Effects of Farmland Conversion to Orchard or Agroforestry on Soil Organic Carbon Fractions in an Arid Desert Oasis Area

Round 1

Reviewer 1 Report

Manuscript entitled “Effects of farmland conversion to orchard or agroforestry on soil labile organic carbon fractions in an arid desert oasis area”

Comments

1. Abstract need quantification
2. Introduction: Informative (only L 56-64 need restructure for mor clarification)
3. Locations for soil sampling need GPS coordinate
4. In table 1 why SD mentioned separately, it should be with mean data
5. Figure 2 need high resolution
6. In all figure error bar with what (SD/SE/other) pl clarify
7. Table 3 is more complicated need to be simplify
8. Overall result text is excellent
9. Whole discussion has major issue with the poor connectivity with results and sentences also jumping. Need major revision for discussion section
10. Conclusion section seed clear-cut recommendation and quantify information of results
11. In last future direction for research should be mentioned
12. References Pl cross check with text and cited references

Overall MS has been written well and informative manner

Author Response

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Author Response File: Author Response.doc

Reviewer 2 Report

The authors conducted a detailed ecological study on Effects of farmland conversion to other agroforestry systems on soil  organic carbon fractions. The study revealed that the conversion of farm land in to the Jujube orchard has increased the Carbon content in the soil. To develop the resilient future the orchards could be maintained in a sustainable manner . While revising your manuscript, I came across some of the important relevant studies conducted in the other Asian  part which I have mentioned in the manuscript.  Your study could be compared with the mentioned studies.

Comments for author File: Comments.pdf

Author Response

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Author Response File: Author Response.doc

Reviewer 3 Report

Dear Authors,

The manuscript contains possibly important results for the readers but in the present form, I cannot support its publication.

1. The introduction should include some more information on more, in-detail results of related researches, not "only" the basic introduction of the examined parameters.
2.  The objectives should reflect the results more closely. Right now the result section starts with results that were not listed in the objectives. Furthermore, the "sole" "to measure the concentrations and vertical distribution of LOC fractions" itself is not an objective. Especially with its comparison with the other two objectives. 
3. The soil sampling methods are not adequate yet, e.g. how were the soil samples taken in case of the trees, besides being within 1 m from the tree crown projection? It is a more strict question in the case of the jujube/wheat intercropping, where exactly the samples were taken? Exactly in between the trees, along the line of the tree trunks or "only" within the 1 m from the tree crown projection and how does this sampling design meet with the wheat area sampling?
4. A basic introduction of the examined soils is greatly missing. It is very difficult to judge the content without some basic descriptions, e.g. soil type, soil layer thickness, sand content (or you mentioned that you removed the stone particles, what was its percentage?), etc.
5. The result section must be checked carefully, e.g. in Lines 153-154, you say that "the differences in DOC concentration throughout the soil profile under the different land-use types were significant only at 0-10 cm (Fig. 3)." but on Fig. 3. you marked SDs at other depths as well.
6. In the results section, it would be nice to follow a string of well-defined objectives that we do miss now.
7. Furthermore, there is some evaluation missing, e.g. Table 2 content is described but all ROC, LFOC, DOC per TOC evaluation is missing, however, the significance values look OK in 2 cases in case a 0.05 level is set. And again, you state that "no significant land use–soil depth interaction was observed for ROC, LFOC or DOC" but what about TOC and the other parameters (ROC/TOC, etc.)?
8. Table 5 contains erratic data, I think.
9.  In the above-mentioned details, you can understand that further parts are not stable, the discussion of the results must be much better explained and established.
10. Discussion, Lines 226-228: "As hypothesized, the levels of ROC, LFOC and DOC in the 0-100 cm soil profile increased after the land use conversion" - I did not find any hypothesis mentioned in any other part of the manuscript. However, it would be nice.
11. DOC in the discussion is nicely described, however, it overlooks the facts introduced in the introduction, Lines 47-51: "Dissolved organic carbon (DOC) accounts for less than 0.25% of the total soil organic carbon (TOC) [17]. Despite its low concentration, it is the primary energy source for soil microorganisms [16, 18], is involved in the transformation of soil organic matter and the transformation and transportation of inorganic material in soils. It can therefore be a key indicator of soil quality due to its rapid response to land use [19-20]." You have much more than 0.25%, even in the control area! Please clarify and explain!
12.   In general, I miss the explanation of the importance of the examinations about the area involved. Why is it significant in the area? What is the proportion of this land use (desert oasis?). How many people does it support or how big of an amount of TOC can be saved in these oases?

You can find some of my further concerns in the comments of the pdf version.

Regards, Reviewer X

Comments for author File: Comments.pdf

Author Response

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Author Response File: Author Response.doc

Round 2

Reviewer 3 Report

I think the paper is publishable.
I marked average everywhere, otherwise, everything is OK, English is fine. Accept is present form.