Optimization of Spring Wheat Irrigation Schedule in Shallow Groundwater Area of Jiefangzha Region in Hetao Irrigation District
Round 1
Reviewer 1 Report
Keywords: Repeats several words of the title Figure 5 and 6: Why don't you have moisture data for the first months? Figure 9. Correct the word consumption of the Y axis Figure 9. How was water consumption determined, phreatic evaporation and seepage? Figure 11. it is not so clear Discussion. Why was the upward flow of water from the water table not measured?Comments for author File: 
Comments.docx
Author Response
Response to Reviewer 1 Comments
Point 1: Keywords: Repeats several words of the title
Response 1:Thanks to the reviewers for the comments, and the keywords that duplicate the title have been removed.
Point 2: Figure 5 and 6: Why don't you have moisture data for the first months?
Response 2: Thanks to the reviewers for the comments, and because there was winter irrigation in the last year, there was no difference in soil moisture between the treatments in the first month, and the soil was still frozen, so the data of soil moisture in the first month was missing.
Point 3: Figure 9. Correct the word consumption of the Y axis 

Response 3:Thanks to the reviewers for the comments, and the word consumption of the Y axis had been correct in revised draft.
Point 4: Figure 9. How was water consumption determined, phreatic evaporation and seepage?
Response 4: Thanks to the reviewers for the comments, and the above data are obtained through the calculation of the verified Aquacrop model. The reference is Reference Manal, Chapter 3 – Aquacrop, Version 4.0 June 2012.
Point 5: Figure 10. it is not so clear.
Thanks to the reviewers for the comments, and the Figure 10 has been redone in the revised version.
Point 6: Discussion. Why was the upward flow of water from the water table not measured?
Response 4: Thanks to the reviewers for the comments, and the upward flow of water from the water table should be monitored, but the experiment belongs to field experiment and the conditions are not available. It is expected that the follow-up study will strengthen that data monitoring.
Author Response File: Author Response.docx
Reviewer 2 Report
This article described modeling of AquaCrop and its implication on irrigation scheduling of spring wheat for a semiarid or arid region in the Hetao Irrigation District in China.
The abstract is long and probably can be more concise. From the abstract, it’s not clear what model was used, or how experiment or study was designed. The AquaCrop model was calibrated and validated, and then used for analyzing different irrigation scenarios for spring wheat for the region, it will be very hard for readers to conclude point 3 and 4 from abstract are from modeling results. When describe number and units, please consider adding space between number and units, and be consistent. In abstract, line 37, consider change “quota” to “allocation”. Line 39, without area, 300 mm is not volume. Consider rewording point (4), very long sentence. In introduction, please consider adding description of spring wheat production in the region. What’s the current irrigation schedule spring wheat? Being a drought tolerant crop itself, is it affected by the decreasing allocation? Line 121-131, model also has its limitations, even for a verified model. Using model is helpful to expose some behaviors among variables, but I would suggest be cautious to state “able to reveal the actual relation among the experiment factors”. Line 134, the Jiefangzha “field” is on the order of 104 hm2, maybe “region” is more suitable? Line 142, how is evaporation of “2096 mm” calculated? Table 1, please also list percentage of sand, silt, clay. Dry unit weight, is it gm-3 or gcm-3? Section 2.2. where is the actual experiment conducted? Is it the same as Jiefangzha? Line 152-153, can you describe what’s the water distribution in the area? Consider change “watering” to “irrigation”. Line 162, how was irrigation applied? Can you provide more detail of the water meters that used? Table 2, the five treatments listed here are actual field experiments. The authors might consider to differentiate with Table 4. Also please provide actual irrigation information for the five treatments. Line 169, provide actual distance to the study area. Line 175, how deep were the soil moisture content samples taken? Line 178, how was the crop harvested? Figure 1, ET0 should be “ETo” Figure 2, Is this from the average of all monitoring wells? Consider adding errorbars. Line 189, sentence “the transpiration was divided…” should be “the evapotranspiration is divided…”. Line 190-197, not sure I followed what authors are talking about. Canopy cover, biomass, harvest index are all very important parameters to AquaCrop, I don’t see calibration or validation results on these parameters. Table 3, please also provide default parameters so reader can compare. Line 240, it is hard to relate 2.5 m groundwater depth with preventing soil salinization, minimizing water diversion, protecting ecological safety, can authors elaborate? Line 250, how is typical year determined? In section 1.6.1, it is determined from rainfall only, but here other parameters are assumed “typical” in the year as well. Figure 3, is this figure showing the Jiefangzha area? Or the Hetao district? In addition, it seems like the “zoning” was done by simply using 2.5 meter as division, how is this zoning method dynamic? In section 1.6.3 and table 4, for the first time all the irrigation scheduling scenarios are presented, it is not clear to readers whether these are being used in experiment or modeling process. Furthermore readers can only tell how many times irrigation were applied for that scenario, they won’t be able to tell how much were applied for each scenario. Figure 5 and 6, it’s not clear which soil depth the graphs are representing. Figure 9, it’s very hard to tell which irrigation scenario is the author referring to. Table 7, what parameters are tested for the four growth stages?
Author Response
Response to Reviewer 2 Comments
Point 1: The abstract is long and probably can be more concise. From the abstract, it’s not clear what model was used, or how experiment or study was designed. The AquaCrop model was calibrated and validated, and then used for analyzing different irrigation scenarios for spring wheat for the region, it will be very hard for readers to conclude point 3 and 4 from abstract are from modeling results.
Response 1:Thanks to the reviewers for the comments, and the abstract had been revised according to the expert opinion.
Point 2: When describe number and units, please consider adding space between number and units, and be consistent.
Response 2: Thanks to the reviewers for the comments, and the space between number and units had been added in revised draft.
Point 3: In abstract, line 37, consider change “quota” to “allocation”. Line 39, without area, 300 mm is not volume. Consider rewording point (4), very long sentence.
Response 3:Thanks to the reviewers for the comments, and similar problems had been corrected in revised draft.
Point 4: In introduction, please consider adding description of spring wheat production in the region. What’s the current irrigation schedule spring wheat? Being a drought tolerant crop itself, is it affected by the decreasing allocation? 

Response 4: Thanks to the reviewers for the comments, and in Hetao Irrigation District, the net irrigation quota of spring wheat has been cut to about 300 mm. In shallow groundwater depth areas, it is difficult to maximize the use of soil moisture and thus the water use efficiency is low. In areas with greater groundwater depth, the groundwater recharge is reduced, resulting in the water deficit during certain growth stages.
Point 5: Line 121-131, model also has its limitations, even for a verified model. Using model is helpful to expose some behaviors among variables, but I would suggest be cautious to state “able to reveal the actual relation among the experiment factors”. 

Response 5: Thanks to the reviewers for the comments. The model application expression had been modified according to the expert opinion in revised draft.
Point 6: Line 134, the Jiefangzha “field” is on the order of 104 hm2, maybe “region” is more suitable?. 

Response 6: Thanks to the reviewers for the comments. The “field” had been replaced by “region” in revised draft.
Point 7: Line 142, how is evaporation of “2096 mm” calculated?
Response 7: Thanks to the reviewers for the comments. The evaporation is from a free water surface, which is monitored by the evaporating dish. It had been supplemented in the revised version.
Point 8: Table 1, please also list percentage of sand, silt, clay. Dry unit weight, is it gm-3 or gcm-3?
Response 8: Thanks to the reviewers for the comments. Dry unit weight is g/cm3, which has been corrected in revised version.
Point 9: Section 2.2. where is the actual experiment conducted? Is it the same as Jiefangzha? Line 152-153, can you describe what’s the water distribution in the area? Consider change “watering” to “irrigation”. Line 162, how was irrigation applied? Can you provide more detail of the water meters that used?
Response 9: Thanks to the reviewers for the comments. Dry unit weight is g/cm3, which has been corrected in revised version. The actual experiment was conducted in Jiefangzha region with a total of 4 times irrigation in spring wheat growth period. “watering” had been replaced by “irrigation” in revised draft. Meanwhile, irrigation mode and irrigation volume had been supplemented in revised version.
Point 10: Table 2, the five treatments listed here are actual field experiments. The authors might consider to differentiate with Table 4. Also please provide actual irrigation information for the five treatments. Line 169, provide actual distance to the study area. Line 175, how deep were the soil moisture content samples taken? Line 178, how was the crop harvested? Figure 1, ET0 should be “ETo”.
Response 10: For the actual field experiments, the five treatments for Table 2 was chosen by previous research results in order to verify model. All possible combinations considered in Table 4. The actual distance to the study are is about 1 km, which had been added in revised version. The deep with 0-100cm for soil moisture content had been added in revise draft. For spring wheat yield, a representative 1 m2 quadrat was chosen from each experiment plot to determine the grain yield after natural air drying, which had been added in revised version. Figure 1, ET0 is ET0, but it is very difficult to change in Figure 1.
Point 11: Figure 2, Is this from the average of all monitoring wells? Consider adding errorbars. Line 189, sentence “the transpiration was divided…” should be “the evapotranspiration is divided…”. Line 190-197, not sure I followed what authors are talking about. Canopy cover, biomass, harvest index are all very important parameters to AquaCrop, I don’t see calibration or validation results on these parameters.
Response 11: The errorbars and the Line 189 had been revised. The “transpiration”had been replaced by the “evapotranspiration” in revised draft. The line 190-197 had been rewritten. The data such as canopy cover, biomass and harvert index were lacked of.
Point 12: Table 3, please also provide default parameters so reader can compare. Line 240, it is hard to relate 2.5 m groundwater depth with preventing soil salinization, minimizing water diversion, protecting ecological safety, can authors elaborate? Line 250, how is typical year determined? In section 1.6.1, it is determined from rainfall only, but here other parameters are assumed “typical” in the year as well. Figure 3, is this figure showing the Jiefangzha area? Or the Hetao district? In addition, it seems like the “zoning” was done by simply using 2.5 meter as division, how is this zoning method dynamic? In section 1.6.3 and table 4, for the first time all the irrigation scheduling scenarios are presented, it is not clear to readers whether these are being used in experiment or modeling process.
Response 12: Thanks to the reviewers for the comments, and the default parameters were provided in Table 3. For JieFangzha region, the average annual groundwater depth is depend on water diverted from the Yellow river. If the groundwater depth is less than 2.5m, the ET, water intake and soil salinization are increase. On the other hand, if the groundwater depth is greater than 2.5m, the natural grassland and vegetation will dried up. The typical year was determined by rainfall, and the other parameters was used from the typical year such as temperature so on. Figure 3 is showing in the Jiefangzha region, which is added in revised draft. In practical application, the groundwater depth of 2.5 m in the previous year can be used to provide dynamic division so as to ensure that the irrigation schedule optimization can be better applied to shallow groundwater areas. In section 1.6.3 and table 4, all the irrigation scheduling scenarios are used in modelling process.
Point 13: Furthermore readers can only tell how many times irrigation were applied for that scenario, they won’t be able to tell how much were applied for each scenario. Figure 5 and 6, it’s not clear which soil depth the graphs are representing. Figure 9, it’s very hard to tell which irrigation scenario is the author referring to. Table 7, what parameters are tested for the four growth stages?
Response 13: Thanks to the reviewers for the comments, and the irrigation quotas for all scenario were added in revised draft. The soil depths for Figure 5 and 6 are all 0-100cm. Figure 9, for each zone, the simulation results for 16 irrigation scenarios were referred to. Table 7, the simulated water consumption for the four growth stages for 16 irrigation scenarios and yield were used to build the crop water production function for each zone.
Author Response File: Author Response.docx
Reviewer 3 Report
Dear Authors
The article "Optimization of Spring Wheat Irrigation Schedule in Shallow Groundwater Area of Jiefangzha Field in Hetao Irrigation District," presents an optimized irrigation scheduling, based on the groundwater depth distribution and the spring wheat growing stage.
The article is very interesting, but it is tough to read and follow. There is too much information that should be filtered and reorganized to ease the paper readability.
The authors should also make a deep English revision.
The article should be under an in-depth review before a new submission.
The following suggestions can be taken into account.
1.- The abstract should be shortened. Results and conclusion should be moved to the corresponding section.
2.- The Introduction could be reorganized in shorter paragraphs. In addition, the authors should include in this section, some lines regarding the optimization methods and models, as well as other similar experiences (if exists).
3.- References should be contextualized, adding some information regarding the articles is being referenced.
4.- In the title, the authors use the word Optimization. Which is the optimization approach that is used in the article? What are the authors optimizing for? Water consumption? Yield?
5.- In section 2.2, how does the authors irrigate the experimental plot? How much water is applied?
6.- Check the section number after de section 2.5.
7.- The irrigation scenarios should be better explained, including the table 4.
Author Response
Response to Reviewer 3 Comments
Point 1: The abstract should be shortened. Results and conclusion should be moved to the corresponding section.
Response 1: Thanks to the reviewers for the comments, and results and conclusion had been moved to the corresponding section in the revised draft.
Point 2: The Introduction could be reorganized in shorter paragraphs. In addition, the authors should include in this section, some lines regarding the optimization methods and models, as well as other similar experiences (if exists).
Response 2: Thanks to the reviewers for the comments, part of the introduction was deleted in the revised draft.
Point 3: References should be contextualized, adding some information regarding the articles is being referenced.
Response 3: Thanks to the reviewers for the comments. The references will be revised according to the editing requirements.
Point 4: In the title, the authors use the word Optimization. Which is the optimization approach that is used in the article? What are the authors optimizing for? Water consumption? Yield?
Response 1: Thanks to the reviewers for the comments, and the optimization approach is the maximizing yield based on the crop water production functions.
Point 5: In section 2.2, how does the authors irrigate the experimental plot? How much water is applied?
Response 2: Thanks to the reviewers for the comments, and each experimental plot is pumped from the canal for irrigation. At the same time, the irrigation quota for each treatment had been added in the revised draft.
Point 6: Check the section number after de section 2.5.
Response 3: Thanks to the reviewers for the comments, and the chapter No. in the revised version has been corrected.
Point 7: The irrigation scenarios should be better explained, including the table 4.
Response 1: Thanks to the reviewers for the comments, and it has been supplemented in the manuscript. Based on the water distribution time of the irrigation area, the reasons for making the irrigation schedule scenario and irrigation quotas were supplemented in the revised draft.
Author Response File: Author Response.docx
Reviewer 4 Report
In the article authors present a very valuable optimization method of zoning irrigation schedule, which solves the problem of groundwater spatial variability in shallow groundwater areas. This study may provide some useful reference for the optimization of irrigation schedules in shallow groundwater areas. In light of predicted climate change it is important to investigate the potential of water saving, especially in the areas of a great agricultural production.
In my opinion the paper is important source of information not only for scientists but also for the local farmers and national policy makers responsible for water management.
I recommend the article for the publication, after a few minor corrections in the text editing.
Comments for author File: 
Comments.pdf
Author Response
Response to Reviewer 3 Comments
Point 1: In the article authors present a very valuable optimization method of zoning irrigation schedule, which solves the problem of groundwater spatial variability in shallow groundwater areas. This study may provide some useful reference for the optimization of irrigation schedules in shallow groundwater areas. In light of predicted climate change it is important to investigate the potential of water saving, especially in the areas of a great agricultural production.
In my opinion the paper is important source of information not only for scientists but also for the local farmers and national policy makers responsible for water management.
I recommend the article for the publication, after a few minor corrections in the text editing.
Response 1: Thanks to the reviewers for the comments, and it has been modified in the article as required.
Author Response File: Author Response.docx
Round 2
Reviewer 3 Report
I appreciate the efforts of the authors to include the suggested correction.
There are, however, some issues that must be corrected.
The abstract is still very unclear. Line 15, for example should be rewritten, and lines after 18 should be removed, and then included in the introduction.
In the Keywords list, authors should use “crop model” or “crop simulation” instead of Aquacrop.
In line 93, replace “continuum” by “system” or “intersystem”.
Line 114. The sentence “In summary, the…” should go as a new paragraph. The same in Line 138 “The findings of previous…”.
In lines 171 and 172 “it is difficult to maximize the use of soil moisture” should be rewritten. I guess the authors wanted to say “to maximize the use of the water in the soil”.
In line 174: What experiments are the authors referring to? This sentence is not clear.
Line 193: The sentence should be rewritten to something like “… region presents arid or semiarid climate characteristics.”
Line 220. The sentence “Five treatments…” should be moved to a new paragraph.
Line 221. Use the term “three replications” instead of “each treatment being repeated 3 times”
Lines 223 to 225. The sentences “As appropriate” is very confusing. Please consider rewrite it.
Line 272. The paragraph is not clear. Please consider rephrasing.
Line 277. The sentence “By limiting canopy…” is very long and confusing. Please rewrite.
Lines 284 to 287. These lines should be checked to improve the readability.
Lines 377 to 382. Please rewrite the paragraph.
Lines 450, 451, 483 use the same text. Please check this.
Section 3.2, 3.3 and 3.4. Results in these sections should better presented. Results are not clear the figures do not help to understand the results.
Figures 6 and 9 are not clear, and graphics does not correspond with the information given in table 4. For example, in the table, authors use an irrigation quota of 200mm, for t24. With this amount of water, soil should saturate but this effect is not appreciated in fig. 6.
In Fig. 9, it is completely unclear what the authors want to demonstrate.
In Conclusions, authors conclusion shouldn’t be numerated.
In my opinion the authors should reorganize and clarify the presentation, as well as, undergo a complete English revision.
Author Response
Response to Reviewer 3 Comments (Round 2)
Due to the inconsistency between the line number in the expert comments (Round 2) and the revised version, the article is modified mainly through comprehensive judgment. The specific modification opinions are as follows:
Point 1: The abstract is still very unclear. Line 15, for example should be rewritten, and lines after 18 should be removed, and then included in the introduction.
Response 1: Thanks to the reviewers for the comments, and the abstract had been revised based on the requirements of academic editors. At the same time, lines after 18 had been removed.
Point 2: In the Keywords list, authors should use “crop model” or “crop simulation” instead of Aquacrop.
Response 2: Thanks to the reviewers for the comments, the Aquacrop had been replaced by crop model in revised draft.
Point 3: In line 93, replace “continuum” by “system” or “intersystem”.
Response 3: Thanks to the reviewers for the comments. The continuum in line 62 had been replaced by system in revised draft.
Point 4: Line 114. The sentence “In summary, the…” should go as a new paragraph. The same in Line 138 “The findings of previous…”.
Response 4: Thanks to the reviewers for the comments, and it had been modified according to the expert opinion.
Point 5: In lines 171 and 172 “it is difficult to maximize the use of soil moisture” should be rewritten. I guess the authors wanted to say “to maximize the use of the water in the soil”.
Response 5: Thanks to the reviewers for the comments, and “it is difficult to maximize the use of soil moisture” in line 98 had been modified according to the expert opinion.
Point 6: In line 174: What experiments are the authors referring to? This sentence is not clear.
Response 6: Thanks to the reviewers for the comments, and the experiments had been replaced by the field experiments in line 101.
Point 7: Line 193: The sentence should be rewritten to something like “… region presents arid or semiarid climate characteristics.”
Response 7: Thanks to the reviewers for the comments, and it had been revised based on the expert’s opinion in line 120.
Point 8: Line 220. The sentence “Five treatments…” should be moved to a new paragraph.
Response 8: Thanks to the reviewers for the comments, and it had been revised based on the expert’s opinion.
Point 9: Line 221. Use the term “three replications” instead of “each treatment being repeated 3 times”.
Response 9: Thanks to the reviewers for the comments, and it had been revised based on the expert’s opinion in line 138.
Point 10: Lines 223 to 225. The sentences “As appropriate” is very confusing. Please consider rewrite it.
Response 10: Thanks to the reviewers for the comments, and the as appropriate to had been replaced by according to in line 140.
Point 11:Line 272. The paragraph is not clear. Please consider rephrasing.
Line 277. The sentence “By limiting canopy…” is very long and confusing. Please rewrite.
Response 11: Thanks to the reviewers for the comments, and the paragraph for the line 169 to 179 had been rewritten.
Point 12: Lines 284 to 287. These lines should be checked to improve the readability.
Response 12: Thanks to the reviewers for the comments, and the line 182 to 187 had been rewritten.
Point 13:Lines 377 to 382. Please rewrite the paragraph.
Lines 450, 451, 483 use the same text. Please check this.
Response 13: No specific location was found due to the line number problem, which will be revised based on specific problems.
Point 14: Section 3.2, 3.3 and 3.4. Results in these sections should better presented. Results are not clear the figures do not help to understand the results.
Figures 6 and 9 are not clear, and graphics does not correspond with the information given in table 4. For example, in the table, authors use an irrigation quota of 200mm, for t24. With this amount of water, soil should saturate but this effect is not appreciated in fig. 6.
In Fig. 9, it is completely unclear what the authors want to demonstrate.
Response 14: Thanks to the reviewers for the comments, the crop model validated for the Figure 6 to Figure 8, which does correspond with the information given in table 2; and the scenarios’ results are shown Figure 9 to Figure 10, which does correspond with the information given in table 4; on the other hand, the irrigation quota is irrigation water amount of the whole growth period, not the single irrigation amount in the growth period.
For t24, the irrigation water amount of the whole growth period is 200mm, and the single irrigation amount is 100mm. For spring wheat, the maximum single irrigation water volume is 100mm, so the soil should not saturate.
Point 15: In Conclusions, authors conclusion shouldn’t be numerated.
Response 15: The conclusions was revised based on expert’s opinion.
Author Response File: Author Response.docx
This manuscript is a resubmission of an earlier submission. The following is a list of the peer review reports and author responses from that submission.
