Crop Residue Removal Effects on Soil Erosion and Phosphorus Loss in Purple Soils Region, Southwestern China
, Kaicheng Yang 1,†, Wenhua Zhuang 1,*, Chao Liu 1, Longguo Li 1, Chi Zhang 1 and Mingming Li 2
Round 1
Reviewer 1 Report
The article “Crop residue removal effects on soil erosion and phosphorus loss in purple soils region, Southwestern China”, evaluates the loss of P through an experimental process.
Concerning the article, I have the following comments
Abstract:
Line 15: The word “Methods:” should be replaced with text. For example: “For the purposes of the present study, the following methods have been applied” …
Line 20: The word “Results:” should be replaced with text.
Line 25: The word “Results:” should be replaced with text.
Introduction
The introduction is complete and into the point. However, in my opinion, is too long. The problem is focused in paragraphs between lines 73 – 84 and 85 – 102. The meaning of these paragraphs should be attributed in one shorter paragraph.
Materials and methods
This part is covered adequately. However, since the authors use rain data, a paragraph with some climate data should be included (for example a table of annual precipitation for the time the experiment lasted)
Results
The part of results is also covered adequately.
Discussion
The authors have based that part at references. In my opinion, they should also discuss the results of their experiment
To become more clear:
4.1 Impact of crop residue on soil aggregate distribution and stability
Should not be change
4.2 Impact of crop residue on soil erosion
The authors should explain with more details the findings of RUSLE 2 simulation
4.3 Impact of straw on TP of aggregates
This paragraph is based at references and formulas. In my opinion that part should be removed from discussion (lines 491 – 509). It can be included in the “Materials and methods” section.
Also, the authors base that paragraph at two samples A and B with hypothetical P concentration and distribution.
My suggestion is to base this paragraph to their experimental data (they may use the hypothesis above if they wish). Lines 530 – 537 cover the experimental part, but I suggest some further development.
Conclusions
No changes are suggested
Author Response
- Abstract:
Line 15: The word “Methods:” should be replaced with text. For example: “For the purposes of the present study, the following methods have been applied” …
Line 20: The word “Results:” should be replaced with text.
Line 25: The word “Results:” should be replaced with text.
Reply: We thank you for this reminder. The style of structured abstracts is chosen according to the requirements of the publication. (Page 1, line 11-29)
- Introduction
The introduction is complete and into the point. However, in my opinion, is too long. The problem is focused in paragraphs between lines 73 – 84 and 85 – 102. The meaning of these paragraphs should be attributed in one shorter paragraph.
Reply: We thank the reviewer for pointing this out. We have made adjustments to these paragraphs according to your suggestions to make them look more concise.(Page 2, line 57-103)
- Materials and methods
This part is covered adequately. However, since the authors use rain data, a paragraph with some climate data should be included (for example a table of annual precipitation for the time the experiment lasted).
Reply: Thank you for the detailed review. We supplemented the Materials and Methods section with temperature and rainfall data for the test field area during the experiment and presented them in Figure 1. (Page 3, line 109-113)
- 4.2 Impact of crop residue on soil erosion
The authors should explain with more details the findings of RUSLE 2 simulation.
Reply: We are grateful for the suggestion. In Section 4.2 of the discussion, we have added details about the results of the RUSLE 2 model simulations and supplemented them with clarification. (Page 15, line 484-487 and 490-492)
- 4.3 Impact of straw on TP of aggregates
This paragraph is based at references and formulas. In my opinion that part should be removed from discussion (lines 491 – 509). It can be included in the “Materials and methods” section.
Reply: We thank the reviewer for pointing this out. To make the meaning of the formula clearer, our explanation of its origin should be accompanied by text. We believe that it would be more appropriate to describe the source of formula in the discussion section rather than placing it in the materials section.
- Also, the authors base that paragraph at two samples A and B with hypothetical P concentration and distribution.
My suggestion is to base this paragraph to their experimental data (they may use the hypothesis above if they wish). Lines 530 – 537 cover the experimental part, but I suggest some further development.
Reply: We thank the reviewer for careful check. We chose samples A and B to explain the formula so that readers can more easily and quickly understand its use. However, the results obtained from our experimental data using these two formulas were not very good, which may have a negative impact on understanding the formula.
Author Response File: 
Author Response.docx
Reviewer 2 Report
1. In the Abstract, the different parts of the ms were listed as “background””methods””results” etc. I donnt know whether it fits the structure of the journal.
2. 0%, 50% and 100% should be denoted in the figure or in the figure title of heading notes, otherwise readers may confuse.
3. In Table 1 and the rests, 4 replicates were implemented? But only one value kept in each treatment?
4. In Fig.5, You mentioned that the 0% straw removal rate resulted higher TP content significantly. However, such pattern could not be observed in the figure.
5. In Fig.6, residue removal rates among the treatments actually not significantly, the conclusion that then become farfetched and less convincing.
6. In the conclusion, since the verification is lacked, the others then not necessarily plausible and conceivable.
Author Response
- In the Abstract, the different parts of the ms were listed as “background””methods””results” etc. I donnt know whether it fits the structure of the journal.
Reply: We thank you for this reminder. The style of structured abstracts is chosen according to the requirements of the publication. (Page 1, line 11-29)
- 0%, 50% and 100% should be denoted in the figure or in the figure title of heading notes, otherwise readers may confuse.
Reply: Thank you for the detailed review. To avoid such confusion, we have added the meaning of 0%, 50% and 100% in the corresponding figure notes. (Page 9, line 299-304; Page11, line 337-340; Page12, line 361-363; Page 13, line 400-401; Page 14, line 421-422; Page 14, line 425-426)
- In Table 1 and the rests, 4 replicates were implemented? But only one value kept in each treatment?
Reply: Thank you for the detailed review. Table 1 shows some basic properties of the soil and there are no replicates. Treatments were replicated four times, and the average of the four replicates is used in the rests to represent the overall condition of the treatments.
- In Fig.5, You mentioned that the 0% straw removal rate resulted higher TP content significantly. However, such pattern could not be observed in the figure.
Reply: We are grateful for the suggestion. In section 3.3.2, we described the differences in the data, including the significant impact of different crop residue removal rates on the distribution of P in larger aggregates. To avoid readers feeling that our conclusions are not fully supported, we emphasized this trend result in the description of Figure 5. (Page 12, line 375-377)
- In Fig.6, residue removal rates among the treatments actually not significantly, the conclusion that then become farfetched and less convincing.
Reply: We thank the reviewer for careful check. As the reviewer pointed out, the differences between treatments are not significant on a yearly basis. However, significant differences appeared after 4 months and 1 year among treatments. Combined with the RUSLE 2 model simulation results mentioned earlier, it can also be confirmed that crop residue removal increases the risk of soil phosphorus loss. Therefore, we added details and discussion of the RUSLE 2 model simulation results in the discussion section. (Page 15, line 484-487 and 490-492)
- In the conclusion, since the verification is lacked, the others then not necessarily plausible and conceivable.
Reply: We thank the reviewer for pointing this out and we have adjusted our expression so that the conclusion is no longer so assertive. For the P loss part, we changed expression from certain to possible. (Page 17, line 560-563)
Author Response File: Author Response.docx
Reviewer 3 Report
I have reviewed the manuscript and I agree with the conclusions drawn by the researchers. The study is well-written and clearly explains the impact of crop residue removal on purple soil erodibility and phosphorus loss. The introduction of the GMC and MGCd values to assess the distribution of chemicals under different soil particle sizes is a novel and effective approach. The findings indicate that phosphorus is more enriched in larger soil aggregates when crop residue is less removed, and suggest that crop residue removal practices should be avoided in purple soil regions of China.
Overall, I recommend accepting this manuscript for publication. The study provides valuable insights into the importance of crop residue management in purple soil regions and could have significant implications for agriculture in China.
Author Response
Thank you so much for your glowing review of our submission. Your recognition means a lot to us and we are deeply grateful for your attention and evaluation. And we will continue to put in effort to ensure that our future submissions meet your high standards and exceed your expectations.
Reviewer 4 Report
The authors proposed to present the change of soil erosion and phosphorus loss in purples soil at a plot scale. However, the results of soil loss and phosphorus in the sediment were not provided and interpreted. The manuscript is not well written. Therefore, I would regret to reject this manuscript.
Line 32: Please move the first two paragraph to the last but before the end of the introduction section.
Line 96-97: Please present a summary on other indicators for evaluating soil P loss risk.
Line 123: Please present some photos for plots.
Line 179: Soil loss may be better.
Line 233: the subtitle is the same as that of 2.6.1?
Line 250: What is the leaching experiment used for? Please give a explanation.
Line 267: Please give the results of soil loss calculated by RUSLE2.
Figs: please note the significance for all the histogram
Line 412: Why the TP in the sediment was not analyzed and interpreted here?
Line 458: Please add a discussion on the results of soil loss calculated by RUSLE2
Author Response
- Line 32: Please move the first two paragraph to the last but before the end of the introduction section.
Reply: We thank you for your suggestion. We intend to first introduce the background of purple soil and the removal of crop residue, and then elaborate on the research objectives and significance of the straw removal rate on soil erosion and phosphorus loss risk. Therefore, to ensure that our expression is smooth and our logic is coherent, we have chosen to continue with the paragraph order in the original manuscript.
- Line 96-97: Please present a summary on other indicators for evaluating soil P loss risk.
Reply: We thank the reviewer for pointing this out. Under your suggestion, we have elaborated on other methods for assessing the risk of phosphorus loss from soil.( page 2, line 70-73)
- Line 123: Please present some photos for plots.
Reply: We are grateful for the suggestion. We have added a photo of the experimental plot in section 2.1. (Page 4, line 126-129)
- Line 179: Soil loss may be better.
Reply: Thank you for the detailed review. Following your suggestion, we have revised the title of section 2.5 to Soil loss simulation. ( page 5, line 175)
- Line 233: the subtitle is the same as that of 2.6.1?
Reply: We thank the reviewer for careful check. We have changed the title of section 2.6.2 to TP in the aggregates.( page 7, line 230)
- Line 250: What is the leaching experiment used for? Please give a explanation.
Reply: We are thankful for the valuable suggestion given by the reviewer. In the introduction section, we have elaborated on the role of leaching experiments. We use leaching experiments to simulate the loss of dissolved P. (Page 2, line 81-84)
- Line 267: Please give the results of soil loss calculated by RUSLE2.
Reply: Thanks to the Reviewer's comments, we have presented the results of soil loss calculated by the RUSLE 2 model in section 3.2.(Page 10, line 335-357)
- Figs: please note the significance for all the histogram
Reply: We are thankful for the valuable suggestion given by the reviewer. In the histograms, areas with significant differences have been marked. Areas without significant differences have not been labeled with letters. This is supplemented in the caption below the image. (Page 9, line 299-304; Page11, line 337-340; Page12, line 361-363; Page 13, line 400-401; Page 14, line 421-422; Page 14, line 425-426)
- Line 412: Why the TP in the sediment was not analyzed and interpreted here?
Reply: We thank the reviewer for the comments. We have added the role of leaching experiments in both the introduction and discussion. We used leaching experiments to simulate the process of dissolved phosphorus loss, so there are no data results for fixed phosphorus in section 3.5. (Page 2, line 81-84; Page 8, line 253-262)
- Line 458: Please add a discussion on the results of soil loss calculated by RUSLE2
Reply: We are thankful for the valuable suggestion given by the reviewer. In Section 4.2 of the discussion, we have added details about the results of the RUSLE 2 model simulations and supplemented them with clarification. (Page 15, line 484-487 and 490-492)
Author Response File: Author Response.docx
Round 2
Reviewer 2 Report
The revised MS is fine to be accepted.
Reviewer 4 Report
My concerns were addressed.
