Stability and applicability of the leaf value model for variable nitrogen application based on SPAD value in rice

Jie Li; Yuehua Feng; Xiaoke Wang; Jinfeng Peng; Dinghua Yang; Guiling Xu; Qiangxin Luo; Lingli Wang; Da Ou; Wei Su

doi:10.1371/journal.pone.0233735

Peer Review History

Original SubmissionJanuary 29, 2020
24 Feb 2020 Decision Letter - Bing Xue, Editor PONE-D-20-02735 Stability and applicability of the leaf value model for variable rate fertilization based on SPAD value in rice PLOS ONE Dear feng, Thank you for submitting your manuscript to PLOS ONE. After careful consideration, we feel that it has merit but does not fully meet PLOS ONE’s publication criteria as it currently stands. Therefore, we invite you to submit a revised version of the manuscript that addresses the points raised during the review process. We would appreciate receiving your revised manuscript by Apr 09 2020 11:59PM. When you are ready to submit your revision, log on to https://www.editorialmanager.com/pone/ and select the 'Submissions Needing Revision' folder to locate your manuscript file. If you would like to make changes to your financial disclosure, please include your updated statement in your cover letter. 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Please do not edit.] Reviewers' comments: Reviewer's Responses to Questions Comments to the Author 1. Is the manuscript technically sound, and do the data support the conclusions? The manuscript must describe a technically sound piece of scientific research with data that supports the conclusions. Experiments must have been conducted rigorously, with appropriate controls, replication, and sample sizes. The conclusions must be drawn appropriately based on the data presented. Reviewer #1: Yes Reviewer #2: Partly ******** 2. Has the statistical analysis been performed appropriately and rigorously? Reviewer #1: Yes Reviewer #2: No ****** 3. Have the authors made all data underlying the findings in their manuscript fully available? The PLOS Data policy requires authors to make all data underlying the findings described in their manuscript fully available without restriction, with rare exception (please refer to the Data Availability Statement in the manuscript PDF file). The data should be provided as part of the manuscript or its supporting information, or deposited to a public repository. For example, in addition to summary statistics, the data points behind means, medians and variance measures should be available. If there are restrictions on publicly sharing data—e.g. participant privacy or use of data from a third party—those must be specified. Reviewer #1: Yes Reviewer #2: No ****** 4. Is the manuscript presented in an intelligible fashion and written in standard English? PLOS ONE does not copyedit accepted manuscripts, so the language in submitted articles must be clear, correct, and unambiguous. Any typographical or grammatical errors should be corrected at revision, so please note any specific errors here. Reviewer #1: Yes Reviewer #2: Yes ****** 5. Review Comments to the Author Please use the space provided to explain your answers to the questions above. You may also include additional comments for the author, including concerns about dual publication, research ethics, or publication ethics. (Please upload your review as an attachment if it exceeds 20,000 characters) Reviewer #1: In this paper, a leaf value model was built based on SPAD value for nitrogen management in rice, and the method was innovative. However, considering the difference of soil environment in different rice varieties and planting areas, it was suggested to conduct further research. Reviewer #2: It is interesting to develop the leaf value model to determine optimal N application rate. However, there are several main questions. (1) The comparison of A2 with A1 is not suitable, A2 involves 4 cultivars and several field locations, A1 involves only one, I suggest to combine A1 and A2 together. (2) How did the authors calculate the apparent N supply of filed in Fig. 1? Please explain in Fig. 1. (3) In Fig.1, I did not see the relationship between actual N application rates and grain yields of rice at harvest, suggest to add. (4) What is the relationship between the model you established and the adoption, I am confused. (5) Please add some more parameters in relation to rice yield components and their responses to N and SPAD values. (6) If possible, please add some experimental photos of SPAD values with changing N application rates. Together, I suggest major revisions. It cannot be accepted according to the present content. Several minor revisions: (1) The language needs to be improved further. (2) The description of results “effect of variable N application based on the leaf value model” is too easy. (3) In Table 3, please explain what are Nw, Ys and Ng. (4) In Table 4, please explain how to calculate Yield, Harvest index, N agronomic efficiency, N recovery efficiency, N partial productivity and N contribution. (5) Conclusions are too easy. (6) Statistical Analysis is too easy, please add some more description. (7) Please separate “Experiment Design” into several parts including such as experimental design, soil and crop management, plant sampling, calculation, to make the materials and methods more clear. ****** 6. PLOS authors have the option to publish the peer review history of their article (what does this mean?). If published, this will include your full peer review and any attached files. If you choose “no”, your identity will remain anonymous but your review may still be made public. Do you want your identity to be public for this peer review?** For information about this choice, including consent withdrawal, please see our Privacy Policy. Reviewer #1: No Reviewer #2: No [NOTE: If reviewer comments were submitted as an attachment file, they will be attached to this email and accessible via the submission site. Please log into your account, locate the manuscript record, and check for the action link "View Attachments". If this link does not appear, there are no attachment files to be viewed.] While revising your submission, please upload your figure files to the Preflight Analysis and Conversion Engine (PACE) digital diagnostic tool, https://pacev2.apexcovantage.com/. PACE helps ensure that figures meet PLOS requirements. To use PACE, you must first register as a user. Registration is free. Then, login and navigate to the UPLOAD tab, where you will find detailed instructions on how to use the tool. If you encounter any issues or have any questions when using PACE, please email us at figures@plos.org. Please note that Supporting Information files do not need this step. https://doi.org/10.1371/journal.pone.0233735.r001
Revision 1
22 Apr 2020 Author Response PONE-D-20-02735 Stability and applicability of the leaf value model for variable rate fertilization based on SPAD value in rice PLOS ONE Dear Xue, Thank you very much for your work in the manuscript submission process. At the same time, thank two reviewers very much for the recognition and valuable suggestions. Their suggestions make our manuscript more excellent. We have submitted revised version of the manuscript in PLOS ONE and ensured that: 1.'Response to Reviewers', 'Revised Manuscript with Track Changes' and 'Manuscript' all were submitted. 2. When the manuscript is revised, we refer to PLOS ONE's style requirements. 3. In the methods section, we do not need to provide information about work permit. The research we have carried out does not involve ethics, safety and other factors. It is a fully liberalized research work. 4. We have put the title page into the main document. 5. Table 2 and 4 have been mentioned in the manuscript. For this revision manuscript, we make sure that it is more perfect and meets the requirements of PLOS ONE, but we are still worried about the places that are not considered. We are looking forward to your reply again. Yuehua Feng Professor College of Agronomy, Guizhou University, Guiyang, Guizhou, 550025, China. Laboratory of Plant Resource Conservation and Germplasm Innovation in Mountainous Region (Ministry of Education), Guizhou University, Guiyang 550025, China. Phone: +86-13984385198 Email: fengyuehua2006@126.com Response to Reviewers Response to Reviewers #1 Reviewer #1: In this paper, a leaf value model was built based on SPAD value for nitrogen management in rice, and the method was innovative. However, considering the difference of soil environment in different rice varieties and planting areas, it was suggested to conduct further research. Response: This is indeed the case. Considering the complexity of the factors, the improvement and application of the leaf value model will be a topics of our main research. For this point, we also add some instructions in the "Conclusion" section of the current manuscript. Response to Reviewers #2 Reviewer #2: The comparison of A2 with A1 is not suitable, A2 involves 4 cultivars and several field locations, A1 involves only one, I suggest to combine A1 and A2 together. Response: The experiments of A1 and A2 were arranged to verify the stability and applicability of the model, but our statement in this paper is easy to cause the comparison of A2 with A1. For this reason, we accepted the opinions of the reviewer #2, readjusted the materials and methods with synthesizing them into one experiment. Reviewer #2: How did the authors calculate the apparent N supply of filed in Fig. 1? Please explain in Fig. 1. Response: There is an explanation in Fig. 1. Reviewer #2: In Fig.1, I did not see the relationship between actual N application rates and grain yields of rice at harvest, suggest to add. Response: In Fig. 1, it is mainly to clarify the relationship between yield and apparent N supply of field (actual N application rate + apparent N supply of soil). Whether this relationship is established or not is crucial to the construction of leaf value model. Reviewer #2: What is the relationship between the model you established and the adoption, I am confused. Response: The leaf value model linked the four aspects of soil condition, rice growth, N application rate and yield. But this connection is not direct. In terms of N, the sources of N that affect rice growth are mainly from soil (the indicator we choose is Alkali-hydrol N) and N application rate, and these N directly affect the growth process and the final yield of rice. Researchers have done a lot of studies in dealing with the relationship between the four aspects. Based on these studies, our approach is to directly perform regression analysis between apparent N supply of field (Nx) (apparent N supply of soil, that is, the content of soil Alkali-hydrol N + N appliation rate) and yield. By this way, we can know how much target yield corresponds to the Nx is, that is apparent total N uptake (Nz). At the same time, in order to avoid the chemical determination of soil Alkali-hydrol N, we estimate the apparent N supply of soil by rice growth status (Ys,SPAD value derivative index). Specifically, the relationship between the Ys and the Nx is established. Through the above two relationships, when the Ys is obtained during the rice growth process, the Nx and apparent N supply of soil can be obtained. The difference between Nz and apparent N supply of soil is the data for manual decision on N. Reviewer #2: Please add some more parameters in relation to rice yield components and their responses to N and SPAD values. Response: Referring to the above reply, in this manuscript, the rice yield composition and its response to N and SPAD values are not the focus we want to express. Reviewer #2: If possible, please add some experimental photos of SPAD values with changing N application rates. Response: We are sorry. No photos of SPAD values with changing N application rates were not taken during the field experiment. Reviewer #2: The language needs to be improved further. Response: The manuscript language has been improved again. Reviewer #2: The description of results “effect of variable N application based on the leaf value model” is too easy. Response: It has been supplemented in the manuscript. Reviewer #2: In Table 3, please explain what are Nw, Ys and Ng. Response: They have been added explanation in Table 3. Reviewer #2: In Table 4, please explain how to calculate Yield, Harvest index, N agronomic efficiency, N recovery efficiency, N partial productivity and N contribution. Response: They have been added explanation in Table 4. At the some time, They are also clearly described in ‘materials and methods’. Reviewer #2: Conclusions are too easy. Response: It has been supplemented in the manuscript. Reviewer #2: Statistical Analysis is too easy, please add some more description. Response: It has been supplemented in the manuscript. Reviewer #2: Please separate “Experiment Design” into several parts including such as experimental design, soil and crop management, plant sampling, calculation, to make the materials and methods more clear. Response: The ‘materials and methods’ section have been revised. Thank two reviewers again for their recognition and valuable suggestions. Attachments Attachment Submitted filename: Response to Reviewers.doc https://doi.org/10.1371/journal.pone.0233735.r002
12 May 2020 Decision Letter - Bing Xue, Editor Stability and applicability of the leaf value model for variable rate fertilization based on SPAD value in rice PONE-D-20-02735R1 Dear Dr. feng, We are pleased to inform you that your manuscript has been judged scientifically suitable for publication and will be formally accepted for publication once it complies with all outstanding technical requirements. Within one week, you will receive an e-mail containing information on the amendments required prior to publication. When all required modifications have been addressed, you will receive a formal acceptance letter and your manuscript will proceed to our production department and be scheduled for publication. Shortly after the formal acceptance letter is sent, an invoice for payment will follow. To ensure an efficient production and billing process, please log into Editorial Manager at https://www.editorialmanager.com/pone/, click the "Update My Information" link at the top of the page, and update your user information. If you have any billing related questions, please contact our Author Billing department directly at authorbilling@plos.org. If your institution or institutions have a press office, please notify them about your upcoming paper to enable them to help maximize its impact. If they will be preparing press materials for this manuscript, you must inform our press team as soon as possible and no later than 48 hours after receiving the formal acceptance. Your manuscript will remain under strict press embargo until 2 pm Eastern Time on the date of publication. For more information, please contact onepress@plos.org. With kind regards, Bing Xue, Ph.D. Academic Editor PLOS ONE Additional Editor Comments (optional): Reviewers' comments: Reviewer's Responses to Questions Comments to the Author 1. If the authors have adequately addressed your comments raised in a previous round of review and you feel that this manuscript is now acceptable for publication, you may indicate that here to bypass the “Comments to the Author” section, enter your conflict of interest statement in the “Confidential to Editor” section, and submit your "Accept" recommendation. Reviewer #2: All comments have been addressed ******** 2. Is the manuscript technically sound, and do the data support the conclusions? The manuscript must describe a technically sound piece of scientific research with data that supports the conclusions. Experiments must have been conducted rigorously, with appropriate controls, replication, and sample sizes. The conclusions must be drawn appropriately based on the data presented. Reviewer #2: Yes ****** 3. Has the statistical analysis been performed appropriately and rigorously? Reviewer #2: Yes ****** 4. Have the authors made all data underlying the findings in their manuscript fully available? The PLOS Data policy requires authors to make all data underlying the findings described in their manuscript fully available without restriction, with rare exception (please refer to the Data Availability Statement in the manuscript PDF file). The data should be provided as part of the manuscript or its supporting information, or deposited to a public repository. For example, in addition to summary statistics, the data points behind means, medians and variance measures should be available. If there are restrictions on publicly sharing data—e.g. participant privacy or use of data from a third party—those must be specified. Reviewer #2: Yes ****** 5. Is the manuscript presented in an intelligible fashion and written in standard English? PLOS ONE does not copyedit accepted manuscripts, so the language in submitted articles must be clear, correct, and unambiguous. Any typographical or grammatical errors should be corrected at revision, so please note any specific errors here. Reviewer #2: Yes ****** 6. Review Comments to the Author Please use the space provided to explain your answers to the questions above. You may also include additional comments for the author, including concerns about dual publication, research ethics, or publication ethics. (Please upload your review as an attachment if it exceeds 20,000 characters) Reviewer #2: Dear authors, I am satisfied with the revision. Accept. Thank you very much for your revision. Best wishes! ****** 7. PLOS authors have the option to publish the peer review history of their article (what does this mean?). If published, this will include your full peer review and any attached files. If you choose “no”, your identity will remain anonymous but your review may still be made public. Do you want your identity to be public for this peer review?** For information about this choice, including consent withdrawal, please see our Privacy Policy. Reviewer #2: No https://doi.org/10.1371/journal.pone.0233735.r003
Formally Accepted
22 May 2020 Acceptance Letter - Bing Xue, Editor PONE-D-20-02735R1 Stability and applicability of the leaf value model for variable nitrogen application based on SPAD value in rice Dear Dr. feng: I am pleased to inform you that your manuscript has been deemed suitable for publication in PLOS ONE. Congratulations! Your manuscript is now with our production department. If your institution or institutions have a press office, please notify them about your upcoming paper at this point, to enable them to help maximize its impact. If they will be preparing press materials for this manuscript, please inform our press team within the next 48 hours. Your manuscript will remain under strict press embargo until 2 pm Eastern Time on the date of publication. For more information please contact onepress@plos.org. For any other questions or concerns, please email plosone@plos.org. Thank you for submitting your work to PLOS ONE. With kind regards, PLOS ONE Editorial Office Staff on behalf of Professor Bing Xue Academic Editor PLOS ONE https://doi.org/10.1371/journal.pone.0233735.r004

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