Experimental Evaluation of the Water Productivity and Water Footprint of a Greenhouse Tomato Crop for Different Blends of Desalinated Seawater and Two Growing Media

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

For this manuscript, suggestions are as follows,

1. lines 265-266, 278-279, 332-333. The manuscript mentions that water productivity (WP) and water footprint (WF) values varied across different crop cycles (C1, C2, C3), but the discussion section does not provide a detailed analysis of these variations. For example, the third crop cycle showed different trends in WP and WF compared to the first two cycles. The authors should provide a more in-depth discussion on the potential reasons for these variations, such as differences in weather conditions, crop management practices, etc.
2. The manuscript states that the green water footprint was zero due to the greenhouse cultivation conditions (lines 310-312). However, it does not clearly explain why the grey water footprint was considered to be more than double the blue water footprint (lines 313-314). The calculation method for the grey water footprint, especially in the context of soilless culture, needs further clarification.
3. The manuscript concludes that soil culture is more favorable than soilless culture in terms of water productivity and water footprint (lines 362-366). However, it does not compare these findings with previous studies on similar topics, which would strengthen the validity of the conclusions.
4. The Results section notes that crop yields varied across seasons due to weather conditions, pests, and diseases (Line 244), but the Discussion does not systematically explore how these factors influenced water productivity and water footprint. For instance, did higher ETc in certain seasons (Figure 3b) lead to increased irrigation demand in specific treatments? Were pest outbreaks more prevalent in one growing medium, affecting yield and thus water productivity?
5. Several inconsistencies in terminology and formatting distract from the manuscript’s clarity. For example, "growing media" is sometimes spelled "growing medium" (e.g., Line 16 vs. Line 112). Units of measurement also show variability (e.g., "L/m²" in Line 155 vs. "mm" in Line 233), CO3H-(Table 1.).
6. The illustrations in the text are not standardized(Figure 7, Figure 6. etc.). Please revise the manuscript according to the requirements of the journal standards.
7. Line 385, what’s meaning of Patents ? Where is the Figure 5 in the content of the manuscript, and the name and unit annotation of the vertical axis are incorrect.

Comments on the Quality of English Language

The English could be improved to more clearly express the research.

Author Response

A detailed response to the reviewer 1 is included in the attached document

Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

This paper holds significant research value in optimizing water resource management and improving agricultural system water productivity. By comparing different salinity levels of desalinated seawater and two growing media (soil and soilless culture), the study provides meaningful experimental data and theoretical support for improving water use efficiency and reducing water footprint, especially in water-scarce regions. However, there is still room for improvement in certain areas. Firstly, although the paper presents a wealth of data, it lacks sufficient discussion on the novelty and background explanation of the experimental results, especially regarding the impact of water quality blending on agricultural productivity. Secondly, the self-explanatory nature of the figures could be further enhanced, especially in the legends and titles of the figures. Optimizing these details would help improve the clarity and readability of the results.

Specific comments：

1 Introduction:

When mentioning that "water scarcity and quality issues may jeopardize agricultural sustainability," it would be helpful to provide more specific details. For example, addressing particular challenges in irrigation systems or water management practices, such as low irrigation efficiency or over-extraction of groundwater, would make the problem statement more precise and relevant.

The hypothesis presented in the paper—that different blends of desalinated seawater with varying salinity levels and two growing media (soil vs. soilless culture) affect water productivity and water footprint—is reasonable and aligns well with current research on optimizing water use in agriculture. However, the hypothesis could be more directly tied to the problem summary presented in the introduction. For example, the introduction could more explicitly explain why different water qualities (salinity levels) might affect crop water productivity, and what specific impacts are expected from using desalinated seawater.

2 M&M:

The selection of different salinity levels for water treatments (e.g., T1, T2, and T3) is explained, but more justification for the choice of these specific salinity levels would be helpful. The expected impacts of each salinity level on crop growth should be better highlighted, especially since these salinity levels could affect water productivity and footprint differently.

The comparison of soil and soilless cultures is valuable, but further explanation of the choice of coconut fiber for soilless systems would be beneficial. How well does this medium reflect actual agricultural practices, and why was it chosen over other substrates? This could improve the study's relevance to real-world agricultural systems.

3 Results

The results section presents the data clearly, but in some places, the descriptions could be more concise. For example, the changes in water consumption and yield across treatments are mentioned multiple times in detail. Some of these descriptions could be combined or restructured to make the comparisons between different treatments more direct and succinct.

Specifically, when discussing the variations in water productivity and water footprint, the detailed data provided in the tables are already clear. It would be helpful to summarize the key findings in the text, rather than repeating extensive data points. By emphasizing the most important differences, the results would be more concise and logically organized.

Figure 6: No green in the figure? Why there is still the legend in this figure

Figure 4 and 5, the axis labels must be the same, all WPs, one with the unit of kg/L, the other with L/kg?

 

4 Discussion

While the paper discusses the different effects on water footprint and water productivity, the novelty of these results is somewhat underemphasized. For instance, although the paper suggests that soilless systems could benefit from leachate recirculation, this point is not analyzed in terms of its innovative value. How does this compare with existing agricultural water management systems, and what are the practical advantages of such improvements?

While the discussion mentions certain results (e.g., the higher water footprint in soilless systems and the more efficient performance of soil systems), it does not delve deeply into the innovative nature of these findings. For example, are there similar studies that have reached different conclusions? How does this study contribute to the existing body of knowledge in optimizing water use and reducing water footprints in agriculture? These points could be emphasized more by comparing with previous literature, especially regarding the impact of different water qualities on agricultural systems.

 

 

Author Response

A detailed response to the reviewer 2 is included in the attached document

Author Response File: Author Response.pdf

Reviewer 3 Report

Comments and Suggestions for Authors

An intersting paper with the aim to increase the sustainability of the local horticultural production, but applicable to the rest of the world.

Marks of significance are missing in Tables 3 and 4 so please add them if statistical analysis has been done. Also, for these tables add the legend for abbreviations used.

A large part of text written in Discussion section could be transferred into Results section, so think about that and add some discussion with aditiona literature sources.

References must be edited according to the Authors Guidelines and checked for numbering in through the aext and in the list.

Comments for author File: Comments.pdf

Author Response

Comment: An interesting paper with the aim to increase the sustainability of the local horticultural production, but applicable to the rest of the world.

Response: We want to thank the reviewer for his comment.

Comment: Marks of significance are missing in Tables 3 and 4 so please add them if statistical analysis has been done. Also, for these tables add the legend for abbreviations used.

Response: We have added a legend to clarify the abbreviations used in these tables. Tables 3 and 4 show a summary of the original data obtained in the experiment. These tables are not intended to depict the results of the statistical analysis. In this paper, we have focused on the influence of both factors, water quality and growing media on the productivity and water footprint. The statistical analysis was performed to analyze the significance of these variables.

Comment: A large part of text written in Discussion section could be transferred into Results section, so think about that and add some discussion with aditiona literature sources.

Response: We agree with the reviewer that the separation line between results and discussion sections is fuzzy, and the structure of the manuscript could be slightly modified and improved by transferring part of the text in Discussion to the Results section. Actually, we have transferred a large part of the discussion section to the result section. Besides, we have enhanced the discussion section by adding new literature sources. We think that the structure of the manuscript is now correct, and the discussion of results is also appropriate.

Comment: References must be edited according to the Authors Guidelines and checked for numbering in through the aext and in the list.

Response: Reference numbering has been revised and corrected as suggested. References have been edited according to the Authors Guidelines. We have used the Software program Zotero to manage references. We have also downloaded the Reference Style recommended by the journal.

Response: In addition, we have revised all the comments written in the attached document and we have properly addressed all of them.

Author Response File: Author Response.pdf

Round 2

Reviewer 2 Report

Comments and Suggestions for Authors

Figure 3： the gap in it should be ommitted and the X-axis should be extended to make the data  more clearly being shown.

Author Response

Comment 1. Figure 3： the gap in it should be omitted and the X-axis should be extended to make the data more clearly being shown.

Response 1. The gap in Figure 3 has been removed. The X-axis has been scaled accordingly to show data more clearly

Author Response File: Author Response.pdf