Weed Suppression in Only-Legume Cover Crop Mixtures
Round 1
Reviewer 1 Report
I disagree with the authors assessment that Figure 2 and 3 do not need to be on the same scale. This data needs to be up front so the reader can make a judgment on the value of the data and not buried in supplementary material.
Figure 4 is weak. The slope in four panels are less than 0.2 making the statistics irrelevant. The trend in panel D is important but changes the interpretation.
Figure 5? As a farmer what should I do?
Author Response
Dear Reviwer1,
I would like to thank you very much for your insightful and thoughtful comments on the manuscript “Weed suppression in only-legume cover crop mixtures” (Manuscript ID: agronomy-606631). Actually, your comments led us to a great improvement in the work. Our revisions reflect all reviewers’ suggestions comments.
Detailed responses to your comments and suggestions are given below and again with all reviewers in the attached pdf. file. With kind and best regards,
Heba Elsalahy
Response to Reviewer 1 comments
Point 1: I disagree with the authors assessment that Figure 2 and 3 do not need to be on the same scale. This data needs to be up front so the reader can make a judgment on the value of the data and not buried in supplementary material.
Response 1: We thank the reviewer for this comment. We have now changed Figures 2 and 3 in accordance with the reviewer’s suggestion.
Point 2: Figure 4 is weak. The slope in four panels are less than 0.2 making the statistics irrelevant. The trend in panel D is important but changes the interpretation.
Response 2: We thank the reviewer for this assessment, but we do not think that Figure 4 itself is weak but that it shows, as highlighted by the reviewer, partly weak effects. This, in our view, is interesting, because it is not in complete agreement with the literature (which may be biased to show strong effects?). In accordance with the reviewer’s comments, we have changed the text in section 4.5. (Discussion), which now reads “Although many studies hypothesized that increase biomass production was intimately related to greater weed suppression [44,45], we have found that this relationship between CCB and WB can be weak and inconsistent in forage legume crops”
Point 3: Figure 5? As a farmer what should I do?
Response 3: We thank the reviewer for this comment. This is indeed one of the key questions. Obviously, the results do not allow a clear-cut recommendation. To capture this in the text more explicitly, we have added the following text to the discussion (Section 4.2, first paragraph): “These results make it more difficult to give any clear recommendations for farmers about whether or not mixing crops helps to suppress weeds. In our case, the results shown in Figure 5 and Table 2 suggest that although mixing species has the potential for weed suppression, the mixing effect is not always reliable and other practices need to be employed for effective weed control.”
Author Response File: 
Author Response.docx
Reviewer 2 Report
The authors consistently improved the paper respect to the previous version. I found some very interesting points in the discussion of the results. However, in my opinion, there are still some amelioration to do to the manuscript before being suitable for publication. In particular, the Results section need to be lightened and should be carefully revised. It looks completely different in style respect to the Introduction and Conclusion sections, particularly in terms of fluidity. The Discussion is too long and should be more concise. It is not immediately clear what do the authors mean with “Diversity effect” and “Proportion effect” since they evaluate the “Mixing ration” of the two crop species as factor. I think they speculate too much on these effects. The research hypothesis they report at the end of the introduction could drive to better organize the Discussion, focusing on the points that help in answering. They should directly answer to the hypotheses in the discussion. Several suggestions and doubts are directly reported in the pdf.
Comments for author File: 
Comments.pdf
Author Response
Dear Reviwer2,
I would like to thank you very much for your insightful and thoughtful comments on the manuscript “Weed suppression in only-legume cover crop mixtures” (Manuscript ID: agronomy-606631). Actually, your comments led us to a great improvement in the work. Our revisions reflect all reviewers’ suggestions comments.
Detailed responses to your comments and suggestions are given below and again with all reviewers in the attached pdf. file. With kind and best regards,
Heba Elsalahy
Response to Reviewer 2 comments
Point 1: The authors consistently improved the paper respect to the previous version. I found some very interesting points in the discussion of the results. However, in my opinion, there are still some amelioration to do to the manuscript before being suitable for publication. In particular, the Results section need to be lightened and should be carefully revised. It looks completely different in style respect to the Introduction and Conclusion sections, particularly in terms of fluidity.
Response 1: We would like to thank the reviewer for the positive evaluation of the work. We have followed all the suggestions of the reviewer in the results section to lighten its complexity.
Point 2: The Discussion is too long and should be more concise.
Response 2: We thank the reviewer for this comment. We agree that the Discussion is long and we have (slightly) shortened it. In doing so, we have tried to strike a balance between conciseness and responding to all requests by all reviewers, not being cryptic or hiding important qualifying aspects of our results.
Point 3: It is not immediately clear what do the authors mean with “Diversity effect” and “Proportion effect” since they evaluate the “Mixing ration” of the two crop species as factor. I think they speculate too much on these effects. The research hypothesis they report at the end of the introduction could drive to better organize the Discussion, focusing on the points that help in answering. They should directly answer to the hypotheses in the discussion.
Response 3: To clarify, the effect of diversity (mixing vs. non-mixing) is conceptually different from the proportion effect (within mixing: what is the best proportion?). Both questions are expressed in different research hypothesis in the introduction. Due to the design we chose, however, both effects can also be analysed together as five mixing ratios (100:0, 67:33, 50:50, 33:67, 0:100), in order to test whether this ratio (as an experimental factor) has a significant effect. This additional analysis makes it easier to compare the effect of this factor with that of other factors (density and time), and to assess the significance of interactions. Our discussion is already organized to follow the research hypothesis, as suggested by the reviewer. Unfortunately, we are unable to see where exactly in the Discussion we are speculating too much in this area. We have tried to be as close to the results and the literature as possible, but finding potential explanations for the peculiarities of the mixture effects does require at least some degree of (educated) speculation.
Point 4: Several suggestions and doubts are directly reported in the pdf.
Response 4: Line numbers below are from original manuscript (Manuscript ID: agronomy-606631) where the comment or edit was made, then, after DONE, line numbers of the corresponding place are given for the revised manuscript. The correction of some very minor spelling mistakes (which has always been done as suggested) has not been reported in the list below.
Line 27: DONE (line 27): the sentence “When considered across all other factors, mixing crops” has been replaced with “mixture”. Line 28: DONE (line 28): The words “, as an average value,” is added to the text. Line 35: DONE (line 36): “Appropriate” has replace the word “An appropriate” Line 37: DONE (line 37): “may have not an” has replaced the words “no effect” Line 38: DONE (line 38): the word “crop” has been added before “diversification” Line 125: DONE (line 125): “29th April” and “25th April” were deleted from the text Line 129: DONE (line 129): “s” is added to legume and “trial” is deleted Line 132: DONE (line 132): “mg/kg” is corrected to “mg kg-1” Line 137: DONE (line 137): the latin name “Trifolium hybridum ,” and “Medicago lupulina L.,” were deleted from the line 137 and checked through the rest of the text (Now the latin names of the studied species are only mentioned in the abstract and the introduction) Line 157: DONE (line 157): “a” is instead of “the Wintersteiger” Line 158: DONE (line 158): “(Wintersteiger AG, Ried im Innkreis, Austria)”is added to the sentence Line 166: DONE (line 166): An image with higher resolution is uploaded Line 177: DONE (line 177): “We quantified weed and cover crop aboveground biomass (WB and CCB, respectively) in three harvest times, during spring, summer and early autumn of each year.” Has replaced the old sentence Line 182: DONE (line 183): “specifically” is added before the word harvested Line 189: DONE (line 190): “more or less after” is replaced by around and “in the two years” is added at the end of the sentence Line 182: DONE (line 162): information on the used machine Line 191: DONE (line 194): “Across the length of the plot, both upper and lower 1 m were not used for sampling, i.e.” is deleted Line 192: DONE (line 194): “seven m of the total nine m plot length” is added Line 195: DONE (line 199): ”to obtain the dry content” is added Line 205: DONE (line 209): “Why did you report this equation if you don't use it for the evaluations” In fact we did use this equation for the evaluation of mixture effect on weed suppression in Table 2 Line 208: DONE (line 212): “effect” is deleted, “and the” is added and “s” is added to effects Line 209: DONE (line 213): “the” is added before CCB Line 213: DONE (line 217):”year” is replaced by “Yr”, “CCA biomass” is replaced with “CCB” and “weed biomass” is replaced with “WB” Line 222: DONE (line 226):” Tukey HSD.test” has been applied in the statistical analysis instead of “LSD” Line 234: DONE (line 238):”as” is replaced with “by” Line 236: DONE (line 240):”Figure 1” is added at the end of the sentence Line 238: DONE (line 242):” analyzing the mean of CCB across all treatments indicated” has been deleted from the text Line 239: DONE (line 243):”was observed on mean CCB” is added after Yr effect and “values” Line 243: DONE (line 247):”, producing higher“ is added and “and produced the highest” is deleted Line 244-245: DONE (line 247-248):”, up to 54.3 and 40.0 % in 2016 and 2017, respectively,” is added; “than the MR of AC:BM 33:67, 50:50, 67:33 and 100:0, respectively” is deleted Line 245: DONE (line 250): “significantly“ is moved to the correct position and “CCB” is now used without biomass through the text Line 247: DONE (line 253): “CCB” is used instead of “CCA biomass” and “decreases” is corrected to “decreased” Line 255: DONE (line 263-264): “,” is added after respectively; “to” is added after comparison Line 256: DONE (line 264-265): “Significant effects were observed for” is added, “.” is added to end the sentence, “In particular,“ is added dominant and “dominant and” is deleted Line 258: DONE (line 267-268): “, when the plants were experiencing an event of heavy rains (Figure 1)” is deleted Line 259: DONE (line 269):”MR” is replaces by mixing ratios Line 264: DONE (line 276):”CCB” is now instead of ”CCA biomass” Line 266: DONE (line 278):”was” instead of “has been” Line 267: DONE (line 279):”yes all the % of the increased CCB at H3 at each given density were significantly higher in 2016 than 2017namely the values 22.1%, 17.7% and 12.0” Line 271: DONE (line 283):”The” is added at the beginning of the sentence, “s” is deleted from the word effects. “, i.e. from H1 to H3“ is deleted Line 274: DONE (line 286):”The MR x Den interactions were not significant for weed biomass, with the exception of those” has replace the old sentence Line 278: DONE (line 326):”in” is added Line 281: DONE (line 324- 331):”All the sentences have been rephrased the paragraphs been moved to line 324” Line 287: DONE (line 289):” the mixing ratios „has replaces “monocultures and mixtures” Line 288: DONE (line 289):”up to is added”, ”by 38.5%, 41.9% an“ is deleted, “respectively is deleted Line 289: DONE (line 293):”On the contrary” is used instead of “in contrary” Line 296-297: DONE (line 301):”weed biomass decreased as the seed density increased, up to 61.6% at 150% seed density” is added Line 298: DONE (line 303):”trends” is added Line 299: DONE (line 303):”this year” is changed to “the same year” Line 301: DONE (line 305-306):”yes the at H2, the reduction in WB was highly significant at 100% and 1505 seed density Line 304: DONE (line 310):”as mean values” has replaced “on average of all the treatments and fallow plot” Line 304: DONE (line 310-312):”Despite the high weed development in fallow plots” has replaced “However, weed growth in zero-crop density plots was still substantial” and “space” is added before “F” Line 305: DONE (line 312):”but” is deleted, “Strongly reduced WB” is added instead of “reduced weed biomass significantly” and “, in comparison with the fallow plot” is deleted Line 307: DONE (line 314):”strongly“ is deleted Line 308: DONE (line 315):”on the other hand2 instead of “however” Line 313: DONE (line 320):”Results” is instead of the experimental Line 315-316: DONE (line 320):”no significant relationship was found between WB and CCB, while” is added Line 317: DONE (line 331):” (Figure 4B). Conversely, in 2017, at” is added, Line 319: DONE (line 333):” .No” is added at the beginning of the sentence Line 321: DONE (line 345):”CCB” is corrected without biomass Line 325: DONE (line 349, line 366):” The data represented are means of n=12 (4 rows x 3 blocks) in 2016 & n=16 (4 rows x 4 blocks) in 2017.” Is deleted from each figure Line 328: DONE (line 352):” next to MR, Den, and MR x Den Line 406-407: DONE (line 432-433):” The data represented in columns are means of n= 36, 216 and 324 in 2016; and n= 48, 288 and 432 in 2017 in the fallow, monocultures and mixtures treatments, respectively.” Is deleted Line 414: DONE (line 439):” , the last after cover crop mulching,” is added Line 414: DONE (line 440-442): regarding the comment of the reviewer2”It is not clear what do you mean with diversity effect and the difference with the proportion effect. Do you mean the effect of mixture than monocrop? Please clarify since you only evaluated the MR factor”. Please see comment above, response to point 3. In addition, in the revised manuscript, a simple clarification was considered. Line 414: DONE (line 439):”and produced 54% and 40% higher biomass than the AC-monoculture in 2016 and 2017, respectively.” Is deleted Line 423: DONE (line 439):” was exceptional and” is deleted Line 426-429: DONE (line 652-654):”Further research is needed to investigate the potential use of allelopathy at the early stage to support our new finding and to determine if it is dependent on species, cultivar and environmental conditions.” Is moved to the end of the conclusion. Line 430: DONE (line 457):” Interestingly,“ is deleted from the text Line 431: DONE (line 458):” than 2017” is added Line 435: DONE (line 465):”However, at H2, AC growth and weed suppression ability were close to BM after successful establishment, suggesting” is deleted Line 438: DONE (line 658-660):”Further research is needed to understand which factors in the soil would alleviate the drought effect on AC.” Is moved to the end of the conclusion Line 439: DONE (line 469):” (almost 28%)“ is deleted Line 440: DONE (line 470):” at H2” is deleted, “probably” is deleted Line 442: DONE (line 472):”plant” instead of plants were” Line 443: DONE (line 473):”was not surprising according to what was reported about its low performance in wet conditions” is deleted and “is in accordance to literature” is added instead Line 444: DONE (line 473):” was not reflected” is deleted, “did not result” is added and “a” is added Line 445: DONE (line 475):”capacity” is instead of “of AC” Line 446: DONE (line 476):”After mulching (H3), the” is added and “, with BM dominating,” is deleted Line 447: DONE (line 477):” the situation early in the season, at” is deleted and “”with the dominance of” is added Line 448: DONE (line 478):”This” instead of “it” Line 449: DONE (line 479):” This response of BM after mulching may mainly be due to the fact that” is deleted and replaced with “actually” Line 450: DONE (line 480):” well“ is deleted Line 453: DONE (line 484):”after” is instead of “from” Line 454: DONE (line 485):” after mulching is clear evidence that BM has” is deleted and “clearly demonstrated its” and “” very wet” is replaces with “such” Line 456: DONE (line 487):”efficient” instead of “efficiency” Line 457: DONE (line 488):” confirms that and suggest” is deleted and “a” is deleted Line 458: DONE (line 661-663):”Therefore, further research is needed to determine an appropriate approach to use these two legumes in environmental engineering and landscape management to suppress weeds or to use them as natural herbicides while increasing soil fertility.” Is moved at the end of the conclusion Line 466: DONE (line 497):”in our study, despite” is added Line 472: DONE (line 661-663):”In addition, the density effect and management effect (mulching) on weed suppression did not modify the diversity effect.” Is deleted
Author Response File: Author Response.docx
This manuscript is a resubmission of an earlier submission. The following is a list of the peer review reports and author responses from that submission.
Round 1
Reviewer 1 Report
Cover crops suppress weed growth. There is nothing new here.
The mulching as described here was essentially short mowing leaving the residual biomass on the plots. It is not clear whether the D0 plots were mulched. If they were then Fig 3C at 0 seed density (no cover) represents regrowth of weeds from essentially 0 to 300 g. This needs to be clarified and discussed. Was the effects at H3 due to competition from cover crops on regrowth (faster growth and shading suppression of the weeds) or the fact that they were covered by plant material? Did the weed biomass actually decrease between H2 and H3? Explain!
In Fig 2, including a line to zero seed density is misleading. A cockroach without legs cannot jump.
Is there any data specifically on suppression of Chenopodium or Echinochloa species? This would be very important.
Need to make the scales on each of the Figure 2 and 3 the same. Including a graph averaging over all treatments
Author Response
Dear editor and Reviewers,
Thank you very much for handling our manuscript on “Weed suppression in only-legume cover crop mixtures”. Manuscript ID: agronomy-565868. We also greatly appreciate the reviewers for their complimentary and critical comments and suggestions that have been immensely helpful. We have included the reviewers’ comments immediately after this letter and responded to them individually in a point-by-point response.
We have indicated exactly how we have addressed each comment or suggestion and have described the changes that we have made in the manuscript. We have also revised the manuscript for spelling and phrasing. We hope that you find our responses satisfactory and that the revised manuscript is now acceptable for publication. We are happy to consider further revisions and thank you for your interest in our research.
For the ease of reading, we uploaded two versions of the revised manuscript, one with track changes and one with all track changes accepted. We hope that this will be useful for the new review.
Sincerely,
Heba Elsalahy, corresponding author
E-mail: [email protected]
Cell phone: +49 (0)15210777456
Tel: +49 (0) 30 -2093 46396
Please find attackmen a zip file includes
The response letter The revised manuscript-edited The revised manuscript with all track changes accepted The supplementary file-edited
Five figures belongs to the main manuscript-edited and again separately uploaded according
Author Response File: Author Response.docx
Reviewer 2 Report
Overall remark 1 :
The term "suppression" is ambiguous :
1) the weeds have a seed stock in the soil
2) the results of the study show that the mulching prevents growth of weeds but not the density and the proportion of cover crop species which limit only the growth of weeds.
Remark 2 (methodology) :
Mulching is not justified in the specific research questions (line 99). Il would have been interesting to follow the evolution of weeds only by removing the biomass to concentrate on the density and the proportion of legumes.
Remark 3 (methodology) :
What crop rotation is used on both sites?
Remark 4 (methodology) :
The weed composition is the same in 2017?
Remark 5 (methodology) :
The figure 1 brings confusion to the experimental design. H2 have the same sowing date than H1 (2016 29 Apr ; 2017 25 Apr).
Remark 6 (results):
In the figures 2 and 3, not indicate the significant differences among the treatments and the interactions (only asterisks).
Remark 7 (results):
Why the “treatment” (mixture/mono) modalities are significant in 2017 and not 2016 whatever the dates : H1 H2 H3?
Remark 8 (results):
In table 2, 10 contrasts are statistically significant and not 8.
Remark 9 (discussion) :
What is the link between seed density and crop biomass productivity ? and is there a characterization of the proportion of the initial mixture at H1 and H2 for explain the link and the weed reduction?
Remark 10 (conclusion) :
How this management of weeds is integrated by the density of the cover and the mulching within a crop rotation?
Author Response
Dear editor and Reviewers,
Thank you very much for handling our manuscript on “Weed suppression in only-legume cover crop mixtures”. Manuscript ID: agronomy-565868. We also greatly appreciate the reviewers for their complimentary and critical comments and suggestions that have been immensely helpful. We have included the reviewers’ comments immediately after this letter and responded to them individually in a point-by-point response.
We have indicated exactly how we have addressed each comment or suggestion and have described the changes that we have made in the manuscript. We have also revised the manuscript for spelling and phrasing. We hope that you find our responses satisfactory and that the revised manuscript is now acceptable for publication. We are happy to consider further revisions and thank you for your interest in our research.
For the ease of reading, we uploaded two versions of the revised manuscript, one with track changes and one with all track changes accepted. We hope that this will be useful for the new review.
Sincerely,
Heba Elsalahy, corresponding author
E-mail: [email protected]
Cell phone: +49 (0)15210777456
Tel: +49 (0) 30 -2093 46396
Please find attackment a zip file includes
The response letter The revised manuscript-edited The revised manuscript with all track changes accepted The supplementary file-edited
Five figures belongs to the main manuscript-edited and again separately uploaded according
Author Response File: Author Response.docx
Reviewer 3 Report
The manuscript reports information on the effect of two legume forage species Trifolium hybridum and Medicago lupulina as cover crops on weed suppression, presenting a two-year field experiment in Germany. Authors tested the two species in monoculture and in their mixture with different species proportions and three sowing densities. Weeds and cover crops biomass were monitored three times at around 40, 64 and 146 days after sowing, being the last harvest time around 80 days after mulching of the cover crops. Authors specifically chose two cover crop species with different growth rates assuming the increase of weed suppression by combining early and late-season competition.
General comments:
I found the paper interesting in its scope even if a bit poor of relevant findings.
Insights on the effects of cover crop mixtures and sowing densities on the weed community (species) also would have made the work more complete and interesting, helping to interpret the results. The introduction is well written, I appreciated the clarity with which the research questions were indicated, even if I would prefer to formulate hypothesis, on the basis of the background, and not open questions. The field methodology, the measurements and the statistical elaboration of data were appropriate to test the hypothesis (questions). However, I found the reporting of the results a bit heavy to follow and the discussion doesn’t respond punctually and schematically to the formulated research questions. In the Discussion section the hypothesis should be clearly recalled and verified on the basis of the results. In my opinion the work needs a general restructuring towards a more analytical presentation. In the current form the paper lacks a bit in readability. The English level is generally good, but the work needs a revision from a native speaker with scientific competences. I found some of the sentences not clear, sometimes the style is too colloquial. There are several typos and spacing errors.
Specific comments:
There is a general annoying problem with the use of acronyms of factors and parameters. They are used through the text in a confusing manner. Acronyms should be spelt out the first time they are used in the body of the paper (I suppose in Materials and Methods section), once an acronym has been defined in the body of the paper, please, don’t repeat the definition again. Exception: figure and table caption, abstract, conclusions should be self-referential. In the “Materials and Methods” section, the description of the experimental design should be completely revised. It is not clear the assignment of the two factors to the plots and subplots, the factors and relative levels should be more clearly presented, and their acronyms indicated. In the “Results” section, I would suggest not repeating values and numbers already shown in the figures and graphs as well as the p values but describe the significances by reporting for example percentages of increase or decrease (as sometimes done). Conclusions are confusing. In my opinion they should be structured following the line drawn by the research questions in the introduction, answering based on the results.
Several other suggestions are directly reported in the pdf.
Comments for author File: Comments.pdf
Author Response
Response to Reviewer #3:
I found the paper interesting in its scope even if a bit poor of relevant findings.
We would like to thank the reviewer for the positive evaluation of the work. We believe that there is a relevant finding: mixing effects were less pronounced than other factors (seed density, identity of species) and were dependent on the growing conditions. Few experiments in the literature have compared the strength of mixing effects with the effects of other factors. We have tried to clarify this main finding in the conclusion (line 631-634).
Insights on the effects of cover crop mixtures and sowing densities on the weed community (species) also would have made the work more complete and interesting, helping to interpret the results.
Thank you for this suggestion. It would have been interesting to explore this aspect. We agree that this would have been interesting. Unfortunately, we did not conduct complete vegetation surveys in all plots. However, we did counts and height measurements in 2017 for the two most dominant species. The results of these measurements are now included in the supplementary material (Figures S3 and S4). In particular, Figure S3 shows that the height measurements of the two species are both positively correlated with the total weed biomass.
The introduction is well written, I appreciated the clarity with which the research questions were indicated, even if I would prefer to formulate hypothesis, on the basis of the background, and not open questions.
We thank the reviewer for this assessment. Following the suggestion, we have translated the research questions into hypotheses (line 126-130). The new set of hypotheses is now: “(1) The two legume species differ in their ability to suppress weeds (2) Mixtures of the two legume species suppress weeds better than expected from the average of the monocultures. (3) Equiproportional mixtures suppress weeds more strongly than other mixtures. (4) Higher seed densities lead to stronger weed suppression. (5) Weed biomass in only-legume binary mixtures is negatively related to crop biomass productivity.”
The field methodology, the measurements and the statistical elaboration of data were appropriate to test the hypothesis (questions). However, I found the reporting of the results a bit heavy to follow.
We thank the reviewer for this assessment of the methodology. In terms of the reporting of the results, we agree that the text was slightly too dense and we thank the reviewer for making suggestions in the results section of the manuscript, which we have largely followed.
The discussion doesn’t respond punctually and schematically to the formulated research questions. In the Discussion section the hypothesis should be clearly recalled and verified on the basis of the results. In my opinion the work needs a general restructuring towards a more analytical presentation.
We have followed this suggestion and have restructured the discussion to match the order and content of the research questions in the introduction. Specifically, we moved the section on time dependence to the end, because it is less central for our study. We start the discussion with the comparison of the two species, because this information is needed to understand potential mixture effects, which is now in the second section of the discussion. To match this order in the introduction, we have added a new hypothesis about the differences between the two legume species.
In the current form the paper lacks a bit in readability. The English level is generally good, but the work needs a revision from a native speaker with scientific competences. I found some of the sentences not clear, sometimes the style is too colloquial. There are several typos and spacing errors.
We have thoroughly checked the manuscript for typos and spacing errors and have also followed the suggestions made by the reviewer in the manuscript.
There is a general annoying problem with the use of acronyms of factors and parameters. They are used through the text in a confusing manner. Acronyms should be spelt out the first time they are used in the body of the paper (I suppose in Materials and Methods section), once an acronym has been defined in the body of the paper, please, don’t repeat the definition again. Exception: figure and table caption, abstract, conclusions should be self-referential. In the “Materials and Methods” section, the description of the experimental design should be completely revised.
We thank the reviewer for this helpful suggestion and have checked the entire manuscript for consistency of acronyms.
It is not clear the assignment of the two factors to the plots and subplots, the factors and relative levels should be more clearly presented, and their acronyms indicated.
This comment seems to be based on a misunderstanding. We are sorry that the original text was unclear in this respect. Sub-plots (in their statistical meaning) were not part of the experiments; the term was only used to denote the two parts of the plot that were treated completely identical, but were – for technical reasons at sowing, separated by a narrow strip of around 15 cm. We have deleted the term sub-plot from the text, so as to avoid any confusion and have added a sentence to clarify this issue. Line 168-171: “Each of the 16 variants was assigned to one plot within a block. When the fallow is not included in the analysis, our design can also be considered as a two-factorial design with density as one factor (with three levels) and treatment as the other factor, determined by the presence and proportion of the two legume species (with five levels) (see Figure S1)”.
In the “Results” section, I would suggest not repeating values and numbers already shown in the figures and graphs as well as the p values but describe the significances by reporting for example percentages of increase or decrease (as sometimes done).
We follow the suggestion as already done by the reviewer in the pdf of the original manuscript.
Conclusions are confusing. In my opinion they should be structured following the line drawn by the research questions in the introduction, answering based on the results.
Because of the changes done to the research hypotheses (line 126-130) and the restructuring of the discussion, the conclusion now follows exactly the same structure, and we have therefore decided not to change it.
Several other suggestions were made by reviewer 3 directly in the pdf. Line numbers below are from original manuscript where the comment or edit was made, then, after DONE, line numbers of the corresponding place are given for the revised manuscript. The correction of some very minor spelling mistakes (which has always been done as suggested) has not been reported in the list below.
Line 16: DONE (line 16): the word “cover” has been added to the text Line 19 and elsewhere (e.g. line 85): DONE (line 19 and elsewhere, e.g. line 106): Replaced “Alsike clover” with “alsike clover”. Line 19: DONE (line 19): “L” is added Line 24: DONE (line 24): “in terms of biomass production” added, “in weed biomass across all treatment and densities by” is deleted, “of” is added. Line 26: DONE (line 26-27) “contrasts between mixtures and their respective monocultures” was replaced by “mixture treatments”. Line 28: DONE (line 31-33): “not different between 100% and 150% relative sowing density” was replaced by “Weed suppression was significantly higher at 100% and 150% seed density than 50%, but no significant differences were determined between 100% and 150% seed density.” Line 29: DONE (line 33): “no” was added, “was observed” was added, “disappeared completely” deleted Line 33: DONE (line 39-40): New keywords: asynchrony; diversification; forage legume; functional traits; interspecific interaction; mixed cropping; weed control. In addition, we have also included the term ‘asynchrony’ in Line 77 in the edited manuscript. Line 48: DONE (line 68): Reference numbers are now moved to after the reference sentence reference [8], [9], [10] and [11]" and the bracket “)” at the end of the sentence is deleted. Line 51: DONE (line 70): “be” is deleted” Line 53: DONE (line 53): “at times” is deleted Line 55: DONE (line 56): “various” is deleted Line 86: DONE (line 108): “Back” is corrected to “black” Line 87:“DONE (line 108-109): “Subsequently, we call this experimental factor ‘treatment’.” Has been changed. Line 109-114: DONE (line 142-147) all repeated data from the meteorological data have been removed. Line 114–116: DONE (line 147-150à line 262-265): The reported of meteorological data has been moved to the beginning of the "Results" section. Line 117–119: DONE: The sentence has been moved to the suggested place (now line 140-142). Line 122: DONE (line 156): the sentence has been corrected, see comment on reviewer 3, point 8. Line 125: DONE (line 159-160): “L.” has been added to both species. Line 126: DONE (line 167-171): The experimental design, the factors and the assignment in the plots have been rewritten completely as below, also see response to reviewer 3, point 8. Line 134: DONE (line 174): “kg ha-1” has been corrected. Line 135: DONE (line 175): “,” is added after respectively. Line 145: DONE (line 188-189): An explanation has been added why we applied dead seeds. Line 150: Regarding “Why not simply reporting the dates of sowing, mulching and harvest operation directly in the text?” Please see our response to the comment 5 of the reviewer 2. We believe that Figure 1 makes it easier to compare the meteorological data of the three harvest times within the two years directly with considering the dates of the sampling dates. Line 153: DONE (line 200): “Abbreviations are“ is removed, ADS is corrected to “Days After Sowing“ and also DAM is corrected to “Days After Mulching” Line 157: DONE (line 203): “(shoot)” has been deleted and “above-ground” has been corrected Line 161: DONE (line 208-209): Days after Sowing has been specified in the text, it was also specified in the caption of Figure1 Line 180: DONE (line 236): “CCS” acronym has been changed to “CCA biomass; cover crop aboveground biomass” Line 185: DONE (line 240-244): factors and acronyms have been introduced to the experimental design Line 206: the text was changed to be reliable. Line 208 – 209: DONE (line 264-266): the text was modified Line 213: DONE (line 269): “always” and (p< 0.001) are deleted, “of” is corrected to “in” and the sentence “but after mulching the density effect disappeared.” is deleted Line 215-217: DONE (line 271-274): “H1” is added,” in both the years BM monoculture produced” is added; the percentage of the productivity of BM in comparison with the other treatments is reported in the text instead of the actual values that have been reported in the graph. Line 218: DONE (line 274): “alsike clover” acronym has been deleted, and (p < 0.001) is deleted Line 220-221: DONE (line 278-281): “In each year, at H1 the mixtures” has replaced “The mixtures at H1 of each year”. “were slightly influenced by the proportion of species and” is deleted, “trend of” has replaced “gradual”. “as BM decreases in percentage respect to AC” has replaced “when BM was reduced in the mixture and replaced by AC” Line 238: DONE (line 297): the sentence was modified Line 289 (Figure 2): PARTLY ONE (line 361): The legend in Figure 2 is now reported on the right side of Panel A to be in consistence with Figure 2 and Figure 3. In addition, the “0” point was eliminated cover crop seed density. However, regarding the other two suggestions of the reviewer3, it is difficult to follow these suggestions on the graph because of the following reasons: (1) To move the legend to the right side of the graph, it will force to compress the graph to get more space and it will not be difficult to make it that consistent with Figure 2 and figure 3. (2) To report factor significance and interaction below each graph as a footnote, it will take additional space and it does not allow for fast and direct visualization of the statistical analysis. Line 306, also 317-218: NOT FOLLOWED (line 382, also 394): The reviewer suggests to move the information from the figure legend to the material and methods, but we believe that to help the reader easily assess the robustness of the underlying data, this information should be displayed here. Line 346: DONE (line 445): Replaced by “cover crop species effect” Line 349: DONE (line 601): “Generally” was deleted Line 353 Comment “Please discuss the effect of Yr on CC also in relation of the different rainfall in the two experimental years.” Line 371: DONE (line 579-581): The suggestion of the reviewer to delete this text was followed. Line 383: (line 449)“Cover crop species effect” instead of “Comparing the two crop species” Line 393: DONE (line 442): Genera in italics. Line 415: DONE (line 480): (unclear sentence): We have revised the sentence to make it clearer, by making the statement more explicit. Line 426: DONE (line 480): Deleted as suggested. Line 466: DONE (line 549): “the early stage, at” is deleted Line 488: Comment: “Why you don't consider the effect of the mulch as physical barrier?” (PARTLY) DONE, see Line 576.
Further additions and edits
Line 52: (line 72-80): “In this context, the diversity of species may also create asymmetric competition through asynchrony in species growth dynamics, i.e. mixing species of different growth rates. This strategy allows for the fast-growing species to compete with the early-season weeds and the slow-growing species to compete with the late-season weeds [12]. This approach would provide effective weed management over the whole season while decreasing the direct competition for resources between the mixed-species.” was added Line 95: “These two species were therefore supposed to represent asynchrony in growth rate and weed suppression” is added as a new sentence. Line 226: “1at H2” is used instead of “At the second harvest,” Line 236: “At H3” is used instead of “in the third harvest”
Author Response File: Author Response.docx
