Next Article in Journal
Dilemmas in and Pathways to Transboundary Water Cooperation between China and India on the Yaluzangbu-Brahmaputra River
Previous Article in Journal
Dune Contribution to Flow Resistance in Alluvial Rivers
Article
Peer-Review Record

Effects of Irrigation Water Salinity on Maize (Zea may L.) Emergence, Growth, Yield, Quality, and Soil Salt

Water 2019, 11(10), 2095; https://doi.org/10.3390/w11102095
Reviewer 1: Anonymous
Reviewer 2: Anonymous
Water 2019, 11(10), 2095; https://doi.org/10.3390/w11102095
Received: 1 September 2019 / Revised: 1 October 2019 / Accepted: 4 October 2019 / Published: 8 October 2019
(This article belongs to the Section Water Use and Scarcity)

Round 1

Reviewer 1 Report

This paper describes an experiment to compare the effects of cultivation of maize under different degrees of salinity in the irrigation water. The experiment is complete and correctly planned, the manuscript is very detailed and technically sound, and the conclusions can be of great interest for other researches worldwide working in this area.

The main deficiency of the manuscript is the writing. In many parts, the paper is difficult to read and understand because there are very long sentences, syntactic and grammatical errors, and many numbers and data expressed in a disorganized way. In my opinion, the manuscript can be improved a lot if it is structured better and errors are corrected.

More specific comments:

A. Most of the cites to the references are incorrectly formatted. Since the cites are indicated with brackets ([1], [2], etc.), you don't have to indicate the year in the cite. For example, instead of "Kang et al. (2005) indicated ... [20]", it should be "Kang et al. indicated ... [20]". All the years should be removed from the cites.

B. All figure and table captions must end with a point.

C. The sentence in lines 186-188 ("Additionally, fresh water (Yellow River water) with an amount of 1500 m3·ha-1...) is repeated. This was already said in lines 178-179. Also, the information of diammonium phosphate, potassium sulphate and urea is repeated, with indicating different quantities. Please clarify the data and avoid repetitions.

D. In subsection 2.4.1, instead of including so much data in the text, it would be better to use a table.

E. In subsection 2.4.4, in equation (1), how can you guarantee that the drainage, D, is 0? It is very difficult to ensure that there is no drainage.

F. In subsection 3.2, in the paragraph from lines 297-308, you don't need to repeat all the data that is contained in table 6. Instead, you should only extract the most relevant results. Also, in lines 324-328, and lines 355-357. Avoid repetitions if new information is not provided.

G. Table 7 should be represented as one or more figures, because it contains too much information and it is difficult to read. The same with table 9. Also, remove "the" in the labels of the table, e.g. "Highest plant height", "Maximum LAI", etc.

H. In figure 6, does "before" and "after" irrigation mean the irrigation of day August 18th, 2017? You should indicate this in the figure caption. How much time "after" the irrigation was it measured?

I. Section 4 (Discussion) should be structured to make it more readable and easier to understand. It should be structured in points, each of them with a concrete idea. You should not repeat the same things that are already said in section 3. And you should be more concise and briefer in the discussions.

J. In the introduction, you have referred to the sustainable goals for development of the UN. However, in the conclusions, you have not described how the obtained results are related to these goals. At the end, you recommend using a salinity of 3 g·L-1. But the salt concentration of shallow groundwater in the experimental area is 1 g·L-1 (line 144). So you need to "add salt" to the water to reach the desired level of 3 g·L-1. This does not seem to be very "sustainable". Instead, you could directly use the available water with 1 g·L-1. Would it be more sustainable? You have to discuss these aspects in the conclusions.

K. Line 22: what is SMP? It has to be defined in the first use.

L. There are many sentences that are unnecessarily long. A sentence consists of subject, verb and predicate. You don't have to joint independent sentences, because you create sentences that are very long and more difficult to understand. For example, I have noted down the following cases of sentences that should be divided (although the manuscript should be completely revised):
1. Line 18: , thus -> . Thus
2. Line 25: , the water -> . The water
3. Line 28: , additionally, -> . Additionally,
4. Line 49: , especially -> . Especially
5. Line 53: , consequently -> . Consequently
6. Line 56 and 105: , meanwhile -> . Meanwhile
7. Line 65: , while Kang -> . Kang
8. Line 67: , however -> . However
9. Line 68, 82 and 552: , moreover -> . Moreover
10. Line 71 and 78: , the results -> . The results
11. Line 548: , meanwhile -> . Meanwhile

M. There are a lot of errors related with the use of "which". You have to remember that "which" is the subject of the sentence, so there should be a verb and a predicate. I have noted down these errors:

1. Line 36: which equipped with effective -> which is equipped with an effective
2. Line 39: which usually -> which are usually
3. Line 196: which installed -> which is installed
4. Line 208: which distributed -> which were distributed
5. Line 252: which distance from the drip tube distributed -> which distance from the drip tube were distributed
6. Line 292: which result -> which results
7. Line 440: which may attribute -> which may be attributed
8. Line 527: which located -> which is located

N. There are many other syntactic and grammatical errors that decrease the quality of the article. You should consider it more seriously and be more careful with writing. Here are some examples, although, again, I recommend you a complete review of the entire manuscript:

Line 29: salinity above -> salinity was above
Line 30: Synthetically -> In short or In conclusion
Line 40: for the considering of -> for the purpose of
Line 43 and 44: agricultural -> agriculture
Line 43: threaten -> threatened
Line 55: increase -> increases
Line 56: provide -> provides
Line 57: result -> results
Line 58: will inhibits -> inhibits or will inhibit
Line 65, 78 and 89: has -> have
Line 82: decrease -> decreases
Line 94 and 95: tend to -> tends to
Line 74: salt salinity -> salinity
Line 116: concentrations -> salt concentrations
Line 118: in hope of contribute to -> hoping to contribute to
Line 120: united nations -> United Nations
Line 130: moreover -> Moreover
Line 171: detail -> detailed
Line 238: was measured -> were measured
Line 261: distributed -> were distributed
Line 287: show -> shows
Line 364: Science -> Since
Line 365: usually used -> is usually used
Line 387: result -> results
Line 401: higher than -> was higher than
Line 409: was shown -> is shown
Line 430: which variation was correspond -> whose variation corresponds
Line 432 and 543: tend to be -> tends to be
Line 461: attribute -> attributed
Line 467: The results was -> The results were
Line 498: result -> results
Line 498: which lead to -> which leads to

Author Response

Dear Reviewer,

Thank you very much for your careful review of our manuscript, we appreciate you very much for the suggestions.

I have revised the manuscript carefully according your suggestions during the past ten days, the main corrections in the manuscript are as flowing:

 

Most of the cites to the references are incorrectly formatted. Since the cites are indicated with brackets ([1], [2], etc.), you don't have to indicate the year in the cite. For example, instead of "Kang et al. (2005) indicated ... [20]", it should be "Kang et al. indicated ... [20]". All the years should be removed from the cites.

All the years were removed from the cites in the text.

All figure and table captions must end with a point.

Points were added at the end of all figure and table captions.

The sentence in lines 186-188 ("Additionally, fresh water (Yellow River water) with an amount of 1500 m3·ha-1...) is repeated. This was already said in lines 178-179. Also, the information of diammonium phosphate, potassium sulphate and urea is repeated, with indicating different quantities. Please clarify the data and avoid repetitions.

①Since the traditional irrigation method is surface flood irrigation, but the irrigation method in the present study was mulched drip irrigation, in order to facilitate readers to compare the experimental irrigation and fertilization schedule with traditional irrigation and fertilization regime, we have stated the surface flood irrigation and traditional fertilization schedule, mulched drip irrigation and experimental fertilization regime, separately.

②Both the surface flood irrigation and mulched drip irrigation have applied supplementary irrigation; while the fertilizer quantities for diammonium phosphate, potassium sulphate and urea in traditional cultivation and experimental cultivation were different.

In subsection 2.4.1, instead of including so much data in the text, it would be better to use a table.

The Section “2.4.1 Meteorological observation“ was moved forward into the Section “2.1 Experimental site“; a new table (Table 1) was build to state the meteorological statistical values.

In subsection 2.4.4, in equation (1), how can you guarantee that the drainage, D, is 0? It is very difficult to ensure that there is no drainage.

We have checked many articles, and found that, with mulched drip irrigation quota for each application of 22.5mm, the amount of drainage was usually ignored.

In subsection 3.2, in the paragraph from lines 297-308, you don't need to repeat all the data that is contained in table 6. Instead, you should only extract the most relevant results. Also, in lines 324-328, and lines 355-357. Avoid repetitions if new information is not provided.

①The sentence “with the increase of irrigation water salinity, the emergence rate decreased. On 6 days after sowing, the emergence rate for S1, S2 and S3 treatment reached 28%, 17%, 11% in 2016, and 30%, 19%, 12% in 2017, respectively,” from line 300-302 was deleted.

②Lines 323-328 and lines 355-357: there are comparations about vegetative growth characteristics and grain quality between S1, S3 and S5 treatment.

Table 7 should be represented as one or more figures, because it contains too much information and it is difficult to read. The same with table 9. Also, remove "the" in the labels of the table, e.g. "Highest plant height", "Maximum LAI", etc.

Table 7 and Table 9 were represented as Figure 5 and Figure 7, respectively.

The word “the” was removed in the labels of Table7.

In figure 6, does "before" and "after" irrigation mean the irrigation of day August 18th, 2017? You should indicate this in the figure caption. How much time "after" the irrigation was it measured?

Yes, "before" and "after" the irrigation in Figure 6 mean the irrigation on August 18th, 2017; “on August 18th, 2017” was added at the end of the caption of Figure 6(a) and Figure 6(b); the caption “…after the irrigation” means the soil salt was measured three days after the irrigation on August 18th, 2017.

Section 4 (Discussion) should be structured to make it more readable and easier to understand. It should be structured in points, each of them with a concrete idea. You should not repeat the same things that are already said in section 3. And you should be more concise and briefer in the discussions.

The Section 4 (Discussion) was restructured and many repeated parts with Section 3 (Results) were deleted. Many long sentences were split into short sentences.

In the introduction, you have referred to the sustainable goals for development of the UN. However, in the conclusions, you have not described how the obtained results are related to these goals. At the end, you recommend using a salinity of 3 g·L-1. But the salt concentration of shallow groundwater in the experimental area is 1 g·L-1 (line 144). So you need to "add salt" to the water to reach the desired level of 3 g·L-1. This does not seem to be very "sustainable". Instead, you could directly use the available water with 1 g·L-1. Would it be more sustainable? You have to discuss these aspects in the conclusions.

The paragraph “Although the average annual salinity of shallow ground water in the experimental area is 1.007 g·L-1, groundwater with salinity of 1-5g·L-1 accounts for more than 80% of the shallow groundwater allowable withdrawal in HID, the results of the present paper will contribute to the sustainable use of shallow ground water for maize irrigation in HID. Additionally, the appropriate utilization of ground water will contribute to promote groundwater renewal and lessen soil salt accumulation, which are helpful to fight against the processes of land salinization” was added in “Conclusion”.

Line 22: what is SMP? It has to be defined in the first use.

The abbreviation “SMP” was replaced by “soil matric potential”.

There are many sentences that are unnecessarily long. A sentence consists of subject, verb and predicate. You don't have to joint independent sentences, because you create sentences that are very long and more difficult to understand. For example, I have noted down the following cases of sentences that should be divided (although the manuscript should be completely revised):
1. Line 18: , thus -> . Thus

“north China, thus, a two year…” was replaced by “north China. A two year…”.
2. Line 25: , the water -> . The water

“…3 g·L-1, the water…” was replaced by “…3 g·L-1. The water…”.
3. Line 28: , additionally, -> . Additionally,

“…salt contents, additionally, both…” was replaced by “…salt contents. Additionally, both…”.
4. Line 49: , especially -> . Especially

“shallow saline groundwater has an abundant 47 storage in HID, and the average salinity of local shallow groundwater (buried depth 10-40 m) is 2.54 g·L-1, especially,” was deleted from line 47-49.
5. Line 53: , consequently -> . Consequently

“…humid seasons, consequently,…” was replaced by “…humid seasons. Consequently,…”.
6. Line 56 and 105: , meanwhile -> . Meanwhile

“…crops growth, meanwhile,…” was replaced by “…crops growth. Meanwhile,…” in line 56; “…Northwest China [24], meanwhile,…” was replaced by “…Northwest China [23]. Meanwhile,…” in line 105.
7. Line 65: , while Kang -> . Kang

“…above 4 g·L-1 [8], while Kang et al.…” was replaced by “…above 4 g·L-1 [7]. Kang et al.…” in line 65.
8. Line 67: , however -> . However

“…waxy maize, however, the seeding biomass.…” was replaced by “…waxy maize. However, the seeding biomass.…” in line 67.
9. Line 68, 82 and 552: , moreover -> . Moreover

“…irrigation water salinity, moreover, the growth rate…” was replaced by “…irrigation water salinity. Moreover, the growth rate…” in line 68; “…irrigation water salinity, moreover, they…” was replaced by “…irrigation water salinity. Moreover, they…” in line 82; “…irrigation water salt concentrations, moreover, the impacts…” was replaced by “…irrigation water salt concentrations. Moreover, the impacts…” in line 552.
10. Line 71 and 78: , the results -> . The results

“…soil salt distribution, the results…” was replaced by “…soil salt distribution. The results…” in line 71; “…agro-hydrological model, the results…” was replaced by “…agro-hydrological model. The results…” in line 78.
11. Line 548: , meanwhile -> . Meanwhile

“…the biomass increased by 9.5%, meanwhile the IWUE and WUE…” was replaced by “…the biomass increased by 9.5%. Meanwhile the IWUE and WUE…” in line 548.

There are a lot of errors related with the use of "which". You have to remember that "which" is the subject of the sentence, so there should be a verb and a predicate. I have noted down these errors: Line 36: which equipped with effective -> which is equipped with an effective

“alluvial plain of the middle Yellow River and is suffering a serious water shortage, which equipped with effective irrigation area of 57.4×104 ha” was deleted in line 35-36.
2. Line 39: which usually -> which are usually

The predicate “are” was added between “which” and “usually” in line 39.
3. Line 196: which installed -> which is installed 

The predicate “is” was added after “which” in line 196.
4. Line 208: which distributed -> which were distributed 

The sentence from line 207-208 was replaced by “Before maize sowing, fifteen sampling locations were selected randomly in the experimental plot, all soil samples were taken at each location in 20 cm increments down to a depth of 100 cm”, and moved forward into section “2.1. Experimental site”.
5. Line 252: which distance from the drip tube distributed -> which distance from the drip tube were distributed

“…which distance from the drip tube distributed…” was replaced by “…which distance from the drip tube were distributed…” in line 253; “As the maize main roots distributed 10-30cm…” was replaced by “As the maize main roots were distributed 10-30cm…” in line 261.

Line 292: which result -> which results

“…which result in…” was replaced by “…which results in…” in line 292.
7. Line 440: which may attribute -> which may be attributed

“…which may attribute to…” was replaced by “…which may be attributed to…” in line 440.
8. Line 527: which located -> which is located

“…in the surface zone which located…” was replaced by “…in the surface zone which is located…” in line 527.

There are many other syntactic and grammatical errors that decrease the quality of the article. You should consider it more seriously and be more careful with writing. Here are some examples, although, again, I recommend you a complete review of the entire manuscript:

Line 29: salinity above -> salinity was above

“salinity above” was replaced by “salinity was above” in line 29, 385, 467, 556.
Line 30: Synthetically -> In short or In conclusion

“Synthetically,…” was replaced by “Summarily,…”.
Line 40: for the considering of -> for the purpose of

“…per year for the considering of sustained and harmonious development…” was replaced by “…per year for the purpose of sustained and harmonious development…” in line 40.
Line 43 and 44: agricultural -> agriculture

The word “agricultural” was replaced by “agriculture” in line 43 and line 44.
Line 43: threaten -> threatened

The word “threaten” was replaced by “threatened” in line 43.
Line 55: increase -> increases

“increase” was replaced by “increases” in line 55.
Line 56: provide -> provides

“provide” was replaced by “provides” in line 56.
Line 57: result -> results

“result” was replaced by “results” in line 57.
Line 58: will inhibits -> inhibits or will inhibit 

“will inhibits” was replaced by “will inhibit” in line 58.
Line 65, 78 and 89: has -> have

“has” was replaced by “have” in line 65, 78 and 89.
Line 82: decrease -> decreases

“decrease” was replaced by “decreases” in line 82.
Line 94 and 95: tend to -> tends to

“tend to” was replaced by “tends to” in line 94, 95.
Line 74: salt salinity -> salinity

“salt salinity” was replaced by “salinity” in line 74.
Line 116: concentrations -> salt concentrations

“concentrations” was replaced by “salt concentrations” in line 29, 71, 116, 171, 273, 280, 317, 352, 354, 394, 397, 401, 412, 429, 435, 493, 556.
Line 118: in hope of contribute to -> hoping to contribute to

“in hope of contribute to” was replaced by “hoping to contribute to” in line 118.
Line 120: united nations -> United Nations

“united nations” was replaced by “United Nations” in line 120.
Line 130: moreover -> Moreover

We have rewritten the section “2.1. Experimental site”, and the word “moreover” was deleted.
Line 171: detail -> detailed

“detail” was replaced by “detailed” in line 172; “are” was replaced by “is” in line 172.
Line 238: was measured -> were measured

“was measured” was replaced by “were measured” in line 238
Line 261: distributed -> were distributed 

“distributed” was replaced by “were distributed” in line 261.
Line 287: show -> shows

“show” was replaced by “shows” in line 287; “show” was replaced by “showed” in line 291.
Line 364: Science -> Since

The sentence from line 364-366 was rewritten, and “Science” was deleted.
Line 365: usually used -> is usually used 

The sentence from line 364-366 was rewritten, and “usually used” was deleted.
Line 387: result -> results

“result” was replaced by “results” in line 387.
Line 401: higher than -> was higher than

“higher than” was replaced by “was higher than” in line 394, 401.
Line 409: was shown -> is shown 

“was shown” was replaced by “is shown” in line 409.
Line 430: which variation was correspond -> whose variation corresponds

The sentence from line 428-433 was replaced by “Considering maize evapotranspiration, seedings emergence rate and growth indexes, irrigation water salinity of 1-3 g·L-1 are recommended in this paper. The results about maize evapotranspiration indicated that, TDS of 3 g·L-1 tends to be the upper limit of irrigation water salinity for maize normal transpiration, which result was in accord with the research of Wang et al. [10]”.
Line 432 and 543: tend to be -> tends to be

“tend to be” was replaced by “tends to be” in line 298, 303, 432, 458 and 543.

Line 461: attribute -> attributed

“attribute” was replaced by “attributed” in line 461;
Line 467: The results was -> The results were

“The results was” was replaced by “The results were” in line 467.
Line 498: result -> results

“result” was replaced by “results” in line 498.
Line 498: which lead to -> which leads to

“which lead to” was replaced by “which leads to” in line 498; “lead to” was replaced by “leads to” in line 58, 274, 289.

Additionally, the reference [2] was deleted, while 6 references were added, all orders of citation were renewed.

 

 

Once again, thank you very much for your review.

Best regards,

Sincerely,

 

Author Response File: Author Response.docx

Reviewer 2 Report

This paper analyzes the effect of different levels of salinity on irrigation water used in maize crop in Hetao area in China. The experiment seems well based. However, the manuscript needs important improvements. Materials and Methods should be re-organized and presented in a sequential and logical order (see some of my comments below). In addition, some additional statistical treatments might be carried out for assessing if there were significant differences in seeding emergence and maize yield and biomass. Discussion should be deeper and clearer, and it should avoid a repetition of results presented.

Moreover, the manuscript needs an extensive edition of language because there are several mistakes and some sentences are too long. I have highlighted some issues in my specific comments but there are several more that need amendment.

 

Specific comments and suggestions:

Lines 17-21. The authors should split this sentence in two. Reference to S1-S5 on line 20 could be removed since salinity levels are given and S1-S5 are not quoted in the abstract. What is the salinity compound expressed in g L-1? Line 22. Replace “were estimated” with “were determined”. The meaning of SMP should be identified clearly for avoiding any confusion. Lines 22-30. The authors might split this long sentence in several ones. The meaning of LAI should be identified. Line 30. “Synthetically” is not correct here. The authors might use other adverbs such as summarily or overall. Line 32. Keywords should be different than the words that appear in the title. Line 35. For no Chinese readers, a reference to the Chinese province where Hetao Irrigation District is located could be useful. Line 36. Water shortage could not have equipped the irrigation area. How could be more irrigation area with water shortage? What does mean effective irrigation area? Line 39. In what chemical compound is expressed salinity concentration? Line 42. Reference [2] is not a document of the Yellow River Water Conservancy Commission. Line 44. “In order to realize the sustainable...”. “Realize” is not correct here. Lines 47-50. This sentence could be shortened giving the key information clearer. Line 53. Change to “seasons. Consequently, “. Line 55. “Due to the typical property of high salt content”. Reword and clarify the sentence. Line 81. Change to “indicated that maize”. Line 94. Change to “shown that soil”. Line 97. Change to “that there was”. Line 100. Change to “that the measurement”. Lines 100-101. “immediately under the drip emitter”. It is not clear if the authors are talking about subsurface drip irrigation or surface drip irrigation. Lines 100-104. The same units should be used for expressing 20 cm (line 100) and 0.2 (line 104). Line 106. Change to “that the SMP”. Lines 124-127. Typical meteorological values seem not necessary if data during experiment is shown on Figure 2 and Section 2.4.1. A brief description about number of samples taken and analysis procedures for obtaining results shown on Tables 1-3 is missed. Table 3. The caption should read that average values are shown in this table. The authors might also present standard deviation or range of the different parameters. The column entitled “Characteristics” and “Project” should be entitled “Parameter”. Procedures for computing reference crop evapotranspiration should be briefly described. Lines 157-158. The authors should provide the chemical compound used for measuring salinity concentration. This is important for those researchers that would like to replicate the present experiment. This is also the reason for suggesting moving Table 4 close to these lines. Distribution of plots for each row would be useful information. Line 164. Scientific names (Zea mays) should appear in italics. Table 4. The fact that two unit levels (g m-3 and g L-1) are used might be an issue for some readers. The sum of the different compounds does not yield the total concentrations for S2-S5. Lines 177-178. Change to “growth period. Additionally, ”. Observation and equipment (Section 2.4) should appear before the results obtained with the described devices appear. My previous comments #22 and #25 were in this sense. Section 2.4.3. Were soil properties determined at the beginning of each season? Line 231. Change to “growth period. Plant height”. Lines 240-241. y and b should have units of kg, but not kg m-2. Line 249. Change to “the methods” Table 5 should appear in Material and Methods, not in Results. Figure 4. P-value of regression equations (which is as important as R2) is missed. Table 6. I would suggest showing seeding emergence rates in percentage. Section 3.2. It would be interesting if a statistical treatment could be carried out. This may strengthen both results and discussion of the effect on seeding emergence. Line 313. It should be “are shown”. Table 7 caption. Not only values for 2016 are shown, but for 2017 too. I would suggest rewording to “Main maize vegetative growth characteristics for the different salinity irrigation water treatments in 2016 and 2017”. Table 8. Why the possible mean differences for maize grain yield and biomass between salinity treatments were not analyzed? This additional analysis could strengthen the results presentation on lines 333-340. Figure 5. P-values of the regression equations are missed. Why only average values are depicted? How were values between replications? Line 350. Change to “starch content. Moreover, the grain”. Lines 364-366. The sentence should be reworded. It should be “Since”, not “Science”. Line 380. Change to “3 g L-1. However, “. Lines 392-393. The soil salt desalinized? Line 401. Change to “influence. However, with”. Lines 414-415 and 417-418. “there was no significant influence of irrigation water salinity” and “have no significant relationship with the irrigation water salt concentrations”. In my opinion, there was an effect of water salinity because there were significant differences between treatments but they were not greater with higher salinity levels. Line 419. “Synthetically” is not a correct adverb here. Figure 8. Letters for mean separation of Figs. 8b) and 8d) do not follow the same pattern than in previous figures (i.e. “a” for smaller values). Lines 428-433. This is a confusing sentence. The authors should reword it. Lines 433-442. The authors should split this long sentence in several ones. Line 442. “were disaccord” is not correct in English. Lines 442 and 444. It should be “the studies” instead of “the study”. Line 443. Change to “that there were little significant effects”. What do the authors mean with “little significant effect”? Line 454. It should be “Li et al.”. Lines 467-468. Change to “The results were in accordance with”. Line 475. Change to “Both IWUE and WUE”. Lines 475-481, 489-495, 501-505, 544-550, and 550-554. The authors should consider splitting these sentence in various ones.

Author Response

Dear Reviewer,

Thank you very much for your careful review of our manuscript, we appreciate you very much for your suggestions.

I have revised the manuscript carefully according your suggestions during the past ten days, and the main corrections in the manuscript are as flowing:

Materials and Methods should be reorganized and presented in a sequential and logical order.

①Table 4 (Compounds dosage for different water salinity levels) was moved forward, and close to “The field experiment was performed with five irrigation water salinity levels (measured in TDS) of 1 g·L-1 (S1), 2 g·L-1 (S2), 3 g·L-1 (S3), 4 g·L-1 (S4), and 5 g·L-1 (S5), respectively, and the treatments were laid out in a randomized complete block design”;

②The section “2.4.1 Meteorological observation” was moved into “2.1. Experimental site”, and “Table 1” was created to show the meteorological statistical values;

③The section “2.4.3 Soil basic properties” was moved into “2.1. Experimental site”, a brief description about the number of samples taken and analysis procedures for obtaining results shown on Tables 1-3 was added;

④Table 5 (Irrigation quota and evapotranspiration) was moved forward from section “3.1. Irrigation” into section “2.4.2. Evapotranspiration”.

Some additional statistical treatments might be carried out for assessing if there were significant differences in seeding emergence and maize yield and biomass.

Significance analysis was carried out on “Table 6 (Seeding emergence for different treatments)” and “Table 9 (Irrigation water salinity effects on grain yield and maize biomass)”. Additionally, according to the suggestions of the other reviewer, the Table 7 and Table 9 were modified into Figure 5 and Figure 7, respectively.

Discussion should be deeper and clearer, and it should avoid a repetition of results presented.

①The section “Discussion” was restructured, many repeated parts with Section 3 (Results) were deleted:

②“…meanwhile, the irrigation water concentrations of 4 g·L-1 and 5 g·L-1 reduced the emergence rate of maize…” from line 435 to line 442 was simplified to “The results may ascribe to the little salt tolerance of maize seedings during germination stage [47]”;

③The sentences from line 447-451 was deleted;

④Repeated parts “the emergence rate for S2 461 treatment was 98% in 2016 and 97% in 2017, respectively, while the emergence rate for S5 treatment 462 was 77% in 2016 and 76% in 2017, respectively” from 461-463 was deleted.

⑤The long sentence from 463-467 was simplified to “Compared with maize yield for S1 treatment, maize yield for S3, S4 and S5 treatment only decreased by 1.43%-35.13%, which indicated that irrigation water salinity levels have negative effects on maize yield when irrigation water salt concentrations was above 2 g·L-1”.

⑥Repeated parts “The IWUE, WUE both decreased linearly with the irrigation water salinity increasing from 1 g·L-1 to 5 g·L-1” in line 475-476 was deleted;

⑦The sentences from line 483-488 was deleted, while the sentence “Thus, sustainable salt concentrations of irrigation water is the precondition of crops high production” was added in line 483. Moreover, the sentences “Taking maize seed production into consideration, irrigation water salinity of 2 g·L-1 was more proper than other water salt concentrations. While taking account of the IWUE and WUE, irrigation water salt concentration of 1 g·L-1 was more appropriate than other water salinity” were added at the beginning of line 460.

⑧The sentences from line 499-500 was modified and moved to the beginning of line 489.

⑨The sentence from line 501-505 was deleted, while the sentence from line 512-517 was moved to the beginning of line 501.

⑩The sentences from line 518-527 was deleted.

According the other reviewer’s suggestion, the paragraph “Although the average annual salinity of shallow ground water in the experimental area is 1.007 g·L-1, groundwater with salinity of 1-5g·L-1 accounts for more than 80% of the shallow groundwater allowable withdrawal in HID, the results of the present paper will contribute to the sustainable use of shallow ground water for maize irrigation in HID. Additionally, the appropriate utilization of ground water will contribute to promote groundwater renewal and lessen soil salt accumulation, which are helpful to fight against the processes of land salinization” was added at the end of section “5. Conclusion”.

The manuscript needs an extensive edition of language because there are several mistakes and some sentences are too long.

Many grammatical errors in original manuscripts have been amended, such as deficiency of sentence predicate, sentence tense, spelling mistakes. Additionally, many long sentences were split into short sentences.

Lines 17-21. The authors should split this sentence in two. Reference to S1-S5 on line 20 could be removed since salinity levels are given and S1-S5 are not quoted in the abstract. What is the salinity compound expressed in?

①The sentence from Line 16-21 was split into 2 sentences;

②The reference to S1-S5 was deleted;

③The salinity expressed in g·L-1 corresponding to “total dissolved solids”, which was illustrated in Line 20 in this revision.

Line 22. Replace “were estimated” with “were determined”. The meaning of SMP should be identified clearly for avoiding any confusion.

The unsuitable word “estimated” in Line 22 was replaced by “determined”; the abbreviation “SMP” was replaced by “soil matric potential”.

Lines 22-30. The authors might split this long sentence in several ones. The meaning of LAI should be identified.

The long sentence from Line 22 to Line 30 was split into three sentences; the abbreviation “LAI” was replaced by “leaf area index”.

Line 30. “Synthetically” is not correct here. The authors might use other adverbs such as summarily or overall.

The unsuitable word “Synthetically” was replaced by “Summarily”.

Line 32. Keywords should be different than the words that appear in the title.

The keywords “Irrigation water salinity; soil salt; maize” was replaced by “Hetao Irrigation District; soil matric potential; salt isoline; saline water;”

Line 35. For no Chinese readers, a reference to the Chinese province where Hetao Irrigation District is located could be useful.

The initial reference “HID (Hetao Irrigation District) is located in the alluvial plain of the middle Yellow River and is suffering a serious water shortage,…” was replaced by “HID (Hetao Irrigation District) is located in the alluvial plain of the middle Yellow River, western Inner Mongolia Autonomous region, China.”

Line 36. Water shortage could not have equipped the irrigation area. How could be more irrigation area with water shortage? What does mean effective irrigation area?

The unsuitable expression “…and is suffering a serious water shortage, which equipped with effective irrigation area of 57.4×104 ha” was deleted.

Line 39. In what chemical compound is expressed salinity concentration?

The salinity concentration was expressed in total dissolved solids. “(in total dissolved solids)” was added behind the sentence “which usually characterized with the annual average salinity of 0.505 g·L-1.”

Line 42. Reference [2] is not a document of the Yellow River Water Conservancy Commission.

The unsuitable reference [2] was deleted.

Line 44. “In order to realize the sustainable...”. “Realize” is not correct here.

The unsuitable word “realize” was replaced by “achieve”.

Lines 47-50. This sentence could be shortened giving the key information clearer.

The tedious expression “…shallow saline groundwater has an abundant storage in HID, and the average salinity of local shallow groundwater (buried depth 10-40 m) is 2.54 g·L-1, especially,…” was deleted.

Line 53. Change to “seasons. Consequently, “.

The sentence from Line 50 to Line 54 was split into two sentences: “…humid seasons, consequently,…” was changed to “…humid seasons. Consequently,…”

Line 55. “Due to the typical property of high salt content”. Reword and clarify the sentence.

The incorrect expression “Due to the typical property of high salt content,…” was replaced by “Due to the typical characteristic of high salt content,…”

Line 81. Change to “indicated that maize”.

The comma between “indicated that” and “maize” was deleted.

Line 94. Change to “shown that soil”.

The comma between “shown that” and “soil” was deleted.

Line 97. Change to “that there was”.

The comma between “that” and “there was” was deleted.

Line 100. Change to “that the measurement”.

The comma between “that” and “the measurement” was deleted.

Lines 100-101. “immediately under the drip emitter”. It is not clear if the authors are talking about subsurface drip irrigation or surface drip irrigation.

The expression “immediately under the drip emitter” was replaced by “immediately under the emitter of surface mulched drip irrigation”.

Lines 100-104. The same units should be used for expressing 20 cm (line 100) and 0.2 (line 104).

The unit “0.2 m” was changed to “20 cm” in Line 104.

Line 106. Change to “that the SMP”.

The comma between “that” and “the SMP” was deleted.

Lines 124-127. Typical meteorological values seem not necessary if data during experiment is shown on Figure 2and Section 2.4.1.

The typical meteorological values in line 124-127 was deleted.

A brief description about number of samples taken and analysis procedures for obtaining results shown on Tables 1-3 is missed.

①“Before maize sowing, fifteen sampling locations were selected randomly in the experimental plot, all soil samples were taken at each location in 20 cm increments down to a depth of 100 cm. The bulk density and porosity were measured by gravimetric method, while the soil particle size for seven layers was determined by the particle size analyzer (Bbckm-conl-trels-230), and the results are shown in Table 2. The total nitrogen was monitored by Kjeldahl distillation method [32], the available phosphorus was determined by the NH4F-extraction method [32], the available potassium was determined by the NH4OAC-extraction method [32], the ammonium nitrogen and was monitored following extraction with 2mol/L KCl and indophenol-blue colorimetry [33], while the nitrate nitrogen was measured by phenol disulfonic acid spectrophotometric method [33], the total phosphorus was measured following dry combustion at 550°C for 2h and extraction with 0.5 M H2SO4 [34], the organic matter was measured by Walkley Black method [35], the chemical characteristics of soil layers are presented in Table 3.” was added in line 128.

②“After maize sowing, six water samples were taken from the irrigation canals and irrigation wells beside the experimental field at 7 days interval. The content of Ca2+ and Mg2+ were measured by an atomic absorption spectrophotometer (Varian spectra AA55, Australia), while the K+ and Na+ were determined by a flame emission spectrophotometer (Model 410 Flame photometer, UK) [36], the Cl- was monitored by the methods of silver nitrate titration, while the SO42- was determined by EDTA Titration method, meanwhile, the soil HCO3- was measured by neutralization titration method. The pH was measured by a pH meter (FE20, METTLER TOLEDO, Shanghai, China), while the TDS (Total Dissolved Solids) was monitored by gravimetric method. The features average value of Yellow River and shallow groundwater are shown in Table 4.” was added in line 145.

Table 3. The caption should read that average values are shown in this table. The authors might also present standard deviation or range of the different parameters. The column entitled “Characteristics” and “Project” should be entitled “Parameter”. Procedures for computing reference crop evapotranspiration should be briefly described.

The caption “The features of Yellow River and shallow groundwater” in Table 3 was replaced by “The features average value of Yellow River and shallow groundwater”; the range of different parameters for Yellow River and shallow groundwater was added in Table 3; the column entitled “Characteristics” and “Project” were replaced by “Parameter”; “the reference crop evapotranspiration is calculated by the FAO Penman-Monteith equation (Allen et al., 1998) [37]. The results of reference crop evapotranspiration and precipitation during maize growing period was shown in Figure 2.” was added in line 148.

Lines 157-158. The authors should provide the chemical compound used for measuring salinity concentration. This is important for those researchers that would like to replicate the present experiment. This is also the reason for suggesting moving Table 4 close to these lines. Distribution of plots for each row would be useful information.

“(measured in TDS)” was added behind “five irrigation water salinity levels” to define the chemical compound used for measuring salinity concentration; line 170-173, while Table 4 was moved forward and close to the sentence from line 157-159.

Line 164. Scientific names (Zea mays) should appear in italics. Table 4. The fact that two unit levels (g m-3 and g L-1) are used might be an issue for some readers.

The format of maize scientific name in line 164 was modified to italics; the table 4 headers were updated to clear the unit of compounds dosage;

The sum of the different compounds does not yield the total concentrations for S2-S5.

Shallow groundwater (act as the solvent) itself contains a certain amount of salt.

Lines 177-178. Change to “growth period. Additionally, ”.

The unsuitable expression “…growth period, additionally,…” was replaced by “…growth period. Additionally,…”

Observation and equipment (Section 2.4) should appear before the results obtained with the described devices appear. My previous comments #22 and #25 were in this sense.

The Section “2.4.1 Meteorological observation“ and Section “2.4.3 Soil basic properties“ were moved forward into the Section “2.1 Experimental site“; a table (Table 1) was build to state the meteorological statistical values.

Section 2.4.3. Were soil properties determined at the beginning of each season?

The Section “2.4.3 Soil basic properties“ was moved into the Section “2.1 Experimental site“, soil samples for basic properties were taken before maize sowing (on May 1, 2016 and May 4, 2017), and soil basic properties were only tested for once every year.

Line 231. Change to “growth period. Plant height”.

The unsuitable expression “…growth period, plant height…” was replaced by “…growth period. Plant height…”.

Lines 240-241. y and b should have units of kg, but not kg m-2.

The incorrect units of “kg·m-2” were replaced by “kg” for y and b.

Line 249. Change to “the methods”

The unsuitable expression “the method” was replaced by “the methods”.

Table 5 should appear in Material and Methods, not in Results.

Table 5 was moved into Section “2.4.2. Evapotranspiration”.

Figure 4. P-value of regression equations (which is as important as R2) is missed.

The P-value of regression equations in Figure 4 was added, both the P-value in 2016 and 2017 were lower than 0.05, which indicated that the quadratic regression models are significant.

Table 6. I would suggest showing seeding emergence rates in percentage.

The emergence rates were modified in percentage.

Section 3.2. It would be interesting if a statistical treatment could be carried out. This may strengthen both results and discussion of the effect on seeding emergence.

Statistical analysis has been added in Table 6.

Line 313. It should be “are shown”.

The unsuitable expression “…is shown in Table 7” was replaced by “…are shown in Table 7”.

Table 7 caption. Not only values for 2016 are shown, but for 2017 too.

The missing word “2017” was added in the title of Table 7, Table 7 was modified to Figure 5 according to the other reviewer’s suggestion.

I would suggest rewording to “Main maize vegetative growth characteristics for the different salinity irrigation water treatments in 2016 and 2017”.

The initial title “The vegetative growth characteristics for different concentrations of irrigation water in 2016” was replaced by “Main maize vegetative growth characteristics for the different salinity irrigation water treatments in 2016 and 2017”.

Table 8. Why the possible mean differences for maize grain yield and biomass between salinity treatments were not analyzed? This additional analysis could strengthen the results presentation on lines 333-340.

The significance analysis was added in Table 8.

Figure 5. P-values of the regression equations are missed. Why only average values are depicted? How were values between replications?

The P-values of the regression equations in Figure 5 were added; the standard deviation was added in Table 8.

Line 350. Change to “starch content. Moreover, the grain”.

The unsuitable expression “…protein content and starch content, moreover,…” was replaced by “…protein content and starch content. Moreover,…”.

Lines 364-366. The sentence should be reworded. It should be “Since”, not “Science”.

The initial sentence “Science the density of the soil salt isoline usually used for indicating the distribution of soil salt, the soil salt isoline for the present study is shown in Figure 6” was replaced by “The results of the soil salt isoline are shown in Figure 6”.

Line 380. Change to “3 g L-1. However, “.

The unsuitable expression “…irrigation water salinity below 3 g·L-1, however,…” was replaced by “…irrigation water salinity below 3 g·L-1. However,…”.

Lines 392-393. The soil salt desalinized?

Yes, when the irrigation water salinity was lower than 2 g·L-1, the soil salt desalinized in the main root zone. Because the irrigation water salinity (1 g·L-1 and 2 g·L-1) is low, additionally, the target soil matric potential was controlled at -20kPa at a depth of 20 cm, which corresponding to 85% of the field capacity, thus result in high irrigation frequency. Salt leaching by irrigation water was dominant.

Line 401. Change to “influence. However, with”.

The unsuitable expression “…accumulating influence, however, when…” was replaced by “…accumulating influence. However, with…”

Lines 414-415 and 417-418. “there was no significant influence of irrigation water salinity” and “have no significant relationship with the irrigation water salt concentrations”. In my opinion, there was an effect of water salinity because there were significant differences between treatments but they were not greater with higher salinity levels.

The unreasonable result “there was no significant influence of irrigation water salinity on soil salt of 40-100 cm layer outside the film” in line 414-415, “the soil salt concentrations of 40-100 cm outside the film have no significant relationship with the irrigation water salt concentrations” in line 417-418 were deleted.

Line 419. “Synthetically” is not a correct adverb here.

The unsuitable word “Synthetically” was replaced by “Summarily”.

Figure 8. Letters for mean separation of Figs. 8b) and 8d) do not follow the same pattern than in previous figures (i.e. “a” for smaller values).

The letters for mean separation of Fig. 8(b) and Fig. 8(d) were amended.

Lines 428-433. This is a confusing sentence. The authors should reword it.

“With the increase of irrigation water salinity, the evapotranspiration had a quadratic relationship with the irrigation water concentrations both in 2016 and 2017, and the evapotranspiration reached the maximum with irrigation water salinity of 3 g·L-1, which variation was correspond to the irrigation quota, the results indicated that, irrigation water with salinity of 3 g·L-1 tend to be the upper threshold for maize root water uptake, which was in accord with the research of Wang et al. (2015) [11]” was replaced by “Both in 2016 and 2017, the evapotranspiration showed a quadratic relationship with the irrigation water concentrations, and the evapotranspiration reached the maximum when irrigation water salinity arrived 3 g·L-1. The results indicated that, TDS of 3 g·L-1 tend to be the upper limit of irrigation water salinity for maize normal transpiration, which result was in accord with the research of Wang et al. (2015) [11]”.

Lines 433-442. The authors should split this long sentence in several ones.

The long sentence in Lines 433-442 was simplified and split into three sentences.

Line 442. “were disaccord” is not correct in English.

The unsuitable expression “…disaccord with…” was replaced by “…inconsistent with…” in line 442 and line 493.

Lines 442 and 444. It should be “the studies” instead of “the study”.

The unsuitable expression “…the study…” was replaced by “…the studies…” in line 442, line 444, line 478, and line 514.

Line 443. Change to “that there were little significant effects”. What do the authors mean with “little significant effect”?

The unsuitable expression “…that, there were little significant effects of irrigation water salinity on 443 seeding emergence” was deleted in line 443.

Line 454. It should be “Li et al.”.

The unsuitable expression “…Li Kejiang et al. (2011),…” was replaced by “…Li et al. (2011),…”.

Lines 467-468. Change to “The results were in accordance with”.

The unsuitable expression “The results were in accord with…” was replaced by “The results were in accordance with…”.

Line 475. Change to “Both IWUE and WUE”.

The unsuitable expression “The IWUE, WUE both…” was replaced by “Both IWUE and WUE…”.

Lines 475-481, 489-495, 501-505, 544-550, and 550-554. The authors should consider splitting these sentence in various ones.

①The long sentence in line 475-481 was simplified to “While the IWUE and WUE decreased by 0.282-0.304 kg·m-3 and 0.442-0.483 kg·m-3 for every 1 g·L-1 increase in salt concentrations of irrigation water, respectively. Which result was consistent with the results of Wang et al., who have expound that, the WUE of spring maize decreased rapidly as irrigation water salinity ranges from 2 g·L-1 to 4 g·L-1 [10].”

②Lines 489-495 was split into 3 sentences;

③Lines 501-505 was deleted;

④Lines 544-550 was split into 3 sentences;

⑤Lines 550-554 was split into 2 sentences.

 

 

Additionally, the reference [2] was deleted, while 6 references were added, all orders of citation were renewed.

 

 

 

Once again, thank you very much for your review.

 

Best regards,

Sincerely,

 

Author Response File: Author Response.docx

Round 2

Reviewer 1 Report

The comments has been answered and the suggested corrections have been done by the authors.

Author Response

Dear Reviewer,

Thank you very much for your careful review of our manuscript, we appreciate you very much for the suggestions.

I have revised the manuscript carefully according to the other reviewer, the main corrections in the manuscript are as flowing:

 

(1) The unsuitable expression “…irrigation water salinity…” was replaced by “…irrigation water salinity levels…” in line 20.

 (2) The unsuitable expression “…by channels, which are usually characterized with the annual average salinity of 0.505 g·L-1 (in total dissolved solids)” was replaced by “…by channels, having an annual average of 0.505 g TDS (total dissolved solids) L-1 [2,3]” in line 20. Additionally, the reference “[2,3]” was added to support the value.

        [2] Sun, G.F.; Qu, Z.Y.; Du, B.; Ren, Z.S.; Liu, A.Q. Water-heat-salt effects of mulched drip irrigation maize with different irrigation scheduling in Hetao Irrigation District. Transactions of the Chinese Society of Agricultural Engineering (Transactions of the CSAE), 2017, 33(12), 144-152. doi: 10.11975/j.issn.1002-6819.2017.12.019 (in Chinese with English abstract)

         [3] Peng, Z.Y.; Wu, J.W.; Huang, J.S. Water and salt movement under partial irrigation in Hetao Irrigation District, Inner Mongolia. Journal of Hydraulic Engineering 2016, 47(1), 110-118. doi: 10.13243/j.cnki.slxb.20141279

 (3) “INESA Analytical Instrument Co., LTD, No. 88, Xutang Road, Songjiang district, Shanghai, China” was added in line 131 to show the name and location for the manufacturer of the particle size analyzer”.

 (4) The unsuitable expression “…[34], the organic matter was measured by Walkley Black method [35], the chemical characteristics…” was replaced by “…[34] and the organic matter was measured by the Walkley Black method [35]. The chemical characteristics…” in line 138.

 (5) The unsuitable expression “…at a depth of 20 cm corresponding to 85% of the Field capacity” was replaced by “…at a depth of 20 cm corresponded to 85% of the Field capacity” in line 140.

 (6) The unsuitable expression “…which is shown in Figure 1, the maximum value…” was replaced by “…which is shown in Figure 2. The maximum value…” in line 144.

 (7) The unsuitable expression “…the local shallow groundwater. the detailed dosage of…” was replaced by “…the local shallow groundwater. The detailed dosage of…” in line 175.

 (8) The unsuitable expression “…180m2 (width 7.2 m× length 25 m), the amount of…” was replaced by “…180m2 (width 7.2 m× length 25 m). The amount of…” in line 178.

 (9) The unsuitable expression “…the drip tubes with 0.3 m emitter intervals were located in the center of each bed (Figure 3a), all plots 180…” was replaced by “…the drip tubes with 0.3 m emitter intervals were located in the center of each bed (Figure 3a). All plots…” in lines 179-180.

 (10) The unsuitable expression “…as shown in Figure 3b, which was a mulched drip irrigation pattern with one tube, crops were planted…” was replaced by “…as shown in Figure 3b, which was a single mulched drip irrigation tube. Corn was planted…” in line 184-185.

 (11) The unsuitable expression “The yield for each treatment was estimated as following equation:” was replaced by “The yield and biomass for each treatment were estimated with the following equations:” in lines 234-235.

 (12) The unsuitable expression “WUE (kg·m-3) and IWUE (kg·m-3) were calculated by the following equation:” was replaced by “WUE (kg·m-3) and IWUE (kg·m-3) were calculated by the following equations: ” in line 239.

 (13) The unsuitable expression “at each growth stage for all treatments at depth of…” was replaced by “at each growth stage for all treatments at depths of…” in line 249.

 (14) The unsuitable expression “at soil to water ratio of 1:5, electrical conductivity EC1:5” was replaced by “at soil to water ratio of 1:5. Electrical conductivity EC1:5…” in lines 252-253.

 (15) The unsuitable expression “…showed a quadratic polynomial pattern, which the evapotranspiration amount…” was replaced by “…showed a quadratic polynomial pattern, in which the evapotranspiration amount…” in line 282.

 (16) The unsuitable expression “…reached 3 g·L-1, then the evapotranspiration…” was replaced by “…reached 3 g·L-1. Then the evapotranspiration…” in line 284.

 (17) The unsuitable expression “…evapotranspiration: on the one hand…” was replaced by “…evapotranspiration. On one hand…” in line 286.

 (18) The unsuitable expression “…irrigation frequency, on the other hand…” was replaced by “…irrigation frequency. On the other hand…” in line 288.

 (19) The unsuitable expression “…maize yield, the emergence rate…” was replaced by “…maize yield. The emergence rate…” in line 292.

 (20) The unsuitable expression “…the seeding emergence rate for S1, S2, S3 and S4 treatment…” was replaced by “…the seeding emergence rate for S1, S2, S3 and S4 treatments…” in line 298.

 (21) The unsuitable expression “…and then tends to be…” was replaced by “…and then tended to be…” in line 297; The unsuitable expression “…the seeding emergence tends to be stable…” was replaced by “…the seeding emergence tended to be stable…” in line 300.

 (22) The unsuitable expression “…and then declined slowly, which reached the maximum…” was replaced by “…and then declined slowly, reaching the maximum…” in line 298.

 (23) The unsuitable expression “…S4 and S5 treatment…” was replaced by “…S4 and S5 treatments…” in lines 299 and 302.

 (24) The unsuitable expression “…S1, S2 and S3 treatment…” was replaced by “…S1, S2 and S3 treatments…” in lines 299, 301 and 303.

 (25) The unsuitable expression “…indexes, the growth parameters of maize increased with the increasing water salt concentrations…” was replaced by “…indexes, which increased with the increasing water salt concentrations…” in line 315.

 (26) The unsuitable expression “…when the salinity of irrigation water arrived 5 g·L-1, …” was replaced by “…when the salinity of irrigation water was 5 g·L-1, …” in lines 317-318.

 (27) The format problem has been amended in line 348.

 (28) The unsuitable expression “…S1, S2 treatment and S4, S5 treatment …” was replaced by “…S1, S2 treatments and S4, S5 treatments …” in line 347.

 (29) The unsuitable expression “…the plastic film: on the one hand…” was replaced by “…the plastic film. On one hand…” in line 385.

 (30) The unsuitable expression “…irrigation water, on the other hand…” was replaced by “…irrigation water but, on the other hand…” in line 386.

 (31) The unsuitable expression “…irrigation water infiltration, thus, the variation…” was replaced by “…irrigation water infiltration. Thus, the variation…” in line 387.

 (32) The expression “…hence, a suitable salt environment was exactly formed…” was replaced by “…hence, a low salinity zone was exactly formed…” in line 481.

 (33) The unsuitable expression “…Which result was consistent with…” was replaced by “…This result was consistent with…” in line 482.

 (34) The unsuitable word “treatment” was replaced by “treatments” in line 334, 336, 337, 430, 431 and 450.

(35) The citation order of all references was updated.

 

Once again, thank you very much for your review.

Best regards,

Sincerely,

Author Response File: Author Response.docx

Reviewer 2 Report

Most of my comments and suggestions on the first submission of this manuscript were included in the revision. The paper is clearer now. However, in my opinion, the paper would improve if the following minor edits were carried out:

 

Lines 20. Change to "irrigation water salinity levels". Lines 38-39. Change to "by channels, having an annual average of 0.505 g TDS (total dissolved solids) L-1." A reference that supports this value would be required. Line 131. The authors should provide the name of the manufacturer of the particle size analyzer and its location. Line 138. Change to "[34] and the organic matter was measured by the Walkley Black method [35]. The chemical characteristics". Line 140. Change to "20 cm corresponded to". Line 144. Change to "Figure 1. The maximum". Lines 158-161 and Figure 2. I would suggest moving these sentences and figure after Table 1, where meteorological data are shown. Change to "groundwater. The detailed". Line 178. Change to ". The amount of". Lines 179-180. Change to "The drip tubes with 0.3 m emitter intervals were located in the center of each bed (Figure 3a). All plots". Lines 184-185. Change to "as shown in Figure 3b, which was a single mulched drip irrigation tube. Corn was planted". Lines 236-237. Change to "The yield and biomass for each treatment were estimated with the following equations:” Line 241. Change to "following equations:". Line 251. Change to "at depths of". Lines 255-256. Change to "1:5. Electrical conductivity". Line 284. Change to "pattern, in which". Line 286. Change to "3 g L-1. Then, the evapotranspiration". Line 288. Change to "evapotranspiration. On one hand,". Line 290. Change to "frequency. On the other hand,". Line 294. Change to "yield. The emergence". Line 298. Change to "and S4 treatments". Lines 299 and 302. Change to " tended to be". Line 300. Change to "slowly, reaching the maximum". Line 301. Change to "and S5 treatments". Lines 303 and 305. Change to "and S3 treatments". Line 317. Change to "indexes, which increased with the increasing". Line 320. Change to "was 5 g L-1". Line 348. There is the figure caption and the explanation of the results in the same line. It should be arranged. Line 350. Change "treatment" with "treatments". Line 387. Change to "film. On one hand, ". Line 388. Change to "water but, on the other hand". Line 389. Change to "infiltration. Thus, ". Line 484. What is a salt suitable environment? Line 485. Change to "This result was consistent".

 

Author Response

Dear Reviewer,

Thank you very much for your careful review of our manuscript again, we appreciate you very much for the suggestions.

I have revised the manuscript carefully according your suggestions, the main corrections in the manuscript are as flowing:

 

Lines 20. Change to "…irrigation water salinity levels…".

(1) The unsuitable expression “…irrigation water salinity…” was replaced by “…irrigation water salinity levels…” in line 20.

Lines 38-39. Change to "by channels, having an annual average of 0.505 g TDS (total dissolved solids) L-1." A reference that supports this value would be required.

(2) The unsuitable expression “…by channels, which are usually characterized with the annual average salinity of 0.505 g·L-1 (in total dissolved solids)” was replaced by “…by channels, having an annual average of 0.505 g TDS (total dissolved solids) L-1 [2,3]” in line 20. Additionally, the reference “[2,3]” was added to support the value.

        [2] Sun, G.F.; Qu, Z.Y.; Du, B.; Ren, Z.S.; Liu, A.Q. Water-heat-salt effects of mulched drip irrigation maize with different irrigation scheduling in Hetao Irrigation District. Transactions of the Chinese Society of Agricultural Engineering (Transactions of the CSAE), 2017, 33(12), 144-152. doi: 10.11975/j.issn.1002-6819.2017.12.019 (in Chinese with English abstract)

        [3] Peng, Z.Y.; Wu, J.W.; Huang, J.S. Water and salt movement under partial irrigation in Hetao Irrigation District, Inner Mongolia. Journal of Hydraulic Engineering 2016, 47(1), 110-118. doi: 10.13243/j.cnki.slxb.20141279

Line 131. The authors should provide the name of the manufacturer of the particle size analyzer and its location.

(3) “INESA Analytical Instrument Co., LTD, No. 88, Xutang Road, Songjiang district, Shanghai, China” was added in line 131 to show the name and location for the manufacturer of the particle size analyzer”.

Line 138. Change to "[34] and the organic matter was measured by the Walkley Black method [35]. The chemical characteristics".

(4) The unsuitable expression “…[34], the organic matter was measured by Walkley Black method [35], the chemical characteristics…” was replaced by “…[34] and the organic matter was measured by the Walkley Black method [35]. The chemical characteristics…” in line 138.

Line 140. Change to "20 cm corresponded to".

(5) The unsuitable expression “…at a depth of 20 cm corresponding to 85% of the Field capacity” was replaced by “…at a depth of 20 cm corresponded to 85% of the Field capacity” in line 140.

Line 144. Change to "Figure 1. The maximum".

(6) The unsuitable expression “…which is shown in Figure 1, the maximum value…” was replaced by “…which is shown in Figure 2. The maximum value…” in line 144.

Lines 158-161 and Figure 2. I would suggest moving these sentences and figure after Table 1, where meteorological data are shown. Change to "groundwater. The detailed".

(7) The unsuitable expression “…the local shallow groundwater. the detailed dosage of…” was replaced by “…the local shallow groundwater. The detailed dosage of…” in line 175.

Line 178. Change to ". The amount of".

(8) The unsuitable expression “…180m2 (width 7.2 m× length 25 m), the amount of…” was replaced by “…180m2 (width 7.2 m× length 25 m). The amount of…” in line 178.

Lines 179-180. Change to "The drip tubes with 0.3 m emitter intervals were located in the center of each bed (Figure 3a). All plots".

(9) The unsuitable expression “…the drip tubes with 0.3 m emitter intervals were located in the center of each bed (Figure 3a), all plots 180…” was replaced by “…the drip tubes with 0.3 m emitter intervals were located in the center of each bed (Figure 3a). All plots…” in lines 179-180.

Lines 184-185. Change to "as shown in Figure 3b, which was a single mulched drip irrigation tube. Corn was planted".

(10) The unsuitable expression “…as shown in Figure 3b, which was a mulched drip irrigation pattern with one tube, crops were planted…” was replaced by “…as shown in Figure 3b, which was a single mulched drip irrigation tube. Corn was planted…” in line 184-185.

Lines 236-237. Change to "The yield and biomass for each treatment were estimated with the following equations:”

(11) The unsuitable expression “The yield for each treatment was estimated as following equation:” was replaced by “The yield and biomass for each treatment were estimated with the following equations:” in lines 234-235.

Line 241. Change to "following equations:".

(12) The unsuitable expression “WUE (kg·m-3) and IWUE (kg·m-3) were calculated by the following equation:” was replaced by “WUE (kg·m-3) and IWUE (kg·m-3) were calculated by the following equations: ” in line 239.

Line 251. Change to "at depths of".

(13) The unsuitable expression “at each growth stage for all treatments at depth of…” was replaced by “at each growth stage for all treatments at depths of…” in line 249.

Lines 255-256. Change to "1:5. Electrical conductivity".

(14) The unsuitable expression “at soil to water ratio of 1:5, electrical conductivity EC1:5” was replaced by “at soil to water ratio of 1:5. Electrical conductivity EC1:5…” in lines 252-253.

Line 284. Change to "pattern, in which".

(15) The unsuitable expression “…showed a quadratic polynomial pattern, which the evapotranspiration amount…” was replaced by “…showed a quadratic polynomial pattern, in which the evapotranspiration amount…” in line 282.

Line 286. Change to "3 g L-1. Then, the evapotranspiration".

(16) The unsuitable expression “…reached 3 g·L-1, then the evapotranspiration…” was replaced by “…reached 3 g·L-1. Then the evapotranspiration…” in line 284.

Line 288. Change to "evapotranspiration. On one hand,".

(17) The unsuitable expression “…evapotranspiration: on the one hand…” was replaced by “…evapotranspiration. On one hand…” in line 286.

Line 290. Change to "frequency. On the other hand,".

(18) The unsuitable expression “…irrigation frequency, on the other hand…” was replaced by “…irrigation frequency. On the other hand…” in line 288.

Line 294. Change to "yield. The emergence".

(19) The unsuitable expression “…maize yield, the emergence rate…” was replaced by “…maize yield. The emergence rate…” in line 292.

Line 298. Change to "and S4 treatments".

(20) The unsuitable expression “…the seeding emergence rate for S1, S2, S3 and S4 treatment…” was replaced by “…the seeding emergence rate for S1, S2, S3 and S4 treatments…” in line 298.

Lines 299 and 302. Change to " tended to be".

(21) The unsuitable expression “…and then tends to be…” was replaced by “…and then tended to be…” in line 297; The unsuitable expression “…the seeding emergence tends to be stable…” was replaced by “…the seeding emergence tended to be stable…” in line 300.

Line 300. Change to "slowly, reaching the maximum".

(22) The unsuitable expression “…and then declined slowly, which reached the maximum…” was replaced by “…and then declined slowly, reaching the maximum…” in line 298.

Line 301. Change to "and S5 treatments".

(23) The unsuitable expression “…S4 and S5 treatment…” was replaced by “…S4 and S5 treatments…” in lines 299 and 302.

Lines 303 and 305. Change to "and S3 treatments".

(24) The unsuitable expression “…S1, S2 and S3 treatment…” was replaced by “…S1, S2 and S3 treatments…” in lines 299, 301 and 303.

Line 317. Change to "indexes, which increased with the increasing".

(25) The unsuitable expression “…indexes, the growth parameters of maize increased with the increasing water salt concentrations…” was replaced by “…indexes, which increased with the increasing water salt concentrations…” in line 315.

Line 320. Change to "was 5 g L-1".

(26) The unsuitable expression “…when the salinity of irrigation water arrived 5 g·L-1, …” was replaced by “…when the salinity of irrigation water was 5 g·L-1, …” in lines 317-318.

Line 348. There is the figure caption and the explanation of the results in the same line. It should be arranged.

(27) The format problem has been amended in line 348.

Line 350. Change "treatment" with "treatments".

(28) The unsuitable expression “…S1, S2 treatment and S4, S5 treatment …” was replaced by “…S1, S2 treatments and S4, S5 treatments …” in line 347.

Line 387. Change to "film. On one hand, ".

(29) The unsuitable expression “…the plastic film: on the one hand…” was replaced by “…the plastic film. On one hand…” in line 385.

Line 388. Change to "water but, on the other hand".

(30) The unsuitable expression “…irrigation water, on the other hand…” was replaced by “…irrigation water but, on the other hand…” in line 386.

Line 389. Change to "infiltration. Thus, ".

(31) The unsuitable expression “…irrigation water infiltration, thus, the variation…” was replaced by “…irrigation water infiltration. Thus, the variation…” in line 387.

Line 484. What is a salt suitable environment?

(32) The expression “…hence, a suitable salt environment was exactly formed…” was replaced by “…hence, a low salinity zone was exactly formed…” in line 481.

Line 485. Change to "This result was consistent".

(33) The unsuitable expression “…Which result was consistent with…” was replaced by “…This result was consistent with…” in line 482.

 

(34) The unsuitable word “treatment” was replaced by “treatments” in line 334, 336, 337, 430, 431 and 450.

(35) The citation order of all references was updated.

 

Once again, thank you very much for your review.

Best regards,

Sincerely,

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.


Round 1

Reviewer 1 Report

1) The paper does not explain if Autumn irrigation have been practiced, and what kind of water was applied; this aspect is crucial!

2) The time trend of salts concentration, namely long term effects, was not handle in this research: from year 1 to year 2 the soil salinity increased? The plots have been placed on the same site in both years? These questions were not explained either discussed. It is related with drainage conditions and with other crops cultivated on the same soil.

3) the "quadratic polynomial" model to be considered like a conclusion of the research seems a not relevant issue (lines 405-406 and repeat at 438-439); and the match is not very good (fig. 8a); and the type of model was not analysed.

Author Response

Dear Reviewer,

    Thank you for your kind suggestion about my manuscript, I have made some revisions according to your kind advises. Detailed as flowing:

 

1) The expression “a supplementary irrigation with Yellow River water (irrigation amount is 2500 m3·ha-1) was applied for soil salt leaching in November every year” was added in the Materials and Methods-2.3 Irrigation and fertilization.

2) The expression “all plotswas settled on the same site in 2016 and 2017” was added in Materials and Methods-2.2. Experimental design.

3) I have checked the model carefully, and the new cubic polynomial model was updated in Figure 8a.

4) I have revised the results and conclusions, the conclusions were seperated from the Disscussion into a section:

The irrigation quota has a cubic polynomial relationship with the concentrations of irrigation water, and the irrigation water salinity of 3 g·L-1 was proved to be the threshold value for maize growth in this paper. Moreover, the leaf area index, dry matter weight and dry coronary weight reached the maximum value as the irrigation water salt concentration reached 2 g·L-1. The relationship between maize yield and the irrigation water concentration were cubic polynomial pattern, while the IWUE decreasing linearly with salinity concentration of irrigation water increasing, and the maize yield reached the maximum as irrigation water salt salinity at 2 g·L-1, meanwhile, the IWUE for irrigation water salinity at 2 g·L-1 was only 3.81% and 4.68% lower than the IWUE for irrigation water concentration at 3 g·L-1. Additionally, with the SMP of -20 kPa, irrigation water concentrations lower than 2 g·L-1 can leach the topsoil salt significantly. With the perspective of production improvement and soil salinization prevention, saline water with salt concentration of 2 g·L-1 is recommended in the present paper.


Author Response File: Author Response.docx

Reviewer 2 Report

Dear editors,


The manuscript 518932 by Jingang Li et al. is an experimental assessment of the impact of irrigation water salinity on maize growth and yield, irrigation water use efficiency, and soil salinization. The authors found that mild levels of salinity can be tolerated by maize and can even be beneficial up to a threshold concentration, but that IWUE consistently declines with increasing irrigation water salinity. These results are promising for agricultural adaptation in water-limited areas, but the paper is primarily descriptive and offers insufficient methodological detail, discussion of the implications of results, or mechanisms that might explain results. Furthermore, the clarity and quality of the writing is unacceptable as it significantly inhibits understanding. 


Recommendation: reconsider after major revision

General comments:


Results are primarily descriptive and do not offer any implications for management or mechanistic explanations of the results. For example, while soil salinity distribution in relation to irrigation water concentration is discussed, there is not treatment of the implications these might have on crop productivity metrics or soil health.


Referenced literature is restricted to China. It would be nice to see that there is a broader geographical relevance for this information. Undoubtedly there is much salinity research in semi-arid agricultural zones around the globe that could complement your results. 


Many run-on sentences! The manuscript needs extensive revision for English grammar. I recommend sending the manuscript for professional editing by a native English speaker before resubmission, as mistakes in English grammar and style significantly impeded understanding of the majority of the document. I have indicated small corrections where possible but there were far too many for me to comment on individually. 


Specific comments:


It would be more effective to present results as an average of 2016 and 2017 years if there is no significant difference between years.


Figure and Table references in the text have all been replaced by an error message ("Error! Reference source not found..."). Please correct.


Remove bullet points between sequential unit abbreviations and include a space between numbers and first unit abbreviation


Remove space after first parenthesis in unit abbreviations found in Table headings


hectares (ha) are the standard SI area unit, please do not use hm 


There is no summary of the meteorological data collected, only stated that it was collected but not addressed after that. A line or two with summary statistics and references to historical averages would suffice.


152-154 the compounds listed are not drugs!


164-167 not clear what are the traditional practices and what has been changed in the current implementation, please reword for clarity


167 specify what is (w/w)?


172, etc., not et al


185 specify what kind of "experimental apparatus"?


180 explain how 20 kPa was obtained as the target SMP, e.g. what % saturation is this? Relating this target to PWP and field capacity for this site would be helpful


Figure 3 (149) more useful would be a diagram of your sampling scheme with depths etc. and/or treatment layout within the field


138-143 specify if this is a randomized complete block design


221 "lever of significant" should be "level of significance"


221 If multiple ANOVAS were conducted, the alpha level must be adjusted for multiple comparisons. Sidak correction is one option.


226-228 I don't understand this sentence


Table 5 (233) headings should read irrigation quota, not quote


Figure 4 y-axis label misspelled


236-239 I was given to understand that the experiment was testing salinity concentrations, not irrigation management strategies (traditional vs. mulched drip). Please clarify.


258 Table 7 title is repeated and in the wrong place


Table 6 and 7 tables do not indicate whether measurements reflect a specific growth stage. Also, I think the in the "notes" you mean to say column, not row. It does not make sense to compare across different columns.


264 - something is happening with your table and figure references in text, please correct!!


287-292 this should be in the discussion, not results


295 p-value should be given to support this claim


295-298 this procedure was not explained in the methods


Figure 5 salinity is misspelled


320 suitability, not suitable


330-336 this analysis was not explained in the methods section


Figure 8 again, the regression analyses were not explained in the methods


407-411 a regression analysis would be appropriate for these data as well, why did you only perform it for yield and IWUE?


417 I am unaware of the term "weak aquifer"

Author Response

Dear Reviewer,

    Thank you for your kind suggestion about my manuscript, I have made some revisions according to your kind advices. Detailed as flowing:

 

(1)    Another thirteen reference were added in the Reference.

(2)    Thank you for your meticulous review, I have revised the manuscript carefull, some run-on sentences were divided into several parts, a lot of problems about English gramar was revised.

(3)    Thank you for your advices, however, the independent results of 2016 and 2017 was still reserved for readers to understand the study.

(4)    All the captions about Tables and Figures were updated.

(5)    The bullet points between sequential unit abbreviations in Table 2 were deleted, and a space between numbers and first unit abbreviation was added throughout the manuscript.

(6)    The space after first parenthesis in unit abbreviations in Tables headings was deleted.

(7)    The unit “hm2” was replaced by “ha” throughout the full text and Figures.

(8)    The summary of meteorological data was added in Materials and Methods-2.4.1. Meteorological observation.

The average annual temperature was 6.94 °C and 6.89 °C in 2016 and 2017, respectively, while the average annual precipitation was 146 mm and 138 mm in 2016 and 2017, respectively. The average annual wind speed was 3.1 m·s-1 and 3.2 m·s-1 in 2016 and 2017, respectively, while the yearly maximum wind speed was 25 m·s-1 and 33 m·s-1 in 2016 and 2017, respectively.

(9)    152-154, the misrepresentation “drugs” were replaced by “compounds”.

(10) 164-167, the not clear section was divided into two parts, the first part focused on the traditional maize irrigation and fertilization, while the second part focused on the irrigation and fertilization of the experiment.

The traditional maize cultivation is generally planted by film covering, while surface flood irrigation was applied for 4 times with 6750 m3·ha-1 in total during maize growth period, additionally, a supplementary irrigation with Yellow River water (irrigation amount is 2500 m3·ha-1) was applied for soil salt leaching in November every year. Meanwhile, base fertilizers, including diammonium phosphate (DAP: 18%N, 46%P, 0%K) of 600 kg·ha-1 and potassium sulfate (including K2SO4, 45%) of 90 kg·ha-1 were uniformly applied to the field before sowing, urea (46.2%N) of 900 kg·ha-1 was given as dressing fertilization

The mulched drip irrigation water with amount of 22.5 mm was applied as soon as the value of tensiometers lower than the target SMP value of -20 kPa for all treatments. Considering the traditional fertilization schedule, diammonium phosphate at a rate of 450 kg·ha-1 and potassium sulphate at a rate of 90 kg·ha-1 were uniformly applied as base fertilization to all plots, and the dressing was supplied with urea (46.2%N) of 450 kg·ha-1 by mixing it with irrigation water at a concentration of 30% (w/w).

(11) 167, the “w/w” is an abbreviation for "by weight", it is often used in chemistry and pharmacology to describe the concentration of a substance in a mixture or solution.

(12) The abbreviation “et al.” was replaced by “etc.” throughout the manuscript.

(13) 185, the vague expression “experimental apparatus” was clarified by “particle size analyzer”.

(14) Figure 3 (149), sampling scheme and treatment layout scheme within the field were supplied in Figure 3.

(15) 138-143, “the treatments were laid out in a randomized complete block design was specified Materials and Methods-2.4.1. Experimental design.

(16) 180, a paragraph was added in the Introduction:

Extensive studies have indicated that, the measurement of SMP at a depth of 20 cm immediately under the drip emitter can be used as an indicator for crop drip irrigation scheduling [27-32]. Moreover, Kang et al. (2005) indicated that soil moisture and salinity condition can be well maintained if the SMP of mulched-drip irrigation with saline water is kept higher than 20 kPa [27], and Li et al. (2018) conducted a two-year field experiment, and suggested that, the SMP threshold higher than 30 kPa can be used to trigger maize mulched-drip irrigation with shallow saline groundwater in HID [33]. In this study, a field experiment was conducted for maize under mulched drip irrigation with different levels of irrigation water salinity, the irrigation was triggered by tensiometers that buried 20 cm underneath the dripper. The present paper will contribute to fight against the processes of land salinization and promote land restoration, and achieve the sustainable goals for development of the united nations [34].

180, a sentence was added in the Materials and Methods-2.1. Experimental site: According to the soil water retention curve, the SMP of -20 kPa at a depth of 20 cm corresponding to 85% of the Field capacity.

(17) 221, “the analysis was performed at α=0.05 lever of significance” instead of “the analysis was performed at α=0.05 lever of significant”.

(18) 226-228, the vague expression “Fresh water with an amount of 22.5 mm was applied for all experiment plots after sowing immediately to ensure uniform germination. After maize sprouting, the same amount of irrigation water (22.5 mm) was only applied when the SMP reached the target values of -20 kPa.” was replaced by “Fresh water with an amount of 22.5 mm was applied for all experiment plots after sowing immediately to ensure uniform germination. After maize sprouting, the same amount of irrigation water (22.5 mm) was only applied when the SMP reached the target values of -20 kPa.”

(19) 233, the headings of Table 5 “quote” were adjusted to “quota”.

(20) Figure 4, the misspelled y-axis label in Figure 4 was replaced by “Irrigation quota (m3·ha-1)”.

(21) 236-239, The redundant expression “The total irrigation quota was significant distinct for different irrigated water concentrations, and the maximum is 360.0mm in 2017, which indicates that mulched drip irrigation is more effective at saving water, compared to the traditional mulched ground irrigation water (averaged 675.0mm per year) in HID” Was deleted.

(22) 258, the changed format about the title of Table 7 was amended.

(23) 254-256, I have added the expresion to explain the measurements reflect the value of indexes at mature stage.

In the "notes" of Table 6 and Table 7, the misspell “row” was adjusted to ”column”.

(24) All the captions about Tables and Figures were updated.

(25) 287-288, the expression has been moved to the Discussion.

(26) The procedure in 295-298 was added into the Materials and Methods.

A simultaneous irrigation for all treatments in maize jointing stage was selected to indicate the soil salt distribution before and after irrigation.

(27) The misspelled “Slinity” in Figure 5 was amended by “Salinity”.

(28) 320, the misspelled “suitable” was replaced by “suitability”.

(29) 330-336, the analysis of soil salt was explained in Materials and Methods.

As the maize main roots of maize distributed 10-750px away from the drip tape horizontally and 0-40 cm underneath the surface, the soil salt content in the main root zone (0-40 cm soil layer in the film) and the secondary root area (40-100 cm soil layer in the film) before sowing and after harvesting was analyzed, as well as 0-40 cm and 40-100 cm soil layer outside the mulch.

(30) The expression about regression analyses were added in the Materials and Methods.

(31) The vague expression “weak aquifer” was updated by “aquitard”.


Author Response File: Author Response.docx

Reviewer 3 Report

The manuscript deals with the investigation of the response to saline water on several morphological parameters of a widely cultivated crop (maize plants) and falls within the scope of Water journal.

This paper reports the results of an experiment designed to investigate the changes occurring in maize plants under different levels of salt stress conditions by analyzing several parameters.

Although the research is interesting and this information could be useful in areas where saline and brackish waters are usually used for irrigation purposes, the manuscript has some weakness.

The main problem is that the text is not clear and extremely confusing and difficult to read, almost impossible. Authors should rewrite it in order to make it less messy and easier to read and understand.  The manuscript is not very well written, the results are only focused on growth parameters, discussion section is limited, some sentences are not supported by the data and the paper has important weakness that I detail below.

Moreover, the paper is descriptive and does not bring any new conclusions concerning saline stress and plant resistance, the interpretation of the results is superficial and not straightforward in the discussion, especially more details about statistical analysis (a better interpretation of the results according to statistical analysis) , and  a better interpretation of the results  are required.

For these reasons, mainly I recommend that the paper be rejected

Apart from the above, other specific items should be taken into consideration

  Specific amendments to correct errors of fact:

Abstract

-Summary is  more or less clear and satisfactory. It is in general sufficiently informative, but they should rewrite some sentences.  For example, They write,  line 22, “.. the irrigation water salinity of 3 g/l was the most advantageous  concentration for maize growth….”. for which growth parameters? It should be added. what “most advantageous” means?. Adjectives so general should be avoided. They have to explain in which specific parameters.

 Advantageous based on…

- Line 28, they write“.. below 3 g/l is recommended in this study”.  what level of salinity is recommended , S1, S2, S3, all of these levels?. They should specify more.

- a suitable Running Head (5-6 words) are not provided

Introduction

-The introduction provides an adequate background about the water shortage in this area and the effect of salinity on crop growth.

- line 56. “ unreasonable irrigation”. Adjectives so general should be avoided.

-line 52-58. This paragraph is too long and difficult to understand.

-line68-69. What crops are authors written about? About crops in general? This sentence is not true. There are a huge number of paper focused on other parameters.

Line 69-73. What crop are authors written about? Wheat or maize? It is not clear.

Material and methods

This section is generally rather detailed and informative, but it could be improved adding and clarifying some information.

-In general, sentences are too long and difficult to read and understand.

-The reference source of the tables and figures is missing in the text and it makes difficult the reading of the manuscript.

-line 122-123. This sentence should be in introduction section

-Adding the electric conductivity (dS m-1) of the irrigation water in the 5 treatments

-About plant growth parameters, they are measured at 7-day intervals and in table 6-7 only one measurement is shown (plant max heght, max lai,….). it should be explained in M and M section

-Line 256. Revise this sentence. (problems with the reference source)

Line 265-267. Revise this paragraph.  (problems with the reference source)

-line 268. They write “… the increasing concentrations at first and then decreased…”.  They have to explain to what specific salinity level. ¿ S2, S3?

- line 270, “ plant height.. reached the maximum value at 3.0 g/l”. According to the statistical analysis, it is not true. In table 6 and 7, plant height in S2 and S3 are not significantly different (same letter).

- line 272. Is “crown dry weight” the same as “ dry coronary weight”?.  It should be consistently named in order to avoid misunderstandings.

-Line 282,  “soil moisture increased…..” where are the data about soil moisture shown?

- line 287-292. This sentence should not be in result section. It should be in discussion section.

-Line 320-328. This paragraph is about interpretation of the results. It should be in discussion section.

- line 357. This paragraph is about interpretation of the results. It should be in discussion section.

-line 369. This paragraph is about interpretation of the results. It should be in discussion section.

-Line 401-403.  This paragraph should be in conclusion section. However, I do not agree with this sentence, as it is not supported by presented data.

Tables and Figures

-They should add standard errors in figure 6 and 7 (or letters) in order to know if treatments are significantly different

-In figure 8, bars of standard errors should be added in order to know if treatments are significantly different.  If not, it is not appropriate to write that “yield reached the maximum at 2 g/l, line 394).  Is yield in s2 higher than in S1 or in S3? You need a statistical analysis. Besides, according to fig 8a, it seems that S3 is higher than S2!! Revise. Be careful.

 

References

-references are updated, but almost 50% of the references are in Chinese (too many, in my opinion)

Author Response

Dear Reviewer,

    Thank you for your kind suggestion about my manuscript, I have made some revisions according to your kind advises. Detailed as flowing:

 

Abstract

(1)    Thank you for your kind suggestions, I have checked the manuscript carefully, many long sentences were divided into several parts, a lot of problems about English gramar were revised.

(2)    The conclusions were seperated from the Disscussion into a independent section.

(3)    Line 22, “…the irrigation water salinity of 3 g/l was the most advantageous concentration for maize growth….” was updated by “the irrigation water salinity of 3 g·L-1 was proved to be the threshold value for maize growth”.

(4)    Line 28, the expression “water salinity of maize mulched drip irrigation at 2 g·L-1 is recommended in this study” was specified in the Abstract.

(5)    Thank you for your advice about the Running Head, however, the format was specified by the Journal Office.

 

Introduction

(1)   Line 56, “unreasonable irrigation” was reolaced by “improper irrigation”.

(2)   Line 52-58, the long paragraph was divided into short sentences:“saline water irrigation not only increase soil moisture in crop root zone, but also provide trace elements for crops, meanwhile, improper irrigation increase salt content in the root zone and decrease the SMP (Soil Matric Potential), which inhibits the water absorption of the crop and lead to soil salinization in the cultivated layer, which is unfavorable to the sustainable cultivation of farmland [5-9]”.

(3)   Line68-69, the improper expression “The effects of saline water irrigation on crop growth mainly focus on plant height, stem diameter, leaf area and dry matter weight” was replaced by “The effects of saline water irrigation on crop growth mainly focus on various plant parameters”.

(4)   Line 69-73, the wrong sentence “the results indicated that irrigation with saline water at concentrations below 3 g·L-1 will reduce the maize yield by no more than 10% compared with fresh water irrigation” was replaced by “the results indicated that irrigation with saline water at concentrations below 3 g·L-1 will reduce the winter wheat yield by no more than 10% compared with fresh water irrigation”.

 

Materials and methods

(1)    Some long sentences were divided into several parts for easier reading.

(2)    All the captions about Tables and Figures were updated.

(3)    Line 122-123, the sentence “the traditional surface irrigation water in HID is mainly drawing from the Yellow River by channels, which has the annual average salinity of 0.505 g·L-1” was added in the introduction.

(4)    To unify the unit, all unit of electric conductivity were replaced by “g·L-1”.

(5)    The sentence “As maize growth indexes reached the maximum value at mature stage, thus the growth indexes at mature stage was analysised” was added in the Materials and methods section.

(6)    Line 256 and Line 265-267, the captions about Tables and Figures were updated.

(7)    Line 268, the sentence “…and reached the maximum at 2 g·L-1 and 3 g·L-1” was added in line 268.

(8)    Line 270, the “plant height” was deleted in line 270.

(9)    Line 272, the mispilled “crown dry weight” was replaced by “dry coronary weight”.

(10) Line 282, the sentence “soil moisture increased with the increase of irrigation quota” was deleted.

(11) Line 287-292, the sentence in line 287-292 has been moved into the Discussion.

(12) Line 320-328, the sentence in line 320-328 has been moved into the Discussion.

(13) Line 357, the sentence in line 357 has been moved into the Discussion.

(14) Line 369, the sentence in line 369 has been moved into the Discussion.

(15) Line 401-403, the sentence in line 401-403 has been moved into the Discussion.

 

Tables and Figures

(1)    All Figures were updated with color.

(2)    Figure 8a, the yields for S2 treatment and S3 treatment were updated, and the yield for S2 treatment was higher than that for S3 treatment.

 

References

Another thirteen references were supplemented into the Reference.

Author Response File: Author Response.docx

Round 2

Reviewer 1 Report

This new version did not improve the main weak points of the manuscript:

1) The paper does not explain if Autumn irrigation have been practiced, and what kind of water was applied; this aspect is crucial! Lines 195-201 not refer Autumn irrigation; it only is refered for traditional maize irrigation, line 187.

2) The time trend of salts concentration, namely long term effects, was not handle in this research: from year 1 to year 2 the soil salinity increased? The plots have been placed on the same site in both years? These questions were not explained either discussed. It is related with drainage conditions and with other crops cultivated on the same soil. The considerations relative to the salinity on paragraph lines 497-522, is contradictory and non-coherent: if salts accumulates on soil surface, how to conclude the long term sustainablity of drip irrigation?


Whne is afirmed "With the perspective of production improvement and soil salinization prevention, saline water with salt concentration of 2 g·L-1 is recommended in the present paper." The study did not prove the critical point of "soil salinization prevention".


3) The sentence (lines 543-544) "The irrigation quota has a cubic polynomial relationship with the concentrations of irrigation water..." is not correct: just, this model was adopted! In my opinion the "quadratic polynomial" model is not a conclusion of the research!


Reviewer 3 Report

I reviewed the first version of this manuscript and I recommended that the paper

be rejected . Now, I continue with my previous recommendation  and my current overall recommendation is :Reject

The manuscript has the same serious flaws: The manuscript is not very well written, the results are only focused on growth parameters, discussion section is limited, some sentences are not supported by the data. Moreover, the paper is descriptive and does not bring any new conclusions concerning saline stress and plant resistance, the interpretation of the results is superficial and not straightforward in the discussion.

 It should not  be published.

Back to TopTop