Grain Yield Formation and Nitrogen Utilization Efficiency of Different Winter Wheat Varieties under Rainfed Conditions in the Huang-Huai-Hai Plain
Round 1
Reviewer 1 Report
All comments are on the document.
Comments for author File: 
Comments.pdf
Author Response
Dear Reviewer,
Enclosed please find a revised version of our manuscript, which was revised exactly following the comments from you. We wish to thank you for your constructive criticisms of the manuscript and have addressed all of your
concerns.
The corrections have been marked up with the “Track Changes” function in the revised manuscript. The main corrections in the paper and responds to the comments are as follows:
Response to Reviewer 1 Comments
Point 1: Which was the objective of this research?
Response 1: Thanks for your questions. We have added objective of this research on line 14-17 of the new revision.
Point 2: Questions about present tense or past tense? In my opinion should be in past tense.
Response 2: Thanks for your comments. We have changed the present tense to past tense in the whole text according to your opinion.
Point 3: What is the aim of include the NUtE?. lf you want to includethis variable, please support with scientific evidence in the first paragraph.
Response 3: Thanks for your comments. We have added objective (include NUtE ) of this research on line 14-17 of the new revision.
Point 4: Please chose keywords different as the title.
Response 4: Thanks for your comments. We have changed some keywords different as the title on line 31 of the new revision.
Point 5: Please rewrite this paragraph.
Response 5: Thanks for your comments. We have rewrited and enriched the content in this paragraph on line 47-55 of the new revision.
Point 6: What dose mean that? It is the objective. It is not necessary to repeating here.
Response 6: Thanks for your comments. We have deleceted those sentences in the new revision.
Point 7: It is necessary to show the results in accordance with the methods section. All in the same order. Chronological if is possible.
Response 7: Thanks for your comments. We have adjusted the order in the methods and results sections, simultaneously, according to your opinion.
Point 8: Was the ANOVA done for varieties, or for the "yield levels"? Please, there must be uniformity on the table.This is because in line 165, you are not assuming asignificance, but on the table(line 172 and 173), you are with assuming that the difference is high (grains spike-1)?
Response 8: Thanks for your comments. The ANOVA should be done for the "yield levels". We have reanalyzed the combined ANOVA across years, yield level and their interactions in Table 2 and 3, and redescribed the results.
Point 9: Consistently it is mentioned the drought stress, but, in this research, are not shown any climate data. In fact, in the anova test, you are mentioning Y V interactions, and never explain this one.
Response 9: Thanks for your comments. We have changed weather conditions into Figure 1,which includes rainfall amount and distribution during wheat growing seasons, and added soil water content before sowing in Table 1. We have discussed the variations of Y, YL, and their interactions in first paragraph of discussion section. Additionally, the annual average precipitation was 500–600 mm in HHHP, and only 30%–40% of the annual precipitation occurred during the winter wheat growing season, the precipitation can not meet winter wheat growth [1]. Meanwhile, the precipitation uneven distribution and without irrigation during the winter wheat growing season leaded to drought under rainfed condition, this area was identified as a drought prone area [2-3]. Many studies on water-saving irrigation had shown that rainfed wheat usually affected by drought stress, lead to the reduction of leaves size, the spike number, the number of grains per spike, photosynthetic capacity, and grain yield compared to limited irrigation wheat [4-6].
[1] Shao, Y., Xie, Y., Wang, C., et al. Effects of different soil conservation tillage ap-proaches on soil nutrients, water use and wheat-maize yield in rainfed dry-land regions of North China. European Journal of Agronomy, 2016,81, 37-45.
[2] Yang, X., Wang, G., Chen, Y.,et al. Reduced groundwater use and increased grain production by optimized irrigation scheduling in winter wheat–summer maize double cropping system—A 16-year field study in North China Plain. Field Crops Research, 2022, 275, 108364.
[3] Chen, N., Li, R., Zhang, X., et al. Drought propagation in Northern China Plain: A comparative analysis of GLDAS and MERRA-2 datasets. Journal of Hydrology, 2020, 588: 125026.
[4] Xu, X., Zhang, Y., Li, J.,et al. Optimizing single irrigation scheme to improve water use efficiency by manipulating winter wheat sink-source relationships in Northern China Plain. Plos One, 2018, 13, e0193895.
[5] Guo, Z., Shi, Y., Yu, Z., et al. Supplemental irrigation affected flag leaves senescence post-anthesis and grain yield of winter wheat in the Huang-Huai-Hai Plain of China. Field Crops Research, 2015, 180, 100-109.
[6] Man J, Yu Z, Shi Y. Radiation interception, chlorophyll fluorescence and senescence of flag leaves in winter wheat under supplemental irrigation. Scientific Reports, 2017, 7(1): 1-13.
Best regards,
Xuexin Xu
Changxing Zhao
Author Response File: 
Author Response.docx
Reviewer 2 Report
Most questions are due to Methods and Materials,
rows 95-99: Why N15P15K15, when P deficiency is very high in soil? Why N was applied in one time - it should be explained, why nitrogen did not wash out in your test and base it.
What about plant protection as no information is provided as well as about varieties resistance to diseases if plant protection was not applied.
Throughout the article, emphasis is placed on drought resistance. Weather conditions are presented in very condensed form. If droughts were severe during testing period explain it with more abundant weather data.
How cultivars were sorted to 3 groups – according results of this experiment or it was based on previous results.
Author Response
Dear Reviewer,
Enclosed please find a revised version of our manuscript, which was revised exactly following the comments from you. We wish to thank you for your constructive criticisms of the manuscript and have addressed all of your
concerns.
The corrections have been marked up with the “Track Changes” function in the revised manuscript. The main corrections in the paper and responds to the comments are as follows:
Response to Reviewer 2 Comments
Point 1: rows 95-99: Why N15P15K15, when P deficiency is very high in soil? Why N was applied in one time - it should be explained, why nitrogen did not wash out in your test and base it.
Response 1: Thanks for your questions. The available phosphorus value was really low in this research, however, the current amount of compound fertilizer could fully meet the normal growth of wheat, additionally, our other research in the same research area also shown there was no phosphorus deficiency problem in wheat growth using this kind and amount of compound fertilizer[1]. One-time application of nitrogen fertilizer before sowing is a common practice of wheat production and researches[2-5]. Irrigation amount and nitrogen application rate were related to wheat nitrogen wash out (nitrate leaching), nitrate leaching accompanied by water drainage from the root zone, excessive irrigation amount (more than 300 mm) with 300 kg ha-1 nitrogen application rate leads to nitrate leaching form wheat root zone[6]. Numerous studies had clarified that one time nitrogen application less than 180 kg ha-1 did not cause nitrate leaching under rainfed wheat[3-5]. In this research, nitrogen application rate was less than 180 kg ha-1 and no irrigation during wheat growing season, therefore, there was no nitrogen wash out in this research.
[1] Zhang X., Xu X.X., Zhao J.K., et al. Grain morphology, quality traits and yield components analysis in wheat varieties of different gluten types under rain-fed condition. Journal of Nuclear Agricultural Sciences, 2022,36(5):1061-1071.
[2] Zhai Y.J., Tan X.F., Ma X.T., et al. Water footprint analysis of wheat production. Ecological Indicators, 2019, 102: 95-102.
[3] Wang H, Guo Z, Shi Y, et al. Impact of tillage practices on nitrogen accumulation and translocation in wheat and soil nitrate-nitrogen leaching in drylands. Soil and Tillage Research, 2015, 153: 20-27.
[4] Duan W., Shi Y., Zhao J., et al. Depth of nitrogen fertiliser placement affects nitrogen accumulation, translocation and nitrate-nitrogen content in soil of rainfed wheat. International Journal of Plant Production, 2015, 9(2): 237-256.
[5] Zhou X.N., Liu Y., Du C.H., et al. Improving water and nitrogen use efficiency of no-irrigation winter wheat-summer maize unde storing available water before growing by optimizing nitrogen fertilizer allocation. Journal of China Agricultural University, 2022,27(1):14-25.
[6] Liu X.W., Shao L.W., Sun H.Y., et al. Responses of yield and water use efficiency to irrigation amount decided by pan evaporation for winter wheat. Agricultural Water Management, 2013, 129: 173-180.
Point 2: What about plant protection as no information is provided as well as about varieties resistance to diseases if plant protection was not applied.
Response 2: Thanks for your comments. We have added plant protection on line 117-119 of the new revision.
Point 3: Throughout the article, emphasis is placed on drought resistance. Weather conditions are presented in very condensed form. If droughts were severe during testing period explain it with more abundant weather data.
Response 3: Thanks for your comments. We have changed weather conditions into Figure 1, and added soil water content before sowing in Table 1.
Point 4: How cultivars were sorted to 3 groups – according results of this experiment or it was based on previous results.
Response 4: Thanks for your questions. Winter wheat varieties were classified into three yield levels according results of this experiment, which was based on grain yield cluster analysis (Figure 2).
Best regards,
Xuexin Xu
Changxing Zhao
Author Response File: Author Response.docx
