Sowing Date and Fertilization Level Are Effective Elements Increasing Soybean Productivity in Rainfall Deficit Conditions in Central Europe

Round 1

Reviewer 1 Report

Dear authors, congrats for the manuscript that is well written with great results. I am sending some suggestions bellow.

- explain the data of planting

- remove the lines in the figures

- give more details about the interaction between  the factors.

Author Response

Dear Reviewer,

Thank you very much for comments and suggestions.

The manuscript was fully corrected according to your comments.

We added more description for interaction. Explanation for data sowing was added.

We did not remove lines in figure, since it is Statistica software and we are not allowed to do it.

All changest are visible in mansucript.

Author Response File: Author Response.doc

Reviewer 2 Report

Soybeans are one of the most important crops in the world. In recent years, there has been a growing interest in the cultivation of soybean in Europe, including countries with a short cultivation tradition of this species. It is related, inter alia, to climate change and the emergence in these countries of conditions more favorable to this thermophilic plant.

The subject of the research falls within the profile of the journal 'Agriculture' and can be published there, but in my opinion it requires significant changes and additions

1. In the Introduction chapter, too little (or no) information was provided on the impact of the date of sowing and nitrogen fertilization on the yield of soybean seed quality. These are the most important factors in the experience. After all, such research has already been conducted. The authors focused mainly on climate change and the impact of weather conditions on soybean cultivation. And in such short, two-year studies, it is difficult to reliably assess the influence of climatic conditions and confirm the relationships.

2. line [79] –  please delete '(MG 0000)' this is given above in line 74

3. line [87-96] - please correct the font size

4. line [95-96] – ‘The difference between the optimal and early sowing dates was at least 7 days’ - this information is superfluous, the exact sowing dates of the soybeans are given below

5. Line [100-102] - in the experiment, the second factor was differentiated nitrogen fertilization. Therefore, please first describe this factor and its levels, and then provide information that uniform P and K fertilization was applied and what doses were applied.

This remark also applies to the terms used for this factor in tables and graphs. Below the tables is -  F1 - basic fertilization; F2 - increased fertilization; - rather it should be: F1 - basic nitrogen fertilization; F2 - increased nitrogen fertilization. Or as it is in the figures N1 and N2. It should be standardized. Also in the figures, the same marking should be used, and it is once N1, N2 or NI, NII.

6. Line [105] – should be g dm^-3, but the amount used per unit weight of the seed must also be specified, e.g. per 100 kg

7. Line [115-117] - please state the active ingredient of the herbicides used to regulate weed infestation

8. Line [130] – ‘The protein, fat and starch content in seed yield were determined by…’ Was it definitely marked starch, or maybe crude fiber? If the crude fiber is then please make the appropriate corrections in the table and in the text.

9. Line [139] - please provide the adopted significance level

10. Line [167] - the beginning of the sentence has been deleted, it needs to be corrected

11. Line [173, 175] - it is enough to enter the temperature to one decimal place

12. Line [180] - since the authors compare the weather conditions from the research years to the average for the multiannual period, it may be worth providing the values for this period in the graphs. Additionally, it is worth calculating the Sielianinov hydrothermal coefficient.

13. Line [217-202] – ‘Early sowing together with increased nitrogen application led to an increase in seed yield, on average by 0.3 dt ha. However, early sowing of soybean does not require increased nitrogen application. The use of the second nitrogen application rate did not result in a significant difference in yield’ - I do not understand this. Perhaps in line 218 it should be ‘However late sowing of soybean….’?

14. Line [229, 231] - increase in the 1000 seed weight; The 1000 seed weight was low.

15. Table 2 - Please explain what the letters next to the values mean. This also applies to the other tables. Why are there no letters in the last column of Table 2?

16. The unit for the NIH is given in table 3 – g kg^-1. Is this correct? I do not think so. A different is given in line 133 – g g^-1

17. Line [247] – ‘Table 3 presents the efficiency of iron uptake by the seeds and the nitrogen harvest….’ - iron or nitrogen?

18. In graph 6 A and B, please enter the unit on the Y axis for the NHI

19. Line [281] - the factors did not affect the chemical analysis, but the results of the analysis or the chemical composition of the seeds

20. Line [308] – thise sentence should be corrected

21. Line [314] – ‘Scheme 1’ - what does it mean

22. Line [321] - is the NHI shown in figure 7 C , D? This is already in figure 6 A, B.

23. Line [339] - this sentence adds nothing, it should be deleted

24. In the 'Methodology' and in the 'Results', the authors write that the second sowing date was optimal. However, as the results of the research showed, the seed yield was higher at an earlier sowing date. In Discussion, the authors should try to explain why the 'optimal sowing date' gave worse results. Or they shouldn't use that term

Author Response

Dear Reviewer!

Thank you very much for comments and suggestions.

The manuscript was fully corrected according to your comments.

In introduction section the information about other factors such as fertilization and date of sowing was provided.

We deleted  MG000 from line 74.

We corrected font size in lines 87-96.

We deleted information from line 95-96 dedicated to differences among treatments about date of time of sowing, which was repetition.

We corrected the order of fertilization description in methodology section.

We uniform the abbreviation dedicated to nitrogen fertilization in all manuscript

The active ingredients of herbicides used for foliar irrigation are already presented in methodology section.

We corrected the terms of seed quality parameters such as crude protein, crude starch and crude fat. We corrected it in tables and figures and in text as well.

The description of letters below tables were added.

Sielianinov hydrothermal index was calculated and presented in manuscript.

We corrected units of NHI in table

We corrected figures which were duplicated.

We corrected discussion section and we added more discussion our findings.

The conclusion was corrected.

All changes are visible in manuscript.

Reviewer 3 Report

Dear editor,

The study evaluated soybean yield at various levels of mineral nitrogen application in rainfall deficit conditions. The general idea of the manuscript is potential interest and the study was well designed but the authors should modify some corrections as follows:

Abstract

- This section should be deeply revised. The experimental factors and treatments should be added in this section.

- Underscore the scientific value-added to your paper in your abstract. Your abstract should clearly state the essence of the problem you are addressing, what you did and what you found and recommend. That will help a prospective reader of the abstract to decide if they wish to read the entire article.

- The main obtained results and values should be added in this section.

Introduction

- Some sentences have grammatically errors. Please subject the manuscript to review made by English Native speaker.

- L 25-27: reference?

- I recommend to authors for adding soybean production in world and also cultivation area in first paragraph.

- Highlight the novelty in introduction.

- please add the negative impacts of climate change on the crop production.

- Please add the objectives and hypothesis at the end of introduction section.

Material and methods

- Please add the soil physical and chemical properties of experimental area.

- Please add the climatic conditions of experimental area during 2014 and 2015 growing seasons.

- Do you measured the soybean quality characteristics such as oil content, fatty acids concentration, etc. I recommend to add the mention parameters.

Results

- The results are written ambiguously. Please delete single years’ data or delete average of two years’ data. I recommend to save the data for different years and delete average of two years’ data.

- in some parameters the interaction effects of experimental factors were significant. So that the authors should be added the effects of interaction of experimental factors on the measured traits and also delete the main effects of experimental factors. If the interaction effects was not significantly impacts on the studies traits, the authors should be add the results of main effects of experimental factors.

Discussion

- L 323-332: This section was repetitive reports from obtained results. Please add the main reason for increasing and decreasing the measured parameters.

- After that, the authors only added the similar results of published researches (for example L345-350, L351-355, L356-357, 358-360, L366-370, L371-374, L381-384, etc.). The article not a review article. These section should be revised and the authors should be discussed based on the main results which obtained in this study.

- The discussion is missed in the study. Please add the main reason for increasing or decreasing the measured parameters not only reported the previous published studies results.

Conclusion

- This section is repetitive and should be rewritten.

- Please make sure your conclusions' section underscores the scientific value-added of your paper, and/or the applicability of your findings/results. Highlight the novelty of your study.

- What suggestions do you have for future research in this field?

Author Response

Dear Reviewer,

Thank you very much for comments and suggestions.

The manuscript was fully corrected according to your comments.

Abstract section was corrected. We add information about factors and information why we conducted experiment.

In introduction we added information about soybean production and missing references. We also highlighted the novelty.

The objective is presented at the end of introduction section.

In methodology section we add information about soil properties.

Full description about climate conditions is provided. We add Sielianinov hydrothermal index power the characteristic of climate in region during this period.

We did not have extra information about seed qulity.

Results section was corrected. We add extra information about results. We add extra figure of factors interaction dedicated to selected year.

We corrected discussion section and we added more discussion of our findings.

The conclusion was corrected. In our opinion direct message is created for audience.

All changes are visible on manuscript.

Author Response File: Author Response.doc

Round 2

Reviewer 2 Report

The authors improved the manuscript, taking into account the comments contained in the review. I have a few more minor comments

line [15] – Marlin or Mavka?

line [134] - it is more correct to specify the content of phosphorus and potassium in mg kg^-1 (according to the SI system)

line [248] – K or k? Please use a uniform designation of the Sielianinov’s hydrothermal index

Figure 4-8,…. - in the legend there should be S1 and S1 for the sowing date, as in the tables, (instead of I term… and II term…)

In the titles of figures 6 and 7, please add (B)

Line [397-398] – Is ‘The crude fat content in the soybean seeds was less varied in comparison with the crude protein and crude fat content’ - this sentence needs to be corrected

Line [423] – should be …2.2-2.7 t ha^-1

Line [496-497] – Is ‘….for the cultivars the seeds contained 372.9 (g kg−1 DW) protein, 180.2 (g kg−1 DW) fat, and 424.7 (g kg−1 DW) crude fibre.’ -  in the experiment, the crude starch content was determined, not the crude fiber content. Are you sure this value (424,7) is correct?

Author Response

Dear Reviewer,

We did correction according to Your comments. Thank you very much for this comments, since the quality of manucript has been improved.

The changes are visible on the test of manuscript.

line [15] – Marlin or Mavka?

Res.:  In abstract the sentence was corrected.

line [134] - it is more correct to specify the content of phosphorus and potassium in mg kg^-1 (according to the SI system)

Res.: We corrected unit according to SI system

line [248] – K or k? Please use a uniform designation of the Sielianinov’s hydrothermal index

Res. The uniform term of index ( K ) was used in test

Figure 4-8,…. - in the legend there should be S1 and S1 for the sowing date, as in the tables, (instead of I term… and II term…)

In the titles of figures 6 and 7, please add (B)

Res. Mentioned figures were corrected. We also corrected title in  of fig 6 and 7

Line [397-398] – Is ‘The crude fat content in the soybean seeds was less varied in comparison with the crude protein and crude fat content’ - this sentence needs to be corrected

Res. Mentioned sentence was corrected

Line [423] – should be …2.2-2.7 t ha^-1

Res. Mentioned sentence was corrected

Line [496-497] – Is ‘….for the cultivars the seeds contained 372.9 (g kg−1 DW) protein, 180.2 (g kg−1 DW) fat, and 424.7 (g kg−1 DW) crude fibre.’ -  in the experiment, the crude starch content was determined, not the crude fiber content. Are you sure this value (424,7) is correct?

Res. The sentence was corrected. The values and parameter were corrected.

Author Response File: Author Response.docx

Reviewer 3 Report

Dear editor,

In the new version of manuscript, the author revised the manuscript based on the reviewer’s comments. However, some comments, especially in discussion section have not been applied.  The authors should be corrected the manuscript based on the below comments.

Discussion

- L 323-332: This section was repetitive reports from obtained results. Please add the main reason for increasing and decreasing the measured parameters.

- After that, the authors only added the similar results of published research (for example L417-431, L432-433, L433-441, L442-446, L447-453, L458-465, etc.). The article not a review article. This section should be revised, and the authors should be discussed based on the main results which obtained in this study.

- The discussion is missed in the study. Please add the main reason for increasing or decreasing the measured parameters not only reported the previous published studies results.

Best regards

Author Response

Dear Reviewer,

Thank you for comments. 

We corrected discussion section. All changes are visible on text of manuscript.

We inserted our findings into mentioned part of discussion. The references which were discribed and not directly linked with our findings were removed.

Kind regards,

Authors

Author Response File: Author Response.docx