Bibliometric Network Analysis of Crop Yield Gap Research over the Past Three Decades

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

This is an interesting article that focuses on a very important topic regarding the current status of the yield gap using a large scientific database. It is well-organized and easy to understand and follow. However, there are some text editing required and need to be checked.

Please find below some comments and suggestions:

 

1.      INTRODUCTION

 

Line 53:55; There are also studies using bioengineering techniques such as Molec- ular design breeding techniques ,Transgenic technology[6], or increasing the photosyn- thetic efficiency of fluctuating light to result in more than 30% increase in soybean yield [7] .

There are also studies using bioengineering techniques such as molecular breeding techniques, transgenic technology [6], or increasing the photosynthetic efficiency under fluctuating light which resulted in more than 30% increase in soybean yield [7].

 

Line 84: the role of “sustainable” agricultural practices [34]  and methos for precision agriculture [35]

the role of sustainable agricultural practices [34] and methods for precision agriculture [35].

 

2. MATERIALS AND METHODS

I would suggest methodology instead of materials and methods.

 

I also would suggest deleting Table 1. as it is a repeat of Figure 1,

Document language in Table 1.: English and Chinese can be added to the text.

Line 98: due to the Significant adjustments

significant

Line 100:101; becauseWheat and maize

because they are 

Line 106; thesis,dissereation thesis,review

thesis, dissertation, review papers

also, fix this Table 1. Document type

 

2.      RESULTS

 

Line 146:147; The number of publications in 2022 was almost 8 times that of 2013,

maybe 8 times that of 1993?

Line 154:155; 15% of all citations whereas the other 75%

25%?

Line 157; Feld crops

Field

Line 184:188; Figure 4 shows the co-occurrence network of countries in the research field, visualizing the relationships between countries based on their publication collaboration. Node size shows the number of publications from each country, while thickness of the links reflects the level of collaboration between countries. The outer color of the nodes represents their betweenness centrality, with higher centrality nodes displaying a purple outer ring.

Figure 5?

In Figure 4; the numbers for France and the Netherlands are missing.

Line 194; the Chinese Academy of Agricultural Sciences and Wageningen University (112 and 95 articles respectively)

155 and 112 articles respectively.

In Figure 5; missing A, B, and C

I also would suggest combining Figures 4 and 5.

 

Line 214; “efficiency gap”"

“use efficiency”

 

Figure 6B would it possible to provide better resolution of the figure on the left side. 

What is strength referring to? in the figure on the right side.

 

Line 215; All keywords classified into ten major clusters (Figure 6B left), ranked in descending order based on their number (Figure 6C).

 

Line 218; The second cluster related remote sensing research

The second cluster was related to remote sensing research

 

Line 219:221; Clusters three, four, seven, and ten are associated with food security, nitrogen fertilizer input, model research, and climate change, while clusters five and eight are related to microbial research, while clusters five and eight are related to microbial research.

-It would be easier to follow the text if clusters were mentioned such as later from line 229:232, for example, the first cluster (#0 transcription factor), third cluster (#2 food security)

Or change the order from 1 to 10

-Does (pattern) refer to model research?

-(#5 meta-analysis) Meta-analysis research which is a very important topic is not mentioned in the text.

 

3.      DISCUSSION

Line 248:249; For instance,[48-49] is the most cited paper in the field over the past three decades (Table 2) and ranks first in terms of publication output within the field (Figure 3).

For instance, [48] is the most cited paper in the field over the past three decades (Table 2) and

The journal (FIELD CROP RES) ranks first in terms of publication output within the field (Figure 3)

Line 261:262; ecology is repeated?

Line 278:280; Also, the analysis does not reveal whether are targeting closing the domestic crop yield gap or encompass other not reveal whether are targeting closing the domestic crop yield gap or encompass other regions in the world.

the analysis did not reveal whether both countries are targeting?

Line 289:293; I would suggest rephrasing these lines as

there are several management practices that are considered sustainable and environmentally friendly such as crop rotation and conservation tillage. In addition, breeding new varieties that are adapted under sustainable management conditions (organic farming for example) represents an efficient way to reduce the crop yield gap.

Line 328:329; Integrating technology, farmers, and government/new technology extension institutions is crucial. I would suggest rephrasing this sentence.

Figure 7. on the right for yield gap: high yield of famers?

 

 

Comments on the Quality of English Language

Minor editing of the English language required

Author Response

Response to Reviewer #1:

1.Line 53:55; There are also studies using bioengineering techniques such as Molec- ular design breeding techniques ,Transgenic technology[6], or increasing the photosyn- thetic efficiency of fluctuating light to result in more than 30% increase in soybean yield [7] .

There are also studies using bioengineering techniques such as molecular breeding techniques,transgenic technology[6],or increasing the photosynthetic efficiency under fluctuating light which resulted in more than 30% increase in soybean yield [7].

• Thank you so much for the reviewer’s time and patience. We agree and have modified the language expressionas your suggestions.

2.Line 84: the role of “sustainable” agricultural practices [34]  and methos for precision agriculture [35]

the role of sustainable agricultural practices [34] and methods for precision agriculture [35].

• Thank you for the reviewer’s suggestions. We agree and have modified the Punctuation usage and spelling of “method”.

3.2. MATERIALS AND METHODS

I would suggest methodology instead of materials and methods.

• Thankyou for the reviewer’s suggestions. We have modified secondary title.

4.I also would suggest deleting Table 1. as it is a repeat of Figure 1,

Document language in Table 1.: English and Chinese can be added to the text.

• Thank you for your suggestions. After a unanimous discussion, we still think that we should keep Table 1, because there are still some differences between it and Figure 1, such as document type, Filtering criteria. the combination of Table 1 and Figure 1 can make the readers more clear about what we are searching for.

5.Line 98: due to the Significant adjustments

significant

• Thanks to the reviewers for detailed suggestions, In order to enhance the logic of the description, we decided to delete this sentence.

6.Line 100:101; becauseWheat and maize

because they are 

• Thanks to the reviewers for detailed suggestions, We agree and have modified the language expressionas your suggestions.

7.Line 106; thesis,dissereation thesis,review

thesis, dissertation, review papers

also, fix this Table 1. Document type

• Thank you for your suggestions.We agree and have modified thedocument type as your suggestions.

8.Line 146:147; The number of publications in 2022 was almost 8 times that of 2013,

maybe 8 times that of 1993?

• Thanks to the reviewer's careful observation, The comparison here should be between 2022 and 2003, a change in the number of publications over a 20-year period.

9. Line 154:155; 15% of all citations whereas the other 75%

25%?

• Thank you for the reviewer’s suggestions. We agree and have modified the proportions.

10.Line 157; Feld crops

Field

• Thank you for the reviewers’ comments. We have modified spelling of words.

11.Line 184:188; Figure 4 shows the co-occurrence network of countries in the research field, visualizing the relationships between countries based on their publication collaboration. Node size shows the number of publications from each country, while thickness of the links reflects the level of collaboration between countries. The outer color of the nodes represents their betweenness centrality, with higher centrality nodes displaying a purple outer ring.

Figure 5?

• Thanks to the reviewer's careful observation, due to an error in editing the image, it erroneously appeared in the other results section and has now been adjusted to and appropriate position.

12.In Figure 4; the numbers for France and the Netherlands are missing.

• Thanks to the reviewer's careful observation, Since the number of posts in the US and China is an order of magnitude higher than in France and the Netherlands, the image was automatically hidden and I readjusted the image.

13.Line 194; the Chinese Academy of Agricultural Sciences and Wageningen University (112 and 95 articles respectively)

155 and 112 articles respectively.

• We thank the reviewers for their careful observations and we have revised the results.

14.In Figure 5; missing A, B, and C

I also would suggest combining Figures 4 and 5.

• Thanks to the reviewer's suggestion, Figure 5 was produced due to a typographical error; the correct situation should be two figures. It was also considered that combining Figures 4 and 5 would make it more difficult for the reader to read them, and also that the original Figure 6 had been split into Figures 6, 7 and 8.

15.Line 214; “efficiency gap”"

“use efficiency”

• Thank you so much for the reviewer’s time and patience. We agree and have modified the keywords as your suggestions.

16.Figure 6B would it possible to provide better resolution of the figure on the left side. 

What is strength referring to? in the figure on the right side.

• Thanks to the reviewer's suggestions, firstly we have enlarged the figure on the left side already to make it easier for the reader to recognize. Secondly the word Strength on the right side, are you referring to the word Strongest? It refers to the extent to which a keyword has been cited over a certain period of time.

17.Line 215; All keywords classified into ten major clusters (Figure 6B left), ranked in descending order based on their number (Figure 6C).

• Thanks to the reviewer's comments, we have modified this sentence as your suggestions.

18.Line 218; The second cluster related remote sensing research

The second cluster was related to remote sensing research

• Thanks to the reviewer's comments, we have modified this sentence as your suggestions.

19.Line 219:221; Clusters three, four, seven, and ten are associated with food security, nitrogen fertilizer input, model research, and climate change, while clusters five and eight are related to microbial research, while clusters five and eight are related to microbial research.

-It would be easier to follow the text if clusters were mentioned such as later from line

229:232, for example, the first cluster (#0 transcription factor), third cluster (#2 food security)

Or change the order from 1 to 10

-Does (pattern) refer to model research?

-(#5 meta-analysis) Meta-analysis research which is a very important topic is not mentioned in the text.

• Thank you for the patience and attentiveness of the reviewers, first of all, we have adjusted the expression Cluster + Numbers with reference to your suggestion, and also added the expression with the keyword Meta-analysis, and the keyword Pattern refers to crop modeling studies.

20.Line 248:249; For instance,[48-49] is the most cited paper in the field over the past three decades (Table 2) and ranks first in terms of publication output within the field (Figure 3).

For instance, [48] is the most cited paper in the field over the past three decades (Table 2) and The journal (FIELD CROP RES) ranks first in terms of publication output within the field (Figure 3)

• Thank you for the patience and attentiveness of the reviewers,I've modified the details of these statements.

21.Line 261:262; ecology is repeated?

• Thank you so much for the reviewer’s time and patience. The correct statement here is environmental science,crop physiology and ecology.

22.Line 278:280; Also, the analysis does not reveal whether are targeting closing the domestic crop yield gap or encompass other not reveal whether are targeting closing the domestic crop yield gap or encompass other regions in the world.

the analysis did not reveal whether both countries are targeting?

• We appreciate your valuable suggestions. We have adjusted the statement here to the following. At the same time, the research theme of the article does not explicitly focus on closing crop yield gaps in the domestic regions or in other regions of the world.

23.Line 289:293; I would suggest rephrasing these lines as there are several management practices that are considered sustainable and environmentally friendly such as crop rotation and conservation tillage. In addition, breeding new varieties that are adapted under sustainable management conditions (organic farming for example) represents an efficient way to reduce the crop yield gap.

• We appreciate your valuable suggestions. We've made the corrections you suggested and added new references

24.Line 328:329; Integrating technology, farmers, and government/new technology extension institutions is crucial. I would suggest rephrasing this sentence.

• Thanks to the reviewer's comments, We've rewritten the sentence as you suggested.

25.Figure 7. on the right for yield gap: high yield of famers?

• Thank you for the reviewer’s comments. The high bar on the right side of the model graph indicates the high yield in the actual yield of the farmer, which we believe is achievable by the farmer through the optimization of technical measures and is also of great research interest.

Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

It is recommended that keywords do not replicate the words, used in the Title.

Line 96-97: Why Web of Science SCIE articles only were subjected to analysis? Why Scopus (generally including more articles on the subject) was ignored?

Line 100-101: Why rice was ignored in the study, as it is even much more important than wheat in global food security?

Line 141: It seems like there is a misprint here, as an entire period of the study is 1993-2023. Not 1993 to 2013.

Line 157 and Line 359: In the first appearance in the text, you name “Agronomy” as the second influential journal after “Field Crops Research”, but in Conclusions another journal is referred to as the second influential journal, namely, “Agronomy Journal”. This point requires revision and thorough check, because “Agronomy” and “Agronomy Journal” are not the same publishers.

Author Response

Response to Reviewer #2:

1. It is recommended that keywords do not replicate the words, used in the Title.

• Thank you so much for the reviewer’s time and patience.We have agreed and made the following changes in response to your comments.,as follows food security; crop; yield gap; research hotspots;Citespace.

2. Line 96-97: Why Web of Science SCIE articles only were subjected to analysis? Why Scopus (generally including more articles on the subject) was ignored?

• Thank you very much for your comments, a review of the information found that the Scopus database is the largest database of abstracts and citations from peer-reviewed literature (scientific journals, books and conference proceedings). It provides a comprehensive overview of global research results in 240 subject areas, including science, technology, medicine, social sciences, arts and humanities. Unfortunately, however, there are only a limited number of universities or research units in China that recognize and use the database, and the China Agricultural University, where I studied, did not purchase the service. Of course, this does not obscure the advantages of the database, so I will certainly do my best to find relevant resources for similar studies in the future.

3. Line 100-101: Why rice was ignored in the study, as it is even much more important than wheat in global food security?

• Thank you very much for your comments and I will answer this question in the following two ways. First, this paper is the very first part of our research project, which focuses on wheat and maize, so we chose these two cereal crops. Secondly, and most importantly, our search formula is set so that the word "yield gap" is found in the title, keywords and abstract of the article. At the same time, to ensure the results, we also put the word rice into the search formula, and found that the number of retrieved documents increased by 1,358 compared to the number of documents without the word rice, and after screening, only 780 documents met the requirements, and the addition of these documents did not have a significant impact on the results of the original analysis.

4. Line 141: It seems like there is a misprint here, as an entire period of the study is 1993-2023. Not 1993 to 2013.

• Thanks to the reviewer's careful observation,We have agreed and adjusted the year intervals as you suggested.       

5. Line 157 and Line 359: In the first appearance in the text, you name “Agronomy” as the second influential journal after “Field Crops Research”, but in Conclusions another journal is referred to as the second influential journal, namely, “Agronomy Journal”. This point requires revision and thorough check, because “Agronomy” and “Agronomy Journal” are not the same publishers.

• Thanks to the reviewer's careful observation, We have agreed and adjusted the name of the magazine according to your suggestions.

Author Response File: Author Response.pdf

Reviewer 3 Report

Comments and Suggestions for Authors

Manuscript ID: agriculture-2667242

Manuscript title: Bibliometric Network Analysis of Crop Yield Gap Research in the Past Three Decades (Review)

The manuscript addressed about the crop yield gap as actual and potential yield at global through using the Web of Science tools. The analyzed the data according to contribute in research in the field of the crop yield gap as per authors, journals, institutes and countries. Overall, well covered last three decades trends and highlighted which areas are efficiently contributed in the field.

In the study, primary role in closing yield gaps is varietal improvement even crop yield variation 30-70% due to variety differential and other factors are showing secondary. Similarly, extreme weather events occurrence due to climate change is highly influencing the crop yield over the globe. Studied on this aspects may sustain to close up the crop yield gap over the globe.

The manuscript is considered after resolve the minor errors as below mentioned

# please see sentence from 141 to143 lines.

# please check the per cent, the both parts are showing 90% instead of 100% in line number (153-155)

# Some of the error is highlighted in the manuscript as yellow color.

 

 

Comments for author File: Comments.pdf

Author Response

Response to Reviewer #3:

1.Line141-142  Over the entire period from 1993 to 2013, the publication rate in the field of “yield 141 gap” was 201 articles annually. However, the first twenty years from 1993 to 2012 ac- 142 counted for only 27.2% (1645) of the total number of publications, i.e., 82 annually.

• Thank you so much for the reviewer’s time and patience.It may be a problem with the layout of the document, and we have modified the year range according to your comments.

2.Line153-154  Over the 153 thirty-year period, the most cited journal accounted for 15% of all citations whereas the 154 other 75% were relatively equally distributed among the other journals.

• Thanks to the reviewer's careful observation,We agree and have modifiedthe percentages based on the data.

3.Line 246 with a 245 noticeable acceleration int he past 10 years (Figure 2).

• Thank you very much for your comments, In order to reduce ambiguity, we have changed the formulation of the time period to from from 2012 to 2022.

4.Line 358 and their articles most commonly citedpublished in journals such as "Field 358 Crop Research" and "Agronomy Journal."

• Thanks to the reviewer's careful observation,We have adjusted the character distance between two words.

Author Response File: Author Response.pdf

Reviewer 4 Report

Comments and Suggestions for Authors

The paper needs to be improved in its results, discussion and conclusions section.

In addition, the authors should improve the discussion by focusing on the technical aspects to strengthen the bibliometric analysis performed.

In the attached document the authors will find some comments that they should work on to improve the paper.

Comments for author File: Comments.pdf

Author Response

Response to Reviewer #4:

1.Line 33 food security; crop; yield gap; research trend; bibliometric analysis

• Thank you for the reviewer’s suggestions. We've recapitulated the article keywords as you suggested.

2.Line 99 adjustments in China's agricultural production policies and a comprehensive translation

• Thank you so much for the reviewer’s time and patience. We have followed your suggestion to improve the content by adding the following reasons for choosing the 1993-2003 time period.This period was selected due to the global innovations in agricultural science and technology and reforms in agricultural markets have led to a sustained increase in food production in most regions of the world,but producton imbalances between and within regions are also becoming more serious.

3.Line 100  Also we focused on maize and wheat becauseWheat and

• Thank you for the reviewer’s suggestions. We have adjusted the word character spacing as you suggested.

4.Line 103-105 TS=(wheat yield gap or maize 103 yield gap or wheat yield influencing factors or maize yield influencing factors or closing 104 yield gap or cereal crop yield gap or cereal crop yield influencing factors.

• Thank you so much for the reviewer’s time and patience.We agree and complete the brackets

5.Line 106  including thesis,dissereation thesis,review

• Thank you for the reviewer’s suggestions. We agree and have modified the document type.It also modified the document type in Table 1.

6.Figure 1. Flowchart of the bibliometric study consisting of data collection stage and bibliometric 136 analysis.Please improve the image resolution.

• Thank you for the reviewer’s suggestions. We have redrawn Figure 1. based on your suggestions.

7.Line 176-181 Figure 3. A) Co-citation analysis of journals in the field of crop yield gap research, with left panel 176 showing the most cited journals in the field, and right panel shows the top 10 journals in terms of 177 citations. B) Co-citation analysis of authors in the field of crop yield gap, left panel shows the first 178 authors of the most cited journals publishing in the field, and right panel shows the top 10 authors 179 in terms of citations. C) Co-occurrence analysis of authors in the field of crop yield gap research, left 180 panel shows Co-occurrence author network, and right panel shows ranking of the top 10 authors in 181 terms of number of publications.Please split the analysis, this graph is very dense and difficult for the reader to understand.

• Thanks to the reviewers for  detailed suggestions,According to the layout of the content of the article, Figure 3 can not be completely separated, we only streamline the explanation part of Figure 3.

8.Line 184 Figure 4 shows the co-occurrence network of countries in the research field, visualiz.For me the figure only shows the number of publications per country, however I do not perceive the relationship between each country. Please correct the figure .

• Thanks to the reviewers for  detailed suggestions,We agree with your comments and add to your query by comparing the characteristics of the volume of publications between countries. The modifications are as follows:The results show theat globally, the United States,China, and Germany are among the top three countries in terms of paper output in the filed of yield gap research. Among them, China and Germany have more cooperation in issuing papers in this field compared to the United States.

9.Line 200  Figure 4. View of national or regional cooperation networks in the field of crop yield gap research.

• Thank you for the reviewer’s suggestions.We modified the capitalization of words.

10.Line 202 Table 2. Top 10 highly cited papers in research areas.the analysis of this picture?

• Thank you for the reviewer’s suggestions.Table 2 migrated under Figure 4 due to software version and layout issues, and Table 2 has now been adjusted under 4.1  with an explanation of the table.4.1.   

11.Line 207 Figure 5. View of the cooperative network of universities or institutions in the field of crop yield gap 207 research and the top 10 institutions in terms of number of publications.I do not see the analysis of the results of this figure 5.

• Thanks to the reviewers for  detailed suggestions, The explanation and analysis of Figure 5 is located in the 3.2. Analysis of geographical distribution and institutions column.

12.Line 237  Figure 6.dividing graph, it is not easy to understand because of the dense.

• Thank you for the reviewer’s suggestions. We have broken down Figure 6 into three parts based on your suggestions, Figure 6,7,8.

13.Line 339-343 [77].[78][79].

• Thank you so much for the reviewer’s time and patience. The two papers are the same, and we have made the correction.

14.Line 355 please include recommendations from the findings of this work for future work.

• Thanks to the reviewers for  detailed suggestions, Based on your suggestions, we have combined the contents of this research bureau with the conclusion section to add future research points in the field. In addition to taking socioeconomic factors into account, utilizing machine learning methods and focusing on small-scale studies .

Author Response File: Author Response.pdf