Screening for Low-Cadmium Accumulation in Maize Varieties Based on Species Sensitivity Distribution and Research on Soil Environmental Thresholds
Round 1
Reviewer 1 Report
The subject of the manuscript is consistent with the scope of the Journal. The abstract conveys the scope of investigations and conclusions drawn. The keywords correspond well to the scope of the research.
A field experiment was conducted to analyze the characteristics of Cd absorption and accumulation in 24 maize varieties at maturity in farmland with different levels of Cd pollution. Cluster analysis and Pareto analysis methods were used to screen for maize varieties with low Cd absorption. In addition, the environmental threshold of Cd in farmland in the study area was estimated based on the Species Sensitivity Distribution (SSD) characteristics of different maize Cd enrichment coefficients (1/BCF).
I think the paper needs some corrections:
1) the research hypotheses have not been clearly formulated,
2) add map with experiment sites to Materials and Methods section,
3) add detailed information about soils (type, granulometric composition, etc.),
4) add detailed information about methods of laboratory analyzes for cadmium, lead, organic matter, total nitrogen, alkalihydrolyzable nitrogen, available phosphorus, available potassium (method names, extractors, apparatus, etc.)?
5) add information about analytical quality control (CRM, standards, etc.),
6) add information about analysis of variance of results to Materials and Methods section,
7) add references for statistical methods to Materials and Methods section,
8) conclusions are too long; conclusions should only refer to the results of the research; move some of the general formulations (based on the assumptions) to the discussion section,
9) correct grammatical errors, add necessary spaces or remove unnecessary spaces.
10) format References section according to Instructions for Authors,
11) format all sections of the manuscript according to Instructions for Authors.
You must check your paper very exactly and correct all mistakes and complete lacking data of papers.
Author Response
Response to Reviewer 1 Comments
The subject of the manuscript is consistent with the scope of the Journal. The abstract conveys the scope of investigations and conclusions drawn. The keywords correspond well to the scope of the research.
A field experiment was conducted to analyze the characteristics of Cd absorption and accumulation in 24 maize varieties at maturity in farmland with different levels of Cd pollution. Cluster analysis and Pareto analysis methods were used to screen for maize varieties with low Cd absorption. In addition, the environmental threshold of Cd in farmland in the study area was estimated based on the Species Sensitivity Distribution (SSD) characteristics of different maize Cd enrichment coefficients (1/BCF). I think the paper needs some corrections:
Point 1: The research hypotheses have not been clearly formulated.
Response 1: Dear Reviewer, thank you for your valuable feedback on the manuscript. In response to your comments, the authors have revised the relevant sections of the preface to better clarify the research hypothesis. The revised sections explicitly state the hypothesis and provide a clear explanation of how it will be tested. These changes are highlighted in red in the manuscript. We believe that these revisions address your concerns and enhance the overall quality of the manuscript.
Point 2: Add map with experiment sites to Materials and Methods section.
Response 2: Dear Reviewer, thank you for your suggestion to add a map with experiment sites to the Materials and Methods section. The authors have followed your suggestion and added a map to section 2.1 of the manuscript, which provides a visual representation of the experiment sites. We believe that this addition enhances the clarity and comprehensiveness of the manuscript. Thank you for your valuable feedback
Point 3: Add detailed information about soils (type, granulometric composition, etc.).
Response 3: Dear Reviewer, thank you for your suggestion to add detailed information about the soil at the experiment sites. The authors have followed your suggestion and added this information to section 2.1 of the manuscript, which is highlighted in red. This additional information can help readers better understand the soil conditions at the experiment sites, allowing them to better evaluate the research results. We believe that this addition enhances the clarity and comprehensiveness of the manuscript. Thank you for your valuable feedback.
Point 4: Add detailed information about methods of laboratory analyzes for cadmium, lead, organic matter, total nitrogen, alkalihydrolyzable nitrogen, available phosphorus, available potassium (method names, extractors, apparatus, etc.)?.
Response 4: Dear Reviewer, thank you for your suggestion to add details of the laboratory analysis methods for the relevant indicators. The authors have followed your suggestion and added this information to section 2.4 of the manuscript, which is highlighted in red. This additional information can help readers better understand the laboratory analysis methods used in the study, allowing them to better evaluate the research results. We believe that this addition enhances the clarity and comprehensiveness of the manuscript. Thank you for your valuable feedback.
Point 5: Add information about analytical quality control (CRM, standards, etc.).
Response 5: Dear Reviewer, thank you for your suggestion. We have carefully considered your comment and have added the relevant information about analytical quality control (CRM, standards, etc.) in section 2.4 of the manuscript. This information has been highlighted in red for your convenience. We believe that this addition strengthens the rigor and reliability of our research, and we appreciate your valuable feedback.
Point 6: Add information about analysis of variance of results to Materials and Methods section.
Response 6: Dear Reviewer, thank you for your suggestion. We have carefully considered your comment and have added information about the analysis of variance of the results to the Materials and Methods section. We believe that this addition further strengthens the rigor and reliability of our research, and we appreciate your valuable feedback. We have made the corresponding changes in the manuscript and marked them in red.
Point 7: Add references for statistical methods to Materials and Methods section.
Response 7: Dear Reviewer, thank you for your suggestion. We have carefully considered your comment and have added references for statistical methods to the Materials and Methods section, specifically in section 2.5 of the manuscript. We believe that this addition further strengthens the rigor and reliability of our research, and we appreciate your valuable feedback.
Point 8: Conclusions are too long; conclusions should only refer to the results of the research; move some of the general formulations (based on the assumptions) to the discussion section.
Response 8: Dear Reviewer, thank you for your suggestion to shorten the Conclusions and focus on the key findings. The authors have followed your suggestion and revised the Conclusions section to be more concise and focused. They have also removed some general statements and assumptions that could be moved to the Discussion section. These changes are highlighted in red. We believe that these revisions improve the clarity and coherence of the manuscript. Thank you for your valuable feedback.
Point 9: Correct grammatical errors, add necessary spaces or remove unnecessary spaces
Response 9: Dear Reviewer, thank you for your attention to detail in reviewing the manuscript. In response to your comments, the authors have carefully reviewed the manuscript and corrected any grammatical and space usage errors. These changes are highlighted in red for your convenience. We believe that these revisions improve the readability and clarity of the manuscript.
Point 10: Format References section according to Instructions for Authors.
Response 10: Dear Reviewer, thank you for your attention to detail in reviewing the manuscript. In response to your comments, the authors have revised the format of the references according to the Instructions for Authors. These changes are highlighted in red for your convenience. We appreciate your valuable feedback.
Point 11: Format all sections of the manuscript according to Instructions for Authors
Response 11: Dear reviewer, according to your comments, the author has revised the format of the entire text according to the Instructions for Authors. For convenience, these changes are marked in red.
Reviewer 2 Report
In the submitted manuscript, only one issue is considered: the accumulation of Cd in different varieties of maize on soil with different pH and Cd concentration. The topic is unoriginal, has no scientific value. However, it has practical value, with good statistics and a good presentation of the results. Formally, the authors solved the problem. The academic editor must determine whether the quality of the submitted manuscript is sufficient for publication in a highly rated journal.
The presented manuscript deals with the problem of Cd accumulation in different varieties of maize. The work was done using only one method, although with very good statistics. The results obtained are of practical importance, but have no scientific value.
In the introduction section, as well as throughout the text, especially in the Discussion section, a lot of general phrases that do not carry any scientific information should be significantly reduced.
In the Methods section, provide an available reference or fully describe the method for determining Cd.
Figure 4 indicate which colors correspond to which clusters
Figure 5 indicate which coefficients correspond to which options
331, 341, 349 - indicate references according to the requirements of the journal
Author Response
Response to Reviewer 2 Comments
In the submitted manuscript, only one issue is considered: the accumulation of Cd in different varieties of maize on soil with different pH and Cd concentration. The topic is unoriginal, has no scientific value. However, it has practical value, with good statistics and a good presentation of the results. Formally, the authors solved the problem. The academic editor must determine whether the quality of the submitted manuscript is sufficient for publication in a highly rated journal.
Point 1: The presented manuscript deals with the problem of Cd accumulation in different varieties of maize. The work was done using only one method, although with very good statistics. The results obtained are of practical importance, but have no scientific value.
Response 1:
Dear Reviewer, thank you for your detailed evaluation of the manuscript. We appreciate your insights on the originality, scientific value, and practical importance of the research. While we understand your concerns about the narrow focus of the study and its limited scientific value, we believe that the practical importance of the research and the rigorous statistical analysis of the results make it a valuable contribution to the field.
In addition, in this study, we adopted novel methods to screen for low-Cd accumulation maize varieties and to estimate the environmental threshold of Cd in soil based on the Species Sensitivity Distribution (SSD) characteristics of different maize Cd enrichment coefficients (1/BCF). These methods are rarely used in maize Cd pollution research, but can provide more scientific and reasonable standards and suggestions.
The SSD method is an ecological risk assessment-based method that can consider the sensitivity differences of different species to pollutants, and derive the pollutant thresholds that protect the diversity and function of ecosystems. This method has been widely applied to the establishment of environmental quality standards (SEQSs) for pollutants such as heavy metals, organic pollutants and radioactive elements in environmental media such as water, soil and plants. However, SSD method is rarely used in maize Cd pollution research, and most studies are based on the Cd enrichment coefficient or transfer factor of a single or a few varieties to estimate the safe threshold of Cd in soil. This method ignores the sensitivity differences of different maize varieties to Cd, which may lead to overestimation or underestimation of the soil Cd threshold, thus affecting the quality safety of maize and soil environmental quality. Therefore, we adopted the SSD method to estimate the environmental threshold of Cd in soil to ensure that 95% of maize varieties would not be polluted by Cd in soil. This is a more scientific and reasonable method, and also an innovative and valuable attempt.
Therefore, we hope that you will recognize our research and provide us with further guidance and suggestions. Thank you!
Point 2: In the introduction section, as well as throughout the text, especially in the Discussion section, a lot of general phrases that do not carry any scientific information should be significantly reduced.
Response 2: Dear Reviewer, thank you for your valuable feedback on our manuscript. We have carefully considered your comment regarding the presence of general phrases that do not carry any scientific information in the introduction and discussion sections. To address this issue, we have revised these sections to improve their clarity and readability. We have broken up long sentences into shorter ones, added citations to clearly indicate which information came from which source, rearranged sentences for improved logical flow, and removed repetitive phrases. These revisions aim to reduce the number of general phrases that do not provide specific scientific information and to improve the overall quality of the manuscript. These changes are highlighted in red in the manuscript. We hope that these revisions address your concerns and improve the manuscript.
Point 3: In the Methods section, provide an available reference or fully describe the method for determining Cd.
Response 3: Dear Reviewer, thank you for your valuable feedback on our manuscript., we have revised the manuscript to include this information. In section 2.4, we have added a detailed description of the method used to determine Cd. We believe that this revision improves the quality of our manuscript by providing readers with a clear and complete understanding of the method used to determine Cd in our study. This information will enable readers to evaluate the rigor and validity of our results and to replicate our methods in their own research. We hope that this revision addresses your concern and improves the manuscript.
Point 4: Figure 4 indicate which colors correspond to which clusters
Response 4: Dear Reviewer, thank you for your valuable feedback on our manuscript. In response to your comment regarding the need to indicate which colors correspond to which clusters in Figure 4 (now Figure 5 in the revised manuscript), we have revised the figure to include this information. In the revised version of Figure 5, we have added dashed lines to separate the different clusters and included a note indicating which color corresponds to each cluster. This revision makes it easier for readers to understand the figure and interpret the data presented. We hope that this revision addresses your concern and improves the clarity of Figure 5.
Point 5: Figure 5 indicate which coefficients correspond to which options
Response 5: Dear Reviewer, thank you for your valuable feedback on our manuscript. In response to your comment regarding the need to indicate which coefficients correspond to which options in Figure 5 (now Figure 6 in the revised manuscript), we have revised the figure and its caption to include this information. In the revised version of Figure 6, we have added text labels in the Figure and also included a note in the figure caption to provide additional clarification. These revisions make it easier for readers to understand the figure and interpret the data presented. We hope that these revisions address your concern and improve the clarity of Figure 6.
Point 6: 331, 341, 349 - indicate references according to the requirements of the journal
Response 6 Dear Reviewer, thank you for your valuable feedback on our manuscript. We have revised the manuscript to include this information. In the revised version of the manuscript, we have indicated the references according to the requirements of the journal and highlighted these changes in red for your convenience. We hope that these revisions address your concern and improve the quality of our manuscript.
Reviewer 3 Report
Reduce the cadmium (Cd) content in crops and decrease human Cd intake that are important for human health. Although there are several similar studies published recently, this study by Cao et al. should still provide valuable information to bring the benefit for local concerns/applications with different Maize varieties.
The manuscript is okay to read. The figures’ quality looks fine.
However, some results are confusing, the statement and the result are inconsistent. The authors need to check the results carefully.
1) The total soil Cd content in test site 1 and in test site 2 are confusing.
Such as line 16 in Abstarct “with total soil Cd content ranging from 0.95 to 1.76 mg·kg−1 at test site 1 and from 1.81 to 2.71 mg·kg−1 at test site 2.”
So, the total soil Cd content in test site 2 should be higher than test site 1. But the statement in line 225 “which is related to the lower soil Cd content in test site 2 compared to test site 1”. The author used this conclusion throughout the text.
2) The total Cd content of maize grains in test site 1 and in test site 2 are very confusing too.
In line 213: ”The mean total Cd content of maize grains in test site 1 was 0.035 ± 0.032 mg kg−1 , with a range of 0.087 to 0.196 mg kg−1.” In line 220: “ The mean total Cd content of maize grains in test site 2 was 0.150 ± 0.021 mg kg−1 , with a range of 0.01 to 0.07 mg·kg−1 for grain Cd content.”
In the statement, the number here in test site 1 was 0.035 ± 0.032 mg kg−1, in test site 2 was 0.150 ± 0.021 mg kg−1, so in test site 2 obviously should be higher than in test site 1. Why it showed a big change when refer to “with a range of”? Why a higher the total Cd content of maize grains in test site 2 can be calculated to a lower content of 0.01 to 0.07 mg·kg−1 vs 0.087 to 0.196 mg kg−1 in test site 1?
Other minors:
The statement in line 274 “Compared to the results of the trial in 2020,” The author didn’t refer to other trials from different years.
The manuscript is okay to read.
Author Response
Response to Reviewer 3 Comments
Reduce the cadmium (Cd) content in crops and decrease human Cd intake that are important for human health. Although there are several similar studies published recently, this study by Cao et al. should still provide valuable information to bring the benefit for local concerns/applications with different Maize varieties.
The manuscript is okay to read. The figures’ quality looks fine.
However, some results are confusing, the statement and the result are inconsistent. The authors need to check the results carefully.
Point 1: The total soil Cd content in test site 1 and in test site 2 are confusing.
Response 1: Dear Reviewer, thank you for bringing to our attention the confusion regarding the total soil Cd content in test site 1 and test site 2. We apologize for any inconvenience caused. During the writing process, we inadvertently reversed the total soil Cd content for test site 1 and test site 2, resulting in inconsistencies between the abstract, section 3.1, and the figures. We have now corrected these errors in the revised version of the manuscript and highlighted these changes in red for your convenience. We hope that these revisions address your concern and improve the clarity of our manuscript.
Point 2: The total Cd content of maize grains in test site 1 and in test site 2 are very confusing too.
Response 2: Dear Reviewer, thank you for bringing to our attention the confusion regarding the total Cd content of maize grains in test site 1 and test site 2. We apologize for any confusion caused. During the writing process, we inadvertently reversed the total Cd content of maize grains for test site 1 and test site 2, resulting in inconsistencies between the abstract, section 3.2, and the figures. We have now corrected these errors in the revised version of the manuscript and highlighted these changes in red for your convenience. In addition, we have also standardized the number of decimal places for the Cd content of maize plants to three digits. We hope that these revisions address your concern and improve the clarity of our manuscript.
Point 3: The statement in line 274 “Compared to the results of the trial in 2020,” The author didn’t refer to other trials from different years.
Response 3: Dear Reviewer, thank you for your feedback. We have noted the error in line 274 and have made the necessary corrections, which are highlighted in red in the manuscript. This was an error on our part and we did not intend to refer to other trials from different years. We hope that these revisions address your concern and improve the clarity of our manuscript. Thank you for your valuable feedback.
Round 2
Reviewer 1 Report
The authors addressed reviewer comments. All sections are rather good.
The corrected manuscript entitled “Screening for Low-Cadmium Accumulation Maize Varieties Based on Species Sensitivity Distribution and Research on Soil Environmental Thresholds” can be accepted for publishing in Agronomy.
Reviewer 3 Report
The authors have satisfactorily addressed all of my comments. The authors did a good revision.
Please check all the formatting carefully before the publication.
