Hydroponics

Hydroponics^[1] is a type of horticulture and a subset of hydroculture which involves growing plants, usually crops or medicinal plants, without soil, by using water-based mineral nutrient solutions in an artificial environment. Terrestrial or aquatic plants may grow freely with their roots exposed to the nutritious liquid or the roots may be mechanically supported by an inert medium such as perlite, gravel, or other substrates.^[2]

Despite inert media, roots can cause changes of the rhizosphere pH and root exudates can affect rhizosphere biology and physiological balance of the nutrient solution when secondary metabolites are produced in plants.^[3]^[4]^[5] Transgenic plants grown hydroponically allow the release of pharmaceutical proteins as part of the root exudate into the hydroponic medium.^[6]

The nutrients used in hydroponic systems can come from many different organic or inorganic sources, including fish excrement, duck manure, purchased chemical fertilizers, or artificial standard or hybrid nutrient solutions.^[7]

In contrast to field cultivation, plants are commonly grown hydroponically in a greenhouse or contained environment on inert media, adapted to the controlled-environment agriculture (CEA) process.^[8] Plants commonly grown hydroponically include tomatoes, peppers, cucumbers, strawberries, lettuces, and cannabis, usually for commercial use, as well as Arabidopsis thaliana, which serves as a model organism in plant science and genetics.^[9]

Hydroponics offers many advantages, notably a decrease in water usage in agriculture. To grow 1 kilogram (2.2 lb) of tomatoes using intensive farming methods requires 214 liters (47 imp gal; 57 U.S. gal) of water;^[10] using hydroponics, 70 liters (15 imp gal; 18 U.S. gal); and only 20 liters (4.4 imp gal; 5.3 U.S. gal) using aeroponics.^[11]

Hydroponic cultures lead to highest biomass and protein production compared to other growth substrates, of plants cultivated in the same environmental conditions and supplied with equal amounts of nutrients.^[12]

Since hydroponic growing takes much less water and nutrients to grow produce, and climate change threatens agricultural yields, it could be possible in the future for people in harsh environments with little accessible water to hydroponically grow their own plant-based food.^[13]^[8]

Hydroponics is not only used on earth, but has also proven itself in plant production experiments in space.^[14]

^ Gericke, William F. (1937). "Hydroponics - crop production in liquid culture media". Science. 85 (2198): 177–178. Bibcode:1937Sci....85..177G. doi:10.1126/science.85.2198.177. PMID 17732930.
^ Gericke, William F. (1945). "The meaning of hydroponics". Science. 101 (2615): 142–143. Bibcode:1945Sci...101..142G. doi:10.1126/science.101.2615.142. PMID 17800488.
^ Nye, P. H. (1981). "Changes of pH across the rhizosphere induced by roots". Plant and Soil. 61 (1–2): 7–26. Bibcode:1981PlSoi..61....7N. doi:10.1007/BF02277359. S2CID 24813211.
^ Walker, T. S.; Bais, H. P.; Grotewold, E.; Vivanco, J. M. (2003). "Root exudation and rhizosphere biology". Plant Physiology. 132 (1): 44–51. doi:10.1104/pp.102.019661. PMC 1540314. PMID 12746510.
^ Suryawanshi, Yogesh (2021). "Hydroponic Cultivation Approaches to Enhance the Contents of the Secondary Metabolites in Plants". Biotechnological Approaches to Enhance Plant Secondary Metabolites. CRC Press.: 71–88. doi:10.1201/9781003034957-5. ISBN 978-1-003-03495-7. S2CID 239706318.
^ Horn, M.E.; Woodard, S.L.; Howard, J.A. (2004). "Plant molecular farming: systems and products". Plant Cell Reports. 22 (10): 711–720. doi:10.1007/s00299-004-0767-1. PMC 7079917. PMID 14997337.
^ Jones, J. B. Jr. (2004). Hydroponics: A Practical Guide for the Soilless Grower (2nd ed.). Boca Raton, London, New York, Washington, D. C.: CRC Press. pp. 153–166. ISBN 978-0-8493-3167-1.
^ ^a ^b "The future of farming: hydroponics". PSCI. Retrieved Aug 25, 2022.
^ "A simplified hydroponic culture of Arabidopsis". Bio-101. Retrieved Mar 4, 2020.
^ "How much water is needed to produce food and how much do we waste?". The Guardian. Retrieved Aug 19, 2022.
^ Zhang, He; Asutosh, Ashish; Hu, Wei (2018-11-27). "Implementing Vertical Farming at University Scale to Promote Sustainable Communities: A Feasibility Analysis". Sustainability. 10 (12): 4429. doi:10.3390/su10124429. ISSN 2071-1050. The paper describes the authors statistical concept modeling in determining the potential advantages of developing a vertical farm at Huazhong University of Science and Technology. While the figures are conservative and project the farm's profitability in 10 to 20 years, it is based on metadata and not on direct observation.
^ Nagel, K.A.; Kastenholz, B.; Gilmer, F.; Schurr, U.; Walter, A. (2010). "Novel detection system for plant protein production of pharmaceuticals and impact on conformational diseases". Protein and Peptide Letters. 17 (6): 723–731. doi:10.2174/092986610791190282. PMID 20015023.
^ Compare: Gericke, William F. (1938). "Crop production without soil". Nature. 141 (3569): 536–540. Bibcode:1938Natur.141..536G. doi:10.1038/141536a0. S2CID 38739387. It is, of course, not inconceivable that industry may develop and manufacture equipment at markedly greater economy than prevails at present, thereby increasing the number of crops that can be grown economically.
^ Stutte, G. W.; Newsham, G.; Morrow, R. M.; Wheeler, R. M. (2012). "Concept for Sustained Plant Production on ISS Using VEGGIE Capillary Mat Rooting System". 41st International Conference on Environmental Systems, 17–21 July 2011, Portland, Oregon. pp. 1–17. doi:10.2514/6.2011-5263. hdl:2060/20110011606. ISBN 978-1-60086-948-8. S2CID 13847293.

[:-1-1] Gericke, William F. (1937). "Hydroponics - crop production in liquid culture media". Science. 85 (2198): 177–178. Bibcode:1937Sci....85..177G. doi:10.1126/science.85.2198.177. PMID 17732930.

[2] Gericke, William F. (1945). "The meaning of hydroponics". Science. 101 (2615): 142–143. Bibcode:1945Sci...101..142G. doi:10.1126/science.101.2615.142. PMID 17800488.

[3] Nye, P. H. (1981). "Changes of pH across the rhizosphere induced by roots". Plant and Soil. 61 (1–2): 7–26. Bibcode:1981PlSoi..61....7N. doi:10.1007/BF02277359. S2CID 24813211.

[4] Walker, T. S.; Bais, H. P.; Grotewold, E.; Vivanco, J. M. (2003). "Root exudation and rhizosphere biology". Plant Physiology. 132 (1): 44–51. doi:10.1104/pp.102.019661. PMC 1540314. PMID 12746510.

[taylorfrancis.com-5] Suryawanshi, Yogesh (2021). "Hydroponic Cultivation Approaches to Enhance the Contents of the Secondary Metabolites in Plants". Biotechnological Approaches to Enhance Plant Secondary Metabolites. CRC Press.: 71–88. doi:10.1201/9781003034957-5. ISBN 978-1-003-03495-7. S2CID 239706318.

[6] Horn, M.E.; Woodard, S.L.; Howard, J.A. (2004). "Plant molecular farming: systems and products". Plant Cell Reports. 22 (10): 711–720. doi:10.1007/s00299-004-0767-1. PMC 7079917. PMID 14997337.

[:-7] Jones, J. B. Jr. (2004). Hydroponics: A Practical Guide for the Soilless Grower (2nd ed.). Boca Raton, London, New York, Washington, D. C.: CRC Press. pp. 153–166. ISBN 978-0-8493-3167-1.

[:-2-8] "The future of farming: hydroponics". PSCI. Retrieved Aug 25, 2022.

[9] "A simplified hydroponic culture of Arabidopsis". Bio-101. Retrieved Mar 4, 2020.

[10] "How much water is needed to produce food and how much do we waste?". The Guardian. Retrieved Aug 19, 2022.

[11] Zhang, He; Asutosh, Ashish; Hu, Wei (2018-11-27). "Implementing Vertical Farming at University Scale to Promote Sustainable Communities: A Feasibility Analysis". Sustainability. 10 (12): 4429. doi:10.3390/su10124429. ISSN 2071-1050. The paper describes the authors statistical concept modeling in determining the potential advantages of developing a vertical farm at Huazhong University of Science and Technology. While the figures are conservative and project the farm's profitability in 10 to 20 years, it is based on metadata and not on direct observation.

[:-3-12] Nagel, K.A.; Kastenholz, B.; Gilmer, F.; Schurr, U.; Walter, A. (2010). "Novel detection system for plant protein production of pharmaceuticals and impact on conformational diseases". Protein and Peptide Letters. 17 (6): 723–731. doi:10.2174/092986610791190282. PMID 20015023.

[13] Compare: Gericke, William F. (1938). "Crop production without soil". Nature. 141 (3569): 536–540. Bibcode:1938Natur.141..536G. doi:10.1038/141536a0. S2CID 38739387. It is, of course, not inconceivable that industry may develop and manufacture equipment at markedly greater economy than prevails at present, thereby increasing the number of crops that can be grown economically.

[14] Stutte, G. W.; Newsham, G.; Morrow, R. M.; Wheeler, R. M. (2012). "Concept for Sustained Plant Production on ISS Using VEGGIE Capillary Mat Rooting System". 41st International Conference on Environmental Systems, 17–21 July 2011, Portland, Oregon. pp. 1–17. doi:10.2514/6.2011-5263. hdl:2060/20110011606. ISBN 978-1-60086-948-8. S2CID 13847293.

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