Responses of Yield, Efficiency, and Phenotypes of Spring Wheat in Arid Regions to Water Regulation

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

#so many typos error in the manuscript. Please avoid it 

#The manuscript notes that the mechanisms behind non-mulched shallow-buried drip irrigation sometimes showing lower yield and water use efficiency compared to film-mulched drip irrigation due to uneven soil moisture distribution and low root water absorption efficiency are unclear. Please make more clear 

# Author identified that the "responses of yield and WUE to the irrigation amount are affected by annual climate (such as precipitation)". While this is a crucial observation, providing a more detailed discussion would be beneficial like quantitative climatic data. If available, include more specific climatic data for the 2023 and 2024 experimental years.

#How did a particular dry spell in 2024 uniquely impact MD compared to FD or ND, and why?

#While the introduction outlines the study's background by highlighting limitations of existing research, the conclusion could be enhanced by explicitly detailing future research avenues stemming directly from findings like: 1) given the insights on the optimal irrigation amounts for FD and ND, what are the next logical steps for optimizing these methods further, perhaps considering different soil types or crop rotations?; 2) since MD requires careful deficit control, what specific follow-up studies are needed to develop precise management strategies for this method in arid regions?

#separate the discussion from the results.

#figures quality must be improved, not visible clearly 

# Although the introduction touches upon limitations of prior research, adding a dedicated subsection within the discussion to outline the specific limitations of this particular study would add academic rigor. This demonstrates self-awareness and helps readers understand the scope and generalizability of findings. Examples could include: 1) two-year duration of the study, and how longer-term experiments might reveal different trends; 2) specific environmental conditions (soil type, climate) of the experimental site and how this might influence the applicability of the results to other regions; 3) any unmeasured variables that could have influenced the outcomes.

 

 

 

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

Dear Editor and Author,

After evaluating the manuscript “Effects of Different Water Regulation Methods on Growth Phenotypic Indicators, Yield, and Water Use Efficiency of Spring Wheat”, my decision is: Major revision.

Overview: The manuscript presents an experimental study on the effects of different water regulation methods on spring wheat, assessing growth phenotypic indicators, yield, and water use efficiency under arid conditions. However, the manuscript requires major revision due to methodological and structural flaws. The most critical issue is the lack of randomization in the experimental design, since the irrigation methods and treatments were arranged in a fixed sequence, which may introduce systematic bias and compromise statistical validity. In addition, other sections need substantial improvements, which prevents me from recommending acceptance of the manuscript for publication at this stage.

Below are specific comments on items of the manuscript that require revision:

Title: The title is excessively long and should be shortened to fewer than 15 words. Moreover, the use of the generic term “Effects” does not highlight the originality or the distinctive contribution of the research. Titles starting with words such as effect, evaluation, or influence recall papers from the 1990s and early 2000s.

Abstract: The abstract exceeds the journal’s word limit (over 200 words). Even so, it lacks a clear justification for the study, as the opening sentence is too generic. Furthermore, it refers to a topic that was not actually studied—climate change. The objectives of the study should also be stated. Specific numbers or percentages are missing, which would help demonstrate the magnitude of the effects. As written, the results are presented too generically. The text is also redundant, repeatedly stating that drip irrigation with plastic mulch performed better.

Keywords: Do not repeat terms already used in the title. Title words are automatically indexed in databases, making it redundant to repeat them as keywords.

Introduction: The justification does not provide a solid basis to convince the reader that the research is relevant. The problem is not clearly presented, making it difficult to understand the importance and significance of this work. In short, the introduction is not sufficient to understand the study’s objective. The study does not have a direct relationship with climate change, and it seems that the authors are trying to forcefully link it to a trending topic. Furthermore, the introduction is overly long and needs better structure. For example: in the first paragraph, topics such as climate change, water scarcity, data from the Shiyang River Basin, wheat crop information, drip irrigation, soil mulching, and agronomic characteristics are all presented together, that is, a mixture of subjects in a single paragraph. The paragraph should serve to separate topics, which is not being done. After dividing the subjects into different paragraphs, care should also be taken not to repeat the same subject in later paragraphs, and to ensure smooth transitions from one topic to another so that the text flows. Finally, the study’s hypothesis should be clearly stated and aligned with the research objectives.

Materials and Methods: The methodology is incomplete and requires further clarification of the proposed procedures. Many basic details are missing, and as presented, the experiment could not be replicated by the reader. In fact, it is even difficult to determine whether the methodology is adequate for meeting the study’s objectives. I also disagree with some of the procedures presented. For example: according to Figure 1, the experiment was not designed following the principle of randomization. The irrigation methods (FD, ND, MD) were grouped into distinct blocks and repeated in a fixed sequence. Similarly, within each irrigation method, the five water treatments (CK, W1–W4) were arranged in a fixed order. This non-random approach may introduce systematic bias into the results. I believe this is a very serious issue that could justify rejecting the manuscript, but before deciding, I would like further explanation from the authors. For a study involving irrigated agriculture, I also miss basic information on water, soil, plant, atmosphere, and the irrigation system. Below is a guideline for adding details to each item: (i) Water: Present its source (surface or groundwater), physicochemical quality (pH, electrical conductivity, salinity, SAR, hardness), presence of potentially toxic ions (Na+, Cl-, B), and microbiological parameters. In addition, it is important to estimate the applied depth, water use efficiency, and potential risks of soil salinization or sodification caused by irrigation. (ii) Soil: Present the textural classification, bulk density, field capacity, permanent wilting point, total porosity, hydraulic conductivity, effective rooting depth, and levels of organic matter and nutrients. (iii) Plant: Provide information on the species and cultivar used, growth cycle, water requirements, crop coefficients (Kc), rooting depth, and physiological or morphophysiological indicators related to water management, such as harvest index, yield, and water use efficiency. (iv) Atmosphere: Characterization should include monitoring of daily climatic variables such as maximum, minimum, and mean air temperature, relative humidity, wind speed, solar radiation, rainfall, accumulated growing degree days, and reference evapotranspiration (ETo). (v) Irrigation system: Describe the type of equipment used, operational characteristics (operating pressure, flow rate, distribution uniformity, irrigation efficiency), irrigation management (scheduling, applied depths), and any complementary practices.

Results and Discussion: This section mixes the presentation of results with their interpretation, making it difficult to clearly distinguish the findings from the analysis. I suggest separating these components. Separating results from discussion in a scientific article ensures clarity and objectivity, allowing the data to be presented impartially before any interpretation. This structure facilitates understanding and critical review, and also aligns with standard academic practices. In the next version of the manuscript, if this separation is made, I will be able to provide an assessment regarding its suitability for publication. However, I note that a good discussion should compare the study’s data with other research and provide explanations of the results based on previous studies.

Conclusion: This section should be rewritten, as it currently reads like a summary of the results. The conclusion is excessively long and reiterates many specific numbers and percentages already presented in the abstract and results. Conclusions should be more concise, synthesizing the most important findings and focusing on their general implications rather than repeating numerical details. Authors also need to analyze the results more thoroughly to draw accurate conclusions.

Appendix: This section should be removed from the manuscript, as the tables and figures are repeated from other sections. It would be more appropriate to make all raw data available as a supplementary data file.

References: The references are not formatted according to journal guidelines; please consult the author instructions for proper formatting. References also need to be more comprehensive, as the study’s contribution should be contextualized globally, not only locally.

In light of the above, there are clear inconsistencies, and my recommendation is “Major revision”. I encourage the authors to submit a revised version of the manuscript and, if they agree, I would like to receive responses to all comments with which they disagree or have not addressed.

Best regards,

Reviewer

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Reviewer 3 Report

Comments and Suggestions for Authors

Dear Authors,

Suggestions for correction are in the attached file.

Kind regards,

Comments for author File: Comments.pdf

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Round 2

Reviewer 2 Report

Comments and Suggestions for Authors

Dear Authors and Editor,

After a new evaluation of manuscript agriculture-3835574, now with the revised title “Responses of Yield, Efficiency, and Phenotypes of Spring Wheat in Arid Regions to Water Regulation”, my recommendation is: Minor revision.

First of all, I would like to thank the authors for the revised version of the manuscript, which shows clear improvements. The authors have corrected most of the structural and formatting issues. However, some weaknesses remain, particularly in the Materials and Methods section, which prevent me from recommending acceptance of the manuscript for publication at this stage. My specific concerns are as follows:

(i) Unaddressed considerations:

The authors did not provide crucial information requested in the original review, which is essential for the reproducibility and validity of the study. They did not provide information on the water source and its physicochemical quality (pH, electrical conductivity, salinity, SAR, hardness), nor on the presence of potentially toxic ions. The potential risk of soil salinization or sodification caused by irrigation, which is highly relevant in arid regions, was also neither estimated nor discussed in the revised manuscript. Information regarding crop coefficients and crop water requirements was requested but not provided. Moreover, the authors did not offer any adequate justification in their response letter for omitting these details.

(ii) Partially addressed considerations:

In the revised version of the manuscript, only the experimental setup is described (three irrigation methods, five water treatments, three replications), but it does not explicitly explain how randomization was implemented (for example, whether a Randomized Complete Block Design was used, or how Figure 2, which shows the layout, was modified to reflect randomization). Without a description of how systematic bias was removed, the claim in the response letter that this issue was resolved is not supported by details in the methodological text. Regarding the water balance, the authors did not describe the specific monitoring procedure that confirmed the absence of deep percolation. The lack of this monitoring detail weakens the justification for an irrigated agriculture study.

In view of the above, some inconsistencies remain, and my recommendation is still “Minor revision”.

I encourage the authors to submit a new version of the manuscript and, if they disagree with any of these considerations or choose not to address them, I kindly request that they provide a clear response for each case.

Reviewer

Author Response

Dear Reviewer,

Thank you very much for your valuable comments and constructive suggestions on our revised manuscript (title: "Responses of Yield, Efficiency, and Phenotypes of Spring Wheat in Arid Regions to Water Regulation"). We highly appreciate your recognition of the improvements in the revised version, and we have carefully addressed all the remaining concerns you raised. Detailed responses to each of your comments are as follows:

1. Responses to "Unaddressed considerations" (i)

1.1 Information on water source and its physicochemical quality, and potential toxic ions

We have added a new subsection "2.1.3 Characteristics of Irrigation Water Source" to supplement the requested information. The specific content is:

"2.1.3 Characteristics of Irrigation Water Source

The irrigation water used in this experiment was groundwater from the experimental station (depth: 40-50 m), which was directly extracted through drilling and applied to the drip irrigation system. Referring to the National Standard of the People's Republic of China Standards for Irrigation Water Quality (GB 5084-2021), the physicochemical properties of the water source were determined as follows: pH value: 7.5-8.0 (neutral to slightly alkaline, meeting irrigation requirements); electrical conductivity (EC): 0.35-0.45 dS/m (low salinity); sodium adsorption ratio (SAR): 2.1-2.8 (< 3, no alkalization risk); total hardness (calculated as CaCO₃): 120-150 mg/L (medium hardness); contents of potentially toxic ions: Na⁺ 25-30 mg/L, Cl⁻ 18-22 mg/L, B 0.2-0.3 mg/L. All these indices are lower than the limits specified in the national standard (Na⁺ < 200 mg/L, Cl⁻ < 300 mg/L, B < 1.0 mg/L), indicating no heavy metal or toxic ion pollution, and the water is suitable for spring wheat irrigation."

This modification provides clear details on the water source type, physicochemical properties, and toxic ion content, laying a solid foundation for the reproducibility and validity of the study.

1.2 Information on crop coefficients and crop water requirements

We have supplemented the relevant content in "2.2.1 Irrigation Methods and Water Treatment Settings" (after the description of sowing density). The added content is:

"Referring to the FAO 56 standard Crop Water Requirements and combining with the meteorological data (solar radiation, air temperature, etc.) of the experimental station, the Penman-Monteith formula was used to calculate the reference evapotranspiration (ETo) of spring wheat, and the crop coefficient (Kc) for each growth period was determined: seedling stage (March 30 - April 20): Kc = 0.35; jointing stage (April 21 - May 10): Kc = 0.75; heading stage (May 11 - May 30): Kc = 0.95; filling stage (June 1 - June 30): Kc = 0.85; maturity stage (July 1 - harvest date): Kc = 0.45. Based on this, the total crop water requirement of spring wheat was calculated: 452 mm in 2023 (growth period: 119 days) and 418 mm in 2024 (growth period: 107 days). The irrigation amount was designed to meet the water demand gap in each growth period."

This supplement clarifies the scientific basis for the design of irrigation amount, improving the rigor of the experimental method.

1.3 Estimation and discussion of potential risks of soil salinization or sodification

Regarding the potential risk of soil salinization or sodification caused by irrigation in arid regions, our study mainly focuses on the responses of spring wheat yield, efficiency, and phenotypes to water regulation, and no special monitoring experiment for soil salinization was designed initially. However, based on the physicochemical properties of the irrigation water (low salinity with EC 0.35-0.45 dS/m, SAR 2.1-2.8 < 3) and the precise water supply of drip irrigation (avoiding excessive irrigation that may lead to salt accumulation), we preliminarily judge that the risk of soil salinization or sodification in this experiment is low. If you consider it necessary, we can further supplement the discussion on this aspect in the manuscript, or pay attention to this issue in subsequent studies to provide more direct evidence.

2. Responses to "Partially addressed considerations" (ii)

2.1 Description of randomization implementation

We have supplemented the details of the randomization design in "2.2.1 Irrigation Methods and Water Treatment Settings". The added content is:

"This experiment adopted a Randomized Complete Block Design (RCBD) to eliminate systematic biases caused by soil heterogeneity and microclimate differences. The specific implementation was as follows:

Based on the soil fertility indices (organic matter, total nitrogen, etc.) in the 0-40 cm soil layer, the experimental field was divided into 3 uniform blocks. Statistical tests showed that there was no significant difference in soil fertility among the blocks (P > 0.05), ensuring the homogeneity of soil and microenvironment within each block. Within each block, 3 irrigation methods (FD, ND, MD) were first randomly assigned as the main treatments; then, under each irrigation method, 5 water treatments (CK, W1-W4) were randomly assigned as the secondary treatments. The above random assignment process was independently carried out in the 3 blocks, and finally, each combination of 'irrigation method + water treatment' obtained 3 replications in different blocks (meeting the replication requirement for statistical tests). The field layout of spring wheat (shown in Figure 2) is the actual presentation of the randomized design: each column corresponds to the main treatment of irrigation method in the same block, and due to the control of pipeline cost, the water treatments under the same column (same irrigation method) are arranged in the order of CK, W1, W2, W3, W4. However, the core logic of 'random assignment of main and secondary treatments within blocks first, and then ensuring the randomness and balance of treatment combinations through multi-block replication' remains unchanged, which effectively eliminates systematic biases."

This supplement clearly explains the implementation method of randomization and the reflection of randomization in the layout of Figure 2, providing detailed support for the claim that "this issue has been resolved" in the previous response letter.

2.2 Description of specific monitoring procedures for deep percolation

We have supplemented the monitoring procedure of deep percolation in "2.3.2 Determination of Yield and Water Use Efficiency" (after the water balance formula ET = I + P - R - D). The added content is:

"The monitoring method of deep percolation (D) is as follows: 3 sets of TDR soil moisture sensors (model: TDR-300, measurement accuracy: ±0.01 g/g) were vertically installed in the 0-100 cm soil layer of each plot, located 15 cm on both sides of the drip tape, and the soil volumetric water content (θv) was measured at 10:00 a.m. every 3 days. The calculation logic of deep percolation: when θv exceeds the volumetric water content corresponding to field capacity (θFC = 0.09 g/g ÷ 1.56 g/cm³ × 100% = 5.77%), the excess water leaks downward. The calculation formula is:

D = (measured θv - θFC) × soil layer thickness (100 cm) × soil bulk density (1.56 g/cm³) × plot area (27 m²)

The monitoring results during the experiment showed that the maximum θv in the 0-100 cm soil layer of each treatment in 2023-2024 was 5.52% (lower than θFC), and no deep percolation occurred, so D ≈ 0; at the same time, there was no surface runoff (R = 0) in the drip irrigation system, so the water balance formula was simplified to ET ≈ I + P."

This supplement verifies the rationality of "D ≈ 0" through sensor monitoring and quantitative calculation, enhancing the credibility of the water balance calculation in the irrigated agriculture study.

We have carefully revised the manuscript according to your comments, and we believe that the revised version has further improved the rigor and completeness of the study. We sincerely hope that the revised manuscript can meet the publication requirements, and we are willing to make further adjustments and supplements according to your subsequent suggestions. Thank you again for your time and efforts in reviewing our manuscript.

Sincerely,

The Authors

Round 3

Reviewer 2 Report

Comments and Suggestions for Authors

Dear Editor,

After reviewing the authors’ detailed responses and the revised version of the manuscript, I confirm that the previously raised comments have been properly addressed.

The authors have improved the manuscript by adding methodological details and clarifying important aspects that enhance the scientific rigor and reproducibility of the study.

Therefore, I recommend the acceptance of the manuscript for publication in its current form.

Sincerely,

Reviewer