Optimizing Tillage and Fertilization Patterns to Improve Soil Physical Properties, NUE and Economic Benefits of Wheat-Maize Crop Rotation Systems
Round 1
Reviewer 1 Report
The authors set experiment on Winter wheat and summer maize rotation for the main cropping pattern in the North China Plain (NCP). There are still problems in farmer production mode, such as shallow tillage layer, and single application of chemical fertilizer caused plow bottom layer thickening and soil pH decrease. A two-factor location experiment was conducted to investigate the effects of different tillage and fertilization patterns on soil physical properties, soil organic carbon (SOC), nitrogen use efficiency and crop yield wheat-maize rotation systems in the 2018-2020. The different treatments were designed as:
i. deep tillage + organic fertilizer (DTF),
ii. shallow tillage + organic fertilizer (STF),
iii. no-tillage + organic fertilizer (NTF),
iv. deep tillage + nitrogen fertilizer (DT),
v. shallow tillage + nitrogen fertilizer (ST),
vi. no-tillage + nitrogen fertilizer (NT).
The following points may consider to improve the manuscript.
1. The comparative results of set parameters with regression analysis could be helpful to understand the different treatments
2. Different form of nitrogen selected to evaluate the nitrogen impact on soil and plant. The relevant literature and evaluation is weak.
3. The overall manuscript seems fine, the discussion part may recheck and improve grammar mistakes.
4. The annual economic benefits for two years 2019 and 2020 results are not reasonable to set a trend for economical assessment. It is suggested to compare the results with other treatments.
Author Response
Dear Reviewer 1:
1.The comparative results of set parameters with regression analysis could be helpful to understand the different treatments.
Response: It is really true as reviewer suggested. We have made correction according to the reviewer’s comments. We added 3.6 correlation analysis to the results. The details are as follows “Soil physical properties, soil organic carbon and nitrogen and yield were analyzed by stepwise regression analysis. Soil water content (X1), bulk density (X2), porosity (X3), <0.25 mm aggregates content (X4), soil organic carbon (X5), soil TN (X6), NO3--N (X7) and NH4+-N (X8) were used as independent variables and yield (Y) as dependent variable. The two stepwise regression equations are as follows:
Correlation analysis showed that total wheat and maize yield in 2018–2019 was significantly negatively correlated with soil TN and significantly positively correlated with soil water content (p < 0.01), with soil total nitrogen and soil water content explaining 75.3% of the yield variation. Total wheat and maize yield in 2019–2020 were significantly positively correlated with soil NO3--N and negatively correlated with bulk density (p < 0.05), with both explaining 57.3% of the yield variation.”
2. Different form of nitrogen selected to evaluate the nitrogen impact on soil and plant. The relevant literature and evaluation are weak.
Response: It is really true as reviewer suggested. We add the corresponding content to the discussion in 4.3 as “The results of Han J et al. showed that the application of organic fertilizer could improve soil fertility to increase soil NO3--N. The results of this study are consistent with them, and the soil NO3--N content showed an increase in organic fertilizer > N fertilizer under the same tillage method in 2020 [60]. The higher NH4+-N content of soil under STF treatment in this study may be due to the fact that organic fertilizer contains a large amount of effective carbon sources, which can increase microbial biomass and activity and promote more NH4+-N assimilation by microorganisms into the soil’s active organic N pool [61].”
3. The overall manuscript seems fine, the discussion part may recheck and improve grammar mistakes.
Response: It is really true as reviewer suggested. For the discussion section, we had MDPI's native English editors check the grammar and correct it, as detailed in the text.
4.The annual economic benefits for two years 2019 and 2020 results are not reasonable to set a trend for economical assessment. It is suggested to compare the results with other treatments.
Response: It is really true as reviewer suggested. We have changed the sentence that did not make sense to “In 2018–2019, the economic value under the STF treatment was significantly higher than under the NTF, DT, ST, and NT treatments at 42,182.26 CNY ha-1 (1.02–12.94% higher; p < 0.05). In 2019–2020, the economic value under the STF treatment was significantly higher than those under the ST and NT treatments at 42,254.54 CNY ha-1 (2.29–9.87% higher; p < 0.05).”.
Thank you especially for your professional comments.
Daijing Zhang
Author Response File: 
Author Response.docx
Reviewer 2 Report
The authors should improve the english language in many parts of their work, so a native speaking english should read the paper. The experinent had significant results for the farmers of the study area, but the presentation needs to be improved.
Comments for author File: 
Comments.pdf
Author Response
Dear Reviewer 2:
1.The authors should improve the English language in many parts of their work, so a native speaking English should read the paper. The experiment had significant results for the farmers of the study area, but the presentation needs to be improved.
Response: It is really true as reviewer suggested. We invited MDPI's native English editors to check the full grammar and correct it, in detail in the text.
Thank you especially for your professional comments.
Daijing Zhang
Reviewer 3 Report
The main goals of the study was to investigate the effects of different tillage and fertilization patterns on soil physical properties, soil organic carbon (SOC), nitrogen use efficiency and crop yield wheat-maize rotation systems. The Authors carried out the two-factor field experiment in the years 2018-2020. The Authors showed interesting results. Authors recommended cropping practice for the NCP with a tillage layer of 20 cm or more, and additional organic fertilizer. Work written correctly, research methods selected correctly as well, results presented in a clear manner, enough literature included, although it was found in the two cases the bad citation of the literature (pointed at the text).
After all small corrections the paper can be publish in the MDPI Agriculture Journal.
Comments for author File: Comments.pdf
Author Response
Dear Reviewer 3:
1.Authors recommended cropping practice for the NCP with a tillage layer of 20 cm or more, and additional organic fertilizer. Work written correctly, research methods selected correctly as well, results presented in a clear manner, enough literature included, although it was found in the two cases the bad citation of the literature (pointed at the text).
Response: It is really true as reviewer suggested. We have corrected the two errors in the literature marked in the text. We deleted this sentence “The results of Alskaf et al. revealed that different tillage and residue management practices had certain effects on the soil physical properties [11]”. In the second place we replaced the literature with “Gai, X.; Liu, H.; Jian, L.; Zhai, L.; Bo, Y.; Wu, S.; Ren, T.; Lei, Q.; Wang, H. Long-term benefits of combining chemical fertilizer and manure applications on crop yields and soil carbon and nitrogen stocks in North China Plain. Agricultural Water Management 2018, 208, 384-392”.
We tried our best to improve the manuscript in accordance with the journal's requirements and revised it in the text using the “Track Changes” model. These changes will not influence the content and framework of the paper. We appreciate for reviewer’s warm work earnestly, and hope that the correction will meet with approval.
Once again, thank you very much for your comments and suggestions.
Sincerely yours，
Daijing Zhang
Author Response File: Author Response.docx
Round 2
Reviewer 2 Report
Dear authors,
In my first attached pdf file I noted a lot of words or expressions that should be improved or corrected. In the file I downloaded I did not see these corrections.
Comments for author File: Comments.pdf
Author Response
Dear Reviewer:
First of all, I sincerely apologize for our mistake. Because of the incompatible PDF reader, the first revision failed to see your comments detail, we sincerely apologize. We have corrected the errors in the article based on your comments carefully. The details can be seen in the article, and the corrections are marked in blue. Here are the answers to your typical questions.
1.Why you constantly write bulk and not bulk density?
Response: Thank you for your suggestions. We have corrected the word "bulk" to "bulk density" in the text, and marked with the blue markings in the text.
2.Please write "From 2018 to 2020" replace "From 2018-2020".
Response: We have replaced "From 2018-2020" with "From 2018 to 2020" in the full text.
3.write it better without using the symbol >
Response: It is really true as reviewer suggested. We have removed the ">" symbol and replaced it with a textual representation, as detailed in the text.
4.The ionic symbols of NO3--N and NH4+-N are removed.
Response: It is really true as reviewer suggested. We have checked the full text of the nitrate and ammonium nitrogen abbreviations and revised them to "NO3-N" and "NH4-N".
5.Fluvo-aquic refer to which soil taxonomy system?
Response: Thank you for your suggestion. After reviewing the literature, we found that what we wrote was really inaccurate and have corrected it to "The soil type is medium loam soil".
Thank you especially for your professional comments.
We tried our best to improve the manuscript in accordance with the journal's requirements and revised it in the text using the “Track Changes” model. These changes will not influence the content and framework of the paper. We appreciate for reviewer’s warm work earnestly, and hope that the correction will meet with approval.
Once again, thank you very much for your comments and suggestions.
Sincerely yours，
Daijing Zhang
Author Response File: Author Response.docx
