Economic and Environmental Sustainability of Olive Production: A Case Study

Round 1

Reviewer 1 Report

The authors propose a manuscript titled “Economic and Environmental Sustainability of Olive Production: A Case Study”. The article is original, well structured and written. The authors consider economic feasibility and life cycle assessment of three different olive system cultivation in the Mediterranean area through joint use of economic and environmental indicators, to identify the key elements to optimize their economic performance but also a minor environmental impact. In particolar the manuscript were considered three different management systems of olive cultivation: Fully Irrigated, Partially Irrigated and Non-Irrigated, while the economic sustainability evaluation of olive cultivation has been carried out through economic indicators taking into account all cost and revenue factors of olive cultivation in each management system. The conclusions show many interesting data and in particular those on the economically sustainable concerning revenue obtained and on management strategies for my point of view it's are the more important. I personally completely agree with the authors. I analyzed the text and gave some few suggestions in order to publishing the manuscript. The concepts are expressed in the correct way on a very interesting and actual topic.

Introduction:

Well done, few observations.

Line 33-34. Please complete the period in the suggested way. “The olive tree (Olea europaea L.) is a species of the Oleaceae family originating from a dry-subtropical climate (choose a reference), from the eastern Mediterranean (Perrino et al. 2011)”.

Lines 35-37. Please complete the period in the suggested way. “….and represents a considerable economic, agricultural and ornamental concern, also playing a role in the maintenance of biodiversity, showing a link with some crop wild relatives of considerable conservation value [e.g. Perrino et al. 2014, choose another one for this topic], and benefit in the economic and social dimensions in rural areas. [1,2,3,4].

References to be added

• Perrino, E.V.; Calabrese, G.; Ladisa, G., Viti, R.; Mimiola, G. First data of vascular flora and floristic biodiversity on secular olive groves in Apulia (Primi dati sulla biodiversità della flora vascolare di oliveti secolari in Puglia). Informatore Botanico Italiano, 2011, 43, 39-64.
• Perrino, E.V.; Wagensommer, R.P.; Medagli, P. The genus Aegilops (Poaceae) in Italy: taxonomy, geographical distribution, ecology, vulnerability and conservation. Systematics and Biodiversity 2014, 12, 331-349.

Line 63-64. Please add a references for crucial concepts that I suppose there are not a discovers from authors. “…In Italy, the highest deficit values are recorded in the southern areas, including Sicily, Sardinia and Puglia (choose a reference)”

2. Olive surfaces and production in Sicily region

Figure 1. It would be better to have the geographic coordinates in the map on the x, y axis.

3. Material and Method and 4. Results

Well done. No observations. The figures and tables are clear.

Author Response

Detailed Responses to the Reviewer #1

Economic and Environmental Sustainability of Olive Production: A Case Study

 

Authors’ response: We would like to thank the reviewers for the useful comments on our manuscript. We have made any effort to improve the paper. In attempting to fully respond to your question we had to take also into account what the other reviewers asked to do. Kindly find below all comments with our detailed responses. We have indicated clearly (in red) where in the revised manuscript changes have been made to address your valuable comments.

 

-Reviewer’s comment: The authors propose a manuscript titled “Economic and Environmental Sustainability of Olive Production: A Case Study”. The article is original, well structured and written. The authors consider economic feasibility and life cycle assessment of three different olive system cultivation in the Mediterranean area through joint use of economic and environmental indicators, to identify the key elements to optimize their economic performance but also a minor environmental impact. In particolar the manuscript were considered three different management systems of olive cultivation: Fully Irrigated, Partially Irrigated and Non-Irrigated, while the economic sustainability evaluation of olive cultivation has been carried out through economic indicators taking into account all cost and revenue factors of olive cultivation in each management system. The conclusions show many interesting data and in particular those on the economically sustainable concerning revenue obtained and on management strategies for my point of view it's are the more important. I personally completely agree with the authors. I analyzed the text and gave some few suggestions in order to publishing the manuscript. The concepts are expressed in the correct way on a very interesting and actual topic..

Authors’ response: Thanks for your comment on the paper. We welcome your appreciation.

 

-Reviewer’s comment: Introduction: Well done, few observations.

Line 33-34. Please complete the period in the suggested way. “The olive tree (Olea europaea L.) is a species of the Oleaceae family originating from a dry-subtropical climate (choose a reference), from the eastern Mediterranean (Perrino et al. 2011)”.

Authors’ response: Thanks for your comment on the paper. We have included the references as you suggested.

 

-Reviewer’s comment: Lines 35-37. Please complete the period in the suggested way. “….and represents a considerable economic, agricultural and ornamental concern, also playing a role in the maintenance of biodiversity, showing a link with some crop wild relatives of considerable conservation value [e.g. Perrino et al. 2014, choose another one for this topic], and benefit in the economic and social dimensions in rural areas. [1,2,3,4].

Authors’ response: Thanks for your comment on the paper. We have included the references as you suggested.

 

-Reviewer’s comment: References to be added

Perrino, E.V.; Calabrese, G.; Ladisa, G., Viti, R.; Mimiola, G. First data of vascular flora and floristic biodiversity on secular olive groves in Apulia (Primi dati sulla biodiversità della flora vascolare di oliveti secolari in Puglia). Informatore Botanico Italiano, 2011, 43, 39-64.

Perrino, E.V.; Wagensommer, R.P.; Medagli, P. The genus Aegilops (Poaceae) in Italy: taxonomy, geographical distribution, ecology, vulnerability and conservation. Systematics and Biodiversity 2014, 12, 331-349..

Authors’ response: Thanks for your comment on the paper. We have included the references as you suggested.

 

-Reviewer’s comment: Line 63-64. Please add a references for crucial concepts that I suppose there are not a discovers from authors. “…In Italy, the highest deficit values are recorded in the southern areas, including Sicily, Sardinia and Puglia (choose a reference)”.

Authors’ response: Thanks for your comment on the paper. We have included the references as you suggested.

 

-Reviewer’s comment: 2. Olive surfaces and production in Sicily region

Figure 1. It would be better to have the geographic coordinates in the map on the x, y axis.

Authors’ response: Thanks for your comment on the paper. We have amended the have the geographic coordinates as you suggested. We have amended the geographic coordinates of the Farm in the text.

 

-Reviewer’s comment: 3. Material and Method and 4. Results

Well done. No observations. The figures and tables are clear.

Authors’ response: Thanks for your comment on the paper. We welcome your appreciation.

 

Author Response File: Author Response.pdf

Reviewer 2 Report

The LCA and WSI methods and economic indicators used to assess the environmental sustainability of olive oil production. Manuscript entitled "Economic and Environmental Sustainability of Olive Production: A Case Study" it is not written clearly and before publication need additional improvement.

Three different management system were analysed and data for research was obtained  from field experiment conducted in University of Catania. Unfortunately no experiment information and authors did not provide the length and period of experiment  also the basic yield data, one of  basic indicators useful for analysed of the environmental impact assessment. Additionally many information, divided in 4 groups and used in this study, was collected from surveys among olive growers. How many surveys were carried out?

These two data sources (University research and survey)  poorly documented at manuscript. There is no clear definition of the extent to which presented data (from the field experiment and the questionnaire were used) for LCA and WSI analysis (see lines 184-195 and 232-239). How f.ex. estimated water consumption for FI and PI management. Basic on University experiment research or information collected from farmers. 

On the other hand, the authors provided a detailed description of the plantation area, olive and oil production in Sicily. My opinion, this chapter (Olive surface and production in Sicily region) can be shortened or removed without any negative influence on the manuscript quality. 

The same remark regarding literature data presented in table 2. Information presented in this table was repeated in references list in the same number as in table 2.

Please check and correct presented data. Water irrigation for treatment FI was 486/per ha while for PI treatment 243 l per ha. In table 6 water consumption increased 103 times fold for PI treatment and 206 times fold for FI comparing to NI. Which  data is correct?

Authors in table 4 presented revenue value and value of 1 kg olive oil and in table 1 described economic indicators. Basic on olive production data (reviewer calculation): in treatment NI olive oil production was 566 kg, PI - 669 kg, FI - 766 kg. If the presented calculation is correct, please check the WSI per kg presented in table 8.

Please check and correct citation from line 298

 

 

Author Response

Detailed Responses to the Reviewer #2

 

Economic and Environmental Sustainability of Olive Production: A Case Study

 

Authors’ response: We would like to thank the reviewers for the useful comments on our manuscript. We have made any effort to improve the paper. In attempting to fully respond to your question we had to take also into account what the other reviewers asked to do. Kindly find below all comments with our detailed responses. We have indicated clearly (in red) where in the revised manuscript changes have been made to address your valuable comments.

 

-Reviewer’s comment: The LCA and WSI methods and economic indicators used to assess the environmental sustainability of olive oil production. Manuscript entitled "Economic and Environmental Sustainability of Olive Production: A Case Study" it is not written clearly and before publication need additional improvement.  

Authors’ response: Thanks for the valuable comments on our paper, which have improved its content, and overall value.

-Reviewer’s comment: Three different management system were analysed and data for research was obtained  from field experiment conducted in University of Catania. Unfortunately no experiment information and authors did not provide the length and period of experiment also the basic yield data, one of basic indicators useful for analysed of the environmental impact assessment. Additionally many information, divided in 4 groups and used in this study, was collected from surveys among olive growers. How many surveys were carried out?

Authors’ response: Thanks for your valuable comments. In this study, applying the LCA methodology, the environmental impacts of three olive management models are assessed and quantified, comparing the three different irrigation systems: 1 FI treatment: with drip irrigation (100% return of ET crop evapotranspiration); 2 PI treatment: partial root-zone drying - PRD (50% ET); 3 NI treatment: not irrigated.

The experimentation is carried out at the Valle dei Margi farm in Grammichele (Catania) (geographic coordinates Lat. 32°15’00’’ and Lon. 14°35’55’’). These are 3 contiguous and homogeneous plots, in which the 3 different irrigation management treatments were carried out (FI, PI, NI). The experiment was carried out in the year 2019-2020, the first year of the experimentation of this study. The yield obtained was equal to 4253 kg/ha for FI, 3615 kg/ha for PI and 2977 kg/ha for NI.

The data was collected from an interview with the olive grower, who provided data on the inventory of the agronomic operations carried out, useful for the purpose of drawing up the inventory (table 3).

We have included this information in the 3.1 paragraph, as you suggested.

 

-Reviewer’s comment: These two data sources (University research and survey) poorly documented at manuscript. There is no clear definition of the extent to which presented data (from the field experiment and the questionnaire were used) for LCA and WSI analysis (see lines 184-195 and 232-239). How f.ex. estimated water consumption for FI and PI management. Basic on University experiment research or information collected from farmers.

On the other hand, the authors provided a detailed description of the plantation area, olive and oil production in Sicily. My opinion, this chapter (Olive surface and production in Sicily region) can be shortened or removed without any negative influence on the manuscript quality.

Authors’ response: Thanks for the comment, with this paragraph we would create a state of the art of olive growing in Sicily, underlining its economic importance. Furthermore, these data show the importance of the sector for the aspects linked not only to the merely productive ones, but also to the creation of jobs and conservation of the rural territory and the environment. For these reasons it seems useful to keep this paragraph to underline the importance of this sector in the context under study.

 

-Reviewer’s comment: The same remark regarding literature data presented in table 2. Information presented in this table was repeated in references list in the same number as in table 2.

Authors’ response: Thanks for the comment, regarding this table, we followed the study of Bernardi et al. (2021), which in an analysis on LCA in the olive sector, underlines the importance of the papers that use the same methodology in the same sector. For these reasons it seems useful to keep this literature table it is useful to underline the importance of the application of the LCA methodology widely used in this sector.

-Reviewer’s comment: Please check and correct presented data. Water irrigation for treatment FI was 486/per ha while for PI treatment 243 l per ha. In table 6 water consumption increased 103 times fold for PI treatment and 206 times fold for FI comparing to NI. Which data is correct?

Authors’ response: Thanks for your comment. However, the result is correct because both the Water depletion indicator presented in Tables 6 and 7 and the Water Stress Index presented in Table 8 do not consider only the water used directly in the process but the water used throughout the life cycle such as the water used for the production of pesticides, fertilizers, to forge machines, in the diesel refining process, etc. The water used in the process is not only the water used in the irrigation but also the water used in the production of the product

-Reviewer’s comment: Authors in table 4 presented revenue value and value of 1 kg olive oil and in table 1 described economic indicators. Basic on olive production data (reviewer calculation): in treatment NI olive oil production was 566 kg, PI - 669 kg, FI - 766 kg. If the presented calculation is correct, please check the WSI per kg presented in table 8.

Authors’ response: Thanks for your comment on the paper. The results obtained by the reviewer were calculated by dividing the revenue per hectare by the revenue per kg. However, there is a basic error because the revenue per kg, as specified in table 4, comes from the sale of “olive oil” while the revenue per hectare comes from the production of “olives”. The results presented in Table 8 are therefore correct. It is important to underline that, as explained, the purpose of this work is to analyze the environmental impacts related to the agricultural phase, and not those related to the transformation phase. Olive oil was used only for the calculation of company revenues, as oil olives are not commercially viable as they are.

-Reviewer’s comment: Please check and correct citation from line 298.

Authors’ response: Thanks for the comment, it has been corrected.

 

Author Response File: Author Response.pdf

Round 2

Reviewer 2 Report

Authors sent answer for all comments and accepted only few of them. Authors not marked clearly (in red) were manuscript was changed. The manuscript  prepared base on two different data sources. Olive production under different irrigation regime was derived from field experiment, and olive growing costs from the survey data. The number of questionnaires carried out in which region and whether the growers used irrigation in accordance with the strict experiment system were still not specified. 

It is not understandable how the Authors defined economic efficiency not referring the income to the whole oil olive entire production, but only to the sold one  I quote "as specified in table 4, comes from the sale of“ olive oil ”while the revenue per hectare comes from the production of“ olives”. The data presented in Table 4 are the basic ones in this manuscript and in current version refer only to part of the oil olive production. Authors should add what size (volume of oil production) sold from each irrigation methods or in some proportion to the whole production volume?

Authors answered the question concern on water consumption. In table 6 for NI system water consumption was 2.39 m³, while for PI 246 m³ and FI 490 m³. While in table 3 water consumption for irrigation for FI was 486 l/per ha (0.486 m³), and for PI 243 l per ha (0.243 m³). Authors answered that calculation is correct and differences is water used for production purposes. "Thanks for your comment. However, the result is correct because both the Water depletion indicator presented in Tables 6 and 7 and the Water Stress Index presented in Table 8 do not consider only the water used directly in the process but the water used throughout the life cycle such as the water used for the production of pesticides, fertilizers, to forge machines, in the diesel refining process, etc. The water used in the process is not only the water used in the irrigation but also the water used in the production of the product". 

It is difficult to explain the over 100-fold (for PI) and 200-fold (for FI) increase compare to NI in water consumption only for production purposes.

 

Author Response

Detailed Responses to the Reviewer #2

 

Economic and Environmental Sustainability of Olive Production: A Case Study

 

Dear Reviewer

We would like to thank you for your useful comments on our manuscript. In the previous submission we inserted the revisions in "track change" mode using the appropriate Microsoft Word function, but probably something went wrong and the pdf file did not show the revisions in evidence.  We apologise for this inconvenience. We have indicated clearly (in red) where in the revised manuscript changes have been made to address your valuable comments.

 

-Reviewer’s comment: Authors sent answer for all comments and accepted only few of them. Authors not marked clearly (in red) were manuscript was changed. The manuscript  prepared base on two different data sources. Olive production under different irrigation regime was derived from field experiment, and olive growing costs from the survey data. The number of questionnaires carried out in which region and whether the growers used irrigation in accordance with the strict experiment system were still not specified.  

Authors’ response: Thank you for your comment on the document. We have amended the text according to your suggestions. In detail we have included a new table to summarize the data collected from the olive grower on the production of olives and oil in the 3 different plots analysed. These amendments are included in the text Line 266-288.

 

-Reviewer’s comment: It is not understandable how the Authors defined economic efficiency not referring the income to the whole oil olive entire production, but only to the sold one  I quote "as specified in table 4, comes from the sale of“ olive oil ”while the revenue per hectare comes from the production of“ olives”. The data presented in Table 4 are the basic ones in this manuscript and in current version refer only to part of the oil olive production. Authors should add what size (volume of oil production) sold from each irrigation methods or in some proportion to the whole production volume?

Authors’ response: Thank you for your comment on the paper. To clarify how the economic analysis was done, Table 1 (Line 284-288) was included, as you suggested, to help clarify the economic results better detailed later (Line 509-511).  

 

-Reviewer’s comment: Authors answered the question concern on water consumption. In table 6 for NI system water consumption was 2.39 m3, while for PI 246 m3 and FI 490 m3. While in table 3 water consumption for irrigation for FI was 486 l/per ha (0.486 m3), and for PI 243 l per ha (0.243 m3). Authors answered that calculation is correct and differences is water used for production purposes. "Thanks for your comment. However, the result is correct because both the Water depletion indicator presented in Tables 6 and 7 and the Water Stress Index presented in Table 8 do not consider only the water used directly in the process but the water used throughout the life cycle such as the water used for the production of pesticides, fertilizers, to forge machines, in the diesel refining process, etc. The water used in the process is not only the water used in the irrigation but also the water used in the production of the product".

It is difficult to explain the over 100-fold (for PI) and 200-fold (for FI) increase compare to NI in water consumption only for production purposes.

Authors’ response:  

Dear Reviewer.

We identified the problem, which was related to the incorrect irrigation measurement unit in table 4 (formerly table 3). We apologize for the inconvenience (Line 494-501). Unfortunately, we had concentrated on checking the computations and the results obtained which, as we said, were correct. We did not detect that there was an error in reporting the unit of measurement of irrigation which should obviously have been in m3/ha. Thank you again for helping us to spot this error, which would have affected the quality of our work.

Author Response File: Author Response.pdf

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

The authors propose the study titled " Economic and Environmental Sustainability of Olive Production: A Case Study". The topic is very interesting, the authors discuss around the economic feasibility and life cycle assessment of three different olive system cultivation in the Mediterranean area through joint use of economic and environmental indicators, to identify the key elements to optimize their economic performance but also a minor environmental impact. For this purpose they were 3 different management systems of olive cultivation were analysed. The manuscript are well written and argued.

Introduction

Line 33. Please add the author name in the scientific name and remember that the scientific name must be write in italic. Olea europaea L.

Add references for the follow statements:

Lines 35-36. “…and represents a considerable economic, agricultural and ornamental concern(REFERENCE). Despite the economic importance of this product in many countries, olive production is associated with several negative effects on the environment with consequences on resource depletion, soil degradation, air emissions and waste generation (REFERENCE)…”

Lines 41-47. “The olive tree is very adapted to extreme environmental conditions, such as drought and high temperatures (REFERENCE). The Mediterranean climate is characterized by an amount of rain- fall ranging from 150 to 800 mm per year and by an uneven distribution of rains, concen trated above all in the winter and spring months. The Mediterranean area, characterized by a climate with a limited level of rainfall, in the last decade, has experienced a certain ncrease in average temperatures and an uneven distribution of rainfall (REFERENCE). These aspects result in a greater demand for the use of water for irrigation even in non-traditional times” (REFERENCE).

Lines 67-70. This, through the rationalization of the cultivation of traditional olive groves, the renewal of the plants and the introduction of new cultivation systems capable of reconciling environmental and economic sustainability [Perrino et al. 2014].

• Add reference
• Perrino, E.V.; Ladisa, G.; Calabrese, G. Flora and plant genetic resources of ancient olive groves of Apulia (southern Italy). Genetic Resource and Crop Evolution 2014, 61, 23-53. https://doi.org/110.1007/s10722-013-0013-1

3. Material and Method

Well done, no observations. The tables and figures are clear.

5. Discussion

Please two plus words on the interisting results

6. Conclusion

Some comments they are duplicated from the introduction

Reviewer 2 Report

The work deals with a topic of great interest: the management of water in the production of an important Mediterranean crop such as the olive tree. However, in my opinion it would be convenient to improve important aspects. Thus, the work includes a high number of references, but the discussion of the results only includes 10 citations, of which almost half deal with a single topic. It would be convenient to improve the discussion of the results and explain their meaning. For this, it would be necessary to indicate how they are calculated and what the impact category of LCIA through ReCiPe Midpoint method (per hectare and per kg of product) and WSI represent.

Other considerations:

Line 33: The scientific name in italics

Line 37: To make an assessment like this one, it would be necessary to include the social effects, the conservation of the ecosystem and the protection of biodiversity.

Lines 46 and 57: It would be necessary to include sources.

Line 171: Figure 2 The legend indicates surface area and production is represented. How are the differences between olive and oil production by region explained?

Lines 215 and 216: Standardize use of acronyms.

Line 353: K for kilo in lowercase.

Reviewer 3 Report

There seems to be potential for a good paper from the underlying data. The writing in the article makes it hard to understand and evaluate.

The methods and data are not clearly described. The authors mention a survey of producers but there is no report of even summary statistics from that questionnaire. Partial budget analysis is mentioned, but there is no information on the specified costs considered. Three treatments are mentioned, which seems to suggest that these are field experiments but also no statistics on those field experiments are offered. Yet a third angle is discussed, that "of a company" but it is not clear if this is an abstract construction or an actual company surveyed.

The treatments are not clearly described. There is no information on how the partial irrigation treatment is designed. The yields are unclear if coming from field experiments or from the survey of producers. The amount of water seems to be simply half of full irrigation, there is no comparison of yield variability to assess if the difference in yields is statistically significant.

The article explains that irrigation is common among the most modern producers, yet it is less profitable than non-irrigated. There is no explanation of why this is. There must be a mistake in the data or the assumptions. Hard to say where because everything is poorly described.

On the life cycle impact assessments it would be expected that partial irrigation impacts would be somewhere between NI and FI but in many instances fall outside that range, without explanation. The must be more than a report of results from the software package, there must be an explanation of what is happening and a hypothesis of why, if possible that hypothesis statistically tested!

The water footprint in relative terms does not make much sense as it seems to suggest that fertilisation, pest management, tillage and pruning have almost no water footprint under irrigation which is patently false!