Soil Organic Carbon Content Prediction Using Soil-Reflected Spectra: A Comparison of Two Regression Methods
, Adunias dos Santos Teixeira 2,*, Marcio Regys Rabelo de Oliveira 3, Mirian Cristina Gomes Costa 4, Isabel Cristina da Silva Araújo 2, Luis Clenio Jario Moreira 5 and Fernando Bezerra Lopes 2Round 1
Reviewer 1 Report
I congratulate you for the effort in producing the manuscript. However, it does not present any novelty in relation to SOC quantification using chemometric methods. The practices presented in the manuscript have already become commonplace. Currently, researchers have been using sequences of algorithms in Python, MatLab, R and Unscrambler, looking for better models for SOC prediction. Unfortunately the work has more of the same.
Author Response
The authors wish to acknowledge the valuable contribution and the time taken by the Reviewer 1 in collaborating with this paper, together with their recommendations which will ensure better understanding of the text. The principal reason for this guide is to list, one by one, the necessary corrections suggested by the three reviewers.
Following your instructions, substantial modifications to the structure and citations have been implemented to improve the quality of the text. Furthermore, each explanation has been carefully elaborated in this guide, as it was the sincere wish of the authors to be clearer and more assertive in their arguments.
Author Response File: 
Author Response.pdf
Reviewer 2 Report
Please see attached document
Comments for author File: Comments.pdf
Author Response
The authors wish to acknowledge the valuable contribution and the time taken by the Reviewer 2 in collaborating with this paper, together with their recommendations which will ensure better understanding of the text. The principal reason for this guide is to list, one by one, the necessary corrections suggested by the three reviewers.
Following your instructions, substantial modifications to the structure and citations have been implemented to improve the quality of the text. Furthermore, each explanation has been carefully elaborated in this guide, as it was the sincere wish of the authors to be clearer and more assertive in their arguments.
Author Response File: Author Response.pdf
Reviewer 3 Report
I'm reviewing "Soil organic carbon content prediction using soil-reflected 2 spectra: A comparison of two regression methods".
The manuscript is well written, matherials and methods are clearly described and the results well presented.
The conclusions section lacks of a clear sinthetic result from the study. I.e. [698] to support the statement "alternative for predicting soil organic carbon content" a revision of Conclusions section is needed. In case of an up to come "sample A3" which model should be used for SOC prediction?
As a reader, I would like to find a 1:1 plot measured-predicted SOC content (maybe more than one plot:untransformed, First Derivative, Smoothed x PCR,PLSR) to get an overall understanding of the proposed models behaviour. This would get the results far way easier to understand and compare.
Along the text few minor points can be improved:
[52] "potentially harmful to the environment" here a reference is missing and/or you should provide an exemplary occurrence.
[54] a typo "-" occurs in "com-ponents"
[137] the point-like samples are not shown in the figure, "(a) Detail of the spatial distribution of the study area"
[203] "big data" should be changed into a description of the size of the collected data (e.g. 150 spectra * 2150 wavelength frames * 2 replica * 65samples =~42*10^6 measurement)
As a further suggestion to improve the presentation of the proposed analysis: a reader would gain by the addition a schematic of the developed instrument shown in figure 3. The proposed image provide a clear documentation of the actual existance of the tool but is very hard to understand without a labelled schematic rapresentation.
Author Response
The authors wish to acknowledge the valuable contribution and the time taken by the Reviewer 3 in collaborating with this paper, together with their recommendations which will ensure better understanding of the text. The principal reason for this guide is to list, one by one, the necessary corrections suggested by the three reviewers.
Following your instructions, substantial modifications to the structure and citations have been implemented to improve the quality of the text. Furthermore, each explanation has been carefully elaborated in this guide, as it was the sincere wish of the authors to be clearer and more assertive in their arguments.
Author Response File: Author Response.pdf
Round 2
Reviewer 2 Report
The revised manuscript addresses my original concerns and I believe the paper is ready for publication apart from that there are some references that are out of sequence (jump from reference 77 to 86) and these should be edited correctly.
Author Response
The authors sincerely thank Reviewer 2 for his contributions, and are pleased that everything was to his liking. Following his request, the manuscript was completely revised while searching for other references that were out of sequence. The modifications were highlighted in the manuscript, after having been correctly inserted in the order required by the journal.
