Quantifying Soil Carbon Sequestration Potential Through Carbon Farming Practices with RothC Model Adapted to Lithuania

Round 1

Reviewer 1 Report (Previous Reviewer 1)

Comments and Suggestions for Authors

The author combined remote sensing data and the RothC model to study the impact of carbon farming practices such as cover crops, no-till farming, and residue retention on soil organic carbon (SOC) changes in the Joniskis region of northern Lithuania during 2019–2020. The article revealed the positive impact of these practices on SOC. The study’s results are comprehensive, and the methods are appropriate; however, revisions are needed before publication:

1. In the introduction, the author mentions that “Carbon sequestration can improve soil fertility and structure, increase water retention, reduce erosion, and nutrient runoff,” but does not specify the mechanisms behind these improvements or provide supporting research, lacking depth.

2. In the results analysis, the article notes that “SOC sequestration rates varied spatially, ranging from approximately 0.23 to 0.32 t C ha−1 year−1 across the municipality,” but fails to provide a detailed explanation of the spatial distribution of SOC changes, such as which areas showed the greatest SOC changes and the common characteristics of these areas.

3. The authors mention that “Residue retention was the least commonly observed practice in both years,” but fail to analyze the reasons behind this, such as whether it is related to farmers' management habits or economic costs, and further clarification is needed on this issue.

4. The article notes that “Areas where cover crops, residue retention, and reduced tillage were implemented simultaneously showed the highest SOC increases,” but lacks an in-depth analysis of the synergistic effects of these practices and fails to explore the underlying mechanisms.

5. The article does not adequately discuss the limitations of the model results. For example, it does not mention the potential impact of model assumptions (such as the uniformity of soil depth and decomposition rates) on the results. It also does not conduct an in-depth discussion of the policy implications of the research findings.

 

Author Response

Comments and Suggestions for Authors

The author combined remote sensing data and the RothC model to study the impact of carbon farming practices such as cover crops, no-till farming, and residue retention on soil organic carbon (SOC) changes in the Joniskis region of northern Lithuania during 2019–2020. The article revealed the positive impact of these practices on SOC. The study’s results are comprehensive, and the methods are appropriate; however, revisions are needed before publication:

1. In the introduction, the author mentions that “Carbon sequestration can improve soil fertility and structure, increase water retention, reduce erosion, and nutrient runoff,” but does not specify the mechanisms behind these improvements or provide supporting research, lacking depth.

Responses 1. We appreciate the reviewer’s suggestion. However, we would like to clarify that in the introduction, the statement regarding the benefits of carbon sequestration on soil fertility and structure is already supported by references [16–19]. The primary focus of this study is on the integration of multiple data sources (remote sensing, GIS, and RothC modeling) to assess SOC sequestration potential rather than providing an in-depth analysis of the biological or chemical mechanisms underlying soil improvements. We believe that further detailing of such mechanisms would go beyond the scope of this methodological framework. Nevertheless, we have retained the general description to provide necessary context for readers. Therefore, we have added a sentence to the introduction noting that these improvements are primarily driven by increased microbial activity, enhanced soil aggregation, and improved water infiltration.

2. In the results analysis, the article notes that “SOC sequestration rates varied spatially, ranging from approximately 0.23 to 0.32 t C ha−1 year−1 across the municipality,” but fails to provide a detailed explanation of the spatial distribution of SOC changes, such as which areas showed the greatest SOC changes and the common characteristics of these areas.

Responses 2. We thank the reviewer for this valuable comment. In the manuscript, we have already indicated zones with higher SOC change. Following the suggestion, we further clarified that the observed spatial differences are mainly linked to the combined application of carbon farming practices rather than soil variability, since the study area is relatively uniform in soil type and predominantly used for cereal production. We have updated the text accordingly to reflect this.

3. The authors mention that “Residue retention was the least commonly observed practice in both years,” but fail to analyze the reasons behind this, such as whether it is related to farmers' management habits or economic costs, and further clarification is needed on this issue.

Responses 3. We thank the reviewer for this insightful comment. We have addressed it by adding an explanation to the 3.1 results section. Specifically, we clarified that the low level of residue retention in this region is likely due to intensive farming practices and the widespread use of winter crops, which limit opportunities for leaving residues on the field.

4. The article notes that “Areas where cover crops, residue retention, and reduced tillage were implemented simultaneously showed the highest SOC increases,” but lacks an in-depth analysis of the synergistic effects of these practices and fails to explore the underlying mechanisms.

Responses 4. We thank the reviewer for this valuable observation. We agree that the synergistic effects of combined carbon farming practices deserve further attention. To address this, we have added a brief explanation in the discussion section outlining how cover crops, residue retention, and reduced tillage may interact to enhance SOC accumulation through complementary mechanisms. However, a detailed mechanistic analysis was beyond the scope of this methodological study and would require long-term field experiments. We hope this addition clarifies the observed patterns and strengthens the interpretation of our findings.

5. The article does not adequately discuss the limitations of the model results. For example, it does not mention the potential impact of model assumptions (such as the uniformity of soil depth and decomposition rates) on the results. It also does not conduct an in-depth discussion of the policy implications of the research findings.

Responses 5. We thank the reviewer for this helpful comment. We would like to note that the manuscript already discusses several limitations of the modelling approach, including the coarse spatial resolution of climate inputs, the binary simplification of management practices, the absence of site-specific calibration data, and structural assumptions of the RothC model such as uniform soil depth and decomposition rates (see Discussion section). To further clarify this, we have now added a sentence explicitly noting that these assumptions may lead to under or overestimation of SOC changes in areas with heterogeneous soil profiles or variable decomposition environments. Regarding policy implications, we agree that this is an important aspect. The manuscript discusses how the results can inform national GHG mitigation strategies, support EU carbon farming initiatives, and guide the design of targeted incentive schemes (see Discussion and Conclusions). While a full policy analysis is beyond the scope of this methodological study, we believe the presented framework provides a valuable foundation for future policy-oriented research.

We sincerely thank the reviewer for the constructive and insightful comments. These suggestions have helped us to clarify key aspects of the manuscript, particularly regarding model limitations and the interpretation of synergistic effects. The feedback also encouraged us to better articulate the policy relevance of our findings. We believe that the revisions made in response to these comments have significantly improved the clarity and overall quality of the paper.

Author Response File: Author Response.docx

Reviewer 2 Report (Previous Reviewer 5)

Comments and Suggestions for Authors

GENERAL COMMENTS

The manuscript entitled "Quantifying Soil Carbon Sequestration Potential through Carbon Farming Practices with RothC Model Adapted to Lithuania" is important as it deals with soil carbon sequestration which is crucial to achieve sustainable agricuture and mitigation of climate change. The findings will be beneficial to policymakers, farming community, researchers, extension and advisory services, students and other readers. The manuscript is within the aims and scope of the Journal. However, there are still some shortcomings in this manuscript that need attention of the authors as indicated below under specific comments.

SPECIFIC COMMENTS

1. There are some improvements in this resubmitted manuscript.
2. However, there are repetitions between the information in Paragraph starting from Line 485 up to a sentence ending in Line 532, with information under Conclusion section. The Author(s) must look at this carefully. I recommend that information starting from Line 485 to a sentence ending in Line 532 be made "Conclusion and Recommendations" to avoid the observed repetitions.
3. The other information that is currently under Conclusion can be put towards the end of Discussion section.

Author Response

Comments and Suggestions for Authors

GENERAL COMMENTS

The manuscript entitled "Quantifying Soil Carbon Sequestration Potential through Carbon Farming Practices with RothC Model Adapted to Lithuania" is important as it deals with soil carbon sequestration which is crucial to achieve sustainable agricuture and mitigation of climate change. The findings will be beneficial to policymakers, farming community, researchers, extension and advisory services, students and other readers. The manuscript is within the aims and scope of the Journal. However, there are still some shortcomings in this manuscript that need attention of the authors as indicated below under specific comments.

SPECIFIC COMMENTS

1. There are some improvements in this resubmitted manuscript.
2. However, there are repetitions between the information in Paragraph starting from Line 485 up to a sentence ending in Line 532, with information under Conclusion section. The Author(s) must look at this carefully. I recommend that information starting from Line 485 to a sentence ending in Line 532 be made "Conclusion and Recommendations" to avoid the observed repetitions.

The other information that is currently under Conclusion can be put towards the end of Discussion section.

 

Responses 1, 2. We thank the reviewer very much for this valuable observation. We have carefully reviewed the relevant sections and revised the structure accordingly. Specifically, we have removed repetitive statements and reorganized the content: the recommendations are now presented exclusively in the “Conclusions and Recommendations” section, while the remaining content previously under “Conclusions” has been integrated into the end of the Discussion section. We believe this restructuring improves clarity, avoids redundancy, and aligns better with the reviewer’s suggestion.

We sincerely thank the reviewer for the constructive and thoughtful comments. Your feedback has helped us to improve the clarity, structure, and scientific rigor of the manuscript. The suggestions regarding content organization, model limitations, and policy relevance were particularly valuable and have been carefully addressed in the revised version.

Author Response File: Author Response.docx

This manuscript is a resubmission of an earlier submission. The following is a list of the peer review reports and author responses from that submission.

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

The authors assessed the potential impact of the adoption of carbon agricultural practices (e.g., cover crops, no-tillage, and residue retention) on soil organic carbon (SOC) changes in the Joniskis region of northern Lithuania by combining remotely sensed data and RothC modeling. The potential of these practices for carbon sequestration at the regional scale is revealed. The article topic has real-world value and is well-structured, but I think it needs to be revised before publication. Specific comments are as follows:

1. The article emphasizes the importance of SOC, but provides less detailed description of specific Lithuanian soil types and climatic conditions. It is recommended to add a description of Lithuanian soil types and climatic characteristics to better understand the context of the study area.

2.The introduction describes the dual role of the AFOLU sector and also emphasizes the importance of SOC in mitigating climate change. However there is a lack of critical synthesis, which should include both land use and climate change as both agriculture and forestry are affected by it, hence the need to emphasize on the impact of these 2 key factors. The following references are suggested to enhance the synthesis: Carbon Balance Matching Relationships and Spatiotemporal Evolution Patterns in China's National-Level Metropolitan Areas; Urban form, land use, and cover change and their impact on carbon dioxide. and cover change and their impact on carbon emissions in the Monterrey Metropolitan area, Mexico; Future impacts of Urban and Peri-urban agriculture on carbon stock and land surface temperatures in India

3. The methodology presentation on the adaptation of the RothC model, while mentioning the use of empirical coefficients from the literature to adjust for carbon inputs and decomposition rates, does not elaborate on the basis for the selection of these coefficients and their applicability. It is recommended that a specific description or rationale for the selection of these coefficients be added.

4. The results analyze the spatial distribution of SOC changes, but there is less discussion of the ecological significance and practical application of these changes. This section should be the focus, and a discussion of the ecological significance of these results is recommended, e.g., do these SOC increases lead to long-term improvements in soil fertility, and what are the effects of these changes on regional ecosystem services?

5.While the article mentions uncertainties in the results, it does not discuss in detail the specific implications of these uncertainties for policy making and land management. For example, estimates of SOC change (0.23-0.32 t C ha-¹ year-¹) may be affected by data resolution, modeling assumptions, and simplification of management practices.

6. The discussion section mentions the limitations of the study, but there are fewer suggestions on how to overcome these limitations. For example, the article mentions that the model was not calibrated due to lack of field SOC measurements.

7.The resolution of some of the graphs is low and it is suggested that the quality of the graphs should be improved so that the reader can view the details more clearly, e.g., Figure 3.4.5.

Reviewer 2 Report

Comments and Suggestions for Authors

Brief summary

This manuscript describes the modelling of soil organic carbon of different agricultural practices using the model RothC. This paper is suitable for publication in ‘Land’.  

 

Broad comments

The manuscript is worthy; however, there are some important aspects that need to be revised, expanded, and explained. This version of the manuscript should be improved before considering it for publication.

Title: It is OK

Key-words: Some are repeated in the title (carbon sequestration and carbon farming).

Abstract: It is OK

Introduction: The introduction is straightforward, however authors should make a much better point at reviewing the existing literature and pinpointing the deficiencies / contradictions / limitations of these studies, and how their study responds to these deficiencies / contradictions / limitations.

Material and methods: The study area, methods, and parameters of the model are fully described. However, here it relies on the main flaws of the manuscript. There are no validation of the farming practices using ground truth, and there is no calibration and validation of the RothC results. Also, I think that only one year is not enough to detect soil organic matter changes in the field.

 

Some specific comments

L53: please add the scientific names

L106: Please add the main soil types using WRB or USDA classification system.

L120. What is modern?

L302: Discussion and Conclusion

Reviewer 3 Report

Comments and Suggestions for Authors

Dear authors,

The article definitely addresses a topical issue concerning the improvement of monitoring soil organic carbon sequestration. This could provide objective results for expanding carbon sequestration agricultural practices. Overall, the article objectively addresses the problem. Still, the authors could consider emphasising specific points and a more in-depth interpretation of the research results. I want to make some suggestions listed below in the attached file.

I hope that the recommendations will help you improve the article. I sincerely hope that the article will be well-received by the scientific community after its publication.

Kind regards!

Comments for author File: Comments.pdf

Reviewer 4 Report

Comments and Suggestions for Authors

Dear Authors,

The manuscript under review presents a valuable methodological framework for estimating soil organic carbon (SOC) changes using remote sensing (RS) and the RothC model in northern Lithuania. The integration of geospatial data and process-based modelling offers a scalable approach for regional carbon assessment, which is highly relevant to current climate policy initiatives. However, while the study is promising, several critical aspects must be addressed to enhance its scientific rigor, clarity, and overall impact.

Comments:

1. The figures presented, especially the maps and graphs, need significant improvement in terms of standardization and quality. They should be created using advanced software such as R, Python, or ArcGIS to ensure precision and reproducibility. For example, Figure 3 lacks essential cartographic elements (scale, north arrow, and standardized legends), while the color gradient in Figure 4 does not effectively convey the SOC variation. All graphical outputs should adhere to cartographic conventions and employ scripting tools to guarantee professional quality.

2. The introduction effectively establishes the importance of SOC sequestration but does not sufficiently articulate the study’s novelty or its potential applications. The authors should better contextualize the research by emphasizing how it addresses regional gaps in SOC modelling specific to Lithuania and how it aligns with EU carbon farming initiatives.

3. The manuscript currently merges the discussion and conclusions into a single section, which dilutes the key messages of the work. It is recommended that these be separated: the discussion should critically compare results with existing studies (e.g., SOC sequestration rates in temperate croplands) and address uncertainties such as binary classifications of practices and the use of coarse climate data. The conclusions should then succinctly summarize the key findings, openly acknowledge the limitations (e.g., absence of ground validation), and propose future research directions such as multi-year simulations.

4. The robustness of the discussion is limited by its superficial engagement with uncertainty and trade-offs. For example, potential errors from remote sensing classifications are not quantified, nor are the trade-offs between different agricultural practices (e.g., cover crops versus residue retention) discussed.

5. The methodological transparency is insufficient for replication. While the general workflow is presented (Figure 1), critical details such as the specific thresholds used for RS classifications (e.g., NDVI values for cover crops) and any modifications made to the RothC model (e.g., adjustments to DPM/RPM ratios) are missing. 

6. The limitations related to data resolution, particularly the use of coarse climate data (0.5° grid), are acknowledged but not quantified. The authors should discuss more explicitly how the application of finer-resolution datasets, such as ERA5-Land, could improve model accuracy and reliability. 

7. The terminology and abbreviations used throughout the manuscript require greater standardization. While "carbon farming practices" is clearly defined, other terms such as "RMFs" should be spelled out upon first use. 

8. The future work section is currently underdeveloped. While the conclusion mentions calibration, the authors should outline specific next steps, such as implementing multi-year simulations to capture long-term SOC trends, conducting field validations through soil sampling, and exploring the integration of machine learning techniques for improved practice detection. 

9. The authors should also consider improving the quality of Figure 1, the workflow diagram, by ensuring it includes station IDs for all meteorological stations used. Additionally, a table should be incorporated detailing each station’s geographical coordinates, altitude, and the percentage of missing data. 

10. I recommend incorporating additional validation metrics, such as Percent Bias (PBIAS) and Willmott's index of agreement (d), to provide a more comprehensive assessment of the model's performance.

I am available for any clarification.

Kind regards.

Reviewer 5 Report

Comments and Suggestions for Authors

GENERAL COMMENTS

The manuscript entitled "Quantifying Soil Carbon Sequestration Potential through Carbon Farming Practices with RothC Model Adapted to Lithuania" is important as it deals with soil carbon sequestration which is crucial to achieve sustainable agricuture and mitigation of climate change. The findings will be beneficial to policymakers, farming community, researchers, extension and advisory services, students and other readers. The manuscript is within the aims and scope of the Journal. However, there are  shortcomings in the manuscript that need attention of the authors as indicated below under specific comments.

SPECIFIC COMMENTS

1. The Authors need to include mean annual rainfall and temperature for Joniskis area under Materials and Methods. This information can be obtained from longterm weather records of Joniskis municipality area. This is important for the benefit of the readers.
2. It is not clear in the manuscript under Materials and Methods, how the data obtained was analysed. Analysis of data obtained using the indicated Models is important to make the manuscript qualify to be a scientific article.
3. For comparisons and analysis, the Authors need to separate data in accordance with level of vegeatative cover, tillage (tilled or no till), crop residues (more or less), etc.
4. The lack of comparisons of data obtained under Materials and Methods section make the Results section not to reflect scientific results. Scientific results will lead to scientific arguments to be made under Discussion section.
5. The Discussion section must be separated from Conclusion. The Authors must read  Instructions for Authors of this Journal.