With the rising pressures on food security, GREENBOX technology was developed as an avenue for fresh leafy vegetable crop production in urban settings. GREENBOX units were designed to be thermally insulated and climate controlled, with an artificial lighting source that utilized soilless cultivation techniques. Previous studies conducted on GREENBOX technology used the Nutrient Film Technique (NFT); however, various hydroponic methods exist, such as the Deep-Water Culture (DWC) method being the most used. The APS Laboratory for Sustainable Food at Florida Gulf Coast University (FGCU) compared the crop growth performance between DWC and NFT systems using GREENBOX technology. The following study monitored environmental conditions and compared productivity and biomass data of Rex Butterhead Lettuce crops between DWC and NFT systems. We assembled two GREENBOX units using commercially available materials and the standard nutrient solution for fertigation. The crops grown in DWC and NFT were in a 4 × 6 configuration. The DWC and NFT systems were used to grow Lettuce Lactuca sativa “Rex Butterhead” over 30 days to full bloom from prepared plugs grown for 14 days. We collected environmental data including Photosynthetic Photon Flux Density (PPFD, μmol/m2∙s), Daily Light Integral (DLI, mol/ m2∙d), temperature (˚C), relative humidity (%), and Vapor Pressure Deficit (VPD, kPa). We collected lettuce crop growth data, which included wet weight (g), dry weight (g), leaf area (cm2), and chlorophyll concentration (μmol/m2). We derived data, including the Specific Leaf Area (SLA, cm2/g) and biomass productivity (kg/m2), from previously collected data. We used descriptive statistics to present the collected data. A paired t-test was performed to understand the differences in biomass and productivity parameters between the DWC and NFT-grown lettuce crops. Both the DWC and NFT-grown crops could grow lettuce crops to harvest weight at full bloom. Observed data demonstrated that the biomass parameters and productivity did not differ significantly between the two hydroponics techniques. Therefore, we believe both hydroponic methods may be similar in growth performance and may be used in future iterations of GREENBOX design and prove suitable for fresh vegetable crop production in urban settings.
References
[1]
Pison, G. (2017) Tous les pays du monde. Population et sociétés, 547, 1-4. https://hal.science/hal-02082693/file/Pop-et-soc_547-2017.tous.les.pays.du.monde.fr.pdf https://doi.org/10.3917/popsoc.547.0001
[2]
Kloas, W., et al. (2015) A New Concept for Aquaponic Systems to Improve Sustainability, Increase Productivity, and Reduce Environmental Impacts. Aquaculture Environment Interactions, 7, 179-192. https://doi.org/10.3354/aei00146
[3]
Kozai, T. (2018) Current Status of Plant Factories with Artificial Lighting (PFALs) and Smart PFALs. In: Kozai, T., Ed., Smart Plant Factory: The Next Generation Indoor Vertical Farms, Singapore, Springer, 3-13. https://doi.org/10.1007/978-981-13-1065-2_1
[4]
Pörtner, L.M., Lambrecht, N., Springmann, M., Bodirsky, B.L., Gaupp, F., Freund, F., Lotze-Campen, H. and Gabrysch, S. (2022) We Need a Food System Transformation—In the Face of the Russia-Ukraine War, Now More than Ever. One Earth, 5, 470-472. https://doi.org/10.1016/j.oneear.2022.04.004
[5]
Wahome, P.K., Oseni, T.O., Masarirambi, M.T. and Shongwe, V.D. (2011) Effects of Different Hydroponics Systems and Growing Media on the Vegetative Growth, Yield and Cut Flower Quality of Gypsophila (Gypsophila paniculata L.). World Journal of Agricultural Sciences, 7, 692-698.
[6]
Khan, S., Purohit, A. and Vadsaria, N. (2021) Hydroponics: Current and Future State of the Art in Farming. Journal of Plant Nutrition, 44, 1515-1538. https://doi.org/10.1080/01904167.2020.1860217
[7]
Hamza, A., Abdelraouf, R.E., Helmy, Y.I. and El-Sawy, S.M.M. (2022) Using Deep Water Culture as One of the Important Hydroponic Systems for Saving Water, Mineral Fertilizers and Improving the Productivity of Lettuce Crop. International Journal of Health Sciences, 6, 2311-2331. https://doi.org/10.53730/ijhs.v6nS9.12932
[8]
Kikuchi, Y., Kanematsu, Y., Yoshikawa, N., Okubo, T. and Takagaki, M. (2018) Environmental and Resource Use Analysis of Plant Factories with Energy Technology Options: A Case Study in Japan. Journal of Cleaner Production, 186, 703-717. https://doi.org/10.1016/j.jclepro.2018.03.110
[9]
Xydis, G.A., Liaros, S. and Avgoustaki, D.D. (2020) Small Scale Plant Factories with Artificial Lighting and Wind Energy Microgeneration: A Multiple Revenue Stream Approach. Journal of Cleaner Production, 255, Article ID: 120227. https://doi.org/10.1016/j.jclepro.2020.120227
[10]
Hayden, A.L. (2006) Aeroponic and Hydroponic Systems for Medicinal Herb, Rhizome, and Root Crops. HortScience, 41, 536-538. https://doi.org/10.21273/HORTSCI.41.3.536
[11]
Grigas, A., Kemzūraitė, A., Steponavičius, D., Steponavičienė, A. and Domeika, R. (2020) Impact of Slope of Growing Trays on Productivity of Wheat Green Fodder by a Nutrient Film Technique System. Water, 12, Article 3009. https://doi.org/10.3390/w12113009
[12]
D’Imperio, M., Renna, M., Cardinali, A., Buttaro, D., Santamaria, P. and Serio, F. (2016) Silicon Biofortification of Leafy Vegetables and Its Bioaccessibility in the Edible Parts. Journal of the Science of Food and Agriculture, 96, 751-756. https://doi.org/10.1002/jsfa.7142
[13]
Liu, C., Wu, J., Raudales, R., McAvoy, R., Theobald, D. and Yang, X. (2018) An Experimental Study on Energy and Water Uses of A Newly Developed Greenbox Farming System. 2018 ASABE Annual International Meeting, Detroit, 29 July-1 August 2018, 2-9. https://doi.org/10.13031/aim.201800891
[14]
Singh, A.K., McAvoy, R.J., Bravo-Ureta, B. and Yang, X. (2021) An Experimental Study on GREENBOX Technology: Feasibility and Performance. 2021 ASABE Annual International Virtual Meeting, 12-16 July 2021, 145-166. https://doi.org/10.13031/aim.202100453
[15]
Singh, A.K., McAvoy, R.J., Bravo-Ureta, B. and Yang, X. (2021) Comparison of Environmental Condition, Productivity, and Resources Use between GREENBOX and Greenhouse for Growing Lettuce. 2021 ASABE Annual International Virtual Meeting, 12-16 July 2021, 2-10. https://doi.org/10.13031/aim.202100455
[16]
Singh, A.K., McAvoy, R.J., Bravo-Ureta, B. and Yang, X. (2022) Financial Feasibility Study of GREENBOX Technology for Crop Production in an Urban Setting. 2022 ASABE Annual International Meeting, Houston, 17-20 July 2022, 1-16. https://doi.org/10.13031/aim.202201068
[17]
Yang, X., Theobald, D., McAvoy, R., Wu, J. and Liu C. (2017) Greenbox Farming: A New System for Urban Agriculture. 2017 ASABE Annual International Meeting, Spokane, 16-19 July 2017, 1 p.
[18]
Singh, A.K. and Yang, X. (2021) GREENBOX Horticulture, an Alternative Avenue of Urban Food Production. Agricultural Sciences, 12, 1473-1489. https://doi.org/10.4236/as.2021.1212094
[19]
Singh, A.K., Bravo-Ureta, B., McAvoy, R. and Yang, X. (2023) GREENBOX Technology II—Comparison of Environmental Conditions, Productivity, and Water Consumption with Greenhouse Operation. Journal of the ASABE.
[20]
Singh, A.K., McAvoy, R., Bravo-Ureta, B. and Yang, X. (2023) GREENBOX Technology I—Technical Feasibility and Performance in Warehouse Environment. Journal of the ASABE.
[21]
National Oceanic and Atmospheric Administration (2022) Climate—Southwest Florida. https://www.weather.gov/wrh/Climate?wfo=tbw
[22]
Zheng, C., Mohammad, S.J., Pengpeng, M., Mengmeng, W., Xiaoying, L. and Shirong, G. (2020) Functional Growth, Photosynthesis and Nutritional Property Analyses of Lettuce Grown under Different Temperature and Light Intensity. The Journal of Horticultural Science and Biotechnology, 96, 53-61. https://www.tandfonline.com/doi/epdf/10.1080/14620316.2020.1807416?needAccess=true&role=button
[23]
Holmes, S.C., Wells, D.E., Pickens, J.M. and Kemble, J.M. (2019) Selection of Heat Tolerant Lettuce (Lactuca sativa L.) Cultivars Grown in Deep Water Culture and Their Marketability. Horticulturae, 5, Article 50. https://doi.org/10.3390/horticulturae5030050
[24]
Anderson, C.J.R. and Rosas-Anderson, P.J. (2017) Leafscan. Version 1.3.21. Mobile Application Software. https://apps.apple.com/app/id1254892230
[25]
Zhu, J., Tremblay, N. and Liang, Y. (2012) Comparing SPAD and at LEAF Values for Chlorophyll Assessment in Crop Species. Canadian Journal of Soil Science, 92, 645-648. https://doi.org/10.4141/cjss2011-100
[26]
R Core Team (2022) R: A Language and Environment for Statistical Computing. R Foundation for Statistical Computing, Vienna, Austria. https://www.R-project.org/
[27]
Paz, M., Fisher, P.R. and Gómez, C. (2019) Minimum Light Requirements for Indoor Gardening of Lettuce. Urban Agriculture & Regional Food Systems, 4, 1-10. https://doi.org/10.2134/urbanag2019.03.0001
[28]
Despommier, D. (2013) Farming up the City: The Rise of Urban Vertical Farms. Trends in Biotechnology, 31, 388-389. https://doi.org/10.1016/j.tibtech.2013.03.008
[29]
Tokunaga, K., Tamaru, C., Ako, H. and Leung, P. (2015) Economics of Small-Scale Commercial Aquaponics in Hawai’i. Journal of the World Aquaculture Society, 46, 20-32. https://doi.org/10.1111/jwas.12173
[30]
Kubota, C. (2016) Chapter 10—Growth, Development, Transpiration and Translocation as Affected by Abiotic Environmental Factors. In: Kozai, T., Niu, G. and Takagaki, M., Eds., Plant Factory, Academic Press, San Diego, 151-164. https://doi.org/10.1016/B978-0-12-801775-3.00010-X
