Effect of Maize (Zea mays) and Soybean (Glycine max) Cropping Systems on Weed Infestation and Resource Use Efficiency

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

Dear Authors,

The manuscript presented to me for evaluation addresses an important topic for agriculture which is the intercropping of legumes and cereals. This cultivation brings many benefits to agriculture as mentioned by the authors. The field research is not innovative and confirms the findings of other field research. Nevertheless, in my opinion the manuscript is interesting. With regard to the content of the manuscript, I have the following suggestions:

Introduction

The introduction section is well written. The authors adequately introduce the reader to the research topic and the reasons why it is important to conduct this type of research. I suggest a minor addition: maize and soybean have different mineral fertilisation requirements especially N. Maize has a very high N requirement, with a much lower one for soya. In order not to reduce yields, high N rates are usually applied, which can have a negative effect on soybean nodulation. However, most often a high N uptake by maize reduces the occurrence of this phenomenon by having the opposite effect, i.e. forcing soybean to have a higher BNF. This generally leads to a higher NUE and is therefore good for the environment. The situation is similar with P and K. I suggest writing this down in the introduction as a better demonstration of the benefits of legume-cereal intercropping with appropriate references.

Materials and methods

In my opinion, the section describes quite well the methodology of the research carried out. I suggest minor additions:

L128 Was soybean seed inoculation used?

L138 Information on mineral fertilisation of the crop is missing. Was fertilisation with N, P, K applied?

L155 Was weed DM also analysed? The fresh weight can largely depend on the time of day or conditions at the time of harvest (mainly due to water uptake). Therefore, the DM of weeds and their number is more illustrative.

L172 Was the moisture content of the seed at the time of determining the yield (after drying) determined

Results

The Results section is adequately recorded. I would suggest supplementing with the correlation between the results obtained. This will allow an assessment of the correlations between the results obtained.

Discussion

In my opinion, the section is adequately written. The authors briefly present the most important variability in the results, relate them to the research of other Researchers and try to explain the mechanisms determining the variability.

The conclusion section adequately summarises the results obtained. I have no comments.

On technical issues of the manuscript: the first two references to references are done in the manner typical of an MDPI publication but the subsequent ones are not. I suggest standardising the references along the lines of L38. Thus, the entire References section should be improved. The References section also needs to be standardised. The names of the publications are sometimes written consecutively in lower case, e.g: European journal of agronomy should be European Journal of Agronomy. There are also inconsistent notations of Authors of manuscripts. Names should also be e.g.: Vigna unguiculata should be written in italics

Author Response

Dear Authors,

The manuscript presented to me for evaluation addresses an important topic for agriculture which is the intercropping of legumes and cereals. This cultivation brings many benefits to agriculture as mentioned by the authors. The field research is not innovative and confirms the findings of another field research. Nevertheless, in my opinion the manuscript is interesting. With regard to the content of the manuscript, I have the following suggestions:

Response: Dear Reviewer thank you very much for supporting comments to our manuscript in all areas and taking the time to review this manuscript, and pointing out and highlighting the mistyping errors and some unclear sentences, we have endeavoured to improve the text, mistyping errors, arranged some unclear sentences and all detailed highlighted comments in blue colour directly in the text. Please find the detailed responses below and the corresponding revisions/corrections highlighted/in track changes in the re-submitted files.

Introduction

The introduction section is well written. The authors adequately introduce the reader to the research topic and the reasons why it is important to conduct this type of research. I suggest a minor addition: maize and soybean have different mineral fertilisation requirements especially N. Maize has a very high N requirement, with a much lower one for soya. In order not to reduce yields, high N rates are usually applied, which can have a negative effect on soybean nodulation. However, most often a high N uptake by maize reduces the occurrence of this phenomenon by having the opposite effect, i.e. forcing soybean to have a higher BNF. This generally leads to a higher NUE and is therefore good for the environment. The situation is similar with P and K. I suggest writing this down in the introduction as a better demonstration of the benefits of legume-cereal intercropping with appropriate references.

Materials and methods

In my opinion, the section describes quite well the methodology of the research carried out. I suggest minor additions:

Response: Thank you, Sir, for pointing this out. We agree with this comment. Therefore, we have revised as per suggestions.

L128 Was soybean seed inoculation used?

Response: Thank you, Sir, for pointing this out, we did not used any inoculation, however we had treated the seeds with a fungicide.

L138 Information on mineral fertilisation of the crop is missing. Was fertilisation with N, P, K applied?

Response: Thank you, Sir, for pointing this out, we have added the information on fertilization in revised versions.

L155 Was weed DM also analysed? The fresh weight can largely depend on the time of day or conditions at the time of harvest (mainly due to water uptake). Therefore, the DM of weeds and their number is more illustrative.

L172 Was the moisture content of the seed at the time of determining the yield (after drying) determined

Response: Thank you, Sir, for pointing this out, we could not determine the moisture, however it was made sure the seeds dried at constant weight by observing.

Results

The Results section is adequately recorded. I would suggest supplementing with the correlation between the results obtained. This will allow an assessment of the correlations between the results obtained.

Response: Thank you, Sir, for pointing this out, Dear Sir, however, we have not added the correlation because we have not tested different genotypes or verities. Moreover, we have the ANOVA has justified the results.

Discussion

In my opinion, the section is adequately written. The authors briefly present the most important variability in the results, relate them to the research of other Researchers and try to explain the mechanisms determining the variability.

Response: Thank you, Sir, for pointing this out.

The conclusion section adequately summarises the results obtained. I have no comments.

Response: Thank you, Sir, for kind support.

On technical issues of the manuscript: the first two references to references are done in the manner typical of an MDPI publication but the subsequent ones are not. I suggest standardising the references along the lines of L38. Thus, the entire References section should be improved. The References section also needs to be standardised. The names of the publications are sometimes written consecutively in lower case, e.g.: European journal of agronomy should be European Journal of Agronomy. There are also inconsistent notations of Authors of manuscripts. Names should also be e.g.: Vigna unguiculata should be written in italics.

Reviewer 2 Report

Comments and Suggestions for Authors

Please have a look to attached manuscript.

Comments for author File: Comments.pdf

Comments on the Quality of English Language

Minor edition is needed.

Author Response

Reviewer 2.

Response: Dear Reviewer thank you very much for supporting comments to our manuscript in all areas and taking the time to review this manuscript, and pointing out and highlighting the mistyping errors and some unclear sentences in peer-review PDF file, we have endeavoured to improve the text, suggested minor edition and mistyping errors, and all detailed highlighted comments in orange colour directly in the text. Please find the detailed responses below and the corresponding revisions/corrections highlighted/in track changes in the re-submitted files.

Reviewer 3 Report

Comments and Suggestions for Authors

Unfortunately, the design of this research appears to be seriously flawed although the lack of clarity in the M&M makes this a bit unclear. The experiment appears to compare soybeans at 100,000/ha or maize at 60,000/ha with an intercropped treatment of maize at 60,000/ha plus soybean at 100,000/ha - giving a total of 160,0000 sown plants/ha. The paper then concludes that differences between the treatments are due to the use of intercropping, ignoring what is effectively a doubling in the sown plant population. This increase in planting density has been shown in other papers to achieve the same outcomes as the ones reported here, thus making it impossible to determine whether the results reported in this paper are due to intercropping, to the change in plant density, or as is more likely, due to the combination.

The authors need to rewrite this paper, acknowledging this flaw in their design, and discussing their valuable results without stating that the differences are due to intercropping while ignoring the differing plant densities of the treatments, or repeat the experiment maintaining plant density across treatments. 

Beyond this, there are many things the authors could improve in this paper. The Literature review is good, but the authors need to concentrate on the more relevant references and discard many of the less important references used throughout. The total of 70 references for this paper is excessive and not required with such straightforward research.

The authors need to establish their terminology and stick with it. For example, the intercropping system is variously referred to as the MSI system and the intercropping system. Choose a descriptor and stick with it!

The Materials and Methods is detailed but fails to clearly define the experimental procedures. For example, nowhere could I find it stated that the treatments were regularly irrigated via furrow irrigation (I assume) or when this irrigation occurred - this information needs to be included. Similarly, it is unclear as to whether the plots were fertilized.

Statements such as "the total bandwidth was 200 cm" (line 128-129) make no sense to the reader in the context of 6 m by 6 m plots, with maize rows 70 cm apart and soybean rows 50 cm apart, and 12 rows of crop in the intercrop treatment. Was that 8 rows of maize in the maize plots, 11 rows of soybean in the soybean plots, and 12 rows in the intercrop? Beyond this, Figure 2 shows that not only did the row spacings differ between treatments, the spacing between plants within a row also differed. To further confuse this, Figure 8 appears to show that the intercropping plots were twice the size of the other plots. This is all confusing and needs to be clarified.

For the observations and measurements, the authors need to be clearer in what they did, showing the equations they used to determine their results  and not just keep referring to others. State clearly what you did! Don't make the reader have to find and interpret multiple papers to try to guess at what you may have done.

For weed density, provide some information about the weeds. Was it primarily a single species? How uniform were the infestations?

The reader is given no useful information on how radiation and water use were determined. Was this done using equations based on equations, or where there some actual measurements taken? Was radiation use efficiency for example, based on equations calculated from the LAI which was calculated from equations using leaf length? Make the methods clear to the reader.

Results.

Only present significant results. Figure 5B, for example, presents the results from the 2 seasons, yet it states that these were not significantly different, so these results should be presented averaged over seasons. Likewise for Figure 6.

The authors need to check the 85% yield increase stated in line 222 - this appears to be incorrect.

Discussion.

This section needs to be totally rewritten, taking into account the confusion in the results from having the treatments at differing row spacings and differing intra-row spacings.

Much of the confusion in the discussion appears to relate to the confusion of the intercrop system and may be addressed when the rest of the paper is clarified. For example, the authors provide results for the intercrop system in Figures 4 and 5 but Figure 3 presents data for each of the species. Consequently, the results show the LAI for each species is lower in the intercrop system, whereas in fact the total leaf area per m^2 (LAI) on this system (of the combined species) is presumably higher than on then monocrops. This confusion of presenting results per species in some places and per system in other places leads to odd and contradictory statements in the discussion such as "Sole cropping of maize and soybean generally had higher LAI, than MSI" (Lines 249-250), whereas in fact the LAI of the sole crops was almost certainly lower than that of the intercrop system. The authors go on for many lines to try to explain why the LAI was lower in the intercrop, when in fact the LAI was higher on the intercrop, as is expected. Line 274 states "increased canopy cover (LAI) in MSI" contradicting their earlier statement that the LAI was lower!

Beyond these confusions, the results of this paper are valuable, but do not support many of the claims made in the discussion.  For example, the 2nd last sentence of the discussion states "Results of this study suggested that that maize-soybean strip intercropping is sustainable cropping system that can not only increased the land productivity, but also can decrease the input use efficiency and supressing the weed density in a sustainable manner." In fact, nowhere in their paper do the authors present results that show the intercropping system is sustainable, although it appears to be an improvement on the lower densities of the monocrops. The improved weed suppression in the intercrop system is very little better than either of the monocrops and in no way suggests a sustainable weed management system. Yes, it is a statistical improvement, but high populations of weed occurred on all treatments and the paper in no way establishes that the intercrop system is sustainable in terms of weed management. There same differences may have been achieved by simply increasing cropping density, as has been shown elsewhere. The statement that intercropping "also can decrease the input use efficiency" appears to be at odds with the rest of the paper and must be assumed to be one of many errors in the discussion.

Further, an earlier statement (lines 289-290) "the different cropping patterns, .... effectively outcompeted the weed competition" again contradicts the statement discussed above which states that the intercropping system was superior for weed control. In fact, there is very little difference in the weed biomass on the various treatments and all systems effectively out competed the crops?

These are but a few of the many issues that need to be addressed by the authors before this paper is suitable for publication.

Comments on the Quality of English Language

The authors have clearly put a lot of effort into this paper, and the paper generally reads well, although the quality of the English is inadequate in many instances. There are grammatical errors in most lines throughout the manuscript, although these are generally minor and could be easily corrected.

The paper falls down in the discussion section where there appear to be contradictory, incomplete and inaccurate sentences that will be more difficult to correct. 

Author Response

Reviewer 3.

Dear Reviewer thank you very much for supporting comments to our manuscript in all areas and taking the time to review this manuscript, and pointing out and highlighting the mistyping errors and some unclear sentences, we have endeavoured to improve the text, mistyping errors, arranged some unclear sentences and all detailed highlighted comments in red colour directly in the text. Please find the detailed responses below and the corresponding revisions/corrections highlighted/in track changes in the re-submitted files.

Comments and Suggestions for Authors

Unfortunately, the design of this research appears to be seriously flawed although the lack of clarity in the M&M makes this a bit unclear. The experiment appears to compare soybeans at 100,000/ha or maize at 60,000/ha with an intercropped treatment of maize at 60,000/ha plus soybean at 100,000/ha - giving a total of 160,0000 sown plants/ha. The paper then concludes that differences between the treatments are due to the use of intercropping, ignoring what is effectively a doubling in the sown plant population. This increase in planting density has been shown in other papers to achieve the same outcomes as the ones reported here, thus making it impossible to determine whether the results reported in this paper are due to intercropping, to the change in plant density, or as is more likely, due to the combination.

Response: Thank you for pointing this out. Actually, in this system we have sown same planting densities as it would be in sole crops, on same piece of land. Therefore, it has better land use/cropping intensity. Furthermore, this not only increased crop intensity, but it also benefiting by various means. Those are reported in several studies. Additionally, it was reported that intercropping, especially maize-soybean intercropping system has facilitative advantages. However, it was not observed as in this study that with increase soil cover, this system also suppressed the weed infestation. Thus, study has further highlighted/added information on the advantageous of this sustainable cropping system.  More specifically, weeds management/supressing without using chemicals or intercultural practices.

The authors need to rewrite this paper, acknowledging this flaw in their design, and discussing their valuable results without stating that the differences are due to intercropping while ignoring the differing plant densities of the treatments, or repeat the experiment maintaining plant density across treatments. 

Beyond this, there are many things the authors could improve in this paper. The Literature review is good, but the authors need to concentrate on the more relevant references and discard many of the less important references used throughout. The total of 70 references for this paper is excessive and not required with such straightforward research.

Response: Thank you for pointing this out, we have incorporated changes in this revised version.

The authors need to establish their terminology and stick with it. For example, the intercropping system is variously referred to as the MSI system and the intercropping system. Choose a descriptor and stick with it!

Response: Thank you for pointing this out, we have incorporated the suggestion.

The Materials and Methods is detailed but fails to clearly define the experimental procedures. For example, nowhere could I find it stated that the treatments were regularly irrigated via furrow irrigation (I assume) or when this irrigation occurred - this information needs to be included. Similarly, it is unclear as to whether the plots were fertilized.

Statements such as "the total bandwidth was 200 cm" (line 128-129) make no sense to the reader in the context of 6 m by 6 m plots, with maize rows 70 cm apart and soybean rows 50 cm apart, and 12 rows of crop in the intercrop treatment. Were those 8 rows of maize in the maize plots, 11 rows of soybean in the soybean plots, and 12 rows in the intercrop? Beyond this, Figure 2 shows that not only did the row spacings differ between treatments, the spacing between plants within a row also differed. To further confuse this, Figure 8 appears to show that the intercropping plots were twice the size of the other plots. This is all confusing and needs to be clarified.

For the observations and measurements, the authors need to be clearer in what they did, showing the equations, they used to determine their results and not just keep referring to others. State clearly what you did! Don't make the reader have to find and interpret multiple papers to try to guess at what you may have done.

For weed density, provide some information about the weeds. Was it primarily a single species? How uniform were the infestations?

Response: Thank you for pointing this out, there was not the exact uniformity, but mostly it has similar kind of weeds in all the cropping systems. That might be due to the similar soil conditions, and management of lands for previous crops, and infested again.

The reader is given no useful information on how radiation and water use were determined. Was this done using equations based on equations, or where there some actual measurements taken? Was radiation use efficiency for example, based on equations calculated from the LAI which was calculated from equations using leaf length? Make the methods clear to the reader.

Response: Thank you for pointing this out, we have modified in this revision.

Results.

Only present significant results. Figure 5B, for example, presents the results from the 2 seasons, yet it states that these were not significantly different, so these results should be presented averaged over seasons. Likewise for Figure 6.

Response: Thank you for pointing this out, we have stated that there was significant interaction between treatments, but not significant interaction between growing season for same treatment. However, we have modified in revised version.

The authors need to check the 85% yield increase stated in line 222 - this appears to be incorrect.

Discussion.

This section needs to be totally rewritten, taking into account the confusion in the results from having the treatments at differing row spacings and differing intra-row spacings.

Much of the confusion in the discussion appears to relate to the confusion of the intercrop system and may be addressed when the rest of the paper is clarified. For example, the authors provide results for the intercrop system in Figures 4 and 5 but Figure 3 presents data for each of the species. Consequently, the results show the LAI for each species is lower in the intercrop system, whereas in fact the total leaf area per m^-2 (LAI) on this system (of the combined species) is presumably higher than on then monocrops. This confusion of presenting results per species in some places and per system in other places leads to odd and contradictory statements in the discussion such as "Sole cropping of maize and soybean generally had higher LAI, than MSI" (Lines 249-250), whereas in fact the LAI of the sole crops was almost certainly lower than that of the intercrop system. The authors go on for many lines to try to explain why the LAI was lower in the intercrop, when in fact the LAI was higher on the intercrop, as is expected. Line 274 states "increased canopy cover (LAI) in MSI" contradicting their earlier statement that the LAI was lower!

Beyond these confusions, the results of this paper are valuable, but do not support many of the claims made in the discussion.  For example, the 2nd last sentence of the discussion states "Results of this study suggested that that maize-soybean strip intercropping is sustainable cropping system that can not only increased the land productivity, but also can decrease the input use efficiency and supressing the weed density in a sustainable manner." In fact, nowhere in their paper do the authors present results that show the intercropping system is sustainable, although it appears to be an improvement on the lower densities of the monocrops. The improved weed suppression in the intercrop system is very little better than either of the monocrops and in no way suggests a sustainable weed management system. Yes, it is a statistical improvement, but high populations of weed occurred on all treatments and the paper in no way establishes that the intercrop system is sustainable in terms of weed management. There same differences may have been achieved by simply increasing cropping density, as has been shown elsewhere. The statement that intercropping "also can decrease the input use efficiency" appears to be at odds with the rest of the paper and must be assumed to be one of many errors in the discussion.

Further, an earlier statement (lines 289-290) "the different cropping patterns, .... effectively outcompeted the weed competition" again contradicts the statement discussed above which states that the intercropping system was superior for weed control. In fact, there is very little difference in the weed biomass on the various treatments and all systems effectively out competed the crops?

These are but a few of the many issues that need to be addressed by the authors before this paper is suitable for publication.

Comments on the Quality of English Language

The authors have clearly put a lot of effort into this paper, and the paper generally reads well, although the quality of the English is inadequate in many instances. There are grammatical errors in most lines throughout the manuscript, although these are generally minor and could be easily corrected.

The paper falls down in the discussion section where there appear to be contradictory, incomplete and inaccurate sentences that will be more difficult to correct.

Reviewer 4 Report

Comments and Suggestions for Authors

Specific comments

As a researcher in the field of agriculture, I am very interested in your work. I have read your article carefully and I see that you have done a lot of work on it.There are two main problems with this article, the first being the lack of logical language and the second being too much over-reasoning. Line 1, The text only expresses the effect of intercropping on weeds and resource use, and does not examine the relationship between weeds and resource use, so the title needs to be revised.

However, if I understand your description correctly, this paper needs a major overhaul in terms of content and formatting, and the changes are as follows.

Abstract

1. The results in the abstract of this paper only involve the two indexes of RUE and LAI, and the results also involve the index of WUE, and the determination method of WUE is not written in the materials and methods. The indexes in this paper should be consistent, and it is suggested to modify.

2. Line13, “faces” should read “facing”.

3. Line 19, ‘design’ should be changed to ‘designed’.

4. Line 22, delete ‘as’ in this line.

5. Line 23, The RUE of weeds was not measured.

6. Line 28, “a” should add before “sustainable”.

7. Line 28, The LER values are too large to be reasonable.

8. There are too much abbreviation.

9. Line 29, ‘suppress’ should be changed to ‘suppresses’.

10. It is necessary to emphasize the importance of banding in one sentence.

11. Specific research contents and methods should be added to the research objectives.

12. Some important quantitative results should be added to the research results.

13. The focus of the full text is the density of weeds, but only one indicator can determine this conclusion. Is it too arbitrary?

14. Lines 30-32, The last sentence should be an overall conclusion and should not be irrelevant to the findings.

Introduction

15. Please be consistent with the date format of the full text, it is recommended to modify.

16. Line 38, The format of the literature citation is inconsistent with the follow-up.

17. It should add “but” before “pose” to describe turning point in line 45.

18. Line 50, “is” should read “was”.

19. Line 50, ‘level’ should be changed to ‘levels’.

20. Line 50, add ‘a’ before ‘high’.

21. Line 64, “have” should read “had”.

22. Line 64, ‘responses’ should be changed to ‘response’.

23. Line 67, ‘practices’ should be changed to ‘practice’.

24. Line 68-69,the presentation of the document should be the same as elsewhere in the article,please revise it.

25. Line 75, “it” should delete.

26. Why do we talk about allelopathy in lines 75-76?

27. Line 80, “weeds infestation” should read “weed infestation”.

28. Line 80, ‘have’ should be changed to ‘has’.

29. Line 85, ‘area’ should be changed to ‘areas’.

30. Line 87-89, you should use proper tense.

31. Line 90, references should be cited in a uniform format.

32. Line 94, ‘enhance’ should be changed to ‘enhanced’.

33. Line 98, “was” should read “were”.

34. It is suggested that the literature related to herbicides in the first and second paragraphs should be put together without the need to describe them separately.

35. It is suggested to add why to study corn and soybean?

36. What is the need for this research? What are the potential research gaps? Please mention it clearly in the introduction.

37. The purpose of the study is not clear,please list,such as the effect of single cropping and intercropping on weed control.

38. Although you have summarized the benefits of intercropping on weed suppression, the supplementary literature describes the inhibition mechanism.

39. According to the purpose of this study, reasonable assumptions are made on the research.

40. The preface introduces the research objectives, please add.

41. The introductory section lacks logic and most of the content is on weeds and pesticides, however the effects of weeds on crop growth and nutrient uptake are not described.

42. The key questions and assumptions are not presented in the introduction.

Materials and Methods

43. Please move Lines 116-118 before Line 105.

44. In lines 106, 107, there is no space between °C and the number.

45. Line 106, ‘summers’ should be changed to ‘summer’.

46. Line 108,The content of the experiment is the data of 21 years and 22 years, but here it appears in 2023. Check the content.

47. Line 110, ‘includes’ should be changed to ‘including’.

48. Line 110, “includes” should read “included”.

49. Figure 2, Why are the distances between single and intercrops different?

50. Please check 2021-22 that this format is accurate.

51. The unit for weeds, “g m²”, is incorrect.

52. Line 114-115,“Monthly minimum (min), maximum (max), average (Avg.) temperature (℃), precipitation (mm) and relative humidity (%) at Tandojam during 2021 (A) and 2022 (B).”should be changed “Monthly minimum (Min), maximum (Max), average (Avg.) temperature (Tem,℃), precipitation (Pre,mm) and relative humidity (RH,%) at Tandojam during 2021 (A) and 2022 (B).”

53. Line 118, “season” should read “seasons”.

54. Line 120, “is” should read “was”.

55. In line 121, the unit of available phosphorus is incorrect.

56. Please check if the unit “plants ha-1” is incorrect.

57. 3.The 116th line should be merged with the 105th line and placed in front of the 105th line. It is recommended to modify.

58. 4.Line 131, ‘were’ should be changed to ‘was’.

59. The unit of 'weed fresh weight ( g m2 ) ' in line 154 was wrong, and it was suggested to modify it.

60. Line 135. Please complete the year, 2021-2022.

61. Line 137-138,the weed measures of this are not clear enough,please add.

62. Line 140,“(SSIWM)”should be deleted.

63. Line 140,The row spacing of monoculture and intercropping are different, so can the follow-up results be comparable?

64. Line 149-150,The cited references are not uniform.

65. Line 149,“(Gao et al., 2010)”,the font size of the document in the article is different from the others,please modify it.

66. In MSI, 40cm between two lines maize isn’t very suitable.

67. It misses some important data, such as height and root density.

68. Line 154. kitchen scale?  Shouldn’t 't it be a test scale?

69. Line 157, ‘uses’ should be changed to ‘use’.

70. Line 159,“(Tsubo & Walker, 2002).”,the font size of the document in the article is different from the others,please modify it.

71. Line 159,The cited references are not uniform.

72. Line 165, “was” should read “were”.

73. Line 165, ‘was’ should be changed to ‘were’.

74. Line 167, ‘combine’ should be changed to ‘combined’.

75. It is recommended to first describe the location of the test site and the basic physical and chemical properties of the soil, and then describe the weather conditions.

76. Some units of data in the basic physical and chemical properties of soil are wrong.

77. There is no specific content related to fertilization and irrigation. How to calculate the water utilization rate? And how is the radiation utilization efficiency calculated?

78. The content of measurement related indicators is few, and the measurement method suggests adding relevant calculation formulas. Some indicators do not indicate the number of repetitions.

79. Why consider LER? Why not use other competitive features.

80. In figure 2,“A. MSI”should be changed “A. Maize-Soybean strip intercropping”.

81. It is suggested that the language should be more professional.

82. Since the water use efficiency is measured, the local irrigation level should be supplemented.

83. Micro-fertilizers involved in the discussion have certain control over weed control, so fertilization methods and amounts should be added to materials and methods.

84. The English abbreviations of the legends in figure 2 do not have full spelling remarks.

Results

85. Should the unit for “Water use efficiency (g m²)” in figure 5 be %?

86. Please standardize the writing of the year throughout the text.

87. Line 182, “is” should read “was”.

88. Both Figure 4 and Figure 1 have two years of data, but Figure 4 and Figure 5 have two annotations and Figure 1 has only one annotation, which is recommended to be modified to be consistent.

89. The unit of 3.3 water use efficiency in the results is g m2, is there a mistake ? Suggested modification.

90. The results are largely used in the histogram, it is recommended to modify.

91. Line 189, “season” should read “seasons”.

92. Line 192,The measurement times are only three times, and the graph is not very beautiful, and the vertical coordinates of the four graphs are bold, some are not bold, and the format is not uniform.

93. In line 199 of ' The lowest weed density ', the unit g m2 used in weed density was wrong, and it was suggested to modify it.

94. You can make some differences in figure 4, 5, 6 and 7, it’s all bar charts.

95. Line 203,“and 16.9”should be changed “and 16.9%”.

96. Line 212, ‘uses’ should be changed to ‘use’.

97. Line 213-215, Please focus on the content of the analysis.

98. Line 221,the unit of water use efficiency needs to be improved.It is suggested to add relevant formulas to the method.

99. Line 223, 243, Means are averaged over three replicates

100. Line 227, “was” should read “were”.

101. Line 233, ‘that’ should be changed to ‘which’.

102. It is recommended to unify the color and format of the chart inside, which is not very beautiful.

103. Is the unit of water utilization correct? It is recommended that the whole article be carefully revised, and some data units are incorrect.

104. The color matching of the picture in this paper is a little confused,it is suggested to modify.

105. Figure 3. It is recommended to modify the picture to better distinguish between soybeans and corn.

106. Figure 4. It is recommended to improve the clarity of the picture.

107. Figure 5. The differences between treatments were compared, and it was suggested to increase the inter-annual comparison.

108. All graphs do very poor.

109. Figure 7, The calculations are wrong.

Discussion

110. The sun picture in Fig.8 is too exaggerated, and it is recommended to modify it.

111. In discussions, you should connect your results and get a conclusion.

112. Line 250. What is the relationship between LAI and resource competition?

113. Lines 254-256, This result should be obtained by analysing the data.

114. Lines 256-258，Please do not over-reason.

115. Line 266, ‘compare’ should be changed to ‘compared’.

116. Line 269,When the sun shines obliquely on crops, it can highlight the difference between intercropping.

117. Line 271-273,“The differences observed between growing seasons might be attributed to variation in soil fertility and environmental conditions, that could have exerted an effect on LAI and the development of the crops”That sentence should be amended.

118. Lines 273-275，Please do not over-reason.

119. Line 276, “relies” should read ‘relied”.

120. Line 280, “implies” should read “implied”.

121. Lines 283, Please do not over-reason.

122. If you want to connect light quality, you should add SPAD data.

123. Line 289, “,” should add after “study”.

124. Lines 290, Is there any weed competition involved in this study, please do not over-reason.

125. Lines 296-298, The results in the paper only show that intercropping reduces weeds and increases water and radiation use The relationship between the reduction of weeds and the increase in efficiency is not analysed in the paper. Please do not over-reason.

126. Line 302,“is” should read “was”.

127. Line 302, ‘is’ should be changed to ‘has been’.

128. Line 308, “have” should read “had”.

129. Line 314, delete ‘the’.

130. Line 347, ‘improve’ should be changed to ‘improved’.

131. Line 352, delete a ‘that’.

132. The measurements of the study are not sufficient for discussion. It is suggested to modify the experimental scheme. And the content of the discussion is too confusing, it is suggested that the discussion be divided.

133. This part of the proposal points are discussed.

134. The limitations of the study were not explicitly mentioned.

135. The conclusion that the discussion involves too many sets and the results are not in control is inconsistent.

136. The entire discussion is illogical, please ask the authors to rewrite the discussion section and discuss each research element separately for each study, please do not over reason.

Conclusions

137. Line 362, add ‘to’ after ‘led’.

138. Please write conclusions based on your research and do not over-reason.

139. Compared with other studies, it is suggested to add some advantages and disadvantages as well as some prospects for future studies.

References

140. There are many names in the references that are problematic, so please check them carefully. For example, 3- 5, 13, etc.

141. The third reference lacks page numbers.

142. References in the 489th line shows http, format and other literature format is not consistent, it is recommended to modify

143. There are redundant dots in the third,fourth,and fifth references,please revise them.

144. Periodical format and periodical format are not unified.

145. The literature is incorrectly arranged.

146. The overall format of the references is incorrect, so it is recommended to revise them carefully.

 

 

Author Response

Reviewer 4.

Response: Dear Reviewer thank you very much for supporting comments to our manuscript in all areas and taking the time to review this manuscript, and pointing out and highlighting the mistyping errors and some unclear sentences, we have endeavoured to improve the text, mistyping errors, arranged some unclear sentences and all detailed highlighted comments in green colour directly in the text. Please find the detailed responses below and the corresponding revisions/corrections highlighted/in track changes in the re-submitted files.

Comments and Suggestions for Authors

Specific comments

As a researcher in the field of agriculture, I am very interested in your work. I have read your article carefully and I see that you have done a lot of work on it. There are two main problems with this article, the first being the lack of logical language and the second being too much over-reasoning. Line 1, The text only expresses the effect of intercropping on weeds and resource use, and does not examine the relationship between weeds and resource use, so the title needs to be revised.

However, if I understand your description correctly, this paper needs a major overhaul in terms of content and formatting, and the changes are as follows.

Abstract

1. The results in the abstract of this paper only involve the two indexes of RUE and LAI, and the results also involve the index of WUE, and the determination method of WUE is not written in the materials and methods. The indexes in this paper should be consistent, and it is suggested to modify.

Response: Thank you, Sir, for pointing this out, and suggestions, we have modified the abstract.

2. Line13, “faces” should read “facing”.

Response: Thank you, Sir, for pointing this out, and suggestions, we have modified it.

3. Line 19, ‘design’ should be changed to ‘designed’.

Response: Thank you, Sir, for pointing this out, and suggestions, we have modified it.

4. Line 22, delete ‘as’ in this line.
5. Line 23, The RUE of weeds was not measured.

Response: Thank you, Sir, for pointing this out, and suggestions, we have modified it.

6. Line 28, “a” should add before “sustainable”.

Response: Thank you, Sir, for pointing this out, we have modified it.

7. Line 28, The LER values are too large to be reasonable.
8. There are too much abbreviation.

Response: Thank you, Sir, for pointing this out, we have reduced it.

9. Line 29, ‘suppress’ should be changed to ‘suppresses’.

Response: Thank you, Sir, for pointing this out, we have modified it.

10. It is necessary to emphasize the importance of banding in one sentence.
11. Specific research contents and methods should be added to the research objectives.
12. Some important quantitative results should be added to the research results.
13. The focus of the full text is the density of weeds, but only one indicator can determine this conclusion. Is it too arbitrary?
14. Lines 30-32, The last sentence should be an overall conclusion and should not be irrelevant to the findings.

Introduction

15. Please be consistent with the date format of the full text, it is recommended to modify.
16. Line 38, The format of the literature citation is inconsistent with the follow-up.
17. It should add “but” before “pose” to describe turning point in line 45.
18. Line 50, “is” should read “was”.

Response: Thank you, Sir, for pointing this out, we have modified it.

19. Line 50, ‘level’ should be changed to ‘levels’.

Response: Thank you, Sir, for pointing this out, we have modified it.

20. Line 50, add ‘a’ before ‘high’.

Response: Thank you, Sir, for pointing this out, we have modified it,

21. Line 64, “have” should read “had”.

Response: Thank you, Sir, for pointing this out, we have modified it.

22. Line 64, ‘responses’ should be changed to ‘response’.

Response: Thank you, Sir, for pointing this out, we have modified it.

23. Line 67, ‘practices’ should be changed to ‘practice’.

Response: Thank you, Sir, for pointing this out, we have modified it.

24. Line 68-69, the presentation of the document should be the same as elsewhere in the article, please revise it.

Response: Thank you, Sir, for pointing this out, we have modified it.

25. Line 75, “it” should delete.

Response: Thank you, Sir, for pointing this out, we have modified it.

26. Why do we talk about allelopathy in lines 75-76?

Response: Thank you, Sir, for pointing this out, we have modified it.

27. Line 80, “weeds infestation” should read “weed infestation”.

Response: Thank you, Sir, for pointing this out, we have modified it.

28. Line 80, ‘have’ should be changed to ‘has’.

Response: Thank you, Sir, for pointing this out, we have modified it.

29. Line 85, ‘area’ should be changed to ‘areas’.

Response: Thank you, Sir, for pointing this out, we have modified it.

30. Line 87-89, you should use proper tense.

Response: Thank you, Sir, for pointing this out, we have modified it.

31. Line 90, references should be cited in a uniform format.

Response: Thank you, Sir, for pointing this out, we have modified it.

32. Line 94, ‘enhance’ should be changed to ‘enhanced’.

Response: Thank you, Sir, for pointing this out, we have modified it.

33. Line 98, “was” should read “were”.

Response: Thank you, Sir, for pointing this out, we have modified it.

34. It is suggested that the literature related to herbicides in the first and second paragraphs should be put together without the need to describe them separately.

Response: Thank you, Sir, for pointing this out, we have modified it.

35. It is suggested to add why to study corn and soybean?

Response: Thank you, Sir, for pointing this out, we have modified it.

36. What is the need for this research? What are the potential research gaps? Please mention it clearly in the introduction.

Response: Thank you, Sir, for pointing this out, we have modified it.

37. The purpose of the study is not clear, please list, such as the effect of single cropping and intercropping on weed control.

Response: Thank you, Sir, for pointing this out, we have modified it.

38. Although you have summarized the benefits of intercropping on weed suppression, the supplementary literature describes the inhibition mechanism.

Response: Thank you, Sir, for pointing this out, we have modified it.

39. According to the purpose of this study, reasonable assumptions are made on the research.

Response: Thank you, Sir, for pointing this out, we have modified it.

40. The preface introduces the research objectives, please add.

Response: Thank you, Sir, for pointing this out, we have modified it.

41. The introductory section lacks logic and most of the content is on weeds and pesticides, however the effects of weeds on crop growth and nutrient uptake are not described.
42. The key questions and assumptions are not presented in the introduction.

Materials and Methods

43. Please move Lines 116-118 before Line 105.

Response: Thank you, Sir, for pointing this out, we have modified it.

44. In lines 106, 107, there is no space between °C and the number.

Response: Thank you, Sir, for pointing this out, we have modified it.

45. Line 106, ‘summers’ should be changed to ‘summer’.

Response: Thank you, Sir, for pointing this out, we have modified it.

46. Line 108, The content of the experiment is the data of 21 years and 22 years, but here it appears in 2023. Check the content.

Response: Thank you, Sir, for pointing this out, we have modified it.

47. Line 110, ‘includes’ should be changed to ‘including’.

Response: Thank you, Sir, for pointing this out, we have modified it.

48. Line 110, “includes” should read “included”.

Response: Thank you, Sir, for pointing this out, we have modified it.

49. Figure 2, Why are the distances between single and intercrops different?
50. Please check 2021-22 that this format is accurate.

Response: Thank you, Sir, for pointing this out, we have modified it.

51. The unit for weeds, “g m²”, is incorrect.

Response: Thank you, Sir, for pointing this out, we have modified it.

52. Line 114-115, “Monthly minimum (min), maximum (max), average (Avg.) temperature (℃), precipitation (mm) and relative humidity (%) at Tandojam during 2021 (A) and 2022 (B).” should be changed “Monthly minimum (Min), maximum (Max), average (Avg.) temperature (Tem, ℃), precipitation (Pre,mm) and relative humidity (RH,%) at Tandojam during 2021 (A) and 2022 (B).”

Response: Thank you, Sir, for pointing this out, we have modified it.

53. Line 118, “season” should read “seasons”.

Response: Thank you, Sir, for pointing this out, we have modified it.

54. Line 120, “is” should read “was”.

Response: Thank you, Sir, for pointing this out, we have modified it.

55. In line 121, the unit of available phosphorus is incorrect.

Response: Thank you, Sir, for pointing this out, we have modified it.

56. Please check if the unit “plants ha-1” is incorrect.

Response: Thank you, Sir, for pointing this out, we have modified it.

57. 3. The 116th line should be merged with the 105th line and placed in front of the 105th line. It is recommended to modify.

Response: Thank you, Sir, for pointing this out, we have modified it.

58. 4. Line 131, ‘were’ should be changed to ‘was’.

Response: Thank you, Sir, for pointing this out, we have modified it.

59. The unit of 'weed fresh weight (g m2) ' in line 154 was wrong, and it was suggested to modify it.

Response: Thank you, Sir, for pointing this out, we have modified it.

60. Line 135. Please complete the year, 2021-2022.

Response: Thank you, Sir, for pointing this out, we have modified it.

61. Line 137-138, the weed measures of this are not clear enough, please add.

Response: Thank you, Sir, for pointing this out, we have modified it.

62. Line 140, “(SSIWM)” should be deleted.

Response: Thank you, Sir, for pointing this out, we have modified it.

63. Line 140, The row spacing of monoculture and intercropping are different, so can the follow-up results be comparable?

Response: Thank you, Sir, for pointing this out, we have modified it.

64. Line 149-150, The cited references are not uniform.

Response: Thank you, Sir, for pointing this out, we have modified it.

65. Line 149, “(Gao et al., 2010)”, the font size of the document in the article is different from the others, please modify it.

Response: Thank you, Sir, for pointing this out, we have modified it.

66. In MSI, 40cm between two lines maize isn’t very suitable.
67. It misses some important data, such as height and root density.
68. Line 154. kitchen scale?  Shouldn’t 't it be a test scale?
69. Line 157, ‘uses’ should be changed to ‘use’.

Response: Thank you, Sir, for pointing this out, we have modified it.

70. Line 159, “(Tsubo & Walker, 2002).”, the font size of the document in the article is different from the others, please modify it.

Response: Thank you, Sir, for pointing this out, we have modified it.

71. Line 159, The cited references are not uniform.

Response: Thank you, Sir, for pointing this out, we have modified it.

72. Line 165, “was” should read “were”.

Response: Thank you, Sir, for pointing this out, we have modified it.

73. Line 165, ‘was’ should be changed to ‘were’.

Response: Thank you, Sir, for pointing this out, we have modified it.

74. Line 167, ‘combine’ should be changed to ‘combined’.

Response: Thank you, Sir, for pointing this out, we have modified it.

75. It is recommended to first describe the location of the test site and the basic physical and chemical properties of the soil, and then describe the weather conditions.

Response: Thank you, Sir, for pointing this out, we have modified it.

76. Some units of data in the basic physical and chemical properties of soil are wrong.

Response: Thank you, Sir, for pointing this out, we have modified it.

77. There is no specific content related to fertilization and irrigation. How to calculate the water utilization rate? And how is the radiation utilization efficiency calculated?

Response: Thank you, Sir, for pointing this out, we for suggestions, we have added the contents in this revised manuscript.

78. The content of measurement related indicators is few, and the measurement method suggests adding relevant calculation formulas. Some indicators do not indicate the number of repetitions.
79. Why consider LER? Why not use other competitive features.
80. In figure 2, “A. MSI” should be changed “A. Maize-Soybean strip intercropping”.
81. It is suggested that the language should be more professional.
82. Since the water use efficiency is measured, the local irrigation level should be supplemented.
83. Micro-fertilizers involved in the discussion have certain control over weed control, so fertilization methods and amounts should be added to materials and methods.
84. The English abbreviations of the legends in figure 2 do not have full spelling remarks.

Results

85. Should the unit for “Water use efficiency (g m²)” in figure 5 be %?
86. Line 182, “is” should read “was”.
87. Both Figure 4 and Figure 1 have two years of data, but Figure 4 and Figure 5 have two annotations and Figure 1 has only one annotation, which is recommended to be modified to be consistent.

Response: Thank you, Sir, for pointing this out, we have modified it.

89. The unit of 3.3 water use efficiency in the results is g m2, is there a mistake? Suggested modification.
90. The results are largely used in the histogram; it is recommended to modify.

Response: Thank you, Sir, for pointing this out, we have modified it.

91. Line 189, “season” should read “seasons”.
92. Line 192, The measurement times are only three times, and the graph is not very beautiful, and the vertical coordinates of the four graphs are bold, some are not bold, and the format is not uniform.
93. In line 199 of ' The lowest weed density ', the unit g m2 used in weed density was wrong, and it was suggested to modify it.
94. You can make some differences in figure 4, 5, 6 and 7, it’s all bar charts.
95. Line 203, “and 16.9” should be changed “and 16.9%”.
96. Line 212, ‘uses’ should be changed to ‘use’.
97. Line 213-215, Please focus on the content of the analysis.
98. Line 221, the unit of water use efficiency needs to be improved. It is suggested to add relevant formulas to the method.
99. Line 223, 243, Means are averaged over three replicates
100. Line 227, “was” should read “were”.
101. Line 233, ‘that’ should be changed to ‘which’.
102. It is recommended to unify the color and format of the chart inside, which is not very beautiful.
103. Is the unit of water utilization, correct? It is recommended that the whole article be carefully revised, and some data units are incorrect.
104. The colour matching of the picture in this paper is a little confused, it is suggested to modify.
105. Figure 3. It is recommended to modify the picture to better distinguish between soybeans and corn.
106. Figure 4. It is recommended to improve the clarity of the picture.
107. Figure 5. The differences between treatments were compared, and it was suggested to increase the inter-annual comparison.
108. All graphs do very poor.
109. Figure 7, The calculations are wrong.

Discussion

110. The sun picture in Fig.8 is too exaggerated, and it is recommended to modify it.

Response: Thank you, Sir, for pointing this out, we have modified it in this revised manuscript.

111. In discussions, you should connect your results and get a conclusion.

Response: Thank you, Sir, for pointing this out, we have modified it in this revised manuscript.

112. Line 250. What is the relationship between LAI and resource competition?

Response: Thank you, Sir, for pointing this out, we have modified it in this revised manuscript.

113. Lines 254-256, This result should be obtained by analysing the data.

Response: Thank you, Sir, for pointing this out, we have modified it in this revised manuscript.

114. Lines 256-258，Please do not over-reason.

Response: Thank you, Sir, for pointing this out, we have modified it in this revised manuscript.

115. Line 266, ‘compare’ should be changed to ‘compared’.

Response: Thank you, Sir, for pointing this out, we have modified it in this revised manuscript.

116. Line 269, When the sun shines obliquely on crops, it can highlight the difference between intercropping.

Response: Thank you, Sir, for pointing this out, we have modified it in this revised manuscript.

117. Line 271-273, “The differences observed between growing seasons might be attributed to variation in soil fertility and environmental conditions, that could have exerted an effect on LAI and the development of the crops “That sentence should be amended.

Response: Thank you, Sir, for pointing this out, we have modified it in this revised manuscript.

118. Lines 273-275，Please do not over-reason.

Response: Thank you, Sir, for pointing this out, we have modified it in this revised manuscript.

119. Line 276, “relies” should read ‘relied”.

Response: Thank you, Sir, for pointing this out, we have modified it in this revised manuscript.

120. Line 280, “implies” should read “implied”.

Response: Thank you, Sir, for pointing this out, we have modified it in this revised manuscript.

121. Lines 283, Please do not over-reason.

Response: Thank you, Sir, for pointing this out, we have modified it in this revised manuscript.

122. If you want to connect light quality, you should add SPAD data.

Response: Thank you, Sir, for pointing this out, we have modified it in this revised manuscript.

123. Line 289, “,” should add after “study”.

Response: Thank you, Sir, for pointing this out, we have modified it in this revised manuscript.

124. Lines 290, Is there any weed competition involved in this study, please do not over-reason.

Response: Thank you, Sir, for pointing this out, we have modified it in this revised manuscript.

125. Lines 296-298, The results in the paper only show that intercropping reduces weeds and increases water and radiation use the relationship between the reduction of weeds and the increase in efficiency is not analysed in the paper. Please do not over-reason.

Response: Thank you, Sir, for pointing this out, we have modified it in this revised manuscript.

126. Line 302, “is” should read “was”.

Response: Thank you, Sir, for pointing this out, we have modified it in this revised manuscript.

127. Line 302, ‘is’ should be changed to ‘has been’.

Response: Thank you, Sir, for pointing this out, we have modified it in this revised manuscript.

128. Line 308, “have” should read “had”.

Response: Thank you, Sir, for pointing this out, we have modified it in this revised manuscript.

129. Line 314, delete ‘the’.

Response: Thank you, Sir, for pointing this out, we have modified it in this revised manuscript.

130. Line 347, ‘improve’ should be changed to ‘improved’.

Response: Thank you, Sir, for pointing this out, we have modified it in this revised manuscript.

131. Line 352, delete a ‘that’.

Response: Thank you, Sir, for pointing this out, we have modified it in this revised manuscript.

132. The measurements of the study are not sufficient for discussion. It is suggested to modify the experimental scheme. And the content of the discussion is too confusing, it is suggested that the discussion be divided.

Response: Thank you, Sir, for pointing this out, we have modified it in this revised manuscript.

133. This part of the proposal points are discussed.

Response: Thank you, Sir, for pointing this out, we have modified it in this revised manuscript.

Response: Thank you, Sir, for pointing this out, we have modified it in this revised manuscript.

134. The limitations of the study were not explicitly mentioned.

Response: Thank you, Sir, for pointing this out, we have modified it in this revised manuscript.

135. The conclusion that the discussion involves too many sets and the results are not in control is inconsistent.

Response: Thank you, Sir, for pointing this out, we have modified it in this revised manuscript.

136. The entire discussion is illogical, please ask the authors to rewrite the discussion section and discuss each research element separately for each study, please do not over reason.

Response: Thank you, Sir, for pointing this out, we have made changes in suggested areas.

Conclusions

137. Line 362, add ‘to’ after ‘led’.

Response: Thank you, Sir, for pointing this out, we have modified it in this revised manuscript.

138. Please write conclusions based on your research and do not over-reason.

Response: Thank you, Sir, for pointing this out, we have modified it in this revised manuscript.

139. Compared with other studies, it is suggested to add some advantages and disadvantages as well as some prospects for future studies.

Response: Thank you, Sir, for pointing this out, we have modified it in this revised manuscript.

References

140. There are many names in the references that are problematic, so please check them carefully. For example, 3- 5, 13, etc.
141. The third reference lacks page numbers.

Response: Thank you, Sir, for pointing this out, we have modified it in this revised manuscript.

142. References in the 489th line shows http, format and other literature format is not consistent, it is recommended to modify

Response: Thank you, Sir, for pointing this out, we have modified it in this revised manuscript.

143. There are redundant dots in the third, fourth, and fifth references, please revise them.

Response: Thank you, Sir, for pointing this out, we have modified it in this revised manuscript.

144. Periodical format and periodical format are not unified.

Response: Thank you, Sir, for pointing this out, we have modified it in this revised manuscript.

145. The literature is incorrectly arranged.

Response: Thank you, Sir, for pointing this out, we have modified it in this revised manuscript.

146. The overall format of the references is incorrect, so it is recommended to revise them carefully.

Response: Thank you, Sir, for pointing this out, we have modified the references in revised manuscript.

Round 2

Reviewer 1 Report

Comments and Suggestions for Authors

Dear Authors,

thank you for addressing the suggestions from the first round of reviews.

I have no further comments.

Author Response

Dear Sir, Thank you, for your useful comments and suggestions on the language and structure of our manuscript. We have modified and addressed all your given suggestions in manuscript accordingly, thank you very much if you feel satisfied with our first round of revisions, we appreciate your scientific suggestions and technical revisions, your support has relatively improved and enhanced quality of our work for further proceeding.

Reviewer 3 Report

Comments and Suggestions for Authors

The author should be congratulated as this paper is vastly improved when compared with the earlier version.

Unfortunately, the fundamental flaw in experimental design and its discussion remains.

The authors state that the purpose of the study was: “to determine the impact of symbiotic interspecific interactions between maize and soybean strip intercropping on the suppression of weed density and resource use efficiency under irrigated conditions”. However, their design compared monocrops of maize and soybean with maize and soybean intercropped at higher density, additional fertilizer and different row configuration, with no way to determine if the improvements in yield etc they observed were due to intercropping, or to their increase planting density, configuration, fertilizer, or to a combination of these. They did not measure or determine any “symbiotic interspecific interactions”.

The authors probably need to change the title of the paper to: “A maize-soybean strip intercropping system at higher plant density, narrower row configuration and with increased fertilizer inputs increased yield and resource use efficiency” and limit their statements to the facts of their paper.

 

In detail

Lines 80/1 states: “Therefore, it requires the development of stronger, ecologically friendly and durable herbicides, weed management practices which exacerbate the cycle of chemical dependency”. Unclear what the authors are trying to say here.

Lines 85/6: “...allelopathy is also a common phenomenon,….” the allelopathic effect is very difficult to prove and has not been commonly shown. Authors need to give a solid reference for this statement or remove it.

Line 93: “Intercropping is an innovative approach…”, actually, intercropping was the normal and monocropping the innovative approach. Authors need to reconcile this claim with the statement “China extensively practices the maize-soybean strip intercropping system” Line 96/7

Line 98: “…the same densities as their sole crops …” the Chinese system uses the same density of monocropping in intercropping, so why were the densities changed in this research?

Lines 154-159: the design is still confusing to the reader. The paper states a “The total bandwidth was 200 cm…”, yet the plots were 6m x 6m, and from the measurements given, the MSI treatments gave a 4.6 m wide plot, the Soy a 4 m wide plot and the maize a 4.2 m wide plot. It seems that everything about the 3 treatments (planting density, row configuration, fertilizer and plot width) were different making it very challenging to compare treatments while ignoring these differences.

Lines 168/9: “We regularly irrigated the crops with canal irrigation water to maintain the field capacity” needs to be explained. The paper indicates plots were flood irrigated, but it would not be possible to maintain plots at field capacity using this system as each irrigation event takes the soil above field capacity, it returns to field capacity after 24-36 hours, and thereafter falls below field capacity. Were plots irrigated every 2-3 days, maintaining them nearly at or above field capacity at all times? Is this extreme level of irrigation normal? It would be a highly inefficient use of water.

Lines 172/3: “…the basal dose of N, P, and K fertilizers were applied at 180, 80, and 100 kg ha-1 in SM and MSI, respectively” plus a 2^nd dose of 75 kg ha-1. This is a huge amount of nitrogen to be applied to a soybean crop, even as an intercrop, and has to bring into question the results of the research. The authors state in the Introduction “…soybean enriches the soil with its nitrogen-fixing ability, facilitating the nitrogen requirement of the maize crop” but then apply an excessive level of nitrogen to these soybeans. This nitrogen application would seem to invalidate the basis of the work, would surely not be normal practice, and surely the authors are not suggesting this should be a normal practice. It is unknown whether the improved yield and landuse efficiency from the intercropping system would have occurred if a normal amount of nitrogen had been applied to this soybean, or if the yield would have been matched by the soybean if alternatively, the mono-cropped soybean had been planted at the higher density and configuration and had this level of nitrogen applied.

Lines 223/225: The authors give no explanation of how they have measured the individual water use for each plot, and it seems unlikely that this was measured. Consequently, the authors CAN NOT include these results in their paper as they did not measure water use efficiency. Total water use as defined in the formulae can only be measured by soil cores and accurate measurement of water on and off each plot at each irrigation. There is no indication in the paper that this occurred. Reference 32, erroneously used here, refers to solar radiation and does not give any technique for measuring water use.

Lines 292/4: as above, if the authors did not measure water use efficiency, these “results” and their discussion need to be removed from this paper. The “water use efficiency” mentioned in Line 292 “water use efficiency (9.0 g/m2)” is not consistent with the stated formulae of “Water use efficiency = Grain yield/total water use” (Line 226). From this formulae, WUE would be expressed as g/l, not the g/m2 given in the paper.

Lines 414/6: “growing of MSI during the spring season not only improved the land productiveness but crops also avoided the extreme effect of torrential monsoon rainfall” the authors need to explain how the advantage of growing the MSI crop during the dry season relates only to the MIS. Surely the monocrops grown at the same time gave the same advantage, or would have had they also been grown at the higher planting density and configuration.

Lines 432/4: As previously, the authors need to change the emphasis of the paper from showing a big advantage from inter-cropping – which their research doesn’t show, to showing a big advantage from intercropping with increased fertilizer input, higher planting density and narrower row spacing – which their research does show. They would also be well advised to undertake further research where they compare the systems at the same planting densities, configuration and fertilizer regimes to show whether intercropping actually does have an advantage. Identification of this need should come at the end of the paper.

Author Response

Dear Sir. we, thank you, for your useful comments and suggestions on the language and structure of our manuscript in second round of revisions. We have modified the manuscript accordingly and showed the comments in the revised MS in yellow color. we appreciate your scientific suggestions and technical revisions, your support has relatively improved and enhanced quality of our work for further proceeding.

Comments and Suggestions for Authors

The author should be congratulated as this paper is vastly improved when compared with the earlier version.

Unfortunately, the fundamental flaw in experimental design and its discussion remains.

The authors state that the purpose of the study was: “to determine the impact of symbiotic interspecific interactions between maize and soybean strip intercropping on the suppression of weed density and resource use efficiency under irrigated conditions”. However, their design compared monocrops of maize and soybean with maize and soybean intercropped at higher density, additional fertilizer and different row configuration, with no way to determine if the improvements in yield etc they observed were due to intercropping, or to their increase planting density, configuration, fertilizer, or to a combination of these. They did not measure or determine any “symbiotic interspecific interactions”.

The authors probably need to change the title of the paper to: “A maize-soybean strip intercropping system at higher plant density, narrower row configuration and with increased fertilizer inputs increased yield and resource use efficiency” and limit their statements to the facts of their paper.

In detail

Lines 80/1 states: “Therefore, it requires the development of stronger, ecologically friendly and durable herbicides, weed management practices which exacerbate the cycle of chemical dependency”. Unclear what the authors are trying to say here.

Lines 85/6: “...allelopathy is also a common phenomenon,….” the allelopathic effect is very difficult to prove and has not been commonly shown. Authors need to give a solid reference for this statement or remove it.

Line 93: “Intercropping is an innovative approach…”, actually, intercropping was the normal and monocropping the innovative approach. Authors need to reconcile this claim with the statement “China extensively practices the maize-soybean strip intercropping system” Line 96/7

Response: Thank you, Sir, for pointing this out, we have modified it in 2^nd round of the revision.

Line 98: “…the same densities as their sole crops …” the Chinese system uses the same density of monocropping in intercropping, so why were the densities changed in this research?

Response: Thank you, Sir, for pointing this out, we have modified it in 2^nd round of the revision.

Lines 154-159: the design is still confusing to the reader. The paper states a “The total bandwidth was 200 cm…”, yet the plots were 6m x 6m, and from the measurements given, the MSI treatments gave a 4.6 m wide plot, the Soy a 4 m wide plot and the maize a 4.2 m wide plot. It seems that everything about the 3 treatments (planting density, row configuration, fertilizer and plot width) were different making it very challenging to compare treatments while ignoring these differences.

Lines 168/9: “We regularly irrigated the crops with canal irrigation water to maintain the field capacity” needs to be explained. The paper indicates plots were flood irrigated, but it would not be possible to maintain plots at field capacity using this system as each irrigation event takes the soil above field capacity, it returns to field capacity after 24-36 hours, and thereafter falls below field capacity. Were plots irrigated every 2-3 days, maintaining them nearly at or above field capacity at all times? Is this extreme level of irrigation normal? It would be a highly inefficient use of water.

Response: Thank you, Sir, for pointing this out, we have modified it in 2^nd round of the revision.

Lines 172/3: “…the basal dose of N, P, and K fertilizers were applied at 180, 80, and 100 kg ha-1 in SM and MSI, respectively” plus a 2^nd dose of 75 kg ha-1. This is a huge amount of nitrogen to be applied to a soybean crop, even as an intercrop, and has to bring into question the results of the research. The authors state in the Introduction “…soybean enriches the soil with its nitrogen-fixing ability, facilitating the nitrogen requirement of the maize crop” but then apply an excessive level of nitrogen to these soybeans. This nitrogen application would seem to invalidate the basis of the work, would surely not be normal practice, and surely the authors are not suggesting this should be a normal practice. It is unknown whether the improved yield and land use efficiency from the intercropping system would have occurred if a normal amount of nitrogen had been applied to this soybean, or if the yield would have been matched by the soybean if alternatively, the mono-cropped soybean had been planted at the higher density and configuration and had this level of nitrogen applied.

Lines 223/225: The authors give no explanation of how they have measured the individual water use for each plot, and it seems unlikely that this was measured. Consequently, the authors CAN NOT include these results in their paper as they did not measure water use efficiency. Total water uses as defined in the formulae can only be measured by soil cores and accurate measurement of water on and off each plot at each irrigation. There is no indication in the paper that this occurred. Reference 32, erroneously used here, refers to solar radiation and does not give any technique for measuring water use.

Response: Thank you, Sir, for pointing this out, we have modified it in 2^nd round of the revision.

Lines 292/4: as above, if the authors did not measure water use efficiency, these “results” and their discussion need to be removed from this paper. The “water use efficiency” mentioned in Line 292 “water use efficiency (9.0 g/m2)” is not consistent with the stated formulae of “Water use efficiency = Grain yield/total water use” (Line 226). From this formulae, WUE would be expressed as g/l, not the g/m2 given in the paper.

Lines 414/6: “growing of MSI during the spring season not only improved the land productiveness but crops also avoided the extreme effect of torrential monsoon rainfall” the authors need to explain how the advantage of growing the MSI crop during the dry season relates only to the MIS. Surely the monocrops grown at the same time gave the same advantage, or would have had they also been grown at the higher planting density and configuration.

Response: Thank you, Sir, for pointing this out, we have modified it in 2^nd round of the revision.

Lines 432/4: As previously, the authors need to change the emphasis of the paper from showing a big advantage from inter-cropping – which their research doesn’t show, to showing a big advantage from intercropping with increased fertilizer input, higher planting density and narrower row spacing – which their research does show. They would also be well advised to undertake further research where they compare the systems at the same planting densities, configuration and fertilizer regimes to show whether intercropping actually does have an advantage. Identification of this need should come at the end of the paper.

Reviewer 4 Report

Comments and Suggestions for Authors

I have carefully reviewed the manuscript and recommend accept

Author Response

Dear Sir, Thank you, for your useful comments and suggestions on the language and structure of our manuscript. We have modified and addressed all your given suggestions in manuscript accordingly, thank you very much if you feel satisfied with our first round of revisions and recommend our manuscript for accept, we appreciate your scientific suggestions and technical revisions, your support has relatively improved and enhanced quality of our work for further proceeding.