Determining the Effects of Nanonutrient Application in Cabbage (Brassica oleracea var. capitate L.) Using Spectrometry and Biomass Estimation with UAV

Round 1

Reviewer 1 Report

Overall comment:

  The authors report on the analysis of the relationship between vegetation indices ((VI) NDVI, GNDVI, NGRDI, RVI, GVI, CCI RARSa, and chlorophyll content (CC)) obtained from two test plots, field and greenhouse, with the aim of determining the effect of nan-nutrients (Zn and Mn) on cabbage, as well as the calculation and validation of dry biomass production in the field using a digital model. Moreover, the authors indicate that the spectral response issued in the field allowed to evaluate the behavior of the crop due to the application of nano-nutrients, which did not occur in the greenhouse, in the same way. The spectral response also allowed the spectral characterization of the crop in its phenological states in the two trials.

These results are quite striking. However, the context of the text is not such that the results of the abstract and conclusion can be easily read unless the paper is read over and over again. Numerous explanations have been omitted or are not clear without reading the references. Furthermore, the writing is not sophisticated, and there are many expressions that are difficult for readers to understand. In order to make the paper accessible to a wide range of readers, a major revision is necessary.

In conclusion, this manuscript appears to be reporting some significant measurements; however, in my opinion, a substantial revision is needed to make this manuscript suitable for publication.

I recommend revising at least according to what I have listed below.

1. Introduction：the introduction is redundant and needs to be refined. The text should be more compact and lead directly to the research objective paragraph.
   • The first two paragraphs should be combined into one paragraph made compact.
   • The third, fourth, and fifth paragraphs should also be combined into a single paragraph to make it more compact.
   • Some more specifics on why cabbage for research purposes and why you focused on those minerals should be given.
2. Materials and equipment: You said, “…which has a spectral resolution of 3nm and a width of 1.5nm.”, What is the "Width of 1.5 nm" in this context?
3. The third paragraph in 4.1, It's hard to understand why the observation (plant) number became 3 or 10. It should be stated more clearly.
4. I didn't understand the meaning of Table 2. I don't understand the meaning of the table with the wavelengths used and the maximum and minimum wavelengths.
5. What is the meaning of F in Table 3-7? F is an abbreviation that is not immediately obvious when reading the text from the front.　It would be better to understand this table than the text.
6. In Sections 6.1 and 6.2, the meaning of Tables 3-8 in the results is not clear, so the authors' explanations are not conveyed to the reader. It should be more clearly and compactly summarized in tables, and it is necessary to devise a way of presenting tables, figures, and results that will help readers understand.
7. There are some English expressions that are not correct. Authors are required to check the manuscript carefully through the text. (For example, "acccepte" in the sentence between Tables 7 and 8.

Author Response

Revision report – agronomy-1486630

Title: Determining the effects of nanonutrients application in cabbage (Brassica oleracea var. capitata) through the use of spectrometry and biomass estimation with UAV

 

Dear Wanda Wang, dear editor and reviewers,

 

Please, find our commented revision report. We addressed the reviewers comments point by point and have thoroughly revised the manuscript based on the input. We are very convinced that our manuscript has improved significantly due to the appreciated and valuable comments and recomendations from all the reviewers. Therefore, we are able now to provide a revised manuscript with the changes highlighted in blue colour for your reference. The answer to each comment is given below (also in blue colour).

 

Although the reviewers have not pointed out serious errors in grammar, the manuscript has also been entirely revised by a professional translation agency to ensure that language completely fulfils the quality requirements of the journal.

 

If you have any further question, we are entirely at your disposal.

 

Best regards, on behalf of all authors

 

 -Authors of agronomy-1486630

 

____________________________________

 

Reviewer: 1

 The authors report on the analysis of the relationship between vegetation indices ((VI) NDVI, GNDVI, NGRDI, RVI, GVI, CCI RARSa, and chlorophyll content (CC)) obtained from two test plots, field and greenhouse, with the aim of determining the effect of nan-nutrients (Zn and Mn) on cabbage, as well as the calculation and validation of dry biomass production in the field using a digital model. Moreover, the authors indicate that the spectral response issued in the field allowed to evaluate the behavior of the crop due to the application of nano-nutrients, which did not occur in the greenhouse, in the same way. The spectral response also allowed the spectral characterization of the crop in its phenological states in the two trials.

These results are quite striking.

 

We are quite grateful for these affirmations and the reviewer´s support.

 

However, the context of the text is not such that the results of the abstract and conclusion can be easily read unless the paper is read over and over again. Numerous explanations have been omitted or are not clear without reading the references. Furthermore, the writing is not sophisticated, and there are many expressions that are difficult for readers to understand. In order to make the paper accessible to a wide range of readers, a major revision is necessary.

In conclusion, this manuscript appears to be reporting some significant measurements; however, in my opinion, a substantial revision is needed to make this manuscript suitable for publication.

 

Thanks again for your comments, we have severely tried to solve the aforementioned problems in an appropriate way.

 

I recommend revising at least according to what I have listed below.

1. Introduction：the introduction is redundant and needs to be refined. The text should be more compact and lead directly to the research objective paragraph.
• The first two paragraphs should be combined into one paragraph made compact.

Thanks for bringing this to our attention, paragraphs 1 and 2 of the introduction have been combined in order to make it more compact in the way stated below:

 

Nowadays, precision agriculture is an innovative approach developed within the management of agricultural production systems, as it allows to analyze and monitor crops, as well as production factors such as seeds, fertilizers, water control, among others (Garcia-Sanchez et al., 2011; Patrício & Rieder, 2018; Gusev et al., 2019; Bauer et al.,. 2019; Nyaga et al., 2021). The use of remote sensors, geographic information systems, global positioning systems and artificial vision systems is having a growing influence and impact on farm management in order to improve yields, reduce costs and use resources efficiently, generating sustainable agriculture (Cassman, 1999; Martínez-Casasnovas & Bordes, 2005; Lowenberg-DeBoer, 2019: Guerrero, 2015; Saiz-Rubio & Rovira-Más, 2020; Sharma et al., 2020). Therefore, the use of this tools in Ecuador is fundamental for the sustainable management of the crop, providing solutions to the main challenges of the agricultural sector. These may include the scaling up or massification of agroecology for food production such as vegetables, fruits and medicinal plants, but also the identification of crops and vegetables in large plots with a higher spatial and temporal resolution, the availability of nutrients and water, the diseases distribution, pests and weeds, and the considerable use of agrochemicals and fertilizers (Chartuni e al., 2006; INIAP, 2018).

 

1.  

The third, fourth, and fifth paragraphs should also be combined into a single paragraph to make it more compact.

Thanks for bringing this to our attention, paragraphs 3, 4 and 5 and 2 of the introduction have been combined in order to make it more compact.

 

On the other hand, Nanotechnology refers to the manipulation of matter at a nanometric level of 1-100nm. Theoretically, nanomaterials such as nanoparticles, nanonutrients and nanofertilizers, are able to be developed based on any chemical substance and plant extracts (Dreher, 2004: Khan et al., 2019; Kumar, N., 2016; & Kumbhat, S. 2016; Nasrollahzadeh et al., 2019). This type of technology has several applications in agricultural systems and has shown a great potential in precision agriculture to improve the ability of plants to absorb nutrients (Mousavi & Rezaei, 2011), reduce the presence of pests and increase the productivity of crops (Rai & Ingle, 2012; Tarafdar et al., 2015; Shalaby et al., 2016; Elemike et al., 2019). Nanonutrients are encapsulated micronutrients that improve the nutritional quality of crops due to their design and composition. These offer a slow-release of nutrients for a more extended period, giving crops more time to take them, avoiding the repeated application of conventional agrochemicals and reducing adverse effects on crops, plants and the environment (Luque & Rubiales, 2009; Alfalahi & Abdulqahar, 2021). Brassicaceae family include many common vegetable crops such as cabbage, broccoli, cauliflower, and kale. Cabbage Brassica oleracea var. capitate is the most cultivated vegetable worldwide (Turan et al., 2005; Xu et al., 2020). By 2007, there were about 3.09 million hectares of cabbage in production globally, with a total production of 69.18 million tons (Petit, 2009; Šamec et al., 2017; Song et al., 2013). Due to its extensive consumption worldwide, it is considered one of the crops that contributes to agricultural diversification, generation of labor force and reduction of imports (Ramos, 2007; Kong et al., 2021). Due to its high content of iron and chlorophyll, it helps in the treatments of depression, insomnia, exhaustion and anxiety (Guambo, 2010; Simons, 2013; Bartram, 2013).

 

Some more specifics on why cabbage for research purposes and why you focused on those minerals should be given.

This has been specifically pointed out in the previous paragraph.

“Cabbage Brassica oleracea var. capitate is the most cultivated vegetable worldwide (Turan et al., 2005; Xu et al., 2020).”

 

1. Materials and equipment: You said, “…which has a spectral resolution of 3nm and a width of 1.5nm.”, What is the "Width of 1.5 nm" in this context?

In this sense, the width of 1.5 nm means the value of the reflectivity taken into account to estimate the final value, e.g. for 660 nm, the band use de average values measured since 658.5 till 661.5 nm.

 

1. The third paragraph in 4.1, It's hard to understand why the observation (plant) number became 3 or 10. It should be stated more clearly.

Thanks for bringing this to our attention, we think that the sentence that is generating the confusion is “Therefore, we considered a size around five to ten observations for analysis.”. To solve this, we decided to delete that sentence.

 

1. I didn't understand the meaning of Table 2. I don't understand the meaning of the table with the wavelengths used and the maximum and minimum wavelengths.

Table 2 documents the size and position of the used bands. In order to not generate a confusion, we deleted the table and added the central value of each band in the text.

 

1. What is the meaning of F in Table 3-7? F is an abbreviation that is not immediately obvious when reading the text from the front. It would be better to understand this table than the text.

F is the statistic in an ANOVA analysis. It is a ratio that shows the difference of the variance inside the group and between groups. If the statistic of F is higher, the difference between groups will be higher. As this is a general statistical test, we therefore don´t considerer that the statistic F need to be clarified.

 

1. In Sections 6.1 and 6.2, the meaning of Tables 3-8 in the results is not clear, so the authors' explanations are not conveyed to the reader. It should be more clearly and compactly summarized in tables, and it is necessary to devise a way of presenting tables, figures, and results that will help readers understand.

We hoped to give a better fluidity of the obtained results by splitting these into a variety of tables, 3 to 5 as well as 6 to 8. Now, based on the valuable comment, we opposed to our own initial though of how to present the tables and summarized them into two single tables. Table 3 to 5 is now table 3, tables 6 to 8 is now table 4. The data are now better to see in single tables and easier to be compared with each other (treatments and trials).

 

1. There are some English expressions that are not correct. Authors are required to check the manuscript carefully through the text. (For example, "acccepte" in the sentence between Tables 7 and 8.

Done, thank you.

Reviewer 2 Report

Dear authors and editor,

The manuscript “Determining the effects of nanonutrients application in cabbage (Brassica oleracea var. capitata) through the use of spectrometry and biomass estimation with UAV” aims at evaluating the opportunity of using spectral data to discriminate between phenological stages and nanonutrients apport in Brassica.

The topic is relevant and contemporary, and the Journal is appropriate.

The introduction needs to be re-organised, as the sections don’t follow a logical order. My suggestion is to begin with the relevance of Brassicaceae, then move to sustainability and link the use of nanotechnologies and precision agriculture, which involves the use of UAVs (therefore, in your manuscript begin with “Brassicaceae family include…”, then a sentence on sustainable management, then “Nanotechnology refers to the manipulation of matter…”, then ” precision agriculture is an innovative approach developed within…”, then “UAVs are remotely or autonomously controlled…”). Moreover, in the Introduction, you state that UAVs are more advantageous than satellites and planes in agricultural applications. You should mention that it depends on the objectives of the study and the size of the plots (referring to https://doi.org/10.3390/agronomy11112098, the price of the UAVs is the highest within the mentioned technologies. Moreover, data handling is more complicated when the images are coming from drones. Just add some sentences to explain from what point of view UAVs are more advantageous).

The methodology is well described, I just miss the statistical test you used to compare the treatments and which phenological stages were monitored. Moreover, harmonise the verb tense across the text.

In the results, it’s hard to understand Tables 3, 5, 6 and 8 as we don’t know how many phenological stages were monitored and if all of them were different. It would be very interesting to understand if the spectral analysis can discriminate between each stage. I, then, realise that you illustrate the phenological stages in the Discussion, but this must be clarified in the M$M.

The Discussion is well detailed, you have analysed each single VI, which is crucial for agricultural research. However, the quality of English in the Discussion is lower than the rest of the text. In general, use the past tense when describing and discussing a scientific experiment.

 

 

 

 

Here are some specific comments:

 

Be careful, sometimes you used VI’s or IV instead of Vis

Define UAV the first time you use it

Harmonise the units, sometimes you use abbreviations, sometimes you don’t

Why don’t you report the link to the repository of your dataset?

The sentence “For NDVI and RVI there is a significant difference between treatment 5, 2 and 3, while for treatment 4 it is demonstrated that there is no significant difference between it and treatment 5 and 2, and in the same way, in treatment 1 it is observed that there is no difference between it and treatment 2 and 3.” is hard to read.

The bibliography doesn’t comply with the Journal style.

Author Response

Revision report – agronomy-1486630

Title: Determining the effects of nanonutrients application in cabbage (Brassica oleracea var. capitata) through the use of spectrometry and biomass estimation with UAV

 

Dear Wanda Wang, dear editor and reviewers,

 

Please, find our commented revision report. We addressed the reviewers comments point by point and have thoroughly revised the manuscript based on the input. We are very convinced that our manuscript has improved significantly due to the appreciated and valuable comments and recomendations from all the reviewers. Therefore, we are able now to provide a revised manuscript with the changes highlighted in blue colour for your reference. The answer to each comment is given below (also in blue colour).

 

Although the reviewers have not pointed out serious errors in grammar, the manuscript has also been entirely revised by a professional translation agency to ensure that language completely fulfils the quality requirements of the journal.

 

If you have any further question, we are entirely at your disposal.

 

Best regards, on behalf of all authors

 

 -Authors of agronomy-1486630

 

____________________________________

Reviewer: 2

The manuscript “Determining the effects of nanonutrients application in cabbage (Brassica oleracea var. capitata) through the use of spectrometry and biomass estimation with UAV” aims at evaluating the opportunity of using spectral data to discriminate between phenological stages and nanonutrients apport in Brassica.

The topic is relevant and contemporary, and the Journal is appropriate.

We are very grateful by all these comments which demonstrate the reviewers support.

 

The introduction needs to be re-organised, as the sections don’t follow a logical order. My suggestion is to begin with the relevance of Brassicaceae, then move to sustainability and link the use of nanotechnologies and precision agriculture, which involves the use of UAVs (therefore, in your manuscript begin with “Brassicaceae family include…”, then a sentence on sustainable management, then “Nanotechnology refers to the manipulation of matter…”, then ” precision agriculture is an innovative approach developed within…”, then “UAVs are remotely or autonomously controlled…”). Moreover, in the Introduction, you state that UAVs are more advantageous than satellites and planes in agricultural applications. You should mention that it depends on the objectives of the study and the size of the plots (referring to https://doi.org/10.3390/agronomy11112098, the price of the UAVs is the highest within the mentioned technologies. Moreover, data handling is more complicated when the images are coming from drones. Just add some sentences to explain from what point of view UAVs are more advantageous).

We highlighted this within the introduction.

 

The methodology is well described, I just miss the statistical test you used to compare the treatments and which phenological stages were monitored. Moreover, harmonise the verb tense across the text.

Thanks for bringing this to our attention, the monitored phenological stages are in Table 1 (Establishment, Vegetative development, head preforming and head formation). We added in this respect the raw data in an extra-file which can be easily downloaded:

https://drive.google.com/drive/folders/1P78bl0FX6B2U2UuYuUbbmZvkzgtPspBs?usp=sharing

 

In the results, it’s hard to understand Tables 3, 5, 6 and 8 as we don’t know how many phenological stages were monitored and if all of them were different. It would be very interesting to understand if the spectral analysis can discriminate between each stage. I, then, realise that you illustrate the phenological stages in the Discussion, but this must be clarified in the M$M.

Thanks for bringing this to our attention, in Table 1 we listed the analyzed phenological stages. The table 1 is in the methodology section. The tables later where than summarized as previously described and asked by reviewer #1.

 

The Discussion is well detailed, you have analysed each single VI, which is crucial for agricultural research. However, the quality of English in the Discussion is lower than the rest of the text. In general, use the past tense when describing and discussing a scientific experiment.

This has been observed and widely corrected as demonstrated throughout this section of the manuscript.

 

 Here are some specific comments:

 Be careful, sometimes you used VI’s or IV instead of Vis

Thanks for bringing this to our attention, we changed all VI’s or IV, for Vis.

 

Define UAV the first time you use it

Thanks for bringing this to our attention, we added this when UAV appears the first time:  “Unmanned Aerial Vehicles (UAV) are remotely or autonomously controlled airplanes or multirotors that are able to follow a pre-programmed flight line operating outside of the internal navigation system (Gupta et al., 2013; Colomina & Molina, 2014; Siebert and Teizer, 2014; Kyrkou et al., 2019).”

Harmonise the units, sometimes you use abbreviations, sometimes you don’t

Accepted and realized, thank you.

 

Why don’t you report the link to the repository of your dataset?

Done, its below:

https://drive.google.com/drive/folders/1P78bl0FX6B2U2UuYuUbbmZvkzgtPspBs?usp=sharing

 

The sentence “For NDVI and RVI there is a significant difference between treatment 5, 2 and 3, while for treatment 4 it is demonstrated that there is no significant difference between it and treatment 5 and 2, and in the same way, in treatment 1 it is observed that there is no difference between it and treatment 2 and 3.” is hard to read.

Cut and changed into two sentences.

 

The bibliography doesn’t comply with the Journal style.

They have been corrected, as indicated in the revised version, while a few more references were added as well, in order to actualize and accomplish some of the reviewers comments.