The Influence of Residue Mixing on the Decomposition of Pepper Root Residues
Round 1
Reviewer 1 Report
The Introduction, Materials and Methods, and Discussion were improved significantly. The purpose and findings of the study were clarified.
The English language in the current version of the manuscript looks much better than before.
Author Response
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Author Response File: 
Author Response.pdf
Reviewer 2 Report
The manuscript entitled “The influence of residues mixing on the decomposition of pepper root residues” submitted by Xianhong Zhang and colleagues tested root decomposition pattern of pepper, soybean and maize alone and or in combination on mass losses, release of nutrient and identification of microbes responsible for the degradation at different incubation time.
No doubt that monocropping of pepper had negative effects on soil quality and crop productivity due to various reasons. The authors reported that the mixing of soybean and maize roots with pepper roots had no beneficial effects on pepper root decomposition and even mixing of maize roots with pepper and soybean had negative effects on root decompositions pattern. The hypothesis of the manuscript is not clear as author not justify about the scope of this study. This study had some inaccuracy terms and sentences entire the manuscript. The abstract is not concise enough and does not highlight the relevant findings of this study. There is information that could be cut out to make it more appealing and synthetic. Please clarify all the abbreviations mention within the text. Introduction contained too much less important information. For example, there is scanty information about area and production of pepper, biomass addition, nutrient added into the soil or removed from the soil, its effects on SOC accumulation, N, P, C:N ratio and soil quality etc. Also add some information about the mixing of soybean and maize with pepper on root degradation, nutrient recycling, nutrients additions, degradation of root, bacterial and fungal genera envolved decomposition of pepper root at different intervals. The methods were described clearly but still need to summarized isolation of DNA, its sequencing and diversity analysis. Relook results section and need to reframe with clarity notably root degradation and microbial community.
Discussion section is basically reasonable but need to elaborate to all the section with facts. Also discuss the role of C:N ratio in root degradation. I think cumulative soil respiration at different incubation period, CO2 emmision, N mineralization and its kinetics of may be included under this study
Author Response
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Author Response File: Author Response.pdf
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
This paper describes an experiment on residue mixing. The research appears to carried out well, but the preentation is such that it is hard to say. Language needs to be improved, as well as clarety of presentation in general.
Some examples:
Introduction: Too short, does not give more background in what effects are found and why, only that effects ar found. E.g. is nitrogen concentration in material important?
Materials and methods: Hard to understand what was done. Some appears to be copied from manual.
Results: I do not understand the difference between e.g. SP-P and SP. Not sure what the difference is between Fig. 5 and table 3 and 4. Choose one graph to show results, and choose the graph that best shows what you think is important. What is CK in Fig. 8?
Discussion: Not clear, does not say clearly what effect were observed. The results from the microbial analysis should be discussed together with the discussion of decomposition rate, can the microbial community and succession help explain the decomposition rate?
Conclusion: Uclear. Shorten, only say the main conclusions from this study.
Author Response
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Author Response File: 
Author Response.docx
Reviewer 2 Report
This manuscript describes study evaluating effects of plant residues mixing on the decomposition rate ad nutrient release. The authors have succinctly explained the importance of this topic in the introduction, their methods, and their results. Unfortunately, it seems to me that it has several flaws that severely limit its value.
Some additional clarity in the methods section will provide the detail and context necessary for both evaluating results and determining connections to other research on this topic. Also, some clear linkages between your findings and the existing literature in your discussion is needed to understand the relevance and value of your findings. It is important to highlight how this paper advances knowledge on this topic in the discussion section.
Line-by-line comments:
In the Keywords it should be good to add Fungal community, Nitrogen and Phosphorus.
Line 32 – What do you mean as “soil sickness of pepper”? Please clarify this in the text.
Line 33 – I think that more correct to say that it “can restrict yield”, not “restrict high yield”.
Line 42 – The sentence is not clear. Which changes in biodiversity lead to the productivity of ecosystems? Additional remarks to this sentence - Ecosystems in both cases have some productivity if they have biodiversity or not.
Lines 47-48 – The sentence “This phenomenon is usually divided into two possibilities.” is unclear.
Line 54 – Please, clarify what is N when you use this abbreviation in the text for the first time.
Lines 76-78 – The sentence looks incorrect.
Lines 94-95 – Please, indicate full name of the analyzer.
Lines 110-117 –It is very difficult to understand this sentence. It is too long and complicate.
Subsection 2.2.2. Please add to this section that you measured the length of the seedling root.
Lines 143-151 – it is not clear where the authors measured CO2 flux? Please clarify this point. Additionally this sentence looks like a recommendation, but not a method description. Who put the vials?
Lines 155-156 – This sentence sounds like bacteria and fungi amplified themselves. And what are the F338/R806 and FITS1/RITS2? Please, add some more information to explain this. Not every one of the future readers is familiar with PCR.
Fig. 1 – What is the difference between (a) and (b) diagrams? Please, explain what these two pictures shows? Why the mass loss is different on these pictures?
Lines 246-249 – The authors say that “ the fungal community Shannon index of MP was significantly lower than that of other treatments...”. However, in Fig.3, we can see that it was so only on Day 7. On Day 56, the Shannon index of MP increased significantly and was similar to that for other treatments. Why authors did not mention that?
Line 258 – What is P here: phosphorus or pepper roots? I think it should be better to change the abbreviation for the pepper root treatment to avoid confusion along the text.
Line 259 – What do you mean as a “root residue microorganisms’? Additionally there is a misprint in this line.
Line 266 – “map treatment” – what do you mean? Is this misprint?
Fig. 5 – Which letters indicate significant difference (as it is written in the figure caption on Lines 282-283)?
Tables 2 and 4 – Please, indicate the units of the relative abundance. Is this percentage or some other?
Line 293 – The number of the figure is not indicated.
Fig. 6 – Is this really percentage on the y-axis?
Fig.9 – It should be better change the name of the y-axis from Dry weight to Biomass (for example). Is this biomass of the seedling roots or the whole seedling? Please, clarify this. Additionally, the first sentence in the figure caption needs correction.
Line 335 – The sentence must begin from the capital letter.
Discussion:
Subsection 4.1. First, the authors did not study carbon return to the soil. So, which way the first sentence can be connected with this study?
Second, in Discussion you should explain you results: Why soybean residues degrade faster? Which different properties and chemical properties can influence on the rate of decomposition? Which interaction between residues can matter?
Subsection 4.2. Lines 355-356 – The reference [35] does not concern pepper, soybean, or maize residues. Please, explain why do you think that maize and soybean residues have a low quality and pepper residues have high quality?
Line 371 – there is incomplete sentence.
Additionally, this section should include a discussion of how your findings advance this field and if/how they vary from previous work that’s been done.
Conclusions. Unfortunately, this study did not provide “help for understanding the residues degradation process” because the authors did not provide a deep analysis of their results and did not discuss their findings in detail.
There are a lot of misprints in the text. There is problem in punctuation (for example, on the Lines 47, 61,129 and many others).
Overall recommendations:
Discussion should be rewritten. A deeper analysis of obtained data should be provided, and the results of this study should be more clearly explained. Microbial and fungi communities and abundance can be used to explain difference in decomposition.
English needs to be improved: there are a lot of incomplete sentences and sentences, which are difficult to understand.
An additional question to the experimental design of the study: why authors did not use only soil as a control for the treatments? It is possible that the addition of plant residues to the soil cannot change nutrient status substantially because soil nutrients were enough for the seedling growth.
Author Response
Please see the attachment.
Author Response File: Author Response.doc
