Life Cycle Assessment in Protected Agriculture: Where Are We Now, and Where Should We Go Next?

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

The bibliographic review carried out on the LCA is very complete, well structured, to which only a few nuances should be noted, such as:

• On page 4, line 114-115, the phrase “The set of retrieved publications included all source types (e.g., article, review, conference paper, books, etc.)” is repeated. Like the phrase on page 5, lines 192-193, “The second part of the review allowed us to investigate how LCA works in protected agriculture” that sentence is also repeated.

• In the last paragraph of section 1.- Introduction, on line 84 it indicates that “These four approaches….” It will be advisable to specify these four approaches, since only two approaches are indicated above. Likewise, in section 6.3 the existence of seven negative effects is discussed, and I only count six, so stating it in parentheses would improve the understanding of the work. Finally, in section 7.2, it points out that there are five aspects related to ecosystems, however in the previous sentence only four aspects are computed.

 

Author Response

Dear reviewer, we thank you for your contributions and suggestions, these have enriched the scientific value of the new document, here are the answers to your concerns

Reviewer 1

The bibliographic review carried out on LCA is very complete, well structured, to which only a few nuances should be pointed out, such as:

R// We express our appreciation to Reviewer 1 for thoroughly reviewing the manuscript. All the suggestions provided have been integrated.

On page 4, lines 114-115, the sentence " The set of publications retrieved included all types of sources (e.g., articles, reviews, conference papers, books, etc.)" is repeated. Like the sentence on page 5, lines 192-193, " The second part of the review allowed us to investigate how LCA works in protected agriculture ", that sentence is also repeated.

R// We have eliminated the two repeated phrases. 

In the last paragraph of section 1.- Introduction, line 84 states that "These four approaches..." It would be advisable to specify these four approaches, since only two approaches are indicated above. Likewise, in section 6.3, the existence of seven negative effects is mentioned, and I only count six, so indicating them in parentheses would improve the understanding of the work. Finally, in section 7.2, it states that there are five aspects related to ecosystems, however in the previous sentence only four aspects are counted.

R// We have applied the changes in the mentioned sections, i.e., in the last paragraph of the introduction and sections 6.3 and 7.2. 

Regards
The authors

Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

Here is a short summary of the key points from this paper:

This paper presents a bibliometric analysis and systematic review exploring the application of Life Cycle Assessment (LCA) in protected agriculture. LCA is an important environmental assessment tool used to evaluate the potential environmental impacts of products and systems. The bibliometric analysis tracks research productivity trends on this topic over time and maps out the geographical distribution of publications, most active institutions/authors, and main research focus areas. Europe, especially Spain and Italy, has dominated contributions in this domain which aligns with the region's prominence in protected agriculture.  
Overall, this review synthesizes current knowledge on LCA in protected agriculture and points to areas needing further development for more standardized and robust evaluations to promote sustainability. my criticisms about this paper are:


1. The introduction lacks specificity when stating the purpose and rationale of the study. More details are needed on the knowledge gaps in LCA for protected agriculture that this review aims to address.

2. The search methodology for the bibliometric analysis should be described in more detail, including the specific databases searched, search terms used, inclusion/exclusion criteria, and process for screening results.

3. When describing the results of the bibliometric analysis, more specifics could be provided on publication trends over time, including numerical data on publications per year. Graphs would help illustrate the trends.

4. In the section on main research lines, there is quite a bit of repetition from the previous section on bibliometric results. This section would benefit from more interpretation and synthesis of the main topics.

5. The description of the systematic review methodology lacks specifics on the process for data extraction and analysis from the reviewed literature. Details on the coding scheme are needed.  

6. In the review of LCA methodology, the descriptions of some phases like life cycle inventory are overly general without clear connections to protected agriculture literature. More examples from the reviewed papers should be included.

7. When describing the different LCA impact categories, there should be more comparison/contrasting between the findings on each category from the reviewed protected agriculture studies.

8. The identification of knowledge gaps and future research needs relies heavily on statements from other literature reviews. More gaps specific to LCA in protected agriculture should be highlighted.

9. The conclusion does not provide a clear summation of the major findings from the systematic review and bibliometric analysis portions of the study. A more integrated conclusion is needed.

10. Throughout the paper, statements are often too broad and lack specific evidence. More citations to findings from reviewed papers are needed to substantiate the claims. for example:
Paragraph in Section 6.2.3 on Greenhouse Structure:
"The greenhouse structure usually causes the most damage to the environment when it comes to global warming and abiotic depletion. This is mostly because of the process of mining minerals and fossil fuels to make raw materials like steel, concrete, and plastic, which also releases a lot of CO2 into the air."

- This broad statement attributes greenhouse structure as the major contributor to certain environmental impacts, but does not cite any of the reviewed literature to substantiate this claim.

Paragraph in Section 6.4 on Interpretation:  
"Consequently, and according to the findings of several studies aimed at improving the environmental performance of greenhouses and roof structures, the implementation of sustainable practices and technologies is imperative."

- This sweeping statement about the need to implement sustainable practices lacks supporting evidence and is too vague regarding what specifically these "findings" demonstrated and what "several studies" showed. More specifics linking back to evidence in the reviewed literature is required to strengthen this claim.

Adding supporting citations from the reviewed literature or presenting relevant data/statistics would help to address the lack of evidence to justify these broader statements and conclusions.

Comments on the Quality of English Language

Here is a short summary of the key points from this paper:

This paper presents a bibliometric analysis and systematic review exploring the application of Life Cycle Assessment (LCA) in protected agriculture. LCA is an important environmental assessment tool used to evaluate the potential environmental impacts of products and systems. The bibliometric analysis tracks research productivity trends on this topic over time and maps out the geographical distribution of publications, most active institutions/authors, and main research focus areas. Europe, especially Spain and Italy, has dominated contributions in this domain which aligns with the region's prominence in protected agriculture.  
Overall, this review synthesizes current knowledge on LCA in protected agriculture and points to areas needing further development for more standardized and robust evaluations to promote sustainability. my criticisms about this paper are:


1. The introduction lacks specificity when stating the purpose and rationale of the study. More details are needed on the knowledge gaps in LCA for protected agriculture that this review aims to address.

2. The search methodology for the bibliometric analysis should be described in more detail, including the specific databases searched, search terms used, inclusion/exclusion criteria, and process for screening results.

3. When describing the results of the bibliometric analysis, more specifics could be provided on publication trends over time, including numerical data on publications per year. Graphs would help illustrate the trends.

4. In the section on main research lines, there is quite a bit of repetition from the previous section on bibliometric results. This section would benefit from more interpretation and synthesis of the main topics.

5. The description of the systematic review methodology lacks specifics on the process for data extraction and analysis from the reviewed literature. Details on the coding scheme are needed.  

6. In the review of LCA methodology, the descriptions of some phases like life cycle inventory are overly general without clear connections to protected agriculture literature. More examples from the reviewed papers should be included.

7. When describing the different LCA impact categories, there should be more comparison/contrasting between the findings on each category from the reviewed protected agriculture studies.

8. The identification of knowledge gaps and future research needs relies heavily on statements from other literature reviews. More gaps specific to LCA in protected agriculture should be highlighted.

9. The conclusion does not provide a clear summation of the major findings from the systematic review and bibliometric analysis portions of the study. A more integrated conclusion is needed.

10. Throughout the paper, statements are often too broad and lack specific evidence. More citations to findings from reviewed papers are needed to substantiate the claims. for example:
Paragraph in Section 6.2.3 on Greenhouse Structure:
"The greenhouse structure usually causes the most damage to the environment when it comes to global warming and abiotic depletion. This is mostly because of the process of mining minerals and fossil fuels to make raw materials like steel, concrete, and plastic, which also releases a lot of CO2 into the air."

- This broad statement attributes greenhouse structure as the major contributor to certain environmental impacts, but does not cite any of the reviewed literature to substantiate this claim.

Paragraph in Section 6.4 on Interpretation:  
"Consequently, and according to the findings of several studies aimed at improving the environmental performance of greenhouses and roof structures, the implementation of sustainable practices and technologies is imperative."

- This sweeping statement about the need to implement sustainable practices lacks supporting evidence and is too vague regarding what specifically these "findings" demonstrated and what "several studies" showed. More specifics linking back to evidence in the reviewed literature is required to strengthen this claim.

Adding supporting citations from the reviewed literature or presenting relevant data/statistics would help to address the lack of evidence to justify these broader statements and conclusions.

Author Response

Dear reviewer, we thank you for your contributions and suggestions, these have enriched the scientific value of the new document, here are the answers to your concerns:

Reviewer 2.

Here is a brief summary of the key points of this article:

This article presents a bibliometric analysis and systematic review exploring the application of Life Cycle Assessment (LCA) in protected agriculture. LCA is an important environmental assessment tool used to evaluate the potential environmental impacts of products and systems. The bibliometric analysis tracks trends in research productivity on this topic over time and traces the geographical distribution of publications, the most active institutions/authors and the main areas of research focus. Europe, especially Spain and Italy, has dominated contributions in this area, which aligns with the region's prominence in protected agriculture.

R// We would like to extend our gratitude to Reviewer 2 for the meticulous review of the manuscript. All suggestions provided by Reviewer 2 have been thoughtfully incorporated.

Overall, this review synthesizes current knowledge on LCA in protected agriculture and points out areas that need further development for more standardized and robust assessments to promote sustainability. My criticisms of this article are:

1. The introduction lacks specificity in stating the purpose and rationale for the study. More detail is needed on the knowledge gaps in LCA for protected agriculture that this review is intended to address.

R// We reviewed and greatly modified the introduction to strengthen the specificity of its proposal and justification.

2. The search methodology for the bibliometric analysis should be described in more detail, including the specific databases searched, search terms used, inclusion/exclusion criteria, and process for screening results.

R// We have improved and detailed the methodological description of the bibliometric analysis.

3. When describing the results of the bibliometric analysis, more specifics could be provided on publication trends over time, including numerical data on publications per year. Graphs would help illustrate the trends.

R// We have included more details and numerical data on the results of the bibliometric analysis in Section 4.

4. 
   In the section on main research lines, there is quite a bit of repetition from the previous section on bibliometric results. This section would benefit from more interpretation and synthesis of the main topics.

R// We significantly enhanced section 5 by eliminating redundant information from the bibliometric analysis results and providing a more concise synthesis of the main themes.

5. 
   The description of the systematic review methodology lacks specifics on the process for data extraction and analysis from the reviewed literature. Details on the coding scheme are needed.
   R// We provide a more in-depth overview of the methodology employed in the systematic review (section 2.4).
6. In the review of LCA methodology, the descriptions of some phases like life cycle inventory are overly general without clear connections to protected agriculture literature. More examples from the reviewed papers should be included.

R// We have revised all phase descriptions to improve the discussion of the reported findings, especially in the life cycle inventory phase.

7. When describing the different LCA impact categories, there should be more comparison/contrasting between the findings on each category from the reviewed protected agriculture studies.

R// We have included further comparisons between the findings of each category of the protected agriculture studies reviewed. The LCA phase 3 review markedly improved

8. The identification of knowledge gaps and future research needs relies heavily on statements from other literature reviews. More gaps specific to LCA in protected agriculture should be highlighted.

R// We have applied multiple changes to the section showing the identification of knowledge gaps and future research needs. Therefore, we further highlight the specific gaps of LCA in protected agriculture and remove phrases associated with social and economic implications.

9. The conclusion does not provide a clear summation of the major findings from the systematic review and bibliometric analysis portions of the study. A more integrated conclusion is needed.

R// We have modified the conclusions to improve their clarity and relevance and to provide concise information that is not described in the abstract section.

10. 
    
    Throughout the paper, statements are often too broad and lack specific evidence. More citations to findings from reviewed papers are needed to substantiate the claims. for example: Paragraph in Section 6.2.3 on Greenhouse Structure: "The greenhouse structure usually causes the most damage to the environment when it comes to global warming and abiotic depletion. This is mostly because of the process of mining minerals and fossil fuels to make raw materials like steel, concrete, and plastic, which also releases a lot of CO2 into the air."

R// We have modified and improved the quality of this sentence.

This broad statement attributes greenhouse structure as the major contributor to certain environmental impacts, but does not cite any of the reviewed literature to substantiate this claim.

R// We have included the references.

Paragraph in Section 6.4 on Interpretation:  "Consequently, and according to the findings of several studies aimed at improving the environmental performance of greenhouses and roof structures, the implementation of sustainable practices and technologies is imperative." This sweeping statement about the need to implement sustainable practices lacks supporting evidence and is too vague regarding what specifically these "findings" demonstrated and what "several studies" showed. More specifics linking back to evidence in the reviewed literature is required to strengthen this claim.

R// We have added more specific information about that phrase in section 6.4 to improve the discussion of the review.

Adding supporting citations from the reviewed literature or presenting relevant data/statistics would help to address the lack of evidence to justify these broader statements and conclusions.

R// We have included the references.

Regards
The authors

Author Response File: Author Response.pdf

Reviewer 3 Report

Comments and Suggestions for Authors

Manuscript by Edwin Villagrán et al. entitled "Life cycle assessment in protected agriculture: where are we now and where should we go next?" has a high level of novelty and addresses an interesting topic from the perspective of agriculture and its future. Having read the manuscript thoroughly, I conclude that the introduction is sufficiently prepared and adequately develops the scientific hypotheses and reasons for the research. The material and methods are adequately described. The results of the study are, in my opinion, compiled with a sufficient amount of relevant and recent scientific literature. The conclusions of the study are based on the results obtained. After reading the manuscript, I conclude that its stated objectives have been met. Despite the above, I have two well-meaning comments on the manuscript: i) although the methods are sufficiently described, I recommend supporting all methods with citations if possible; ii) in my opinion, the blue colour in Figure 3 is poorly readable, I kindly ask the authors to consider using a darker blue colour. Finally, thanks for the opportunity to review this interesting manuscript. I wish the authors every success in their future research.

Author Response

Dear reviewer, we thank you for your contributions and suggestions, these have enriched the scientific value of the new document, here are the answers to your concerns:

Reviewer 3.

Manuscript by Edwin Villagrán et al. entitled "Life cycle assessment in protected agriculture: where are we now and where should we go next?" has a high level of novelty and addresses an interesting topic from the perspective of agriculture and its future. Having read the manuscript thoroughly, I conclude that the introduction is sufficiently prepared and adequately develops the scientific hypotheses and reasons for the research. The material and methods are adequately described. The results of the study are, in my opinion, compiled with a sufficient amount of relevant and recent scientific literature. The conclusions of the study are based on the results obtained. After reading the manuscript, I conclude that its stated objectives have been met. Despite the above, I have two well-meaning comments on the manuscript:

R// We thank Reviewer 3 for reviewing the manuscript and providing positive comments. We apply all the recommendations. 

1. i) although the methods are sufficiently described, I recommend supporting all methods with citations if possible;

R// We have carefully reviewed the methodology. We have added two bibliographic references to the methodology section in Section 2.1. In addition, we have included the search equation in the paper.

1. ii) in my opinion, the blue colour in Figure 3 is poorly readable, I kindly ask the authors to consider using a darker blue colour.

R// We have changed the tone of the blue in Figure 3 to a darker and more distinguishable blue.

Finally, thanks for the opportunity to review this interesting manuscript. I wish the authors every success in their future research.

R// Thank you very much again for this opportunity.

Regards
The authors

Author Response File: Author Response.pdf

Reviewer 4 Report

Comments and Suggestions for Authors

This manuscript is very well written and represents a carefully planned and meticulous literature review on LCA in protected agriculture. It’s important to keep in mind that anyone looking for a synthesis of findings of LCA in such production systems may be disappointed, as that was not the objective of the authors. Their purpose was in thoroughly surveying the ways in which LCA has been applied to protected agriculture, not in summarizing the results of those LCA studies. I have just a few comments/questions/suggestions:

Line 42: The authors write that protected agriculture “is an alternative to the intensified food production that humanity has implemented in recent decades.” Protected agriculture is arguably one of the most intensified approaches to food production if measured in any of the most common ways – material inputs or yields per unit area, energy consumption or GHG emissions, cost, etc. So, as written, this sentence doesn’t seem to make sense.

Line 297: The authors write: “America has had a European influence on rooftop greenhouse research to establish urban gardening in commercial parks.” This sentence is not clear. Do they mean that America has had an influence or Europe has had an influence? I assume they mean that Europe has influenced the Americas in rooftop greenhouse research. And do they mean all of the Americas – North and South? Please reword and add necessary detail to avoid possible confusion.

Line 317: The authors have decided to use the word “techno” instead of technology here, but just in this one instance. Please spell it out.

 

Author Response

Dear reviewer, we thank you for your contributions and suggestions, these have enriched the scientific value of the new document, here are the answers to your concerns:

Reviewer 4.

This manuscript is very well written and represents a carefully planned and meticulous literature review on LCA in protected agriculture. It’s important to keep in mind that anyone looking for a synthesis of findings of LCA in such production systems may be disappointed, as that was not the objective of the authors. Their purpose was in thoroughly surveying the ways in which LCA has been applied to protected agriculture, not in summarizing the results of those LCA studies. I have just a few comments/questions/suggestions:

R// Thank you, esteemed reviewer, for your valuable feedback. The comments, questions, and suggestions are highly relevant, and each one is addressed below.

 

Line 42: The authors write that protected agriculture “is an alternative to the intensified food production that humanity has implemented in recent decades.” Protected agriculture is arguably one of the most intensified approaches to food production if measured in any of the most common ways – material inputs or yields per unit area, energy consumption or GHG emissions, cost, etc. So, as written, this sentence doesn’t seem to make sense.

R// The sentence was corrected. Please see lines 33–37.

Line 297: The authors write: “America has had a European influence on rooftop greenhouse research to establish urban gardening in commercial parks.” This sentence is not clear. Do they mean that America has had an influence or Europe has had an influence? I assume they mean that Europe has influenced the Americas in rooftop greenhouse research. And do they mean all of the Americas – North and South? Please reword and add necessary detail to avoid possible confusion.

R// We apply the pertinent adjustments. When the text mentions "United States," it refers to the continent, not the United States. Other sentences in the same section refer explicitly to the United States. See lines 283 and 284.

Line 317: The authors have decided to use the word “techno” instead of technology here, but just in this one instance. Please spell it out.

R// The meaning of “techno cluster” was included in the statement in Figure 3 (lines 316-317) and in the text (line 305).

Greetings and we remain attentive to any other request.

The authors

Regards
The authors

Author Response File: Author Response.pdf

Round 2

Reviewer 2 Report

Comments and Suggestions for Authors

I think the paper can be accepted in the current version

Comments on the Quality of English Language

I think the paper can be accepted in the current version