Limited Short-Term Impact of Annual Cover Crops on Soil Carbon and Soil Enzyme Activity in Subtropical Tree Crop Systems
Round 1
Reviewer 1 Report
Comments and Suggestions for Authors
Dear authors,
Even if your treatments show a lack of residual effects, I believe a basic statistical analysis should still be performed on your data, especially since you are comparing results over time and between sites. Additionally, there is a lack of discussion regarding the relationship between cover crops and weeds in relation to the observed results.
Author Response
Comment: Even if your treatments show a lack of residual effects, I believe a basic statistical analysis should still be performed on your data, especially since you are comparing results over time and between sites. Additionally, there is a lack of discussion regarding the relationship between cover crops and weeds in relation to the observed results.
Response: Significance testing was carried out for each variable, and each site was determined to be an independent dataset. This fit with our own knowledge of the sites, with slightly varied soils, management and climate histories. Therefore, while all results were reported, analysis of differences between sites was not deemed appropriate.
As stated in the methods:
Dependency between sites for winter and summer biomass production was assessed using the Granger test (lmtest v 0.9-40; [14]). Winter and summer biomass datasets for all sites were found to be independent of each other. Normality of biomass data was assessed using a Shapiro-Wilk test. Biomass from the winter and summer cuts at all sites were found to be significantly (P < 0.05) non-normal distributed. Therefore, biomass production in treatments was assessed for significant differences using a Kruskal-Wallis test and a significance level of 0.05. These steps were carried out using the native R functions [15].
For each soil variable, dependency between sites was tested using the Granger test. All sites were found to be independent, and therefore differences in soil properties between the control and cover crop treatments were determined for each site individually. For each site, a linear mixed model was created examining treatment, sampling date and their interaction as fixed effects, and block as a random effect on each soil variable. Significant differences between treatments, sampling dates and their interactions were then assessed using an ANOVA and post-hoc testing was conducted using estimated marginal means. This utilised the lme4 (v 1.1-37; [16]) and emmeans (v 1.11.0; [17]) packages in R.
Reviewer 2 Report
Comments and Suggestions for Authors
Comments and suggestions
Title: Limited short-term impact of annual cover crops on soil carbon and soil enzyme activity in subtropical tree crop systems
Authors: Abraham J. Gibson / Lee. J Kearney / Karina Griffin / Michael T. Rose / Terry J. Rose1
Manuscript number: agronomy-3708698
Summary of the manuscript:
The manuscript examines different methods of applying cover crops in plantations. These processes are involved in soil carbon turnover and also determine enzymatic processes. The authors sought to determine the effect of short-term cover crops planted between existing perennial ground covers on several key soil functions and parameters. These treatments were compared with control treatments that did not include cover crops.
The research topic and its results scope fits the aims of the journal. This study is a new and valuable contribution to an international journal. It is suitable for publication in the Agronomy journal. The experiment was meticulously designed, and the study provided a large amount of good quality data. The authors used well-chosen and appropriate methods for this study. The data are generally well presented.
The Abstract is appropriately concise and sufficiently detailed. In any case, it summarizes the essential elements of the manuscript well and is attention-grabbing.
Keywords: They are relevant. However, it would be advisable to replace those that are also included in the title of the manuscript. This will give you more options for searching for the manuscript after it is published.
The Introduction chapter supports and complements the research topic of the manuscript. The introductory chapter contains appropriate and timely references. These prove that the Authors have compared their research with the experiences of previous research on similar topics. The references used in this chapter are timely and fresh.
I would like to note that the Latin names of several plants are mentioned in the chapter by the Authors, correctly. However, the Latin names should always be written in italics.
For example: Persea americana Mill. I suggest that this be checked and corrected throughout the manuscript.
Line 45, 52, 53. In many cases, the powers are not represented correctly. These need to be standardized because they are extremely confusing to read.
Line 61 This claim should be supported by further references.
Since one of the main questions of the study is soil biology and the effects of enzymes in the soil, it would be necessary to supplement this chapter here. The same is true for soil carbon turnover.
It would certainly be good to highlight here what soil biology and soil carbon turnover experiences have been gained by previous researches in similar (subtropical) areas. In my opinion, such research exists, but if not, then similar soil biology research experiences could be mentioned, and how they are related to cover crops and cultivated plants.
Line 70-71 This sentence should be rephrased a bit. Because it is not correct to say " is not known".... it would be better to say "not fully known" or "many functions of cover crops are not yet known...".
Based on literature data, functions that can characterize cover crops should be mentioned, e.g. attracting pollinating insects to the plantations (suggested reference: Ferschl et al. (2024) Effects of Species-Rich Perennial Inter-Row Cover on Weed Flora and Soil Coverage in an Apple Orchard: A Case Study of Opportunities and Limitations in a Dry Continental Climate.), influencing soil organic matter, improving structure, determining water balance.
The last paragraph of the chapter, which outlines the objective, will now be more appropriate if supplemented with the above modification. Of course, the above examples should be supported by further literature.
The Methods are appropriate and sufficiently detailed.
Line 81-84. The sampling / research area has been presented properly. However, I would suggest that a map be included in this chapter, where the sampling area is clearly marked. This is very important because it helps in the later use of the data and results generated during the investigation. I would also suggest that the GPS coordinates be marked.
Similarly to the above, a more detailed description of laboratory testing methods is necessary, especially since many methods are currently used to measure different carbon/organic matter fractions in soil, and this is necessary for the comparability of results. I also recommend referencing the measurement methods.
Line 155 The title of chapter 2.3 is incorrect. It details soil sampling and preparation, not soil function methodology.
I suggest that there should be two new subheadings. The first should be a definition of soil silt and nitrogen forms, and the second should be a description of soil functions.
Results: the interpretation of results is generally proper. Results chapter is very detailed, but this is due to a large amount of data and analysis used for the manuscript. These chapters are well-structured and properly constructed. This chapters provide detailed and perfectly summarizes the new and novel results. It contains a number of useful experience and findings.
The authors show the results in tabular and figure form and its show a lot of results. Evaluation of these results is appropriate and draws realistic conclusions in the next chapter (Discussion). On the other hand, it make useful and interesting findings that may be interested.
In my opinion, the many figures used are very clear and detailed. The figures are essential for interpreting the results. They are illustrative, practical and needed to illustrate the results and the statements.
Line 220-222 In my opinion, this part was left in the chapter by accident. It is not necessary.
Discussion: The interpretations and the conclusions are sound and justified by the data. Discussion is also too detailed, but it sums up the results correctly, which also results from the analysis of large amounts of data. It does not draw far-reaching conclusions, only realistic conclusions. It also well-structured and properly constructed. It provides an adequate evaluation of the results obtained compared to other similar research experiences.
The manuscript is suitable for publication after the above corrections. Interesting and very nice work. I wish the Authors much success.
Author Response
Comment: Keywords: They are relevant. However, it would be advisable to replace those that are also included in the title of the manuscript. This will give you more options for searching for the manuscript after it is published.
Response: Soil carbon and soil enzyme activity have been replaced with soil function.
Comment: I would like to note that the Latin names of several plants are mentioned in the chapter by the Authors, correctly. However, the Latin names should always be written in italics.
For example: Persea americana Mill. I suggest that this be checked and corrected throughout the manuscript.
Response: These have been updated throughout the manuscript.
Comment 3: Line 45, 52, 53. In many cases, the powers are not represented correctly. These need to be standardized because they are extremely confusing to read.
Response: These have been corrected.
Comment: Line 61 This claim should be supported by further references.
Response: More references have been added:
[12] Abad FJ, Marín D, Imbert B, Virto I, Garbisu C, Santesteban LG (2023) Under-vine cover crops: Impact on physical and biological soil proprieties in an irrigated Mediterranean vineyard. Sci Hortic 311:111797 https://doi.org/10.1016/j.scienta.2022.111797
[13] Liu C-Y, Wang Y-y, Chen X-y, Tan H, Jin X-m, Lu Q, He S-b, Long M-X (2022) Cover cropping increases soil fungal-bacterial community diversity and network complexity in apple orchards on the Loess Plateau, China. Front Environ Sci 10:916288 doi:10.3389/fenvs.2022.916288
[14] Rubio-Asensio, J.S.; Abbatantuono, F.; Ramírez-Cuesta, J.M.; Hortelano, D.; Ruíz, J.L.; Parra, M.; Martínez-Meroño, R.M.; In-trigliolo, D.S.; Buesa, I. Effects of Cover Crops and Drip Fertigation Regime in a Young Almond Agroecosystem. Agronomy 2022, 12, 2606. https://doi.org/10.3390/agronomy1211260
Comment: Since one of the main questions of the study is soil biology and the effects of enzymes in the soil, it would be necessary to supplement this chapter here. The same is true for soil carbon turnover.
It would certainly be good to highlight here what soil biology and soil carbon turnover experiences have been gained by previous researches in similar (subtropical) areas. In my opinion, such research exists, but if not, then similar soil biology research experiences could be mentioned, and how they are related to cover crops and cultivated plants.
Response: Supplemental references and this section has been updated to:
“A number of studies have observed increases in soil biology measures, soil carbon (C) and soil functional indices due to the use of cover crops in perennial tree crop systems [1, 11,12,13,], however, most studies examine the effects of annual cover crops species compared to bare fallow controls. When comparing a cover crop to a fallow, it could be expected that there is a large scope to shift the soil microbiome and soil function parameters because of the substantial difference in C inputs and then further nutrient cycling shifts as a result of increased organic matter.”
Comment: Line 70-71 This sentence should be rephrased a bit. Because it is not correct to say " is not known".... it would be better to say "not fully known" or "many functions of cover crops are not yet known...".
Response: This has been updated to “Improved soil biological function due to the use of mixed-species annual cover crops in the inter-row of tree crops where permanent groundcover exists has not been demonstrated.”
Comment: Based on literature data, functions that can characterize cover crops should be mentioned, e.g. attracting pollinating insects to the plantations (suggested reference: Ferschl et al. (2024) Effects of Species-Rich Perennial Inter-Row Cover on Weed Flora and Soil Coverage in an Apple Orchard: A Case Study of Opportunities and Limitations in a Dry Continental Climate.), influencing soil organic matter, improving structure, determining water balance.
The last paragraph of the chapter, which outlines the objective, will now be more appropriate if supplemented with the above modification. Of course, the above examples should be supported by further literature.
Response: Line 75 has been updated to reflect that soil carbon and enzyme processes are the key category of impact being investigated in the study. The reference has been added.
Comment: Line 81-84. The sampling / research area has been presented properly. However, I would suggest that a map be included in this chapter, where the sampling area is clearly marked. This is very important because it helps in the later use of the data and results generated during the investigation. I would also suggest that the GPS coordinates be marked.
Response: Given the small scale of the experiment and separation of the sites across the region, a site/experiment map was not aesthetic or useful and so not included.
Comment: Similarly to the above, a more detailed description of laboratory testing methods is necessary, especially since many methods are currently used to measure different carbon/organic matter fractions in soil, and this is necessary for the comparability of results. I also recommend referencing the measurement methods.
Response: References have been added and clarifications made to the methods.
Comment: Line 155 The title of chapter 2.3 is incorrect. It details soil sampling and preparation, not soil function methodology.
I suggest that there should be two new subheadings. The first should be a definition of soil silt and nitrogen forms, and the second should be a description of soil functions.
Response: This change has been made.
Comment: Line 220-222 In my opinion, this part was left in the chapter by accident. It is not necessary.
Response: This has been removed.
Reviewer 3 Report
Comments and Suggestions for Authors
Introduction
I missed information that supported the study's hypotheses. Is there any evidence that perenial ground covers (sole) and cover crops (togather with ground cover) could result in similar/diferente benefits to soil quality?
I would like to suggest including information about the soi analyses used. Especially the enzymes and protein.
Material and methods
Ln 81-87: Is it posssible to include the soil chemical properties, texture, any other relevant attribute.
Ln 81-87: the year preciptation was far above the anual mean
Ln 166: LECO combustion? Isnt LECO the equipament manufacturer? The method name might be Dry combustion
There were only two treatments in each site? how many replicates per treatments? How the plots were allocated in the field?
Results
Ln 220-222: remove
Author Response
Comment: I missed information that supported the study's hypotheses. Is there any evidence that perennial ground covers (sole) and cover crops (together with ground cover) could result in similar/different benefits to soil quality?
Response: No, but ecological theory and general studies on plant diversity suggest that greater plant diversity leads to greater soil resilience. For example, Cappelli et al. 2024 reported that increasing plant diversity increased soil microbial diversity and soil function. We therefore examined whether increasing diversity of plants through annual cover crops could improve soil function where perennial groundcovers already existed.
Cappelli SL, Domeignoz-Horta LA, Loaiza V, Laine A-L (2022) Plant biodiversity promotes sustainable agriculture directly and via belowground effects. Trends in Plant Science 27, 675-687. https://doi.org/10.1016/j.tplants.2022.02.003
Comment: I would like to suggest including information about the soil analyses used. Especially the enzymes and protein.
Response: Line 75 has been updated to more clearly identify the target parameters.
Comment: Ln 81-87: Is it possible to include the soil chemical properties, texture, any other relevant attribute.
Response: These have been added as Table 1.
Comment: Ln 81-87: the year precipitation was far above the annual mean
Response: No change has been made as annual rainfall is given in the previous sentence.
Comment: Ln 166: LECO combustion? Isn’t LECO the equipment manufacturer? The method name might be Dry combustion
Response: This has been changed to dry combustion.
Comment: There were only two treatments in each site? how many replicates per treatments? How the plots were allocated in the field?
Response: Line 97-100 has been updated to “Cover crop treatments were established as three individual 10-m-long plots within a single inter-row. These were each interspersed with 10-m-long control (no cover crop) plots (i.e., three replicates).”
Lines 119-120 have been updated to: Three treatment plots comprised the entire inter-row length of the 40-m-long rows, with alternate inter-rows designated as control or cover crop plots (i.e., three replicates).
Comment: Ln 220-222: remove
Response: This has been removed.
Reviewer 4 Report
Comments and Suggestions for Authors
This study examined the effects of inter-seeding annual cover crops into perennial ground covers on soil functions in humid subtropical Australian orchards. While annual cover crops increased inter-row biomass, they suppressed perennial ground covers, causing bare soil exposure and elevated erosion risk. Management decisions must consider not only biomass and soil carbon, nitrogen but also the sustainability of perennial crops and erosion control. I recommend major revision, below are my suggestions:
1.Title: The current title misrepresents findings. It implies minimal impact on soil functions, yet the coffee plantation showed significant erosion risk. Revise to accurately reflect both limited soil benefits and increased erosion potential.
2.Introduction: While the overall logic of the Introduction is coherent, lines 56–69, which present the rationale for the study, are seriously under-supported by scientific literature. The authors should cite relevant studies to strengthen these arguments. Additionally, lines 70–79 articulate the study's objectives, but the core content should be concisely stated as follows: "to evaluate the effects of inter-seeding annual cover crops into existing perennial ground covers on soil carbon, nutrient cycling, and biomass production in commercial plantations in the humid subtropics, and to investigate the potential benefits and risks of this practice." The current wording is unnecessarily verbose and should be revised for clarity.
Materials and Methods: The study analyzes soil carbon, nitrogen, and nutrient cycling-related enzyme activities when annual cover crops are sown among perennial ground covers across three plantations. To enhance data reliability, please indicate that the number of replicate plots (n) at each site is at least three. Given that bare soil exposure, despite significant biomass gains was observed in the coffee plantation, I recommend including a soil aggregate stability analysis. This parameter sensitively reflects subtle changes in soil structure resulting from management practices.
Results:
At line 223, increases and decreases in biomass should be converted to annual total biomass, and results should directly compare control and treatment groups. Furthermore, discuss whether increased biomass can translate into economic benefits (i.e., how much additional profit could result), as this information is valuable for growers' decision-making.
At line 253, Supplementary Figure 1 is not present in the supplementary materials, so the findings regarding bare soil coverage cannot be verified. Ensure all supplementary figures are provided.
Lines 266–409 mainly compare temporal variations by sampling time, which are likely due to rainfall and climate. The manuscript's main objective, however, should be the differences between control and treatment groups. Please supplement the information with direct comparisons of key soil parameters between these groups.
For Figures 2 and 3 (lines 399 and 410), consider converting these into bar charts with an additional column for the mean across the five sampling periods. This would clarify the results and facilitate direct comparison between control and treatment groups. Overall, the results section is quite disorganized and currently lacks effective, interpretable data presentation.
Discussion: The authors should first summarize their main findings before proceeding to in-depth discussion in the context of existing literature. For example, lines 462–486 do not indicate which results are under discussion—this should be improved. I suspect this section relates to Table 2, but currently, supporting references are insufficient. Please incorporate recent literature to provide a more robust, stepwise discussion.
Conclusions: The current results do not adequately support the main conclusions of the manuscript.
Minor Corrections:
Line 53: Correct to superscript.
Line 163: Unify the abbreviation for total soil nitrogen (currently “SN” in line 163, “TN” in line 166 and 277), please use one consistently, preferably “TN” throughout the manuscript.
Line 166: Provide the full name for “LECO” at first use.
Line 167: If soil organic carbon is equivalent to total carbon, use “TC” consistently throughout.
Lines 196–202: Add a reference for the soil protein extraction method.
Line 208: Use a lowercase “p” if referring to a statistical p-value.
Line 218: The final sentence appears incomplete, please add the necessary information (e.g., “R version x.x.x”).
Lines 220–222: Remove irrelevant content not related to the paper.
Line 227: “ha-1” should be formatted as a superscript (ha⁻¹). Check for similar errors elsewhere (e.g., lines 501 and 503).
Line 247: Fig.2e cannot be found in the manuscript.
Line 493: Remove “e.g.,”.
Line 605: Separate this into two parts, place references in a standalone paragraph.
Author Response
Comment: The current title misrepresents findings. It implies minimal impact on soil functions, yet the coffee plantation showed significant erosion risk. Revise to accurately reflect both limited soil benefits and increased erosion potential.
Response: While we agree the impacts to the perennial species exacerbates erosion risk, erosion was not measured as part of the study. Therefore, we do not feel it should be included in the title.
Comment: While the overall logic of the Introduction is coherent, lines 56–69, which present the rationale for the study, are seriously under-supported by scientific literature. The authors should cite relevant studies to strengthen these arguments. Additionally, lines 70–79 articulate the study's objectives, but the core content should be concisely stated as follows: "to evaluate the effects of inter-seeding annual cover crops into existing perennial ground covers on soil carbon, nutrient cycling, and biomass production in commercial plantations in the humid subtropics, and to investigate the potential benefits and risks of this practice." The current wording is unnecessarily verbose and should be revised for clarity.
Response: additional references and clarity has been made to Lines 56-69. Lines 70-79 have been updated to:
“Improved soil biological function due to the use of mixed-species annual cover crops in the inter-row of tree crops where permanent groundcover exists has not been demonstrated. The aim of the present study was therefore to examine the impact of short-term cover crops over-sown into existing perennial groundcovers on soil C and N, protein and enzyme activity. These were compared to control treatments with no annual cover crops, across three typical tree crop systems in the subtropics. If additional benefits are not generated, then the cost of implementing this practice is a direct loss for farm decision-makers. This study therefore aims to generate this information for informed decision making and investment regarding the sustainability of perennial tree cropping systems. This information is further important for demonstrating sustainability credentials within the industry. “
Comment: The study analyzes soil carbon, nitrogen, and nutrient cycling-related enzyme activities when annual cover crops are sown among perennial ground covers across three plantations. To enhance data reliability, please indicate that the number of replicate plots (n) at each site is at least three. Given that bare soil exposure, despite significant biomass gains was observed in the coffee plantation, I recommend including a soil aggregate stability analysis. This parameter sensitively reflects subtle changes in soil structure resulting from management practices.
Response: The methods have been updated to indicate three replicates were used:
Line 97-100 has been updated to “Cover crop treatments were established as three individual 10-m-long plots within a single inter-row. These were each interspersed with 10-m-long control (no cover crop) plots (i.e., three replicates).”
Lines 119-120 have been updated to: Three treatment plots comprised the entire inter-row length of the 40-m-long rows, with alternate inter-rows designated as control or cover crop plots (i.e., three replicates).
Soil aggregate stability is beyond the scope and not able to be included as samples have been crushed.
Comment: At line 223, increases and decreases in biomass should be converted to annual total biomass, and results should directly compare control and treatment groups. Furthermore, discuss whether increased biomass can translate into economic benefits (i.e., how much additional profit could result), as this information is valuable for growers' decision-making.
Response: This change has not been made as the annual species do not persist for 12 months, and so it is more accurate to present biomass production over the period they are present in the groundcover. The cover crops are not harvested or harvestable so no extra profit can be calculated.
Comment: At line 253, Supplementary Figure 1 is not present in the supplementary materials, so the findings regarding bare soil coverage cannot be verified. Ensure all supplementary figures are provided.
Response: This has been added and text updated.
Comment: Lines 266–409 mainly compare temporal variations by sampling time, which are likely due to rainfall and climate. The manuscript's main objective, however, should be the differences between control and treatment groups. Please supplement the information with direct comparisons of key soil parameters between these groups.
Response: Significant differences between treatments are presented in Table 5, while comparison of treatments is frequently made throughout the text of the results.
Comment: For Figures 2 and 3 (lines 399 and 410), consider converting these into bar charts with an additional column for the mean across the five sampling periods. This would clarify the results and facilitate direct comparison between control and treatment groups. Overall, the results section is quite disorganized and currently lacks effective, interpretable data presentation.
Response: Comparison is made in text and line graphs are more appropriate for timeseries or repeat measures. We are inclined to leave the line figures as it allows all sites to be presented.
Comment: The authors should first summarize their main findings before proceeding to in-depth discussion in the context of existing literature. For example, lines 462–486 do not indicate which results are under discussion—this should be improved. I suspect this section relates to Table 2, but currently, supporting references are insufficient. Please incorporate recent literature to provide a more robust, stepwise discussion.
Response: A brief summary has been given at the start of the introductory paragraph of the discussion; “The biomass production from annual cover crops was not sufficient to shift the soil function parameters measured.”
Comment: The current results do not adequately support the main conclusions of the manuscript.
Response: The conclusion has been updated to:
“Any integration of annual cover crops in tree crop systems with endemic perennial groundcovers needs to be appropriate for regional conditions. Where summer growing perennials are present, over-sowing winter annuals can produce more biomass overall without impacting on the persistence of the perennial groundcovers. Vigorous annual summer cover crops can produce additional biomass. However, there was little, positive impact on soil function parameters. Further, high biomass production can risk killing permanent summer growing perennials, creating bare ground which is then susceptible to erosion. Whether lower seeding rates to avoid intense competition could enable integration of summer cover crops without detrimental effects on perennial groundcovers is not known.
Comment: Line 53: Correct to superscript.
Response: Corrected
Comment: Line 163: Unify the abbreviation for total soil nitrogen (currently “SN” in line 163, “TN” in line 166 and 277), please use one consistently, preferably “TN” throughout the manuscript.
Response: there is one instance of TN, which has been changed to SN for soil nitrogen as outlined in the abbreviations.
Comment: Line 166: Provide the full name for “LECO” at first use.
Response: This has been changed to dry combustion.
Comment: Line 167: If soil organic carbon is equivalent to total carbon, use “TC” consistently throughout.
Response: We have not made this change as TC is equivalent to SOC, which is a more widely accepted and understood indicator of soil health/function.
Comment: Lines 196–202: Add a reference for the soil protein extraction method.
Response: Reference has been added:
Stott, D.E., 2019. Recommended Soil Health Indicators and Associated Laboratory Procedures. Soil Health Technical Note No. 450-03. U.S. Department of Agriculture, Natural Resources Conservation Service.
Comment: Line 208: Use a lowercase “p” if referring to a statistical p-value.
Response: This has been updated.
Comment: Line 218: The final sentence appears incomplete, please add the necessary information (e.g., “R version x.x.x”).
Response: Added.
Comment: Lines 220–222: Remove irrelevant content not related to the paper.
Response: Removed.
Comment: Line 227: “ha-1” should be formatted as a superscript (ha⁻¹). Check for similar errors elsewhere (e.g., lines 501 and 503).
Response: Formatting corrected.
Comment: Line 247: Fig.2e cannot be found in the manuscript.
Response: This has been changed to “Figure 2”.
Comment: Line 493: Remove “e.g.,”.
Response: Removed.
Comment: Line 605: Separate this into two parts, place references in a standalone paragraph.
Response: Unclear what this is referring to as 605 is the final line in the manuscript.
Round 2
Reviewer 1 Report
Comments and Suggestions for Authors
Dear authors, thanks for the better statistical explanation. I think that now the article sound better and can be publisehd.
Author Response
Comment: Dear authors, thanks for the better statistical explanation. I think that now the article sound better and can be published.
Response: Thank your for your review.
Reviewer 2 Report
Comments and Suggestions for Authors
The authors have revised the manuscript accordingly in response to the review. The previous version of the manuscript has been revised based on my latest review, the suggestions and comments have been reviewed in detail, and the manuscript has been modified accordingly. With these changes and additions, the manuscript is suitable for publication in the journal. I have no further suggestions or requests regarding the manuscript. I recommend the manuscript for publication in its current form.
Thank you. Excellent work.
I wish the authors much more success!
Author Response
Comment:
The authors have revised the manuscript accordingly in response to the review. The previous version of the manuscript has been revised based on my latest review, the suggestions and comments have been reviewed in detail, and the manuscript has been modified accordingly. With these changes and additions, the manuscript is suitable for publication in the journal. I have no further suggestions or requests regarding the manuscript. I recommend the manuscript for publication in its current form.
Thank you. Excellent work.
I wish the authors much more success!
Response: Thank you for your review.
Reviewer 3 Report
Comments and Suggestions for Authors
Dear authors,
Everything looks fine.
I just missed information about the enzymes in the introduction (why choose these specfic set of soil enzymes, which soil functions are they related). But is just a suggestion.
Ln 205: reference number incorrect
Author Response
Comment: I just missed information about the enzymes in the introduction (why choose these specfic set of soil enzymes, which soil functions are they related). But is just a suggestion.
Response: We now see the original intent of this comment. We have added that the soill enzymes are associated with the cycling of nutrients to the soil to the introduction (Line 75), and added justification of their selection to the methods and referred (Line 206-207).
Comment: Ln 205: reference number incorrect
Response: This has been corrected.
Reviewer 4 Report
Comments and Suggestions for Authors
Although the manuscript’s overall academic quality has improved following the authors' revisions, there are still some important issues that need to be addressed.
1.The revised manuscript places further emphasis on the finding that high-yield summer cover crops in coffee plantations suppress and even eliminate perennial groundcover species, resulting in exposed bare inter-row soil within three weeks after sowing. However, the title suggests the effects are limited, which is contradictory. The authors should address this inconsistency and clarify whether the impact is significant or limited.
2. I suggest that the authors consider using bar charts instead of the current figures. This would allow for a clearer comparison between the control and cover crop treatments at each sampling time, helping to better visualize the differences in results.
3. Although the authors state that statistical analysis was conducted, it appears they mainly compared the averaged values across the five time points. The research area experiences extremely significant differences in rainfall between March and September, so comparing across different seasons may not be meaningful or relevant to the main findings.
4. The issue of superscripts mentioned previously still persists in several places (e.g., lines 513 and 515). Please ensure all such issues are thoroughly corrected.
Author Response
Comment: The revised manuscript places further emphasis on the finding that high-yield summer cover crops in coffee plantations suppress and even eliminate perennial groundcover species, resulting in exposed bare inter-row soil within three weeks after sowing. However, the title suggests the effects are limited, which is contradictory. The authors should address this inconsistency and clarify whether the impact is significant or limited.
We appreciate this concern; however, we do not agree that this is inconsistent with the title. as this was not a measured parameter, with the title explicitly stating the cover crops had limited impact on soil carbon and soil enzyme activity. If we had measured biomass production after the cover crops or some form of legacy effect or soil erosion than it would be included. We think this observation is still worth highlighting from a farmer participatory framework that the research is based on, but without quantification it cannot be included in the title.
Comment: I suggest that the authors consider using bar charts instead of the current figures. This would allow for a clearer comparison between the control and cover crop treatments at each sampling time, helping to better visualize the differences in results.
and
Comment: Although the authors state that statistical analysis was conducted, it appears they mainly compared the averaged values across the five time points. The research area experiences extremely significant differences in rainfall between March and September, so comparing across different seasons may not be meaningful or relevant to the main findings.
Response: We have responded to these points together as they are related. Line charts are used because we analysed statistical variation over time using a linear mixed model (as shown in Table 5). As a result, a line graph is correct. Comparison using bars would not necessarily be easier as the means would be close together with large variation. This is due to the data not the presentation. Means across treatments are summarised as there are no significant differences, while we clearly show the temporal variability in the text and on the figures.
Comment: The issue of superscripts mentioned previously still persists in several places (e.g., lines 513 and 515). Please ensure all such issues are thoroughly corrected.
Response: These have been corrected, thank you.
