ambiguity and ensures consistency with the conceptual framework presented in the manuscript.

Data analysis

Comment 12: Lines 73–74: the phrase "and other related terms" is vague and non-operational, making it impossible to reproduce the search strategy; at the same time, the list of keywords does not include the basic term "soil structure," although in the previous statement, it is precisely structure that is declared as the central category of analysis and the subject of discussion.

Response 12: We thank the reviewer for noting this issue. The phrase “and other related terms” has been removed, and the keyword list has been revised for clarity and reproducibility. The term “soil structure” has now been explicitly added to reflect its central role in the manuscript. This improvement ensures that the search strategy is transparent and consistent with the scope of the review.

Soil Structural Stability: Theoretical Foundations

Comment 13: Line 89 (also context 88–91): the phrase "Good soil structure" is an undefined evaluative label with no operational content or criteria for attribution, which contradicts the scientific accuracy of the section "Soil Structural Stability: Theoretical Foundations"; the absence of a definition of "good" makes it impossible to verify the statement about its impact on "gas and water transport, root penetration ..." and also creates a terminological gap between the description of "soil structure" and the subsequent mention of "erosion resistance" without linking it to specific structural parameters.

Response 13: We thank the reviewer for pointing out the imprecise use of the term “good soil structure.” The text in lines 88–91 has been revised to replace this evaluative wording with operational structural parameters, including aggregate stability, pore size distribution, and pore continuity. The revised text clarifies how these measurable features influence gas exchange, water movement, root penetration, and erosion resistance, thereby improving the scientific accuracy of this section.

Comment 14: Lines 91–92: the phrase “Formation of the structural units of soil (soil aggregates)” contains the arbitrary term “structural units of soil”, which does not correspond to the established nomenclature of soil morphological organisation; such wording blurs the boundaries between concepts and creates terminological ambiguity in the presentation

Response 14: We thank the reviewer for pointing out the terminological ambiguity. The phrase “structural units of soil” in lines 91–92 has been replaced with the scientifically accurate wording “soil aggregates, which are the fundamental building blocks of soil structure.” This revision aligns the terminology with established soil morphological nomenclature and eliminates ambiguity.

Comment 15: Lines 100–105: double repetition of the same content regarding the definition/measurement of aggregate stability — first, "It is usually expressed as the percentage of aggregates that remain after being exposed to destabilising stress", then almost verbatim, "The percentage of aggregates that remain after being exposed to destabilising stress is typically used to quantify aggregate stability.

Response 15: We thank the reviewer for this observation. The duplicate sentences defining aggregate stability in lines 100–105 have been removed. They have been replaced with a single concise and scientifically precise definition describing how aggregate stability is quantified. This revision improves clarity and eliminates redundancy.

Comment 16: The size classes of aggregates used by the authors should be defined. Usually, a distinction is made between microaggregates (< 0.25 mm), mesoaggregates (0.25–10 mm) and macroaggregates (> 10 mm). Aggregates are also distinguished as true (having internal porosity) and false (solid), as well as water-stable and water-unstable. It is true water-stable mesoaggregates that are considered to be of agronomic value (providing the same value and soil health).

Response 16: We appreciate the reviewer’s clarification regarding aggregate size classes and morphological distinctions. The manuscript has been revised to include explicit definitions of microaggregates (< 0.25 mm), mesoaggregates (0.25–10 mm), and macroaggregates (> 10 mm), as well as the distinction between true and false aggregates. We have also incorporated the reviewer’s note regarding water-stable and water-unstable aggregates and clarified the agronomic importance of water-stable mesoaggregates. This addition enhances the precision and completeness of the structural framework used throughout the review.

Comment 17: Lines 133–136: The statement "macroaggregates and larger soil aggregates are closely related to higher microbial activities... due to ... stable environments" is questionable, since macroaggregates usually form a more porous environment with increased aeration and rapid gas exchange, which does not ensure the "stability" of microenvironments and may limit the activity of moisture-loving microbial taxa; the above generalisation does not take into account the opposite effects of hyperaeration and higher moisture variability in the interporous space of large aggregates.

Response 17: Thank you for the comment. The text in lines 133–136 has been revised to remove the inaccurate generalisation about macroaggregates providing stable environments. The revised wording clarifies that macroaggregates create more aerated and dynamic conditions, while microaggregates offer more stable moisture and chemical environments. This correction reflects the contrasting microhabitats and aligns with established microbial–aggregate interactions.

Comment 18: Lines 149–153: The ambiguous phrase "soil aggregate structure" is used, which confuses at least three different concepts: 1) soil aggregates (individual aggregates as elements), 2) soil structure (spatial organisation of the soil body and pore space), 3) internal structure of the aggregate (intra-aggregate structure). In the given sentence, it is unclear whether it refers to the internal organisation of aggregates that affects wetting and destruction, or to the structure of the soil as a whole system that determines infiltration and permeability.

Response 18: We agree with the reviewer that the phrase “soil aggregate structure” was ambiguous. The text has been revised to specify “the internal structure of aggregates,” which accurately reflects the intended meaning in the context of wetting and breakdown. This correction eliminates terminological confusion between aggregates, soil structure, and intra-aggregate organisation.

Comment 19: Lines 168–170: The statement that "larger but less stable macroaggregates enhance the hydraulic properties ... by increasing the saturated hydraulic conductivity" is an overgeneralisation; aggregate size is not a reliable predictor of hydraulic properties, and the mere presence of macroaggregates does not guarantee an increase in conductivity. The coexistence of fractions of different sizes significantly modifies flows: even a small proportion of microaggregates, when macroaggregates dominate, can clog cracks and interaggregate channels, sharply reducing saturated hydraulic conductivity and infiltration; The wording given in the manuscript ignores this well-known competition between pore scales.

Response 19: We appreciate the reviewer’s clarification. The text in lines 168–170 has been revised to remove the overgeneralisation that macroaggregates inherently increase saturated hydraulic conductivity. The revised wording explains that hydraulic properties depend on macropore continuity and interactions between pore scales, including potential clogging by smaller aggregates. This correction aligns the manuscript with established soil physics principles.

Comment 20: Lines 187–189: the statement "Macro-aggregates with a size larger than 0.25 mm are essential for SOC storage..." is presented without reference to the accepted size classification and contains a terminological inconsistency: in many schemes, the fraction >0.25 mm to 10 mm is referred to as meso-aggregates, not macro-aggregates; therefore, there is no verification of the boundary and category used.

Response 20: Thank you for the clarification. The text in lines 187–189 has been revised to reflect the accepted size classes by specifying that aggregates in the 0.25–10 mm range (mesoaggregates) are important for SOC storage. We also clarified the distinction between meso- and macroaggregates and revised the explanation of their roles in SOC protection. This correction resolves the terminological inconsistency.

Comment 21: Lines 209–216, 219–226: the text does not differentiate the role of aggregate fractions for different types of erosion. For water erosion, the decisive factor is the proportion of water-resistant lumps >10 mm, which increase the micro- and macro-roughness of the surface; effectiveness is limited by the durability of these lumps. For wind erosion, the presence of fine particles and aggregates <0.25 mm, which are prone to blowing away, is critical. Generalisations about "aggregate stability" without reference to size classes distort the causality of the processes described.

Response 21: The point raised has been taken care of and the information has been accordingly reassessed.

Comment 22: Lines 246–249: the list of "biotic (plant roots, fungi, SOM) and abiotic (inorganic materials) binding agents and processes" is overly narrow and does not represent the diversity of both aggregation and disaggregation processes; key abiotic mechanisms are missing (moisture-induced swelling/shrinking cycles, wetting-drying, freezing-thawing, droplet impact, delamination and slaking), as well as biotic processes of pedo- and bioturbation, particle transit through the intestines of macrofauna, and fragmentation of plant residues; at the same time, the statement about SOM as a "primary factor" is generalising and does not take into account that in the hierarchical model, part of the aggregates are formed due to mineral-cation bridges and organo-mineral complexes without the dominance of SOM. Such a reduction contradicts later sections of the manuscript, which already recognise the role of various biotic agents and processes of destruction/turnover.

Response 22: The list of binding agents and processes in lines 246–249 has been revised to include a broader range of biotic and abiotic mechanisms that contribute to both aggregation and disaggregation. We also clarified that, in addition to SOM-driven binding, aggregates can form through mineral–cation bridges and organo-mineral interactions. This revision corrects the earlier oversimplification and aligns the section with the hierarchical model presented later in the manuscript.

Comment 23: Lines 281–292: the presentation overly generalises "clay minerals" and does not reflect the known contrasts between clay types and the cation composition of the soil solution. The influence of montmorillonite, illite, and kaolinite on aggregation and stability varies significantly; the difference between the effects of Na⁺ and Ca²⁺/Mg²⁺ (dispersion/flocculation) is critical, as is the role of Fe/Al oxides and humic substances in organo-mineral binding — these aspects are not articulated in the paragraph. The formula about "specific cation effects (e.g., potassium and sodium) ... through non-classical polarisation" is presented without sufficient context of the mechanism and limits of applicability, despite the presence of a relevant reference; also, the statement about "intense attraction ... constructive distance ... due to compression" leaves unclear the conditions under which such compression is realised.

Response 23: We are grateful for pointing this out. We have tried to present information in a clearer way and also tried to specify how different minerals may differ in their impact on soil aggregate stability under different cationic milieu.

Comment 24: Lines 625–638: Tillage's consideration is too formal and does not take into account the decisive dependence of the aggregate structure on soil moisture during tillage; there is no mention of the narrow "window" of optimal moisture content, which narrows sharply in arid conditions to a few days, while it is precisely this that determines the proportion of water-resistant aggregates after mechanical impact. It is also not specified that the effects of tillage on infiltration/compaction and erosion sensitivity are contrasting at different moisture and structural conditions, despite the statements about the destruction of aggregates, changes in density and microbial activity.

Response 24: Yeah agree, The section in lines 625–638 has been revised to emphasise the critical role of soil moisture during tillage and the concept of an optimal moisture window, which is particularly narrow in arid regions. We also clarified that tillage effects on aggregate stability, infiltration, compaction, and erosion risk depend on whether operations occur within or outside this moisture window. This revision removes the earlier oversimplification and presents the contrasting structural outcomes more accurately.

Round 2

Reviewer 1 Report

Comments and Suggestions for Authors

The reviewer acknowledges the authors' efforts in revising the manuscript, although some issues remain. In particular, no substantial changes were made to Table 1, only the reference numbers were updated. For example, a single citation on water infiltration or carbon sequestration is insufficient. Additionally, Table 2, although added, could be further developed. The use of ± symbols to indicate positive or negative effects is unnecessary, as the nature of these effects is already clear. Bibliographic references are also missing, as reported in Table 1. That said, the overall quality of the work has improved.

Author Response

Comment: The reviewer acknowledges the authors' efforts in revising the manuscript, although some issues remain. In particular, no substantial changes were made to Table 1, only the reference numbers were updated. For example, a single citation on water infiltration or carbon sequestration is insufficient. Additionally, Table 2, although added, could be further developed. The use of ± symbols to indicate positive or negative effects is unnecessary, as the nature of these effects is already clear. Bibliographic references are also missing, as reported in Table 1. That said, the overall quality of the work has improved.
Response: We sincerely thank the reviewer for their constructive feedback and appreciation of our revisions. We have revised Table 1 by adding additional citations and ensured that all missing references are now included. Table 2 has also been further developed, and the unnecessary ± symbols have been removed. We appreciate the reviewer’s feedback, which helped improve the quality of our manuscript.

Reviewer 3 Report

Comments and Suggestions for Authors

Author Response

The authors have provided comprehensive responses to all reviewer comments and have made appropriate revisions to the manuscript, which has substantially improved its quality. In its revised form, I consider the manuscript suitable for publication.
Response:
We sincerely thank the reviewer for the positive assessment and supportive comments. We are grateful that the revisions were found appropriate and that the improved manuscript is now considered suitable for publication. We appreciate the reviewer’s time and thoughtful evaluation.