High-Resolution Airborne Hyperspectral Imagery for Assessing Yield, Biomass, Grain N Concentration, and N Output in Spring Wheat

Round 1

Reviewer 1 Report

Dear authors,

First of all, I appreciate the modifications you made within the currently submitted version of your manuscript. However, I also believe that my previous comment was not incorporated sufficiently:

"The goals presented between lines 112 and 118 could be better addressed in the Discusssion and Conclusions section. Both sections are well-written and easy to follow. However, its re-structuralization in line with the goals of the paper would be beneficial."

I see that the Introduction in lines 113 to 115 now explicitly distinguishes between the two general objectives. In contrast, I have not found any corresponding action in the Discussion section. I would expect a structure that will ease the readability of a discussion to each general objective, e.g. two separate sub-sections with appropriate content.

Author Response

The Discussion and the Conclusions have been reorganized following reviewers advise. The Discussion has been subdivided in three subsections according to the specific questions stated in the objectives. The Conclusions were rewritten to follow the same order. Please see the track changes manuscript version.

Reviewer 2 Report

All the issues have been acceptably addressed ...

Author Response

Thank you for your comments

Reviewer 3 Report

The paper has been improved, but I still miss the need to enhance the discussion section and to better clarify the results obtained.

I have found it noticeable that most of the minor comments I have made have been carried out, but suggestions for improving the results and discussion have been overlooked and unanswered.

It is an excellent piece of work but needs a final polishing to highlight not only the implications and future work but to make clear to the reader the possibilities and scope.

Please note comments from the previous version:

• The discussion section would require a more significant effort to bring together the implications and the future work to be developed with modifications that could lead to better interpretation. The manuscript’s quality is excellent; however, some errors found could have been edited by a professional proofreader; reviewers should not be in charge of this task.
• Results, main concern: It is cumbersome to follow the errors established from RMSE, sometimes dimensionless (%), sometimes in the corresponding units. Wouldn’t it be more convenient to standardise it? They can then be compared, and the reader can see the implications and errors in each relationship. Otherwise, it becomes very confusing.

Author Response

We thank the reviewer for his comments that help to improve the quality of the manuscript. Please find our answers in the next lines.

• The discussion section would require a more significant effort to bring together the implications and the future work to be developed with modifications that could lead to better interpretation. The manuscript’s quality is excellent; however, some errors found could have been edited by a professional proofreader; reviewers should not be in charge of this task.

The Discussion has been modified. First, it has been reorganized in three subsections according to the specific questions stated in the objectives. Then, new paragraphs have been added to connect this work with the actual strategies for fertilizer recommendation and to emphasize the implications for future work. Please, see the new Discussion in the track changes version.

The manuscript has been reviewed by a Professional Editor, please find a certificate attached.

• Results, main concern: It is cumbersome to follow the errors established from RMSE, sometimes dimensionless (%), sometimes in the corresponding units. Wouldn’t it be more convenient to standardise it? They can then be compared, and the reader can see the implications and errors in each relationship. Otherwise, it becomes very confusing.

We think that expressing the RMSE in the variables units has many advantages over expressing the relative RMSE or standardize. The reader can immediately see what the error committed in the assessment is, for instance 400 kg ha^-1 in yield or 0.2% in grain N concentration. It is much more intuitive than the relative error and useful for any researcher familiar with the topic. Therefore, we would like to leave the RMSE express as the units of the variable.

Please notice that in the manuscript, the RMSE has always the same units of the corresponding variable. These units are either kg ha^-1 when referring to yield or biomass, kg N ha^-1 when referring to N output, or % N in the grain when referring to GNC. The GNC is the g of N per kg of grain dry matter expressed as a %, which are the units use for all researchers in this topic. To avoid any confusion, the RMSE units were changed from ‘(%)’ to ‘(%N)’ throughout the manuscript when the RMSE refers to GNC. Please notice, if the RMSE was standardized would be expressed as the relative error of a percentage, very confusing for the reads in our opinion.

Author Response File: Author Response.pdf

Reviewer 4 Report

See the attached file.

Comments for author File: Comments.pdf

Author Response

We thank the reviewer for his comments that help to improve the quality of the manuscript. Please find our answers in the attached file.

Author Response File: Author Response.pdf