Impact of Monoculture and Various Ratios of Intercropped Oats and Daikon Radish Cover Crops on Soil Properties, Weed Suppression, and Spinach Yield

Round 1

Reviewer 1 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.

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 abstract could elaborate more on the research findings regarding weed suppression and spinach yield.
2. The specific reasons for the key differences between different treatments are not clearly stated in the abstract; it is recommended to add explanations.
3. The research objective is not clearly stated. It is suggested to explicitly clarify that this study aims to explore the effects of different ratios of oat and radish mixed sowing on soil health, weed suppression and spinach yield.
4. The conclusion section should emphasize the optimal processing combination.
5. The subject in line 12 is integrating  ( gerund phrase, singular concept ), and the predicate should be improved. The suggestion was changed to : ' Integrating cover crops into spinach ( Spinacia oleracea L. ) production systems improves soil health... '
6. Weed suppression is a dependent variable and should not be set to two treatments.
7. The use of processing abbreviations should be reduced in the summary.
8. Lack of research background : The abstract does not clearly explain the innovation of the research in the optimization of the mixed sowing ratio of covered crops, especially the difference and supplement with the existing research.
9. Although ' maximum yield ' and ' weed inhibition rate ' were mentioned, direct comparison data with the control group were lacking.
10. Re-do the Graphical Abstract.
11. The experimental treatment is unclear.
12. The research results are not comprehensive.

Keywords

13. “Earthworm” Please think about whether this keyword is appropriate.

Introduction

14. More background could be provided on the reasons for selecting oats and daikon radish for intercropping.
15. Please introduce in greater detail the methodology used to determine the optimal intercropping ratio as hypothesized.
16. The expression of research hypotheses at the end of the introduction is relatively brief. Only two hypotheses are proposed without a brief explanation of the basis for putting forward the hypotheses. It is recommended to supplement the brief basis to make the hypothesis logic more coherent.
17. The cited literature is slightly outdated, and it is recommended to supplement relevant research in recent years (such as 2023-2024).
18. “optimal oat-to-radish planting ratio remains poorly documented”should be more specific, pointing out how this study fills this gap.
19. The hypothesis part of the study should be more clearly listed, and it is recommended to state points.
20. It is not explained why spinach is selected as a subsequent economic crop, and additional reasons are recommended.
21. At the end of the introduction, the specific objectives and innovations of this study should be clarified.
22. Line 58, “have”should read “had”.
23. The 66 th row C : N middle space is inconsistent with the 64 th row C : N space, and it is recommended to modify.
24. Line 71, “evaluates”should read “evaluated”.
25. The literature review is not systematic enough : there is a lack of frontier literature support for the effect of mixed planting ratio of mulching crops on soil microorganisms and enzyme activities, especially the lack of recent related research citations.
26. The second hypothesis that ' increased biomass is associated with improved soil properties ' is too broad and should be more specific to certain indicators (such as SOC, enzyme activity).
27. It was not pointed out that there was a lack of current research on the comprehensive effect of oat and radish mixed sowing ratio on spinach system, especially the long-term field experiment data.
28. “well-selected mixture of cover crop species”，Which specific species are we referring to?
29. The article only mentioned radishes but did not cover oats. Both coverings should be explained and a simple comparison should be made.
30. If the assumption is not very reasonable, please clearly define the main point of the article and specifically formulate the hypothesis.

Materials and Methods

31. Line101,since fertilization of cover crop is not a common practice and irrigation occurred every seven days Irrigate once every seven days, and specify the time period (early, middle, or late).
32. On line 110, the explanation of the calculation symbols in Equation 1 is inconsistent with the preceding text, please modify.
33. Statistical analyses should distinguish between significant and highly significant effects and conduct follow-up analyses accordingly.
34. The specific sampling time, such as the specific month in spring, is not clearly specified in the soil sampling part. Details need to be supplemented to ensure the repeatability of the experiment.
35. The ratio of material to method is 30 rows of oats and 70 rows of radish ? Here should be clear is the proportion of intercropping seeds.
36. The title of Table 1 should be defined as ' Baseline soil characteristics of the experimental site ( 0-15 cm depth ) '.
37. Line 110-111,“and Yab and Yba denote biomass species a and b in monoculture, respectively. ”should be changed “and Yaa and Ybb denote biomass species a and b in monoculture, respectively.”
38. Line 136,Using 6 and 10℃should be explained as germination temperature conditions, such as Germination tests were conducted at 6 and 10℃.
39. Line 147, the title is not formatted correctly.
40. Line 155,“Land Equivalence”should be changed “Land Equivalent Ratio”.
41. In 2.2.1,all formulas in the lowercase please modify, all fonts should be used in the new Roman font.
42. The basic soil data of the experimental site should be displayed in tabular form, not only described, and easy to read.
43. The calculation basis of seeding rate is not clear.
44. Should ' no fertilizers were applied ' explain the reason, in order to exclude fertilizer interference?
45. Cover crop biomass sampling method should be more detailed, please add sampling time, sample number, drying conditions.
46. The soil sampling depth (0-15 cm) should be explained. Is it related to the distribution of spinach roots?
47. There are many references on the determination method of soil enzyme activity, and it is suggested to unify the method standard.
48. Spinach sowing plant spacing information is insufficient, such as row spacing, plant spacing, sowing method (no-tillage direct seeding) should be clearly explained.
49. The number and time of weeding treatment should be specific.
50. Please explain the meaning of the written ratio in the materials and methods. Please explain in detail whether it is the row ratio or the seed ratio.
51. In the ordinate of Figure 1, the temperature °C in the temperature ° C should be enclosed in parentheses and changed to Temperature ( °C ).
52. The explanation of formula 1 does not explain aa and bb, and the font is wrong. Please unify the font.
53. The table should be made into a three-line table.
54. The description of experimental design is not complete. Please supplement field management ( such as irrigation, pest control ).
55. The soil sampling method is not detailed. Please add whether the sampling point avoids the crop root area and whether the sample is mixed.
56. There is no description of the ecological habits of weed species, and there is no background introduction to the ecological characteristics of major weeds ( such as Chenopodium album ) and their response to management.
57. Combine the planting methods of spinach with those of the coverings.
58. Please provide detailed information on field management, such as irrigation, fertilization, and weeding.
59. Describe the sampling method for supplementary soil samples.
60. The table format of Table 1 is not a three-line format, which is recommended to be modified.
61. The first formula explanation has problems, and the formula format also has problems.

Results

62. The results section should avoid redundant presentation of data; it is recommended to summarize trends in the text and present specific values in tables. Please revise.
63. The analysis of spinach yield at the end is too similar to the abstract, please provide a more detailed explanation.
64. In Section 3.2.7, it is stated that "daikon radish monoculture, along with the 30:70 and 10:90 (O:D) intercropping treatments, resulted in the shortest infiltration times". However, the infiltration times among these three treatments are not compared, and only the general description of "the shortest" is used. It is suggested to supplement the data comparison to make the conclusion more accurate.
65. The unit ' Kg ha^-1' in Table 7 should be unified as lowercase ' kg ha^-1'.
66. On line 163, no space should be added between the (1.03±1) symbol and the number.
67. Line 277 ,the thermal soil distribution is distorted. It is recommended to use vector graphics.
68. Line 285,“(O: D)”should be changed “(O:D)”.
69. Line 308,“6±3.0 and 13.0±2.3 g m^-2,”should be changed “9.6±3.0 g m^-2and 13.0±2.3 g m^-2”.
70. Table 2 and table 3 are not standard three-line format is not correct.
71. Table 3 suggests paying attention to the units.
72. Without the significance labeling of key indicators, the significance level ( P value ) of each indicator in the year, treatment and interaction should be explained in the text.
73. Whether there is a space in the middle of O : D should be consistent with the full text.
74. In the result, the header font thickening should be consistent, and it is recommended to modify.
75. In Table 7, the Kg ha-1 in Kg ha-1 should be lowercase, and it is recommended to modify.
76. The description of the results in the article is not detailed enough and how it affects is not indicated.
77. The table should be made into a three-line table.
78. A few more figures should be added to the experiment to indicate the trend.
79. The unit labeling is not clear, which affects the understanding of the data.
80. 2, the key correlations ( such as the relationship between biomass and SOC ) were not fully explained in the text.
81. The expression of soil microbial data is unclear. The use of ' logarithm ( MPN g 1 ) ' in MPN units is easy to cause misunderstanding, and it should be clear whether it is a logarithmic conversion value.
82. The content of Fig.2 fails to provide a comprehensive explanation.
83. The relationship between soil enzyme activity and soil microbial communities has not been thoroughly discussed.
84. There is insufficient analysis of the results based on different configuration ratios.
85. How is cost reduction manifested?
86. There is no space between the number “(0.96±016 %)”in line 182 and the percent sign.
87. The table is not a three-line, it is recommended to modify.

Discussion

88. The discussion should delve deeper into the underlying mechanisms, such as why the 30:70 ratio contributed most significantly to SOC increase.
89. Line355 Correction:"Singh and Kaur [50]" or "(Singh and Kaur,)" Typographical Error.
90. In line 360: "the 30:70 (O:D) ratio yielded the highest SOC compared to the control after two years, likely due to the rapid decomposition of daikon radish residues". This sentence only infers that it is related to the rapid decomposition of daikon radish residues, but does not combine the role of oat residues under this ratio, such as the synergistic effect between oat residues and daikon radish residues. It is recommended to supplement the analysis to improve the explanation.
91. Line previous studies affirm that cover crops generally outperform fallow systems in supporting earthworm populations [59,60].What kind of fallow system. previous studies affirm that cover crops generally outperform fallow systems in supporting earthworm populations [59,60]. Which type of soil is healthy requires an explanation of the small classification of soil health.
92. Section 4.2 does not analyze the reasons for the differences in the changes of weed populations between the two years. It is recommended to supplement the discussion on the differences in data between the two years to make the result analysis more comprehensive and echo Section 3.3 mentioned earlier.
93. Line 411，“effects [73, 74].”should be changed “effects [73,74].”
94. Line 416，“The ' 5:1 oat to daikon radish seed ratio ' was consistent with the seeding rate ( 100 kg ha-1 oats, 20 kg ha-1daikon ) mentioned in the text, but the proportion calculation method should be clearly explained in the method section.”
95. The relationship between biomass and soil organic carbon was not fully explained. Although it was assumed that higher biomass would lead to higher SOC, the results showed that 30: 70 treatment had the highest SOC rather than the highest biomass oat monoculture, and the role of decomposition rate should be discussed in depth.
96. The difference between years was not well explained: the weed pressure was greater in the second year, but the spinach yield was higher in some treatments, and the possible reasons need to be discussed.
97. There is a comma in front of [ 50 ] in line 353, so it is suggested to modify it.
98. You should connect the focus of your inquiry and explore deeper mechanisms.
99. You should streamline the key points of the results, not blindly repeat them.

Conclusions

100. The current conclusion mixes the two major findings—soil improvement and weed suppression/yield enhancement—in a logically disjointed manner. Please restructure.
101. The conclusion part only summarizes the effects and application values of different mixed sowing ratios, and does not mention the limitations of this study. It is recommended to supplement the research limitations to reflect the integrity of the study.
102. The conclusion is too general: the main research findings should be clearly listed.
103. No specific agronomic measures are proposed: for example, it is recommended that farmers choose what proportion under what conditions.
104. The conclusion part repeats the content of the results and discussion, and should avoid simple repetition.
105. The optimal mixed sowing ratio was not explicitly recommended, and the strategy differences under different targets ( soil health vs weed suppression ) were not pointed out.
106. The problems that should be paid attention to in practical popularization (such as sowing time, cost-benefit analysis) were not put forward. It was suggested to supplement the discussion on economic analysis (such as saving weeding cost).
107. The limitations of the study were not pointed out. For example, the experiment was only two years, which failed to reflect the long-term effect. Extrapolation under different soil types or climatic conditions was not mentioned.
108. The conclusion failed to provide the optimal mixing ratio.
109. Please conduct an economic analysis to identify the reasons for reducing the cost of spinach.

References

110. In the reference, there are individual year fonts that are not bolded, and it is recommended to unify the format.
111. Please unify whether it is "http" or "DOI".

Author Response

Please see the attachment 

Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

MS: Monoculture and Various Ratios Intercropped Oats and Daikon Radish Cover Crops Impact on Soil Properties, Weed Suppression, and Spinach Yield

 

 

I have carefully read the entire manuscript and provide the following comments for your consideration:

 

-The background and key knowledge gap in the abstract are unclear. If it has already been established that introducing cover crops into spinach production can improve soil health, what is the significance of conducting this study?

 

-The description of experimental treatments in the abstract is vague. How many treatments were included? What parameters were measured? Overall, it is confusing—why was weed management introduced as a factor?

 

-Is the inclusion of weed management strategies necessary? It seems that no meaningful results related to weed management effects were presented.

 

-The introduction is not well written, as it fails to highlight the key scientific question. Why was this study conducted? Where is the novelty? As stated in L42–70, many of the reported benefits have already been well documented, so the necessity of this study is questionable.

 

-L92–103: The experimental setup described here is inconsistent with what is presented in the abstract.

 

-Sections 2.3 (Spinach Experiment) and 2.2 (Experimental Layout and Treatments)—what are their differences and connections? The overall explanation of the experimental design is confusing.

 

-Limiting soil analysis to the 0–15 cm layer may not be sufficient to capture the full impact of cover crops on soil improvement. Please explain why deeper soil layers were not considered.

 

-Cover crop biomass was collected only once, 45 days after planting. The lack of dynamic data across the growing season or at different growth stages may underestimate or overestimate the long-term effects of cover crops on soil and weed suppression.

 

-The results section presents a large amount of data but lacks mechanistic discussion. For example, why did the 30:70 O:D treatment have the highest SOC, while the 10:90 treatment had the highest microbial population?

 

-There are overly long sentences in the manuscript, which should be revised for conciseness.

 

-References. It would be best to consult the specific guidelines provided by the journal for instructions on formatting and referencing.

Author Response

Please see the Attachment

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

Comments and Suggestions for Authors

Thanks for revising the paper. I have checked the revision and I am satisfied with the changes you made to this manuscript.