Predictive Model to Evaluate Water and Nutrient Uptake in Vertically Grown Lettuce under Mediterranean Greenhouse Conditions

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

Please find attached

Comments for author File: Comments.pdf

Comments on the Quality of English Language

Minor improvement is required

Author Response

Please refer to the manuscript titled "Predictive Model to Evaluate Water and Nutrient Uptake in Vertically Grown Lettuce under Mediterranean Greenhouse Conditions." The article addresses food security and sustainable production systems, highlighting how vertical crops can mitigate water and nutrient usage, ultimately enhancing agricultural production in greenhouse conditions. It investigates into the application of irrigation techniques and fertigation processes to boost lettuce production while achieving substantial water savings. I have thoroughly assessed the manuscript and recognized its contribution to guiding farming communities in establishing more greenhouse systems and implementing precision irrigation. The focus on reducing excess irrigation is commendable and holds promise for increased agricultural output. However, some critical points require clarification.

A: Thank you for your comments.

 

In the introduction part, please provide a more detailed explanation of how sustainable strategies optimize the crop growth and development process. Additionally, elucidate on conventional agriculture production methods to draw a clearer distinction with vertical farming. The article should delve deeper into how vertical farming holds significant potential for reducing water and fertilizer usage.

A: These concepts have been emphasized and clarified in the introductory part and in the summary.

Authors should explicitly emphasize the importance of research and development activities in determining the feasibility of implementing this greenhouse crop system at the environmental level.

A: The paragraph (Line 127) has been modified to emphasize this importance

 

In the materials and methods section, please specify the soilless media employed for greenhouse agricultural crop production.

A: The model and the cultivation are carried out in the absence of substrate, so the medium used cannot be specified.

Authors should elaborate on the significance of the relationships incorporated into the models. Clarify how weather conditions, including temperature, humidity, irradiance, and wind velocity, serve as critical parameters for effective agricultural water productivity and irrigation planning.

A: The importance of climatic conditions as critical parameters for effective production and irrigation planning is specified in section 2.1.1.

It would be beneficial if the authors include a separate section comparing their study with other research on conventional greenhouse production versus vertical farming before reaching the conclusion. This would provide a more comprehensive understanding for readers and facilitate clarity for farming communities considering adoption.

A: Results and conclusions compare the results of this study with other research on conventional greenhouse production versus vertical farming before reaching the conclusion

 

The results and discussion part is appropriately written. However, in the conclusion, regarding future work, connect or elaborate on future endeavors related to sensor-based system operations, integrating precision irrigation with weather stations.

A: A reference to that reference to future work is included at the end of outcomes and discussion.

 

Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

Title: Predictive Model to Evaluate Water and Nutrient Uptake in Vertically Grown Lettuce under Mediterranean Greenhouse Conditions.

 

What is the main difference between hydroponic farming and vertical farming in urban agriculture? Hydroponic farming uses nutrient-rich water solutions, while vertical farming focuses on growing plants in stacked layers or inclined surfaces. Both can be used in urban settings

Vertical farming is the practice of growing crops in vertically stacked layers. It often incorporates controlled-environment agriculture, which aims to optimize plant growth, and soilless farming techniques such as hydroponics, aquaponics, and aeroponics.

Yes, vertical crops under greenhouse conditions are more competitive to conventional  agriculture and even horizontal hydroponics systems, due to their more yield and  development of aboveground biomass, but at the same time are limited by the shade projection of the highest levels

Your research is very interesting and applicable in the vertical cultivation of lettuce in hydroponic technology.

I agree with the presented research results and especially that in that method it is unlikely that the disease will occur.

Continue this technological research on other types of salad.

I suggest that the paper be published in its entirety.

 

Author Response

Comments and Suggestions for Authors

Title: Predictive Model to Evaluate Water and Nutrient Uptake in Vertically Grown Lettuce under Mediterranean Greenhouse Conditions.

What is the main difference between hydroponic farming and vertical farming in urban agriculture? Hydroponic farming uses nutrient-rich water solutions, while vertical farming focuses on growing plants in stacked layers or inclined surfaces. Both can be used in urban settings.

A: We agree with your concepts. Both, hydroponic farming as well as vertical farming use nutrient-rich water solutions. While vertical farming focuses on growing plants in stacked layers or inclined surfaces. Different vertical levels superposed were proven by us and our results showed we have to envisage how to improve the method by trying the radiation homogeneously reach the lower levels of growing crops. Fortunately, this method is easily proven to be useful in urban areas given the needed areas are smaller. However, it does not mean we might not use the open field spaces in rural areas. The selection of instrumentation requires more rigorous criteria in order to reach high efficiency in the use of fertilizers.

Vertical farming is the practice of growing crops in vertically stacked layers. It often incorporates controlled-environment agriculture, which aims to optimize plant growth, and soilless farming techniques such as hydroponics, aquaponics, and aeroponics.

A: Yes, vertical crops under greenhouse conditions are more competitive to conventional agriculture and even horizontal hydroponics systems, due to their more yield and development of aboveground biomass, but at the same time are limited to small size plants and by the shade projection of the highest levels

Your research is very interesting and applicable in the vertical cultivation of lettuce in hydroponic technology.

I agree with the presented research results and especially that in that method it is unlikely that the disease will occur.

Continue this technological research on other types of salad.

I suggest that the paper be published in its entirety.

Author Response File: Author Response.pdf

Reviewer 3 Report

Comments and Suggestions for Authors

Comments

 

Abstract

 

Line 16

It may be too assertive to put agriculture in such a position. Rather, it would be better to direct reader's attention to unsustainable agricultural practices.

 

Line 18 to 19

The authors should point out whether hydroponics is the agricultural technique that is of interest here.

 

Line 26 to 27

It is understood that the authors try to bring out the explanatory power of the ANOVA model. However, it would be preferrable if the significant main effects can be explicitly stated.

 

Introduction

 

Line 37 to 46

Since this study was based on a close-loop system, it would be relevant to introduce how agricultural activities may lead the nutrient depletion in soil and land pollution.

 

Line 52 to 53

Is vertical farming a better term?

 

Line 69 to 102

As the Pennman-Monteith Equation would play an important role later in the paper, the authors are recommended to mention the usefulness of the equation in the context of this study.

 

Materials and Methods

 

Line 135 to 155

The application of Equation (1) may suffer from a weakness arising from the physical layout of the lettuce plants. Since lower rows of plants would be inherently shaded by the plants in the upper rows, the term Rn may be a bit overestimated for plants in the lower rows. How did the authors tackle this problem?

 

Line 197

What are the radiative properties of the roof-cover materials?

 

Line 205 to 210

Has the outdoor environment right outside the greenhouse been monitored as well? Sudden changes in the outdoor environment may have impacts on the indoor greenhouse environment.

 

Line 339 to 344

Has any sensitivity analysis been conducted to determine the influential parameters on the modelling performance?

 

Results and Discussion

 

Line 347 to 354

The goodness-of-fit and the predictor variables have been qualified as "good" and "acceptable" respectively. Are there any evidence for such qualifications?

 

Line 355 to 363

Are the absolute values of the modelling performance relevant to the agricultural context? Can existing equipment used in the study detect the nutrients at such resolution and accuracy?

 

Line 396

In the ANOVA table, some confusion is detected. It seems that pairwise comparison has been conducted between LD(50) and HD(80). First, there are already asterisks showing the statistical significance of the difference. Second, there are only two classes of this categorical factor. Therefore, it is believed that the results of the pairwise comparison need not to be shown

 

Conclusions

 

I have no critical comments on this section

 

Comments on the Quality of English Language

After polishing the language, this manuscript can be published.

Author Response

Abstract

Line 16. It may be too assertive to put agriculture in such a position. Rather, it would be better to direct reader's attention to unsustainable agricultural practices.

A: It changed the composition of the beginning to express the same idea.

Line 18 to 19. The authors should point out whether hydroponics is the agricultural technique that is of interest here.

A: Totally agree with you, so the hydroponics techniques concept was included and added to vertical crop term.

Line 26 to 27. It is understood that the authors try to bring out the explanatory power of the ANOVA model. However, it would be preferrable if the significant main effects can be explicitly stated.

A: It included a phrase with the most relevant statistical outputs of the ANOVA.

 

Introduction

Line 37 to 46. Since this study was based on a close-loop system, it would be relevant to introduce how agricultural activities may lead the nutrient depletion in soil and land pollution.

A: It understands that it is important mark the differences between open and close systems, so a well-known pollution issue was included to express idea about unsuitable nutrient quantities that open systems used commonly, producing seriously negative effects on water bodies.

Line 52 to 53. Is vertical farming a better term?

A: It is possible use this term, but “vertical farming” concept is more common associate to crops in multi-level racks with artificial lighting as plant factories. In this way, we wanted use “vertical crop” term to refer the type of crop assessed.

Line 69 to 102. As the Pennman-Monteith Equation would play an important role later in the paper, the authors are recommended to mention the usefulness of the equation in the context of this study.

A: A paragraph with the relevance of this equation was added to the paper.

 

Materials and Methods

Line 135 to 155. The application of Equation (1) may suffer from a weakness arising from the physical layout of the lettuce plants. Since lower rows of plants would be inherently shaded by the plants in the upper rows, the term Rn may be a bit overestimated for plants in the lower rows. How did the authors tackle this problem?

A: It is an issue that we saw from the start of the experiment, so the pragmatic resolution consisted in estimate a mean value of the transmissivity coefficient that will represent the multiple crop levels. We include this explain at the first paragraph in the section 2.3.

Line 197. What are the radiative properties of the roof-cover materials?

A: the properties were added and specified.

Line 205 to 210. Has the outdoor environment right outside the greenhouse been monitored as well? Sudden changes in the outdoor environment may have impacts on the indoor greenhouse environment.

A: The experiment had an automatic climate station (ACS) installed outside and placed 15 m from the greenhouse.

Line 339 to 344. Has any sensitivity analysis been conducted to determine the influential parameters on the modelling performance?

A: Hupet & Vanclooster (2001) showed that the estimation error due to inappropriate sampling for the cumulated ETo is relatively low, reaching 3.8% for the less intensive temporal sampling. Therefore, our sampling is intensive (one measurement per hour) which would generate a negligible error, we did not consider suitable to carry out sensitivity analysis, in the water uptake submodel given this is the most prone submodel to stochastic variation.

Hupet, F.; Vanclooster, M. Effect of the sampling frequency of meteorological variables on the estimation of the reference evapotranspiration. J. Hydrol. 2001, 243, 192–204, doi:10.1016/S0022-1694(00)00413-3.

 

Results and Discussion

Line 347 to 354. The goodness-of-fit and the predictor variables have been qualified as "good" and "acceptable" respectively. Are there any evidence for such qualifications?

A: It added a statistical reference that argument this qualification.

Line 355 to 363. Are the absolute values of the modelling performance relevant to the agricultural context? Can existing equipment used in the study detect the nutrients at such resolution and accuracy?

A: Independent of the context, a modelling process might use statistical metrics to assess the performance model or equation. We used the more common metrics. This accuracy was achieved due to generalized reduced gradient (GRG) method, whose target value was associated to the Mean Absolute Errors (MAE).

The absolute values of modelling quality are similar to those obtained with other similar models used in the agricultural context. Average nutrient values are presented with the same resolution and accuracy of the measuring instrument used

Line 396. In the ANOVA table, some confusion is detected. It seems that pairwise comparison has been conducted between LD(50) and HD(80). First, there are already asterisks showing the statistical significance of the difference. Second, there are only two classes of this categorical factor. Therefore, it is believed that the results of the pairwise comparison need not to be shown

A: We have removed the unnecessary information in the table 2 and redrafted the corresponding paragraph.

 

Conclusions

I have no critical comments on this section.

Thanks.

Author Response File: Author Response.pdf