Optimizing Fertilization Strategies to Promote Leaf-Use Ginkgo Productivity and Ecosystem Economic Benefits: An Integrated Evaluation of a Field Trial in Southern China

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

The author designed the experiment to study the Optimal fertilization strategy to promotes the Ginkgo biloba productivity and ecosystem economic benefits: an integrated evaluation of a field trial in southern China. The article is in good shape but have some discrepancies which need to be improved before further consideration.

Please revise the article as follow.

L48, write the area 200,000 ha in the form of millions or thousands.

Line 56, increasing improving need to be revised.

The introduction section is good but have limited studies related to nutrient management of the ginkgo crop. Write those studies and their limitations.
The caption off the figure 1 should be written at the bottom of the figure and write a, b, c, and d with the figures and explain their captions.

Line 133 to 147, How many replications you have in the experiment which is unclear in the experiment design.

The values of the Table 1 are not properly visible and the figures. Please adjust them properly in the revised article.

L188-189, don’t start the sentence with the numeric value. Please revise.

L196 to 210, write all the prices in the form of the table for better understanding of the readers.

From equation 11 to 21, please explain all the parameters of the equation. Which represents what and in which units.

Explain the figure 2, properly and write the a, b and c with each figure and explain their captions.

The figure 3 and figure 4, please write their full caption and figure caption always written under the figure. Please revise. Also increase the resolution of the figures. The content written in the figures is very hard to read.

The figures are not adjusted properly on the article. Kindly adjust them properly.

Comments on the Quality of English Language

Minor editing of English language required.

Author Response

Reviewer #1:

Comments and Suggestions for Authors

1. The author designed the experiment to study the Optimal fertilization strategy to promotes the Ginkgo biloba productivity and ecosystem economic benefits: an integrated evaluation of a field trial in southern China. The article is in good shape but have some discrepancies which need to be improved before further consideration.

Reply: Thank you very much your constructive comments on this paper, which have helped to improve the quality of our manuscript. We have carefully revised the manuscript according to the following responses to your comments.

Please revise the article as follow.

2. L48, write the area 200,000 ha in the form of millions or thousands.

Reply: Done. Please see line 44.

3. Line 56, increasing improving need to be revised.

Reply: Done. Please see line 51.

4. The introduction section is good but have limited studies related to nutrient management of the ginkgo crop. Write those studies and their limitations.

Reply: Thank you, we have made the necessary modifications. Please see lines 64-67.

5. The caption off the figure 1 should be written at the bottom of the figure and write a, b, c, and d with the figures and explain their captions.

Reply: Thank you for your suggestion. We have made the necessary modifications according to your advice.

6. Line 133 to 147, How many replications you have in the experiment which is unclear in the experiment design.

Reply: We have revised the Materials and methods carefully to make it more complete, especially the experimental design. We explained the replication in the revision (please see lines 128-140).

7. The values of the Table 1 are not properly visible and the figures. Please adjust them properly in the revised article.

 Reply: We have added relevant content in the revised draft and provided high-definition original images. Please see lines 152-157. 

8. L188-189, don’t start the sentence with the numeric value. Please revise.

 Reply: Thanks. We have corrected it. Please see lines 186-194.

9. L196 to 210, write all the prices in the form of the table for better understanding of the readers.

Reply: Thank you for this suggestion. We tried several different methods to present this information in tables, but in all cases the layout of the tables was unsatisfactory. Thus, we have decided that this data is best presented in the text of the manuscript instead.  

10. From equation 11 to 21, please explain all the parameters of the equation. Which represents what and in which units.

Reply: Thank you for your suggestion. We have provided detailed explanations in the Supplementary Materials. Please see line 220.

11. Explain the figure 2, properly and write the a, b and c with each figure and explain their captions.

Reply: Thanks. In the revised version, we have corrected all tables and Figures.

12. The figure 3 and figure 4, please write their full caption and figure caption always written under the figure. Please revise. Also increase the resolution of the figures. The content written in the figures is very hard to read.

Reply: We have added relevant content in the revised draft and provided high-definition original images.

13. The figures are not adjusted properly on the article. Kindly adjust them properly.

 Reply: Thank you. We have revised all figures according to your suggestions.

14. Comments on the Quality of English Language.Minor editing of English language required.

Reply: Thank you. We have carefully revised the manuscript according to your specific comments. In addition, the co-author Professor Douglass F. Jacobs (Purdue University, USA) has carefully edited the English language in our revision.

Reviewer 2 Report

Comments and Suggestions for Authors

The article is interesting, but should be corrected. My observations and comments:

1. Reference sources are cited incorrectly and the reference list is not provided according to the requirements. See instruction for Authors: "In the text, reference numbers should be placed in square brackets [ ], and placed before the punctuation; for example [1], [1–3] or [1,3]." and "References must be numbered in order of appearance in the text (including table captions and figure legends) and listed individually at the end of the manuscript."

2. Line 121. Are these coordinates real? Specifying them online shows a point in the sea.

3. Lines 123-124. It is more important to indicate the temperature and precipitation during the study period than the annual amount.
I think these indicators should be presented in more detail.

4. Line 124. The soil type should be specified based on a global framework, e.g. WRB 2022.. That would be more understandable. The texture of the soil should be specified according to the soil texture triangle, that is, the amount of sand, silt and clay particles.

5. Titles of  Figures should be below the figure and should reflect the content of the image. It is not enough to write "Figure 1, Figure 2 and so on". All abbreviations should also be explained in the notes so that you do not have to go back to the methodology in each case.

6. Table 1. Fertilization treatments and their labeling should be presented more clearly. It can be understood that the plants were fertilized three times in different periods.

7. Line 156. How was the SPAD determined if the leaves of all experimental ginkgo trees were harvested on August 30? See lines 157-158.

8. Lines 162-163. Is it really fresh weight? Because the leaves may have lost some water during natural drying.

9. Lines 177-178. It is not clear what the difference is between direct and indirect N₂O emissions? Because the reason is provided the same.

10. Subsection 3.1. The data is discussed very briefly, comparing only with the control treatment. Fertilization rates should also be compared with each other, because it is beforehand clear that fertilization will have a positive effect.

11. Figures 2-4 and Tables 2-3. What does this whiskers mean? There are SE or SD? Should be clarified.

12. Lines 256-257. This statement is incorrect because in the figure the area of ​​leaves is marked from "a" to "d" and the thickness is marked from  "a" to "c".

13. Lines 258-259 and Figure 4. Whether  this statement is correct we can't see or check in the Figure 4. Therefore, it should be good to present the results of the statistical analysis as an supplemental table.

14. Line 259. Visual observations are not accurate. Observations must be based on values.

15. Subsection 3.3. There is a lot of data, but its analysis is very short. Fertilization rates should be compared not only with the control, but also with each other to find out which one is the best method.

16. Line 299. It is Table S3 or Table 4?

17. Lines 367-371. These statements should be confirmed by correlation-regression analysis.

18. Lines 30-31, 413 and 439. Why not 3.0-2.5-1.5? Treatment 4–1.5–2.5 g tree^-1 is T7, but not T6. In Lines 410-412 you write "In our study, the TOPSIS evaluation results showed that T6 in FLG group was the most suitable fertilization strategy for leaf-use  ginkgo trees, followed by T9 and T7 in FLG group." In the Table 1. we can see, that T6 in FLG is 3.0-2.5-1.5 g tree^-1 but not 4–1.5–2.5 g tree^-1.

19. Other comments are provided in the article.

20. The article presents only one year of data. The results of the field research are mostly dependent on meteorological conditions and soil properties. Not clear if these results and conclusions will be the same next year and in a different location? I think it is the main problem.

Comments for author File: Comments.pdf

Author Response

Reviewer #2:

The article is interesting, but should be corrected. My observations and comments:

1. Reference sources are cited incorrectly and the reference list is not provided according to the requirements. See instruction for Authors: "In the text, reference numbers should be placed in square brackets [ ], and placed before the punctuation; for example [1], [1–3] or [1,3]." and "References must be numbered in order of appearance in the text (including table captions and figure legends) and listed individually at the end of the manuscript."

Reply: Thank you for this reminder. The revised manuscript has been modified according to the Journal template, including the reference format and chart format.

2. Line 121. Are these coordinates real? Specifying them online shows a point in the sea.

Reply: This was our mistake. We have corrected it, please see line114.

3. Lines 123-124. It is more important to indicate the temperature and precipitation during the study period than the annual amount.I think these indicators should be presented in more detail.

Reply: This is a valuable suggestion, as we have provided the temperature and precipitation during the study period in the revised version. Please see line 116.

4. Line 124. The soil type should be specified based on a global framework, e.g. WRB 2022.. That would be more understandable. The texture of the soil should be specified according to the soil texture triangle, that is, the amount of sand, silt and clay particles.

Reply: Thank you. Relevant reference has been added (see lines 117-119).

5. Titles of Figures should be below the figure and should reflect the content of the image. It is not enough to write "Figure 1, Figure 2 and so on". All abbreviations should also be explained in the notes so that you do not have to go back to the methodology in each case.

Reply: Thank you for your suggestion. In the revised manuscript, we provided more detailed information, including image titles, letter meanings, abbreviation meanings, etc.

6. Table 1. Fertilization treatments and their labeling should be presented more clearly. It can be understood that the plants were fertilized three times in different periods.

Reply: Thank you for your suggestion. We realize that there was indeed some ambiguity in the previous description. In the revised manuscript, we have provided detailed explanations below Table 1. Please see lines 152-157.

7. Line 156. How was the SPAD determined if the leaves of all experimental ginkgo trees were harvested on August 30? See lines 157-158.

Reply: Our incorrect statement has been corrected. Please see line 161.

8. Lines 162-163. Is it really fresh weight? Because the leaves may have lost some water during natural drying.

Reply: In our study, all leaves were washed three times with deionized water, then spread out and air dried naturally for 1-2 hours, and weighed to determine fresh weight. The entire process takes a short time, so we believe that the impact on fresh weight is very small. Our main purpose in doing this is to remove the dust remaining on the blade surface. We have revised the manuscript to include a more appropriate description. Please see lines 165-166.

9. Lines 177-178. It is not clear what the difference is between direct and indirect N₂O emissions? Because the reason is provided the same.

Reply: Direct emissions refer to the direct soil N₂O emissions generated by the application of nitrogen fertilizer (urea), calculated by formula (3), while indirect emissions refer to N₂O emissions caused by nitrogen loss through volatilization, deposition, and leaching runoff pathways, calculated by formula (4). We explained in the revised manuscript. Please see lines 188-190.

10. Subsection 3.1. The data is discussed very briefly, comparing only with the control treatment. Fertilization rates should also be compared with each other, because it is beforehand clear that fertilization will have a positive effect.

Reply: Thank you for your constructive feedback. We have added relevant content to the revised draft. Please see lines 254-256.

11. Figures 2-4 and Tables 2-3. What does this whiskers mean? There are SE or SD? Should be clarified.

Reply: Thank you for your suggestion. In the revised manuscript, we provided more detailed information, including image titles, letter meanings, abbreviation meanings, etc.

12. Lines 256-257. This statement is incorrect because in the figure the area of ​​leaves is marked from "a" to "d" and the thickness is marked from "a" to "c".

Reply: Thank you for your careful inspection. We have corrected this mistake.

13. Lines 258-259 and Figure 4. Whether this statement is correct we can't see or check in the Figure 4. Therefore, it should be good to present the results of the statistical analysis as a supplemental table.

Reply: This is a great suggestion. We have added Table S3 in the Supplementary Materials, which details the specific data and differences between treatments.

14. Line 259. Visual observations are not accurate. Observations must be based on values.

Reply: We have added the corresponding data and processing methods in the Supplementary Materials.

15. Subsection 3.3. There is a lot of data, but its analysis is very short. Fertilization rates should be compared not only with the control, but also with each other to find out which one is the best method.

Reply: We have added corresponding descriptions to enrich the content of this section. Please see lines 292-293,297-298,300-301.

16. Line 299. It is Table S3 or Table 4?

Reply: Thank you for your careful review. We have corrected this error and thoroughly checked the entire text to avoid similar issues. Please see line 334.

17. Lines 367-371. These statements should be confirmed by correlation-regression analysis.

Reply: Thank you for your suggestion. These statements are in reference to other past literature, not to the conclusion of our article, so no correlation analysis was conducted.

18. Lines 30-31, 413 and 439. Why not 3.0-2.5-1.5? Treatment 4–1.5–2.5 g tree-1 is T7, but not T6. In Lines 410-412 you write "In our study, the TOPSIS evaluation results showed that T6 in FLG group was the most suitable fertilization strategy for leaf-use  ginkgo trees, followed by T9 and T7 in FLG group." In the Table 1. we can see, that T6 in FLG is 3.0-2.5-1.5 g tree-1 but not 4–1.5–2.5 g tree^-1.

Reply: Thank you for your careful inspection. We have carefully corrected similar errors throughout the text.

19. Other comments are provided in the article.

Reply: We carefully examined the entire text and made adjustments according to the journal format to avoid some minor errors.

20. The article presents only one year of data. The results of the field research are mostly dependent on meteorological conditions and soil properties. Not clear if these results and conclusions will be the same next year and in a different location? I think it is the main problem.

Reply: Thank you for this comment. We agree that the results of this study are limited to this particular site and environmental conditions, but these conditions are fairly well representative of this region. Nonetheless, we have qualified in the manuscript that the results could vary across different site types and climatic regimes.

Reviewer 3 Report

Comments and Suggestions for Authors

The manuscript “Optimal fertilization strategy promotes the Ginkgo biloba productivity and ecosystem economic benefits: an integrated evaluation of a field trial in southern China” is devoted to a topical issue related to optimization of growing conditions for the medicinal plant Ginkgo. Recently, the number of people suffering from cerebrovascular accidents, dementia and other diseases associated with the brain vessels has been growing. Preparations based on substances obtained from ginkgo leaves help improve cerebral circulation, which helps slow down brain degradation in the early stages of the disease. The increasing need for extracts of this plant makes this work especially relevant. The authors studied in detail the strategy of applying fertilizers (macro elements) according to the annual development cycle, but this strategy provides for only a single application, which is usually not used in complex fertilization systems. The authors should pay attention to the following points:

First of all, I would like to attract your attention to the design of the manuscript. Please use the Journal template. Pay special attention to references to sources of literature (use numbers in square brackets), the list of references, the location of tables and figures, as well as their titles, which are missing.

Lines 2-3 Please change “Ginkgo biloba productivity” to “Ginkgo productivity” or “Ginkgo biloba L. productivity”.

Line 37 Please write the botanical names of the species correctly “Ginkgo biloba L.”

Please shorten the abstract, pay attention to the translation, make it more correct.

Line 16 “…including the ideal amount”. It's better to use "optimal"

Lines 134-149 Please describe the method in more detail (whether a single treatment was used, or whether a combination of treatments was carried out).149

Fig 2, 3. Please edit the axis titles and write the figure titles according to the Journal template requirements. E.g.: “Average leaf thickness”, “Average leaf surface area” and etc.

Subsection 3.1. It would also be informative to use the relative dry weight (dry weight/fresh weight, %) to estimate the water content of leaf tissues.

In the titles of the figures 2, 3, 5, table 2, 3… indicate also what the letters mean (in deviations).

Lines 280-281 Please rephrase “The GHG during the life cycle was mainly caused by N fertilization, which tends to increase with increasing N fertilization rate”.

In experiments of this kind, two controls are usually used: negative (no treatment) and positive (the best known variant of fertilizer application). This experimental setup facilitates the evaluation of the effectiveness of the methods used. Since your work only includes a negative control, please compare the best obtained variants with the most effective known variant of fertilizer (e.g. with the one you mentioned Wang et al., 2016) in the discussion.

Lines 330-332 “Another reason that FBD did not significantly increase leaf yield in this study is that fertilization leads to a large loss of fertilizer when other vegetation grows most vigorously (Van Do et al., 2019)”. Please describe in more detail what you mean.

Lines 334-337 Please improve this part of the Discussion. It is obvious that spring application of fertilizers (especially nitrogen fertilizers) is the most effective, as this is the period of the most active vegetative growth and consumption of nutrients. Therefore, spring fertilizers have the strongest effect on the indicators of leaf mass and surface area. From the second half of summer, the consumption of nutrients decreases, the need for high doses of fertilizers is reduced, and the shoots begin to “ripen”.

Lines 449-463 Please format the text in accordance with the Journal template.

Comments on the Quality of English Language

Line 56 Please rephrase “Fertilization is an important strategy for increasing improving the medicinal…”

Line 298, 386 and further in the text please rephrase “leaf-use ginkgo trees”

 

Line 99-100 please rephrase “yield maximization”

 

 

Author Response

Reviewer #3:

The manuscript “Optimal fertilization strategy promotes the Ginkgo biloba productivity and ecosystem economic benefits: an integrated evaluation of a field trial in southern China” is devoted to a topical issue related to optimization of growing conditions for the medicinal plant Ginkgo. Recently, the number of people suffering from cerebrovascular accidents, dementia and other diseases associated with the brain vessels has been growing. Preparations based on substances obtained from ginkgo leaves help improve cerebral circulation, which helps slow down brain degradation in the early stages of the disease. The increasing need for extracts of this plant makes this work especially relevant. The authors studied in detail the strategy of applying fertilizers (macro elements) according to the annual development cycle, but this strategy provides for only a single application, which is usually not used in complex fertilization systems. The authors should pay attention to the following points:

1. First of all, I would like to attract your attention to the design of the manuscript. Please use the Journal template. Pay special attention to references to sources of literature (use numbers in square brackets), the list of references, the location of tables and figures, as well as their titles, which are missing.

Reply: Thank you very much your constructive comments on this paper, which have helped to improve the quality of our manuscript. We have carefully revised the manuscript according to the following responses to your comments. We also referred to the journal template and modified the references, table and chart positions of the literature sources.

2. Lines 2-3 Please change “Ginkgo biloba productivity” to “Ginkgo productivity” or “Ginkgo biloba productivity”.

Reply: Done. Please see line 2.

3. Line 37Please write the botanical names of the species correctly “Ginkgo biloba”

Reply: Done. Please see line 33.

4. Please shorten the abstract, pay attention to the translation, make it more correct.

Reply: As mentioned in our reply to the previous comment, the length of the abstract has been cut by almost 17%, with the number of words of the full text reduced from 307 to 257. Thank you again for your helpful and constructive suggestions. Please see lines 12-29.

5. Line 16“…including the ideal amount”. It's better to use "optimal"

Reply: In the revised manuscript, we uniformly replace “the ideal amount” with “optimal”.

6. Lines 134-149Please describe the method in more detail (whether a single treatment was used, or whether a combination of treatments was carried out).

Reply: We apologize as this was unclear in the previous manuscript. To ensure the success of the field experiment, we used 5 repeated experimental blocks to establish the aforementioned deciduous leaf-use ginkgo plantation. In each experimental block, 27 different N-P₂O₅-K₂O fertilization (9 treatments for 3 fertilization time) ratios treatments were randomly assigned, with no fertilization as the control (CK). In this way, there were 5 effective survey trees for each treatment. We have clarified this in the revised version. Please see lines 128-139.

7. Fig 2, 3.Please edit the axis titles and write the figure titles according to the Journal template requirements. E.g.: “Average leaf thickness”, “Average leaf surface area” and etc.7.

Reply: Done.

8. Subsection 3.1.It would also be informative to use the relative dry weight (dry weight/fresh weight, %) to estimate the water content of leaf tissues.

Reply: We fully understand this comment. We provided fresh and dry weight data in the article. In fact, the sales volume of long ginkgo leaves in the market is calculated based on fresh or dry weight. This study used the dry weight calculation method to directly calculate the economic yield of leaf-use ginkgo leaves; therefore, we did not provide further moisture content data.

9. In the titles of the figures 2, 3, 5, table 2, 3…indicate also what the letters mean (in deviations).

Reply: Thanks for your suggestion. In the revised manuscripts, we have added relevant information about image titles, letter meanings, abbreviation meanings, etc.

10. Lines 280-281（286-287）Please rephrase “The GHG during the life cycle was mainly caused by N fertilization, which tends to increase with increasing N fertilization rate”.

Reply: Done. Please see lines 309-310.

11. In experiments of this kind, two controls are usually used: negative (no treatment) and positive (the best known variant of fertilizer application). This experimental setup facilitates the evaluation of the effectiveness of the methods used. Since your work only includes a negative control, please compare the best obtained variants with the most effective known variant of fertilizer (e.g. with the one you mentioned Wang et al., 2016) in the discussion.

Reply: We understand this comment. Unfortunately, most studies also use different ages, varieties, and research areas of ginkgo trees. For this reason, many data cannot be directly compared.  However, we have tried to provide a more detailed comparison in the discussion.

12. Lines 330-332“Another reason that FBD did not significantly increase leaf yield in this study is that fertilization leads to a large loss of fertilizer when other vegetation grows most vigorously (Van Do et al., 2019)”. Please describe in more detail what you mean.

Reply: We have provided a more detailed explanation on this point. Please see lines 371-375.

13. Lines 334-337Please improve this part of the Discussion. It is obvious that spring application of fertilizers (especially nitrogen fertilizers) is the most effective, as this is the period of the most active vegetative growth and consumption of nutrients. Therefore, spring fertilizers have the strongest effect on the indicators of leaf mass and surface area. From the second half of summer, the consumption of nutrients decreases, the need for high doses of fertilizers is reduced, and the shoots begin to “ripen”.

Reply: Thank you for your suggestion. We have revised this part of the content. Please see lines 371-375.

14. Lines 449-463Please format the text in accordance with the Journal template.

Reply: Thank you for your reminder. The revised manuscript has been modified according to the Journal template, including the reference format and chart format.

15. Line 56Please rephrase “Fertilization is an important strategy for increasing improving the medicinal…”

Reply: Done. Please see line 51.

16. Line 298, 386 and further in the textplease rephrase “leaf-use ginkgo trees”

Reply: Based on your suggestion, we have changed “ginkgo” to “leaf-use ginkgo” in the manuscript.

17. Line 99-100please rephrase “yield maximization”

Reply: Done. Please see line 97.