Distribution Characteristics and Drivers of Soil Carbon and Nitrogen in the Drylands of Central Asia
Round 1
Reviewer 1 Report
The paper nicely utilizes existing data sets to evaluate the drivers of soil C, N and C:N in the target dryland agroecological zone. Great to see the data being put to use. Whilst the trends are largely as one would expect, the it is useful to have the ranges and magnitude constrained.
Two points that the paper make could be further discussed. The ranges of total C look like preferred states of 0-.5 % and 11-16%. Do these "states" occur in particular geomorphic conditions? And the C:N ratio (60% of land between 12 and 29 already a wide range) is interesting....what about the other 40%? I have found some really low C:N ratios in mountainous areas during some consultancy work - so would be interested to see if where the really low C:N ratios are that you found (if any). I think that low soil C:N might be under-reported, so if you have found some it might ignite more interest in the paper.
The data sources, whilst claim to be at resolution of 250 m, are not actually measured at 250 m resolution for target analytes. Some further discussion about the confidence of extimates is required, and this migh require some discussion about how the values were estimated (but not too much). Confidence is particularly vulnerable when you start to compound uncertainty, such as to get C:N values.
Some editing needed
Abstract - define MAT and AGB to make it stand alone
ln 35 Preface or Introduction?
ln 54, 58 elsewhere carbon to C, nitrogen to N except where starting a sentence
ln 84 questions
ln 108-110 imbalance and distribution of what? Suggest delete.
ln 128 - etc?
ln 129. need discussion of uncertainty of property values.
ln 152-157 and elsewhere. Be sensible about significant figures (eg 49.07% should be 49%).
Table 1. Insert somewhere what the abbreviations are for variables used elsewhere.
ln 152-157 C:N....what about the other 40%?
Ln 210-215. Delete or use in introdustion.
ln 248-250. This is a bit obvious....if C:N goes down C and N are being impacted differently. I think that you could give some options....more complete decomposition of OM so more loss of C, lowerC:N plant inputs (unlikely), more free-living microbial N fixation relative to plant photosynthesis.
ln 265-267. Make clear that the N2O comment is from Dai et al, and suggest how relevant it is to this land.
There is an extra full stop somewhere....see if you can find it.
Author Response
Dear Reviewer：
We appreciate your review of our manuscript and we think you have made a number of very interesting suggestions that we need to improve in this study, and after discussion among all the authors, we have responded to your comments as well as made changes in the text as follows.
As mentioned in the paper, the range of total carbon is mainly concentrated between 0-5.5g/kg and 11-16g/kg, and after comparing with the land cover types we found that the 0-5.5g/kg range is mainly concentrated in desert covered areas, while the 11-16g/kg range is mainly concentrated in grassland covered areas, we believe this is a very meaningful phenomenon, which may require We believe that this is a very meaningful phenomenon, which may require a deeper study to explore to figure out the reasons for this phenomenon, and we will continue to work on it in the next step.
Areas with C: N below 10 are mainly located in southern Turkmenistan and the Turpan region of Xinjiang, China (e.g., the Flaming Mountains), and 60% of the study area has C: N between 12 and 29. We recalculated the proportion of different ranges and found that C:N in the study area is mainly concentrated in the range of 9 - 12, accounting for about 36% of the study area.
This study uses the global gridded soil information database (SoilGrids) from the ISRIC website, which uses state-of-the-art machine learning methods to map the spatial distribution of soil properties globally. The SoilGrids prediction model uses over 230,000 soil profile observations from the WoSIS database for fitting and a range of environmental covariates.
I have detailed our response in my submission.
Author Response File: 
Author Response.pdf
Reviewer 2 Report
Dear authors,
Thank you for the opportunity to review this Manuscript (Distribution characteristics and drivers of soil carbon and nitrogen in the drylands of Central Asia). The study has great results and demonstrates that the distributions of soil C and N contents in the dry zone of Central Asia have greater similarity, with C content mainly concentrated, soil N content, and the soil C:N. There is some aspect that should be reviewed by authors, but the Manuscript is well-written.
ABSTRACCT
What is MAT and AGB?
INTRODUCTION
The introduction is very good and give important information about the study. I suggest remove the lines 90- 99. There is no need of answer of goals in the Introduction.
MATERIAL AND METHODS
Line 125: Explain, if the “Terra Climate dataset” is a open source
Line 129: What is GEE?
Where is the citation of Table 1 in the text
Table 1: substitute doi for name of the authors (Common citation)
RESULTS AND DISCUSSION
In all Figures and Tables, explain the MAP, AGB, MAP e Ele.
Interesting Figure 4
Explain why MAT had the highest relative importance with regard to changes in C:N
Figure 5, explain the correlation in the routes. How it was analyzed?
The authors did not explore the results for arid soil. The results focus on all conditions. This is the important result of study. For example, the correlation is not explored to arid soil
Explain this result “Aridity had a highly significant negative effect on the variation of soil C content”
Line 266: How the authors know the “N cycling processes” in the area
Author Response
Dear Reviewer,
Thank you very much for your comments on our manuscript, which we consider to be very helpful, and after discussion among all authors, Our response to your proposal is set out in detail in our submission
Author Response File: Author Response.pdf
Reviewer 3 Report
Dear Author,
After I have read through your manuscript. Your manuscript has been well prepared. your research topic is also interesting. Overall, I would accept your manuscript for publication.
Author Response
Dear reviewer,
Thank you for your recognition of our work。
Best wishes
