Can Unmanned Aerial Vehicle Images Be Used to Estimate Forage Production Parameters in Agroforestry Systems in the Caatinga?

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

This manuscript (applsci-3022917) demonstrates that environmental changes in the Caatinga biome have led to the degradation of approximately 50% of its original vegetation, making it the third most degraded biome in Brazil, primarily due to improper grazing practices. This study compared the ability of various indices to predict the biomass and leaf area index (LAI) of forage crops in agroforestry systems (AFS) in the Caatinga. The normalized green red difference index (NGRDI) and visible atmospherically resistant index (VARI) showed the highest correlations with biomass and LAI, especially when trees were removed from orthomosaics. The classification and regression tree (CART) models had the lowest RMSE and highest CCC values, indicating superior performance in estimating these parameters.

In general, this manuscript is well written, detailed, and suitable for publication. The sections are appropriate. However, minor changes are necessary before application.

Comments:

Keywords in alphabetical order;

I suggest that the authors describe precisely and in detail the step-by-step process for corrections in 2.2. Unmanned Aerial Vehicle Flight Pattern and 2.3. Unmanned aerial vehicle flight pattern. For example, when they present the packages used, they do not describe whether the codes were applied to the images that have already been processed, which incidentally need to describe the methods for converting digital numbers to reflectance and processing with ENVI.

Therefore, the material and methods section needs to be rewritten to adequately detail. The name of the manufacturer (city, state, or country) is included.

The captions need to be improved. For example, they should describe all the elements that appear, as well as a complete and explanatory description, so that readers do not need to return to the text to know what it is about. The sample number was included when appropriate.

Adequate descriptions of the drone settings, flight time, data collection speed, altitude, software and applications for data correction, which stations were used is necessary. Include in the discussion, what are the main problems for the correction of the images and formation of the orthomosaics and possible perspectives to improve, using the data for correction.

References are okay, however, make sure to include more recent references.

Comments on the Quality of English Language

English needs minor corrections regarding spelling in some sentences.

Author Response

Dear Editor-in-Chief and Reviewer,
We appreciate the time and effort you and the reviewers dedicated to providing feedback on our manuscript and are grateful for the insightful comments and valuable improvements to our paper.
All necessary adjustments have been made.
Please see the attachment.
All the best.

Author Response File: Author Response.docx

Reviewer 2 Report

Comments and Suggestions for Authors

Thank you very much for the opportunity to review the paper "Can UAV images be used to estimate forage production parameters in agroforestry systems in the Caatinga?". Prca presents a comparison of the predictive ability of various biomass and leaf area indexes of forage crops in AFS in the Caatinga biome and an assessment of the impact of removing system components on model performance.

I have no comments on the paper, as the introduction extensively and comprehensively presents the agroforestry problems of modeling biomass and leaf area index of agroforestry forage plants in the Caatinga biome. The methodology was explained very simply, in detail what posed to understand the work to a wide audience. The work is provided with numerous graphics and figures which will also facilitate its reception.

The discussion and results were also written correctly. 

Author Response

Dear Editor-in-Chief and Reviewer,
We appreciate the time and effort you and the reviewers dedicated to providing feedback on our manuscript and are grateful for the insightful comments and valuable improvements to our paper.
All necessary adjustments have been made.
Please see the attachment.
All the best.

Author Response File: Author Response.docx

Reviewer 3 Report

Comments and Suggestions for Authors

Wagner et all present a very interesting case study of Caatinga on how to evaluate the vegetation of crops using UAV remote sensing technology, orthophoto maps using band decomposing analysis of orthophoto map and identify suited models to predict the state of the crops and biomass. It is very interesting the approach of the study where evaluated biomass parameters in the state of dry, wet, and natural. I suggest a small improvement to your study by adding a map of the spatial occurrence of species in the orthophoto map of 2021 and 2022 it will add more scientific value.

Author Response

Dear Editor-in-Chief and Reviewer,
We appreciate the time and effort you and the reviewers dedicated to providing feedback on our manuscript and are grateful for the insightful comments and valuable improvements to our paper.
All necessary adjustments have been made.
Please see the attachment.
All the best.

Author Response File: Author Response.docx