Growth and Quality of Leaf and Romaine Lettuce Grown on a Vertical Farm in an Aquaponics System: Results of Farm Research
Round 1
Reviewer 1 Report
Dear Authors,
- Write the units in the same way – mg/l, o not mg/L (Page 5). Write (N-O3-), no N-O3- (Table 1).
- I would recommend using the term biometric parameters rather than morphological plant characteristics (Page 5), because morphology comprises the macroscopically visible characteristics, such as geometry, shape, size or colour of plant organs (root, stem, leaf and flower).
- It would be clearer if the individual graphs in Figure 1 were marked with letters: A, B ....(Page 6).
- Chlorophyll index (CI) should be written, CI, explain why you write CCI ?
- In all tables ‚frech weight‘ and ‚dry weight‘ should be written FW, DW.
- In tables 4 and 5, replace the letters b, a, ab, .....as in Tables 2 and 3.
- The 'chlorophyll flavonoid concentration' is written when you have determined the content of these materials (Page 8).
- It should be written not mg/100 g, but mg 100-1 (Page 10).
- Tables titles should be shortened and more concrete. Macro (P, K...) and microelements (Fe,...) and lettuce cultivars should not be mentioned in the titles.
- To unify it - https://doi.org/10.1007/s10499-022-00946-z - the color, underline and 94(2), 197–204, not 94(2): 197–204 in the References.
Author Response
Dear Reviewer,
Thank you very much for your suggestions that have improved the quality of my manuscript. Detailed responses are provided below. All changes were marked in the manuscript using the "Track Changes" function.
Point 1. Write the units in the same way (Page 5). It has been revised.
Point 2. I would recommend using the term biometric parameters rather than morphological plant characteristics (Page 5), because morphology comprises the macroscopically visible characteristics, such as geometry, shape, size or colour of plant organs (root, stem, leaf and flower). Write the units in the same way (Page 5). It has been revised.
Point 3. It would be clearer if the individual graphs in Figure 1 were marked with letters: A, B ....(Page 6). It has been revised.
Point 4. Chlorophyll index (CI) should be written, CI, explain why you write CCI ? The name of CCI was changed to CI.
Point 5. In all tables ‚frech weight‘ and ‚dry weight‘ should be written FW, DW. Units have been changed as suggested by the reviewer.
Point 6. In tables 4 and 5, replace the letters b, a, ab, .....as in Tables 2 and 3. It has been changed.
Point 7. The 'chlorophyll flavonoid concentration' is written when you have determined the content of these materials (Page 8). It has been changed to content.
Point 8. It should be written not mg/100 g, but mg 100-1 (Page 10). It has been changed.
Point 9. Tables titles should be shortened and more concrete. Macro (P, K...) and microelements (Fe,...) and lettuce cultivars should not be mentioned in the titles. Only abbreviations of chemical elements are given in the titles. The names of cultivars of two types of lettuce are listed so that the author can understand the content of the table without reading the section "material and methods".
Point 10. To unify it - https://doi.org/10.1007/s10499-022-00946-z - the color, underline and 94(2), 197–204, not 94(2): 197–204 in the References. It has been improoved.
Reviewer 2 Report
ABSTRACT:
The abstract must have a rationale, an objective, materials and methods, results, and conclusions. The first sentence must be a rationale and please write a problem statement for this study. Thus, the authors should mention the treatments and experimental design to explain the main findings. Please mention if the system of plant Factories was conducted under controlled environmental conditions or not.
INTRODUCTION:
The introduction section is relatively short and missing main points such as the integration of plant factories (as hydroponics part) with recirculating aquaculture system to be aquaponics system.
Lines 44-46. The authors mentioned that Monsees et al. [5] showed that the production of lettuce in separate aquaponic systems achieves the same yield and quality as conventional hydroponic systems.
The authors should insert the accurate information by mentioning that the aquaponics system used in Monsees et al. [5] is a decoupled aquaponics system where you can optimize the environmental condition for fish, microbes and plants such as Ph, EC and water temperature, in addition, it can apply an inorganic fertilizer without effect on microbes and fish.
1-Lines 59-71: There is no need to insert information about the Lettuce (Lactuca sativa L.); it was discussed by many studies before. Therefore, the critical point is to insert the specific details on the updated strategy for increasing and improving the growth, yield and nutritional value, such as mineral concentration, phytochemical and secondary metabolite for lettuce under aquaponics system.
MATERIALS AND METHODS
Many points are missing in the M&M and some questions.
1. The planting density for lettuce in the aquaponics system is not provided. Instead, please mention the planting density in plants per meter square. Also, please mention the seedling age. My question is, how old is the seedling when shifting to an aquaponics system??
2. Please mention the fish stocking density in Kg per m3
3. Why do the authors not use the decoupled aquaponic system for plant factories?
4. Why are the pH and EC not controlled?
5. What about the root zone temperature? It is well known that under plant factories, the water parameters should be optimized for maximum growth for the plant.
6. Why is the life cycle for the plant only 21 days? It should be 28 days.
7. What is the experimental design for this experiment?
It is well known that the aquaponics system not provided the ideal concentration for macro and micronutrients and should supply an inorganic fertilizer to improve the growth and yield of lettuce. However, in this study, the authors used coupled aquaponics, which can not apply inorganic fertilizer. So, my question is, why did the authors not use the decoupled aquaponics?
RESULTS AND DISCUSSION
Table1. Table 1. The electrical conductivity EC (mS/cm), pH, and mineral composition (N-NO3-, N-NH4+, P, K, Ca and Mg), of aquaponic nutrient solution.
Please mention if this concentration was before starting the experiment or at the end of the experiment.
If it is at the end of the experiment, please mention the mineral composition after running the aquaponics system for three months and before shifting the lettuce seedling to plant factories.
The results and discussion section must be presented separately and Under specific subtitles.
The discussion section must be presented under certain subtitles, as the authors did for the results. This means as the authors presented their results under certain subtitles in Results, are they also suggesting developing subtitles under the Discussion section? The authors mostly only compare their results with the literature's results. However, they do not discuss the mechanisms by which the results are obtained.
Conclusion
The conclusion should have the main findings only.
Author Response
Dear Reviewer,
First of all, I would like to thank you for your suggestions, which have definitely improved our article. All substantive and technical comments have been included in the revised manuscript. It was explained that the research was aimed at checking the possibility of obtaining an adequate yield and good quality of leaf and romaine lettuce grown in an aquaponic system with recirculation, only on organic fertilizers produced by fish without supplementing with mineral fertilizers in a plant factory, and to determine the mineral status and the content of health-promoting bioactive compounds in lettuce leaves. The details of the revisions to the manuscript and our responses to the referees’ were marked up using the “Track Changes” function.
Abstract
The abstract was supplemented with a description of the research problem, main findings and information that the research was carried out in a plant factory under controlled environmental conditions.
Introduction
The introduction section explains that the decoupled aquaponic technology proposed by Monses et al. can be optimized by using a coupled system in which environmental conditions for fish, microbes and plants, such as pH, EC and water temperature, will be optimised. In such a hydroponic system, it is possible to use organic fertilizers as an alternative to minerals, which is crucial in meeting the challenges of agriculture and climate change around the world. The description of the research objective has been corrected. It was indicated that the research was aimed at checking the possibility of obtaining an adequate yield and good quality of leaf and romaine lettuce grown in an aquaponic system with recirculation, only on organic fertilizers produced by fish without supplementing with mineral fertilizers in the plant factory, and to determine the mineral status and the content of health-promoting bioactive compounds in lettuce leaves.
Materials and methods
Point 1. The planting density for lettuce in the aquaponics system is not provided. Instead, please mention the planting density in plants per meter square. Also, please mention the seedling age. My question is, how old is the seedling when shifting to an aquaponics system? The methodology was supplemented with missing details. Three-week-old seedlings were planted, planting density of 40 seedlings per square meter.
Point 2. Please mention the fish stocking density in Kg per m3. The stocking density of fish was 6.5 kg m-3
Point 3. Why do the authors not use the decoupled aquaponic system for plant factories? The aim of our research was the production of bioponic lettuce, using only natural fertilizers, without the use of mineral fertilizers, which was added in the introduction.
Point 4. Why are the pH and EC not controlled? EC and pH was controlled and the results are presented in table 1.
Point 5. What about the root zone temperature? It is well known that under plant factories, the water parameters should be optimized for maximum growth for the plant. Plants were produced in controlled environmental production, temperature in the hall with plants, as well as in hall with fishes was maintained at 23°C, so temperature of root zone was closed to 23°C.
Point 6. Why is the life cycle for the plant only 21 days? It should be 28 days. We shortened the lettuce production time to 3 weeks in order to obtain good quality plants and a satisfactory yield. Young plants have lower nutrient requirements than older ones. Extending the growing time would result in nutrient deficiencies in the plants and would probably reduce the quality of the lettuce. This aspect was raised in the discussion.
Point 7. What is the experimental design for this experiment? The research was conducted in a commercial plant factory under controlled environmental conditions. Biometric measurements were performed on the basis of 18 randomly selected plants for each lettuce cultivar, similarly in the case of chemical analyses. This was described in the material and methods.
Point 8. It is well known that the aquaponics system not provided the ideal concentration for macro and micronutrients and should supply an inorganic fertilizer to improve the growth and yield of lettuce. However, in this study, the authors used coupled aquaponics, which can not apply inorganic fertilizer. So, my question is, why did the authors not use the decoupled aquaponics?
The aim of the study was to obtain an adequate yield and good quality of leaf and romaine lettuce grown in an organic aquaponic system, without minerals. We have shown that this is possible for some cultivars of romaine lettuce.
Results and Discussion
Point 1. The mineral composition before shifting the lettuce to plant factory is given in table 1, first row (September 19). The content o minerals in tap water is given in the material and methods section.
Point 2. The results and discussion section must be presented separately and Under specific subtitles.The discussion section must be presented under certain subtitles, as the authors did for the results. This means as the authors presented their results under certain subtitles in Results, are they also suggesting developing subtitles under the Discussion section? The authors mostly only compare their results with the literature's results. However, they do not discuss the mechanisms by which the results are obtained. As suggested by the reviewer, the discussion section has been divided into subsections, similarly to the results section. In our opinion, the obtained results were sufficiently discussed with the latest achievements of other authors.
Conclusions
The conclusions have been slightly improved.
Reviewer 3 Report
Vertical farming in plant factories has become popular in recent years. Advantages against climate change; It has advantages such as water saving, climate control, and easy access to food in metropolitan cities. Aquaponic is a system that allows fish and plants to be grown together, and makes it possible to produce animal protein and fresh vegetables with limited water.
The research article entitled “Growth and quality of leaf and romaine lettuce grown on a vertical farm in an aquaponics system: results of farm research". In the study, the yield, mineral status and health-promoting bioactive compounds of leaf and romaine lettuce cultivars grown in a recirculating aquaponic system in a plant factory were investigated. The manuscript is well-written with valid methodology and well-explained results. Readers of this journal may find this article to be relevant.
Although pH, EC and some mineral nutrients are low for hydroponic growth of lettuce plant. The yield per unit area was found interesting with bioactive compounds and low nitrate content. Cultivation of lettuce plant together with fish compensates for some deficiencies and disadvantages. I think commercially interesting results have been achieved.
As a suggestion, the phrase "destructive standard laboratory methods, especially in plant factories" can be corrected in Line 332-333. For standard plant factories different than aquaponic, the statement of "destructive" is not correct in my opinion.
The article is acceptable for printing as is.
Author Response
Dear Reviewer,
Thank you for your review of our article. All responses to reviewers' questions were marked up using the “Track Changes” function.
Your suggestion: the phrase "destructive standard laboratory methods, especially in plant factories" can be corrected in Line 332-333. For standard plant factories different than aquaponic, the statement of "destructive" is not correct in my opinion.
Our response to the suggestion. Analytical methods are divided into non-destructive and destructive. We believe the use of the term "destructive" is appropriate.
Round 2
Reviewer 2 Report
The production of lettuce under aquaponics without applying fertilizers was discussed earlier by many studies and it is well known that aquaponics not provided all Macro and micronutrients. In addition, the growers used the plant factory to optimize all physicochemical parameters such EC, Ph and root zone temperature, but these parameters were not optimized in this study. So, what are the benefits of using Plant Factory?
Author Response
Dear rewiever,
We agree with you, that aquaponics does not provide sufficient nutrient content, but this is the case with long-term, e.g. 4-week lettuce cultivation. Our earlier research shows that the uptake of nutrients in the last Dear reviewer,4 week of cultivation increases very quickly due to the rapid growth of plant mass, and the content of nutrients may be insufficient for proper plant growth. In our current research, we have proven that the content of macro and micronutrients is sufficient for lettuce grown in a 3-week cycle to obtain good organic marketable yield of lettuce without application of mineral fertilizer (photo 1).
