Short-Term Effects of Different Straw Returning Methods on the Soil Physicochemical Properties and Quality Index in Dryland Farming in NE China
Round 1
Reviewer 1 Report
I found the document very clear and well organized.
I have only one comment, please see the attached file. That small comment regards the only part of the text that was not clear and should be rewritten.
Comments for author File: 
Comments.pdf
Author Response
Point 1: I have only one comment, please see the attached file. That small comment regards the only part of the text that was not clear and should be rewritten.

Response 1: Considering the Reviewer’s suggestion, we have rewritten this part as “ In addition, EIS was more advantageous on the accumulation rate of HEC and HAC compared to SM, SP, and SG. The reasons for the beneficial effects of EIS and SG treatments were probably related to the crushed straw used. Crushed straw was broken the organizational structure and outer cuticle of the original straw, which greatly increased the contact surface of straw cellulose, hemicellulose, and lignin with the soil, and thus greatly accelerated straw decomposition and nutrient release, and finally decreased the duration of straw decomposition”.
Reviewer 2 Report
As I reader I was very interested to see how this study was conducted in order to assess soil physiochemical properties and soil quality. However, following the abstract and introduction, I became lost. There is poor connectivity in this study. An explanation on why the various soil properties were selected is needed. Also, how soil quality is assessed, and how soil properties can change. Why are the soil quality results at the end of the discussion? This does not allow the reader to make sense of this work. The paper needs to be restructured throughout. Also, start with the most important result and work backwards.
Introduction:
A little more detail is needed on the two new methods of straw treatment.
Crashed into pieces: use other words – pulverized? Does the combine harvester pulverize the straw at harvest?
How is straw granulized? Is this done by a combine harvester in the field, or is the straw removed from the field and then later re-applied? Or done in the field?
More information is in experimental design, this is the wrong place. Move it up to introduction. What is the length of the straw in SM/SP?
In the objectives, it is not known how soil quality will be assessed. Add detail
CK not a treatment, it is the control. Later referred to as control in results section.
Experimental design:
Fertiliser rates not doses.
2.3. Soil sampling and lab procedures:
Soil penetration resistance….field method. Move this text up to appear before sample processing.
Results
Give the abbreviations for straw treatments/soil analysis again in table/figure titles.
3.5 FTIR – does this really add anything? What is the difference between C-H and C=O bonds in this context? Again this needs to be explained in the choice of soil analysis. Why selected and what will it convey? Table 4 does not carry statistics – why?
No soil quality results mentioned?
Discussion
For the first time, the soil properties are linked “soil aggregate stability, soil penetration resistance, and soil dry BD were used as indicators of soil structure”…this should appear in introduction/objectives.
…’accelerate the combination of straw and soil OC fractions’. Better explanation needed. This comes later in 4.2 under refer 26. This is needed earlier.
Why is SQ appearing in discussion not results?
Explain Figure 3a, the individual weights do not appear to be that varied. Almost all are >1.0. Why is this? Also there is no explanation for Table 5. Why are loading values important?
Author Response
Please see the attachment.
Author Response File: Author Response.pdf
Reviewer 3 Report
The manuscript titled Short-term effects of different straw returning methods on soil physicochemical properties and quality index in dryland farming in NE China assessed four different straw returning methods, and one control. The goal of this manuscript was to assess new methods of straw returning and their impacts on soil organic carbon, bulk density, penetration resistance, soil humus fractions, and aggregate stability. Overall, the methods were sound and the comparison to control plot replicates is adequate. However, the interpretation of the results needs some work. The changes in soil physicochemical properties were assessed on a concentration basis, which is only part of the picture. Knowing the bulk density and plot scale volume, the researchers should scale up and use these data to help with their data interpretation. The specifics for this are discussed below. Please do these calculations and rewrite the results and discussion sections accordingly.
Abstract:
Define what straw is after the first time you mention it. In this case, I am assuming you are dealing with maize stover (the organic content of the crop that is left over after harvest).
Introduction:
1st paragraph Line 4: Crop residues can improve tillage? Is this the actual physical process of tilling, or are you talking about the residues improving soil quality after the physical act of tilling? Please explain.
Once again, when you introduce the term “straw,” make sure you specify what exactly you are talking about (maize stover).
3rd paragraph Lines 9-13: The actual different methods of returning the straw to the soil shouldn’t change the C:N of the material itself. Why should these methods alleviate this concern of the high C:N. Please explain, or remove the C:N content in this paragraph.
3rd paragraph Line 11: Replace “into the” with “to a depth of” and delete “soil depth.”
Methods and Materials:
1st paragraph Line 5: Why only to a depth of 20 cm if the straw is incorporated down to 25 cm? Please explain.
2nd paragraph Line 2: 5 x 10 m2 should be 5 m x 10 m. Only use squared units when talking about the final surface area.
2nd paragraph: How was the CK plot treated for tillage? Please add this to the methods section. The reader needs to know how each plot was treated.
2nd paragraph Line 11: Replace “doses” with “applications.”
4th paragraph Line 2: There is some debate whether or not soil humus will change over a short time period, and this study only looked at two treatment years. Were you expecting a big change going into this study? If so, please explain to the readers.
Results:
1st paragraph Line 1: How would tillage of the CK plots affect the bulk density results? That is why we need information about tillage treatment in the Methods and Materials section.
2nd paragraph Line 1: The concentration for SOC may have increased, but when I scaled this up to the plot scale with bulk density, the CK treatment actually has a larger amount of SOC on a mass basis. Concentrations are great, but they are only a part of the story. Since you have bulk density for each plot, you should scale up and test the effects that way. A way of truly testing if the straw additions made a difference would have been to take samples from each plot before the treatment, and determine how each parameter changed after that. I would encourage you to scale up for each plot and consider revisions to this manuscript based on the results.
4th paragraph (the paragraph after Table 3): How do these aggregate results compare when you factor in a larger bulk density for the CK plots?
Discussion:
1st paragraph Line 8: When you say “but there were no significant effects at any depth,” what do you mean by “any depth?” I thought that you only sampled from 0-20 cm, and by the way the methods read, the reader has to assume that this is a compiled sample that is not broken out by depth.
2nd paragraph Line 6: Please don’t use an engineering/geologist term like “overburden” in a predominately soil science paper. Instead, use a term like top soil.
3rd paragraph Lines 5-9: Rephrase the sentence that begins with “Meanwhile, the crushed straw used in EIS and SG treatments…” It is currently confusing to read.
4th paragraph Line 7: Replace “…is 0-20 cm.” with “…from 0-20 cm.”
4th paragraph Lines 7-9: How do soil enzymes and microbial biomass relate to this paragraph that was talking about HAC/FAC ratios and ΔlogK? Please make a smoother transition and explain your reasoning along the way.
4th paragraph Line 12: Talking about “increased soil enzyme activity” may be stretching your data results a bit.
5th paragraph Line 10: Replace “…in 0-20 cm” with “…from 0-20 cm.” Delete “depth.”
Conclusions:
1st paragraph Line 3: Increasing SOC concentration when comparing the control and the treatments at the most. Remember, there is still more SOC mass in the control (CK).
Author Response
Please see the attachment.
Author Response File: Author Response.pdf
Round 2
Reviewer 3 Report
After reading the second round of edits for the manuscript Short-term effects of different straw returning methods on soil physicochemical properties and quality index in dryland farming in NE China as well as the author responses to reviewer comments, there is still one thing that stands out as a potential problem for this manuscript. The authors said that they deleted the bulk density and compactness data because the tests were "slightly biased." What does this mean? The bulk density data went from being one of the main points to this paper as stated in the abstract, results, discussion, and conclusion to just being deleted. Without these bulk density estimates, you are unable to scale the soil carbon concentrations up to soil carbon stocks (total soil carbon mass). Total soil carbon mass is often times used in studies because it gives the full picture of how much carbon is in a specific plot/field. Just using and comparing concentrations is not enough.
Author Response
Point 1: After reading the second round of edits for the manuscript Short-term effects of different straw returning methods on soil physicochemical properties and quality index in dryland farming in NE China as well as the author responses to reviewer comments, there is still one thing that stands out as a potential problem for this manuscript. The authors said that they deleted the bulk density and compactness data because the tests were "slightly biased." What does this mean? The bulk density data went from being one of the main points to this paper as stated in the abstract, results, discussion, and conclusion to just being deleted. Without these bulk density estimates, you are unable to scale the soil carbon concentrations up to soil carbon stocks (total soil carbon mass). Total soil carbon mass is often times used in studies because it gives the full picture of how much carbon is in a specific plot/field. Just using and comparing concentrations is not enough.
Response 1: The soil organic carbon (SOC) data in our article is actually calculated soil total organic carbon content (TOC), not concentration, which we have stated in materials and methods before. To avoid misunderstanding, we have changed the SOC to TOC in the full text. The data on soil bulk density and compactness were deleted because these data may cause some readers to misunderstand our research.
Round 3
Reviewer 3 Report
The corrections to this manuscript titled Short-term effects of different straw returning methods on soil physicochemical properties and quality index in dryland farming in NE China, does meet the minimum changes needed for publishing. I do encourage you all to be more transparent with reviewers in the future if you ever have to remove data from a main finding again. Scientific discovery should not rely on sweeping data under a rug or hiding it in a closet. If data doesn't support your hypothesis, say that and help future research in this field.
Author Response
Point 1: The corrections to this manuscript titled Short-term effects of different straw returning methods on soil physicochemical properties and quality index in dryland farming in NE China, does meet the minimum changes needed for publishing. I do encourage you all to be more transparent with reviewers in the future if you ever have to remove data from a main finding again. Scientific discovery should not rely on sweeping data under a rug or hiding it in a closet. If data doesn't support your hypothesis, say that and help future research in this field.
Response 1: Thanks for the reviewer's suggestion and we are very sorry for our negligence. In the future, we will listen to the reviewers' suggestions to make our research more open and transparent to the reviewers.
