Externalities of Pesticides and Their Internalization in the Wheat–Maize Cropping System—A Case Study in China’s Northern Plains
Round 1
Reviewer 1 Report
Refers to the manuscript: Externalities of pesticides and their internalization in the wheat-maize cropping system - A case study in China's northern plains.
Thank you for a very interesting case study on assessing the external costs of pesticide use in the wheat and corn farming system in China's northern plains. These studies were designed and conducted correctly. Below are some comments. It would be appropriate to consider their inclusion in the manuscript or clarification. I wish you much success in continuing and expanding your research.
Detailed comments:
1. The abstract should be more precise, detailing the purpose, concept and methodology of the research. The abstract of a good article in a reputable journal always ends with outlining the benefits of the obtained results and recommendations as a solution to the problem under study. This information is missing from the abstract.
2. Keywords should not repeat phrases from the title of the manuscript: "Pesticides", "Externalities". Please change it.
3. In the introduction, the authors made an interesting review of the literature, but the current state of knowledge should be clearly and precisely defined. The introduction should be supplemented with newer items. In the introduction, a hypothesis should be put forward: what is the difference between this work and the available literature? The last paragraph closing the introductory part always emphasizes the innovative aspects of the conducted experiments with a clear goal and the significance of the obtained research results for the broadly understood environment. The purpose of the conducted research is not precisely presented, it should be formulated in more detail. The manuscript introduction should be expanded and reformatted to provide a more comprehensive approach.
4. The research methods were correctly selected and correctly described. However, the authors did not carry out a statistical analysis that would confirm the reliability of the obtained results. This should be supplemented.
5. The results of the conducted research have been carefully developed and documented. The discussion of the obtained results was carried out correctly. All figures and tables presented in the text are legible and correctly interpreted. I have no objections.
6. Conclusions need to be improved a bit. They must be persuasive statements about what was found to be novel, impacting strong support for the results and discussion. It should be clearly stated what is new in the international literature of the conducted research and the final recommendations should be emphasized.
7. Some of the literature items are old, it may be worth replacing them with newer reports.
After minor corrections, I recommend publishing this article.
Author Response
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Author Response File: 
Author Response.doc
Reviewer 2 Report
I reviewed the article titled: Externalities of pesticides and their internalization in the wheat-maize cropping system -A case study in China's northern plains" and I found it interesting and well prepared. Research conducted by the Authors are comprehensible and interesting to read.
In general, conceptualization was done accordingly to proper manners in agronomy sciences. Presentation of the results is on a sufficiently high level. Despite that, the topic is difficult to be considered as an innovative one. Still, the background was nicely introduced in pinpointing crucial problems that need to be solved making it reasonable to follow this kind of research. Methods selected by the authors have been reasonably chosen according to the actual state of knowledge but it’s description needs some corrections. As for the result section, it is worth mentioning that obtained results are indeed scientifically valuable. Descriptive presentation of obtained outcomes is pleasant to read and easy to understand. There are some minor corrections that must be implemented before recommending the manuscript to be published.
Please see the detailed review below:
I Introduction
· The sentence, "On average, approximately 99.9% of chemical pesticides used are released directly into the environment (Kumar et al., 2021)," lacks context or explanation. It would be beneficial to clarify what is meant by "released directly into the environment" and provide more details on the study by Kumar et al. to understand the significance of this statement.
· The sentence, "Most studies assessing external costs from pesticides are based on toxicity impacts on humans and the environment (Peter et al., 2012)," could be improved by providing more context about the specific external costs examined in those studies.
· The sentence, "The WWSM system is the main cropping pattern in the North China Plain, where wheat and maize production account for approximately 50% and 40% of the total national production, respectively (Zhou et al., 2019)," could be improved by providing more context about the WWSM system and its significance in the region. Additionally, including more details about the study by Zhou et al. would provide further support for the information presented.
II Materials and Methods
· In the sentence, "The underlying logic of these calculations is to consider China's financial expenditure on agriculture as the total input for ensuring food security," it would be clearer to mention that the calculations aim to estimate the positive externality of pesticide use based on China's financial expenditure on agriculture.
· In the sentence, "The external costs of pesticide use must be internalized and reflected in the market," it would be helpful to explain why it is important to internalize the external costs of pesticide use.
· In the sentence, "Agro-ecological taxes can serve as an effective economic instrument to internalize the external costs associated with pesticide use," it would be beneficial to briefly explain how agro-ecological taxes work and their role in internalizing external costs.
· In the sentence, "The eco-tax ratio can be used as a reference," it would be useful to explain what the eco-tax ratio represents, not only how it is calculated.
III Results
· In the sentence, "According to Eq. (5-6), the positive external value of pesticide use is 171.2 USD ha-1 for the WWSM system, summed from wheat (59.3 USD ha-1) and maize (111.9 USD ha-1)," it would be beneficial to explain the significance of the positive external value.
· The sentence, "Pesticides used in maize production accounted for most (283.2 USD ha-1, 66.8%) of the total external costs in the WWSM," would be stronger with additional context.
IV discussion
· In the sentence, "The heavy use of pesticides in Botou has led to highly externalities," it would be clearer to specify the type of externalities resulting from the heavy pesticide use.
· In the sentence, "Our research data shows that the pesticide usage in Botou City is 14.09 kg ha-1," it would be helpful to include the time period for which this pesticide usage is measured
· In the sentence, "Therefore, Botou has great potential for pesticide reduction and efficiency improvement," it would be beneficial to provide supporting evidence or reasons explaining why Botou has this potential.
· In the sentence, "The risk can be minimized by wearing personal protective equipment (PPE)," it would be useful to provide additional information on the effectiveness of PPE in reducing pesticide exposure.
· In the sentence, "The top two active ingredients in WWSM are sourced only from maize production," it would be beneficial to briefly explain the significance of these active ingredients within the context of the research.
· In the sentence, "However, the same effect could theoretically be achieved with a single application of imidacloprid," it would be helpful to provide reasons or evidence supporting why using a single application of imidacloprid is more environmentally friendly compared to using clothianidin.
V Conclusions
The conclusions are supported by both results and discussion sections. It is proper. Unfortunately, the opportunity to inform about the future research demands was not fulfilled at all. This should be corrected.
Author Response
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Author Response File: Author Response.doc
Reviewer 3 Report
The work must be published in the newspaper in question. There were very few corrections and suggestions. Everything has been noted in the attached manuscript copy . All these considerations can be resolved jointly between the editor and the authors.
Comments for author File: 
Comments.pdf
Author Response
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Author Response File: Author Response.docx
Reviewer 4 Report
The manuscript by Li and colleagues shows how relevant is the impact of pesticides is at several points often neglected, such as applicators and fauna. More important yet is to include such impacts, in economic terms, in crop production. I found the manuscript clear and easy to follow, and have no further comments to it, except that a few typos that require attention.
I understand that it is very complicated to build indexes or quotients that capture the whole scenario or context of a problem, but medical cost for intoxication in human, yield losses by pollinator decrease, research invested in reducing costs of pesticide use, etc, should be at least addressed in the discussion section. Please be aware that mode of application contributes enormously to pesticide drift. Also, wheat and maize are not pollinator dependent, so please mention this. Also important is to mention the cost of losing biodiversity for other ecosystems, including agroecosystems, i.e. the effects would be noticeable in other crop systems.
Author Response
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Author Response File: Author Response.doc
Reviewer 5 Report
This manuscript (sustainability-2477756) explored on the external costs of pesticides and internalized them into the market prices of wheat and maize crops in the China Northern Plain, and provide a method to internalize the externalities of pesticide use in farming systems. It was found that the negative external costs of pesticide use in Botou outweigh the positive external values, and the herbicide usage yields more detrimental effects compared to the usage of insecticide and fungicide. And the author proposes an ecological tax on pesticide users by the result of this study. The manuscript is written generally. However, the data is sufficient to support its main conclusion. It meets in the present form the criteria to be published in the journal. However, minor revision should be addressed prior to publication.
Abstract
In the sentence “External costs varied significantly according to environmental receptors: applicators accounted for 45% of the total external costs, followed by pickers (32%), consumers (11%), groundwater (4.5%), fish (3.9%), beneficial insects (1.7%), birds (1.3%), and bees (1.1%).”, the sum of these values has exceeded 100%, please check the data carefully,
Introduction
Why do we study the lethal and sublethal effects of patchouli essential oil emulsion for the tomato leafminer?
Materials and methods
In “2.1. Study site and data collection”, 12.7 °, or 12.7 ℃ ?
Result
Why choose Botou City, is this place representative? Why don't you choose more places in different provinces?
In table 1, How do you define what is the main active ingredients, because there are two ingredients in many pesticides,
Please check the correct spelling of “Emamectin·Benzoate”,
In the first paragraph of page four, “LC50” should be “LC50”, “50” needs to be subscripted,
In the first paragraph of page fiver, there should be a “.” between “Eq. (3)” and “the”,
In “3.2. Net value of pesticide use”, in the words “171.2 USD ha-1”, “-1” needs to be superscripted,
Author Response
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Author Response File: Author Response.doc
Reviewer 6 Report
1. General Comments
The present paper, very interesting to read, refers a high problem in cropping systems namely the use of pesticides (insecticides, fungicides, and herbicides). The authors search a way to measure, numerically, the costs and benefits of the use of these products allowing to choose an environmentally and low-cost solution. It is good to have papers concerning this subject. As a scientific reader, I found the paper very interesting and understandable.
2. Section by section
2.1. - Introduction
This section is very comprehensible, interesting and has recent bibliography to support the discussion made. The authors present a good review about pesticides toxicity emphasizing the differences between the products analysed.
The article also provides a good revision about the active ingredients used as insecticides showing that neonicotinoids and pyrethroids are less toxic for terrestrial organisms.
2.2. - Material and Methods
Material and Methods are easy to understand. The mathematical model is well explained. For the reader is simple to understand the equations used in the presented work and apply the methodology developed in other situations. Consequently, is possible to replicate the assay with the information provided. Statistical methods seem to be appropriated.
2.3. - Results
Results are well presented; graphic component is interesting and gives information easy to understand.
2.4. Discussion:
Discussion is well conducted and points out a relevant approach to manage the choice of pesticides to be used in cropping systems. Discussion is well supported in bibliographic references.
The work has a relevant practical application, supported by numerical indicators.
Author Response
Please see the attachment.
Author Response File: Author Response.doc
