Optimizing Sowing Patterns and Nitrogen Management Strategies Used to Balance Maize Crop Productivity, N2O Emissions, and Economic Benefits in the Loess Plateau Region of China
Round 1
Reviewer 1 Report
Dear editor and authors, the article is interesting, however there are serious statistical errors that need to be adjusted, in addition there are other comments as follows:
Introduction
- The names of plant species must be placed in italics (example: line 56)
- The paragraph on line 55 to 78 is long, the authors can divide it into two, one talking about the study area and the other about the use and advantages of RFPM
-The paragraph following the one mentioned above is also long and should be divided
-Some information provided in the introduction needs references (example: Line 88 to 90)
-The authors need to provide more information on the use of slow release fertilzer for N supply and why the release is gradual.
Results
- The authors' experiment was carried out in a factorial scheme, however the authors do not show whether there was interaction between the studied factors, and if there is interaction the comparison of the factors must be done within the levels of the other factor, the authors need to provide such information on the significance of the interactions, to present the data appropriately.
- The height data of the plants is not very informative as the authors have the dry mass data, I suggest removing the height data
- Figure legends should be improved.
- Table 1 shows interaction between the studied factors, for the analyzed variables, however, the authors compare independently of this interaction, without unfolding the levels of one variable within another, thus the statistical approach of presented data is wrong.
- The problem with the statistical approach and the factorial scheme remains throughout the results section.
- In figure 5, the authors have little data to do the regression, did they use only 3 means? If so, the statistical power of the model is too low. Authors need to plot all points, not just the mean, and fit models by specifying new regression coefficients
- In figure 6, although significant, the regression shows low values of R2, which greatly limits the information contained, the significance found is due to the amount of data used, the authors need to review this figure and the inferences they make from it.
Discussion
- The whole discussion needs to be redone, it is very segmented, and the authors need to better discuss their data, especially with regard to more efficient N management due to the practices studied. Authors should not divide these into topics, and a paragraph should have a logical sequence to the next, please correct this.
Conclusion
The conclusion section should be rewritten, because as it is written, it is a summary of the observed data, the discussion section should be based on answering the work hypothesis
Author Response
Dear reviewer
Re: Manuscript ID: agronomy-2578817 and Title: Optimizing sowing patterns and nitrogen management strate-gies to balance maize crop productivity, N2O emissions, and economic benefit in the Loess Plateau region of China Thank you for your comments concerning our manuscript entitled “Optimizing sowing patterns and nitrogen management strate-gies to balance maize crop productivity, N2O emissions, and economic benefit in the Loess Plateau region of China” (agronomy-2578817). Those comments are valuable and very helpful. We have read through comments carefully and have made corrections. Revisions in the text are shown using red font, and strikethrough font for deletions. The responses to the reviewer's comments are marked in red and presented following.
We would love to thank you for allowing us to resubmit a revised copy of the manuscript and we highly appreciate your time and consideration.
Sincerely
Juan Han
Author Response File: 
Author Response.pdf
Reviewer 2 Report
Review Report
Manuscript ID: agronomy-2578817
Title: Optimizing planting patterns and nitrogen management strategies to balance maize crop productivity, N2O emissions, and economic benefit in the Loess Plateau region of China
Authors: Shiju Liu , Wei Li , Lulu Liu , Xiaoxia Wen , Yuncheng Liao , Guangxin Zhang * , Juan Han *
Dear authors,
I found a few details that I think need to be improved. I described all these details in the reviewer's comments in the pdf file.
After taking them into account, I recommend submitting the manuscript for printing in the MDPI Journal - Agronomy.
Required corrections:
Row 2: Please consider replacing the word "planting" with "sowing". When referring to wheat, barley, and maize, we usually use the term "sowing". The term "planting" refers rather to potato tubers, vegetable seedlings, rice seedlings, etc.
So, I recommend changing the manuscript title as follows: Optimizing sowing patterns and nitrogen management strategies to balance maize crop productivity, N2O emissions, and economic benefit in the Loess Plateau region of China
Please consider changing this term throughout the whole manuscript.
Row 17 and many others: why control treatment (without N fertilization is N1, it should be N0, right? The next treatments should be N1, N2, N3. Please consider changing these treatment symbols throughout the whole manuscript.
Row 132 and others: Please add methodology and equipment for determination. Provide the type of apparatus, electrode, spectrophotometer, producer, city, and country) See reviewer comment (pdf.file)
Row 144: Please add urea 46% N (Hubei Sanning Chemical Co., Ltd., Hubei, China). Please confirm if this is true.
Row 151: superphosphate 46% P2O5 (producer, city, country). Please confirm if this is true.
Row 152: potassium salt 57% K2O (producer, city, country)
Row 152: Please add the doses of fertilizer for P2O5 and K2O separately.
Row 155: Please add the producer of the plastic film (name, city, and country)
Row 160: Please add information about the cultivar, did you use a Chinese cultivar? Please provide the producer (breeder) name, city, and country.
Row 169: Please add the name of the measuring meter for LAI (producer, city, country)
Row 184: (Agilent Technologies Inc., Santa Clara, CA, USA). Please confirm if this is true.
Row 204: “…used AA3 HR AutoAnalyzer (Seal Analytical, Ltd. Mequon, WI, USA). Please confirm if this is true.
Row 227: SPSS v. 20.0 (IBM, New York, NY, USA) and GraphPad Prism 8.0 (GraphPad Software, Boston, MA, USA)
Row 311: Please change subsection 3.4. title to Selected Soil Physical and Chemical Properties, and their Relationships with N2O flux
Across the whole manuscript: please check one more time carefully the new corrected treatment names as follows:
N1 change to N0 no N fertilizer
N2 change to N1 normal urea as base fertilizer
N3 change to N2 split application of normal urea at sowing and large flare period at a ratio of 3:2
N4 change to N3 all controlled-release urea as base fertilizer
Please change FP – flat planting to FS – flat sowing
Please change PP – planting patterns to SP – sowing patterns
Yours sincerely
Reviewer
Comments for author File: Comments.pdf
Author Response
Response to Reviewer 2 Comments
Point 1: Row 2: Please consider replacing the word "planting" with "sowing". When referring to wheat, barley, and maize, we usually use the term "sowing". The term "planting" refers rather to potato tubers, vegetable seedlings, rice seedlings, etc.
So, I recommend changing the manuscript title as follows: Optimizing sowing patterns and nitrogen management strategies to balance maize crop productivity, N2O emissions, and economic benefit in the Loess Plateau region of China
Please consider changing this term throughout the whole manuscript.
Response 1: We are grateful for the suggestion. According to your comment, we have replaced the word "planting" with "sowing" throughout the whole manuscript, and changed the title of the manuscript as follow: "Optimizing sowing patterns and nitrogen management strategies to balance maize crop productivity, N2O emissions, and economic benefit in the Loess Plateau region of China”. (in red)
Point 2: Row 17 and many others: why control treatment (without N fertilization is N1, it should be N0, right? The next treatments should be N1, N2, N3. Please consider changing these treatment symbols throughout the whole manuscript.
Response 2: We are grateful for the suggestion. According to your comment, across the whole manuscript, we have corrected the treatment names as follows:
N1 changed to N0 no N fertilizer
N2 changed to N1 normal urea as base fertilizer
N3 changed to N2 split application of normal urea at sowing and large flare period at a ratio of 3:2
N4 changed to N3 all controlled-release urea as base fertilizer
FP – flat planting changed to FS – flat sowing
PP – planting patterns changed to SP – sowing patterns . (in red)
Point 3: Row 132 and others: Please add methodology and equipment for determination. Provide the type of apparatus, electrode, spectrophotometer, producer, city, and country) See reviewer comment (pdf.file).
Response 3: Thank you very much for your helpful suggestion. According to your comment, line 213 to 227, we have added the determined methodology and equipment, providing the type of apparatus, electrode, spectrophotometer, producer, city, and country, as follow:
Before maize sowing in 2015, five-point sampling method was used to collect 0-20cm soil layer soil samples. pH was determined by the potentiometric method in a KCl solution with a concentration of 1 mol L-1, using a pH 538 laboratory pH meter and a WTW electrode (WTW, Berlin, Germany). Content of organic carbon (OC) was de-termined on a TOC Analyzer (Shimadzu Corporation, Kyoto, Japan) with an SSM-5000A (Solid Sample Module) adapter. Total N was assayed with the Kjeldahl distillation method after mineralization of ash and soil in concentrated sulfuric acid (VI) with the addition of hydrogen peroxide as a catalyst. Wet digestion of samples was performed in a speed digester K-439 digestion furnace (BÜCHI Labortechnik AG, Flawil, Switzerland) equipped with a scrubber K-415 vapor absorber (BÜCHI Labor-technik AG, Flawil, Switzerland). Nitrogen distillation was performed using a K-355 steam still (BÜCHI Labortechnik AG, Flawil, Switzerland). The content of available phosphorus was determined by molybdenum-antimony resistance colorimetry (Ultra-violet and visible spectrophotometer, Uniko (Shanghai) Instrument Co., LTD, Shanghai, China). The available potassium was determined by flame spectrophotometry (Flame photometer, Sherwood Scientific Ltd, UK). (in red)
Point 4: Row 144: Please add urea 46% N (Hubei Sanning Chemical Co., Ltd., Hubei, China). Please confirm if this is true.
Response 4: Thank you very much for your helpful suggestion. According to your comment, line 157 to 158, we have added urea 46% N (Shaanxi Jinzheng Da Agricultural Science and Technology Co. Ltd, Shaanxi, China). (in red)
Point 5: Row 151: superphosphate 46% P2O5 (producer, city, country). Please confirm if this is true.
Response 5: Thank you very much for your helpful suggestion. According to your comment, line 159 to 160, we have added superphosphate (12% P2O5) (Yunnan Anning Xingya phosphorous chemical Co., LTD, Yunnan, China). (in red)
Point 6: potassium salt 57% K2O (producer, city, country).
Response 6: Thank you very much for your helpful suggestion. According to your comment, line 160 to 161, we have added potassium sulfate (52% K2O) (Sdic Xinjiang Lop Nur Potash Salt Co., LTD, Xinjiang, China). (in red)
Point 7: Please add the doses of fertilizer for P2O5 and K2O separately.
Response 7: We deeply appreciate your suggestion. According to your comment, line 159 to 162, we have added the doses of fertilizer for P2O5 and K2O separately, as followed:
The application rates of superphosphate (12% P2O5) (Yunnan Anning Xingya phos-phorous chemical Co., LTD, Yunnan, China) and potassium sulfate (52% K2O) (Sdic Xinjiang Lop Nur Potash Salt Co., LTD, Xinjiang, China) were 150 kg P2O5 ha–1 and 150 kg K2O ha-1, respectively. (in red)
Point 8: Please add the producer of the plastic film (name, city, and country).
Response 8: We deeply appreciate your suggestion. According to your comment, line 166, we have added the producer of the plastic film (Wanfeng Plastic Industry Co., Ltd, Shaanxi, China). (in red)
Point 9: Please add information about the cultivar, did you use a Chinese cultivar? Please provide the producer (breeder) name, city, and country.
Response 9: Thank you very much for your helpful suggestion. According to your comment, line 170 to 171, we have added information about the cultivar (Henan Qiu Le seed industry technology Co., LTD, Henan, China). (in red)
Point 10: Please add the name of the measuring meter for LAI (producer, city, country).
Response 10: Thank you very much for your helpful suggestion. According to your comment, line 181 to 182, we have added the determination method of LAI as follows:
LAI was determined by SunScan canopy analyzer (Delta-T, UK). (in red)
Point 11: (Agilent Technologies Inc., Santa Clara, CA, USA). Please confirm if this is true.
Response 11: Thank you very much for your helpful suggestion. According to your comment, line 196, we have changed "(Agilent Technologies, USA)" to "(Agilent Technologies, Santa Clara, CA, USA)". (in red)
Point 12: “…used AA3 HR AutoAnalyzer (Seal Analytical, Ltd. Mequon, WI, USA). Please confirm if this is true.
Response 12: Thank you very much for your helpful suggestion. According to your comment, line 231, we have added "used AA3 HR AutoAnalyzer (Seal Analytical, Ltd. Mequon, WI, USA)". (in red)
Point 13: SPSS v. 20.0 (IBM, New York, NY, USA) and GraphPad Prism 8.0 (GraphPad Software, Boston, MA, USA).
Response 13: Thank you very much for your helpful suggestion. According to your comment, line 254 to 255, we have changed “SPSS 20.0 and GraphPad Prism 8.0” to “SPSS v. 20.0 (IBM, New York, NY, USA) and GraphPad Prism 8.0 (GraphPad Software, Boston, MA, USA)”. (in red)
Point 14: Please change subsection 3.4. title to Selected Soil Physical and Chemical Properties, and their Relationships with N2O flux.
Response 14: Thank you very much for your helpful suggestion. According to your comment, line 343, We have changed subsection 3.4. title to “Selected Soil Physical and Chemical Properties, and their Relationships with N2O flux”. (in red)
Point 15: Across the whole manuscript: please check one more time carefully the new corrected treatment names as follows:
N1 change to N0 no N fertilizer
N2 change to N1 normal urea as base fertilizer
N3 change to N2 split application of normal urea at sowing and large flare period at a ratio of 3:2
N4 change to N3 all controlled-release urea as base fertilizer
Please change FP – flat planting to FS – flat sowing
Please change PP – planting patterns to SP – sowing patterns.
Response 15: Thank you very much for your helpful suggestion. According to your comment, across the whole manuscript, we have corrected the treatment names as follows:
N1 changed to N0 no N fertilizer
N2 changed to N1 normal urea as base fertilizer
N3 changed to N2 split application of normal urea at sowing and large flare period at a ratio of 3:2
N4 changed to N3 all controlled-release urea as base fertilizer
FP – flat planting changed to FS – flat sowing
PP – planting patterns changed to SP – sowing patterns . (in blue)
Round 2
Reviewer 1 Report
The manuscript can be accepted in the current form.
Author Response
Dear reviewer,
Re: Manuscript ID: agronomy-2578817 and Title: Optimizing sowing patterns and nitrogen management strate-gies to balance maize crop productivity, N2O emissions, and economic benefit in the Loess Plateau region of China
Thank you for your comments concerning our manuscript entitled “Optimizing sowing patterns and nitrogen management strate-gies to balance maize crop productivity, N2O emissions, and economic benefit in the Loess Plateau region of China” (agronomy-2578817). I deeply admire the reviewer's meticulous work and professionalism. Thank you very much for agreeing to accept our manuscript.
Wish you a pleasant work!
Sincerely,
Juan Han
