Editing Hydroponics (section)

== History ==
[[File:Hydro system.jpg|thumb|Inside an ebb-and-flow hydroponic system employing individual buckets connected by fill/drain hoses.]]
The earliest published work on growing terrestrial plants without soil was the 1627 book ''Sylva Sylvarum'' or 'A Natural History' by [[Francis Bacon]], printed a year after his death. As a result of his work, water culture became a popular research technique. In 1699, [[John Woodward (naturalist)|John Woodward]] published his water culture experiments with [[spearmint]]. He found that plants in less-pure water sources grew better than plants in distilled water. By 1842, a list of nine elements believed to be essential for plant growth had been compiled, and the discoveries of German botanists [[Julius von Sachs]] and [[Wilhelm Knop]], in the years 1859–1875, resulted in a development of the technique of soilless cultivation.{{sfn|Douglas|1975|pp=1–3}} To quote von Sachs directly: ''"In the year 1860, I published the results of experiments which demonstrated that [[Embryophyte|land plants]] are capable of absorbing their nutritive matters out of watery solutions, without the aid of soil, and that it is possible in this way not only to maintain plants alive and growing for a long time, as had long been known, but also to bring about a vigorous increase of their organic substance, and even the production of seed capable of [[germination]]."''<ref>{{cite book |last1=Sachs |first1=Julius |title=Lectures on the Physiology of Plants |date=1887 |publisher=Clarendon Press |page=283 |url=https://books.google.com/books?id=ZLvPAAAAMAAJ&dq=%22In%20the%20year%201860%2C%20I%20published%20the%20results%20of%20experiments%20which%20demonstrated%20that%20land%20plants%20are%20capable%20of%20absorbing%20their%20nutritive%20matters%20out%20of%20watery%20solutions%2C%20without%20the%20aid%20of%20soil%2C%20and%20that%20it%20is%20possible%20in%20this%20way%20not%20only%20to%20maintain%20plants%20alive%20and%20growing%20for%20a%20long%20time%2C%20as%20had%20long%20been%20known%2C%20but%20also%20to%20bring%20about%20a%20vigorous%20increase%20of%20their%20organic%20substance%2C%20and%20even%20the%20production%20of%20seed%20capable%20of%20germination.%22&pg=PA283 }}</ref> Growth of terrestrial plants without soil in mineral nutrient solutions was later called "solution culture" in reference to "soil culture". It quickly became a standard research and teaching technique in the 19th and 20th centuries and is still widely used in [[plant nutrition]] science.<ref>{{Cite journal|last=Breazeale|first=J. F.|date=1906|title=The relation of sodium to potassium in soil and solution cultures|journal=Journal of the American Chemical Society|volume=28|issue=8|pages=1013–1025|doi=10.1021/ja01974a008|bibcode=1906JAChS..28.1013B |url=https://zenodo.org/record/1887883}}</ref>

Around the 1930s plant nutritionists investigated [[Plant pathology|diseases]] of certain plants, and thereby, observed symptoms related to existing soil conditions such as [[Soil salinity|salinity]]. In this context, water culture experiments were undertaken with the hope of delivering similar symptoms under controlled laboratory conditions.<ref>{{cite journal|title=Nutrition of strawberry plant under controlled conditions. (a) Effects of deficiencies of boron and certain other elements, (b) susceptibility to injury from sodium salts|last1=Hoagland |first1=D.R. |last2=Snyder |first2=W.C.|journal=Proceedings of the American Society for Horticultural Science|year=1933|volume=30|pages=288–294}}</ref> This approach forced by [[Dennis Robert Hoagland]] led to innovative model systems (e.g., [[green algae]] [[Nitella]]) and [[Dennis Robert Hoagland#Hewitt's Table 30A|standardized nutrient recipes]] playing an increasingly important role in modern [[plant physiology]].<ref name="nas">{{cite web|title=Dennis Robert Hoagland: 1884-1949|work=Biographical Memoirs of the National Academy of Sciences|url=http://www.nasonline.org/publications/biographical-memoirs/memoir-pdfs/hoagland-dennis-r.pdf|access-date=2 December 2020}}</ref> In 1929, [[William Frederick Gericke]] of the University of California at Berkeley began publicly promoting that the principles of solution culture be used for [[agriculture|agricultural crop production]].<ref>{{Cite journal|last= Gericke|first= William F.|date= 1929|title= Aquiculture - a means of crop production|journal= American Journal of Botany|volume= 16|pages= 862–867}}</ref><ref>{{Cite journal|last=Dunn|first=H. H.|date=October 1929|title=Plant "Pills" Grow Bumper Crops|url=https://books.google.com/books?id=VigDAAAAMBAJ&pg=PA29|journal=[[Popular Science|Popular Science Monthly]]|pages=29–30}}</ref><ref>{{Cite journal|last1=Thiyagarajan|first1=G.|last2=Umadevi|first2=R.|last3=Ramesh|first3=K.|date=Jan 2007|title=Hydroponics|url=http://www.techno-preneur.net/information-desk/sciencetech-magazine/2007/jan07/Hydroponics.pdf|journal=Science Tech Entrepreneur|archive-url=https://web.archive.org/web/20091229051310/http://www.techno-preneur.net/information-desk/sciencetech-magazine/2007/jan07/Hydroponics.pdf|archive-date=December 29, 2009|via=[[Wayback Machine]]}}</ref> He first termed this cultivation method "aquiculture" created in analogy to "agriculture" but later found that the cognate term [[aquaculture]] was already applied to culture of [[Aquatic animal|aquatic organisms]]. Gericke created a sensation by growing tomato vines {{convert|25|ft|m|abbr=off|spell=in}} high in his backyard in mineral nutrient solutions rather than soil.<ref>{{Cite news|url=https://home.howstuffworks.com/lawn-garden/professional-landscaping/hydroponics.htm|title=How Hydroponics Works|last=Turner|first=Bambi|date=Oct 20, 2008|work=HowStuffWorks|access-date=May 29, 2012|publisher=InfoSpace Holdings LLC|language=en}}</ref> He then introduced the term ''Hydroponics'', water culture, in 1937, proposed to him by [[:es:William Albert Setchell|W. A. Setchell]], a [[phycology|phycologist]] with an extensive education in the classics.<ref name=":-1">{{Cite journal |last=Gericke |first=William F. |date=1937 |title=Hydroponics - crop production in liquid culture media |journal=Science |volume=85 |issue=2198 |pages=177–178 |bibcode=1937Sci....85..177G |doi=10.1126/science.85.2198.177 |pmid=17732930}}</ref><ref>{{cite web|url=http://ucjeps.berkeley.edu/setchell.html|title=Biography of W.A. Setchell|publisher=The University and Jepson Herbaria, University of California|archive-url=https://web.archive.org/web/20151015233655/http://ucjeps.berkeley.edu/setchell.html|archive-date=October 15, 2015|access-date=Nov 21, 2018}}</ref> Hydroponics is derived from [[neologism]] υδρωπονικά (derived from Greek ύδωρ=water and πονέω=cultivate), constructed in analogy to γεωπονικά (derived from Greek γαία=earth and πονέω=cultivate),<ref>{{cite web|url=https://www.perseus.tufts.edu/hopper/text?doc=Perseus:text:1999.04.0057:entry=gewponiko/s|title=A Greek-English Lexicon|last1=Liddell|first1=H. G.|last2=Scott|first2=R.|website=www.perseus.tufts.edu|access-date=Nov 21, 2018}}</ref> [[geoponica]], that which concerns agriculture, replacing, γεω-, earth, with ὑδρο-, water.{{sfn|Douglas|1975|pp=1–3}}

Despite initial successes, however, Gericke realized that the time was not yet ripe for the general [[Technology|technical application]] and [[Commerce|commercial use]] of hydroponics for producing crops.<ref>{{cite web|url=https://youtube.com/watch?v=foRUrxkx2MU/| archive-url=https://ghostarchive.org/varchive/youtube/20211031/foRUrxkx2MU| archive-date=2021-10-31 | url-status=live|title=First hydroponics experiment video of William Frederick Gericke in 1930s|date=June 25, 2021|website=[[YouTube]]}}{{cbignore}}</ref> He also wanted to make sure all aspects of hydroponic cultivation were researched and tested before making any of the specifics available to the public.<ref>{{Cite news|url= https://gardenculturemagazine.com/history-of-hydroponics-part-iii-applying-the-science/|title= History of hydroponics|work= Garden Culture Magazine|access-date= Aug 18, 2022|language= en-US}}</ref> Reports of Gericke's work and his claims that hydroponics would revolutionize plant agriculture prompted a huge number of requests for further information. Gericke had been denied use of the university's [[greenhouse]]s for his experiments due to the administration's skepticism, and when the university tried to compel him to release his preliminary nutrient recipes developed at home, he requested greenhouse space and time to improve them using appropriate research facilities. While he was eventually provided greenhouse space, the university assigned [[Dennis Robert Hoagland|Hoagland]] and [[Daniel I. Arnon|Arnon]] to re-evaluate Gericke's claims and show his formula held no benefit over soil grown plant yields, a view held by Hoagland. Because of these irreconcilable conflicts, Gericke left his academic position in 1937 in a climate that was politically unfavorable and continued his research independently in his greenhouse. In 1940, Gericke, whose work is considered to be the basis for all forms of hydroponic growing, published the book, ''Complete Guide to Soilless Gardening''. Therein, for the first time, he published his basic formulas involving the macro- and micronutrient salts for hydroponically-grown plants.<ref name=Gericke />

As a result of research of Gericke's claims by order of the Director of the ''California Agricultural Experiment Station'' of the [[University of California, Berkeley|University of California]], [[Claude B. Hutchison|Claude Hutchison]], Dennis Hoagland and [[Daniel Arnon]] wrote a classic 1938 agricultural bulletin, ''The Water Culture Method for Growing Plants Without Soil'', one of the most important works on solution culture ever, which made the claim that hydroponic [[crop yield]]s were no better than crop yields obtained with good-quality soils.<ref>{{Cite book|hdl=2027/uc2.ark:/13960/t51g1sb8j |title=The water-culture method for growing plants without soil|last1=Hoagland|first1=D. R|last2=Arnon|first2=D. I|publisher=University of California, College of Agriculture, Agricultural Experiment Station|year=1938|series=Circular|location=Berkeley, CA |oclc=870260644}}</ref> Ultimately, crop yields would be limited by factors other than mineral nutrients, especially light and aeration of the culture medium.<ref>{{Cite journal|last1=Arnon|first1=D. I.|last2=Hoagland|first2=D. R.|date=1940|title=Crop production in artificial culture solutions and in soils with special reference to factors influencing yields and absorption of inorganic nutrients|journal=Soil Science|volume=50|issue=1|pages=463–485}}</ref> However, in the introduction to his landmark book on soilless cultivation, published two years later, Gericke pointed out that the results published by Hoagland and Arnon in comparing the yields of experimental plants in sand, soil and solution cultures, were based on several [[Observational error|systemic errors]] (''"...these experimenters have made the mistake of limiting the productive capacity of hydroponics to that of soil. Comparison can be only by growing as great a number of plants in each case as the fertility of the culture medium can support."'').<ref name=Gericke />
[[File:Hydroponic farming, USA (9386).jpg|thumb|A lettuce hydroponic farm in [[Fellsmere, Florida]], USA.]]
For example, the Hoagland and Arnon study did not adequately appreciate that hydroponics has other key benefits compared to soil culture including the fact that the roots of the plant have constant access to [[oxygen]] and that the plants have access to as much or as little water and nutrients as they need.<ref name=Gericke /><ref>{{Cite news|url=https://www.hydroponic-urban-gardening.com/hydroponics-guide/various-hydroponics-systems/?L=1&tx_pwcomments_pi1%5Bcomment%5D=22&cHash=9b7ec89c9c292cc1efca10f6d13f3b45&tx_pwcomments_pi1%5BcommentToReplyTo%5D=22&tx_pwcomments_pi1%5Baction%5D=new&tx_pwcomments_pi1%5Bcontroller%5D=Comment|title=Various hydroponics systems|work=Hydroponic Urban Gardening Blog|access-date=Feb 5, 2020|language=en-US}}</ref> This is important as one of the most common errors when cultivating plants is over- and underwatering; hydroponics prevents this from occurring as large amounts of water, which may drown root systems in soil, can be made available to the plant in hydroponics, and any water not used, is drained away, recirculated, or actively aerated, eliminating [[Anoxic waters|anoxic]] conditions in the root area. In soil, a grower needs to be very experienced to know exactly how much water to feed the plant. Too much and the plant will be unable to access oxygen because [[Soil gas|air]] in the [[Pore space in soil|soil pores]] is displaced, which can lead to [[root rot]]; too little and the plant will undergo [[Moisture stress|water stress]] or lose the ability to [[Active transport|absorb]] nutrients, which are typically moved into the roots while [[Solvation|dissolved]], leading to nutrient deficiency symptoms such as [[chlorosis]] or [[fertilizer burn]]. Eventually, Gericke's advanced ideas led to the implementation of hydroponics into commercial agriculture while Hoagland's views and helpful support by the University prompted [[Dennis Robert Hoagland#Bibliography|Hoagland and his associates]] to develop several new formulas (recipes) for mineral nutrient solutions, universally known as [[Hoagland solution]].<ref>{{cite book |last1=Texier |first1=William |title=Hydroponics For Everybody: All About Home Horticulture |date=2013 |publisher=Mamaéditions.com |isbn=978-2-84594-081-9 |page=235 }}{{self-published inline|date=March 2025}}</ref>

One of the earliest successes of hydroponics occurred on [[Wake Island]], a rocky atoll in the Pacific Ocean used as a refueling stop for [[Pan American Airlines]]. Hydroponics was used there in the 1930s to grow vegetables for the passengers. Hydroponics was a necessity on Wake Island because there was no soil, and it was prohibitively expensive to airlift in fresh vegetables.<ref>{{Cite journal|last=Taylor|first=F. J.|date=Jul 1939|title=Nice Clean Gardening|url=https://books.google.com/books?id=GkEEAAAAMBAJ&pg=PA14|journal=[[The Rotarian]]|volume=55|issue=1|pages=14–15|issn=0035-838X}}</ref>

From 1943 to 1946, [[Daniel I. Arnon]] served as a major in the [[United States Army]] and used his prior expertise with plant nutrition to feed troops stationed on barren [[Ponape Island]] in the western [[Pacific Ocean|Pacific]] by growing crops in gravel and nutrient-rich water because there was no [[arable land]] available.<ref name=NYTObit>{{cite news |last1=Sullivan |first1=Walter |title=Daniel Arnon, 84, Researcher And Expert on Photosynthesis |url=https://www.nytimes.com/1994/12/23/obituaries/daniel-arnon-84-researcher-and-expert-on-photosynthesis.html |work=The New York Times |date=23 December 1994 }}</ref>

In the 1960s, Allen Cooper of England developed the [[nutrient film technique]].<ref>{{Cite book|title=The ABC of NFT: nutrient film technique: the world's first method of crop production without a solid rooting medium|last=Cooper|first=A. J.|date=1979|publisher=Grower Books|isbn=0-901361-22-4|location=London|oclc=5809348}}{{pn|date=March 2025}}</ref> [[The Land (Disney)|The Land Pavilion]] at Walt Disney World's EPCOT Center opened in 1982 and prominently features a variety of hydroponic techniques.

In recent decades, [[NASA]] has done extensive hydroponic research for its [[Controlled Ecological Life Support System]] (CELSS). Hydroponics research mimicking a Martian environment uses LED lighting to grow in a different color spectrum with much less heat. [[Raymond M. Wheeler|Ray Wheeler]], a plant physiologist at Kennedy Space Center's Space Life Science Lab, believes that hydroponics will create advances within space travel, as a [[bioregenerative life support system]].<ref>{{cite web|url=https://www.nasa.gov/vision/earth/livingthings/biofarming.html|title=Farming for the Future|last=Heiney|first=A.|date=Aug 27, 2004|website=www.nasa.gov|access-date=Nov 21, 2018|archive-date=August 29, 2023|archive-url=https://web.archive.org/web/20230829074535/https://www.nasa.gov/vision/earth/livingthings/biofarming.html}}</ref>

As of 2017, Canada had hundreds of acres of large-scale commercial hydroponic greenhouses, producing tomatoes, peppers and cucumbers.<ref name="marketplace2017">{{cite web|last1=Schaefer|first1=Karen|title=Canadian greenhouse industry seeks methods to reduce pollution into Lake Erie|url=http://www.marketplace.org/2017/01/02/sustainability/canadian-greenhouse-industry-seeks-methods-reduce-pollution-lake-erie|website=Marketplace.org|access-date=17 January 2017|date=2017-01-02}}</ref>

Due to technological advancements within the industry and numerous [[Factors of production|economic factors]], the global hydroponics market is forecast to grow from US$226.45 million in 2016 to US$724.87 million by 2023.<ref>{{cite web|url=https://www.businesswire.com/news/home/20171206006224/en/|title=Global Hydroponics Market Report 2017-2023: Market is expected to grow from $226.45 million in 2016 to reach $724.87 million by 2023 - Research and Markets|last1=Wood|first1=Laura|date=Dec 6, 2017|website=Business Wire|publisher=Berkshire Hathaway|language=en|access-date=Apr 1, 2018}}</ref>{{Update inline|date=April 2023|reason=It is now 2023, has this prediction come true?}}