1940 Original Scientist Hydroponics Photo Fantastic Vintage

$425.42 Buy It Now, FREE Shipping, 30-Day Returns, eBay Money Back Guarantee
Seller: memorabilia111 ✉️ (808) 100%, Location: Ann Arbor, Michigan, US, Ships to: US & many other countries, Item: 176270374084 1940 ORIGINAL SCIENTIST HYDROPONICS PHOTO FANTASTIC VINTAGE. A VINTAGE ORIGINAL VERY RARE 1940 PHOTO OF HYDROPONICS PIONEER DR. WILLIAM F. GERICKE. PHOTO MEASURES APPROXIMATELY 6 X 6 2/3 INCHES William Frederick Gericke (b. 1882), plant nutritionist, University of California, and pioneer in hydroponic agriculture; he is credited with coining the term "hydroponics."
Dr. Gericke, Noted Crop Expert, Dies BERKELEY - Dr. William F. Gericke, who originated and developed soilless crop production, died yesterday at Elmwood Convalescent Home where he had been a patient in recent weeks. Dr. Gericke, 88, coined the work "hydroponics" to describe the process of cultivating plants in a nutrient solution without using soil. When, as a University of California professor in 1925, he proved the success of the technique, he was swamped with correspondence from throughout the world seeking information on the procedures. In 1937 he left the university of concentrate on his research, which he continued until only a couple of weeks before his death. His widow, Grace, of 1555 Scenic Ave., who Dr. Gericke married in 1955 said "his aim was to solve world food problems in the most efficient, productive and economical way. He was interested in helping humanity find a way to be able to feed itself." Funeral services will be held tomorrow at 10:30 a.m. at Epworth United Mathodist Church, and burial will be at Sunset View Cemetery in El Cerrito. [Oakland Tribune 30 Sep 1970] When William Frederick Gericke was born on 30 August 1882, in Nebraska, United States, his father, Charles Gericke, was 35 and his mother, Fredriche Weinhousen, was 22. He married Grace Hannah Wood in 1955, in United States. He lived in Elkhorn Township, Dodge, Nebraska, United States in 1900 and Cuming Township, Dodge, Nebraska, United States in 1910. He died on 29 September 1970, in Berkeley, Alameda, California, United States, at the age of 88, and was buried in El Cerrito, Contra Costa, California, United States. Hydroponic gardens may sound Greek to you. Yes, it may confound you like no other. Take heed, however, if you’re wanting to make the most of your life on planet Earth, there is no wiser decision than getting into hydroponic gardening today. Especially true for New Yorkers and Californians, and for people who have to make do with limited living space - not to mention skyrocketing rents. With more and more Americans tipping the scales and increasingly putting the nation in top podium globally in terms of obesity, this may just be what the doctor ordered. To a large degree.   Cities have become a far cry from long ago when they were a beacon of hope - becoming synonymous with cultural decay and pollution instead, and the results says it all. Much as we have advanced technologically, there are still over 600,000 people succumbing to heart disease yearly. You may not have heard of hydroponic gardens. True. But for a healthier and happier you, it’s high time you should.  Read on.  Rows and rows of green lettuce - horticulture History of Hydroponic Gardens   Strictly speaking, hydroponics is a form of hydroculture - a broader method of growing plants without using soil. Water is the key difference. In hydroponics, you only use water and the nutrient solutions nurture the plants. In other forms of hydroculture, we use an inert. Specifically, these are solid growing mediums other than soil. Such soil alternatives are inorganic.   There are tremendous advantages growing through an indoor hydroponic garden. However, it was not until 1627 that the idea was officially hatched. Then, Francis Bacon, a most influential English statesman and scientist, published his work on growing plants without the use of soil. Then, truly, a revolutionary idea - albeit printed posthumously on a book entitled ‘A Natural History’ (i.e., Sylva Sylvarum).   As novel as it is, the idea took ground and spread. Shortly thereafter, in 1699, John Woodward, a notable English naturalist, gave solid proof to Bacon’s theories. Woodward was happy to let the world know how his spearmints thrived in ‘less-pure’ water than in clearer and purer distilled water. Duly published in a book and these water culture experiments became the stepping stone for other scientists to build upon.   Centuries later in 1842, two German botanists named Wilhelm Knopp and Julius von Sachs picked the cudgels up. They laid the groundwork for the science behind soilless plants to prosper. Specifically, they listed nine elements for growing terrestrial plants without the benefit of solid soil. Aptly, these Germans referred to the whole process as ‘solution culture’. And their research quickly became the standard text on the subject.   All this gathered steam in 1929. Then, an American ‘showman’ scientist named William Frederick Gericke (1882 - 1970) gained credit as the author of the word hydroponics. Gericke was a Nebraska-born notable plant physiologist and crop expert at the University of California. He stunned the world by growing tomato as high as 25 feet or 7.6 meters using nutrient-rich solutions right in his own yard.  Man vertically waving american flag Its Conquest of America Moreover, Gericke first used the word hydroponics, a term suggested to him in 1937 by W. A. Setchell. Though Setchell was a noted phycologist, he was also an expert in the classics.   Derived from the Greek language, hydroponics is a neologism of the Greek word for water (ύδωρ) and cultivate (πονέω). In a sense, two words turned into one.   As stunning and brilliant as Gericke is, however, he met substantial opposition. Fearing perhaps the prospects of soil-less farming, the university itself forbid him to use its greenhouses. The scientist had to do his research at home. Eventually, the university allowed Gericke to use its greenhouses but with reservations. It assigned two fellow scientists, Arnon and Hoagland, to reformulate Gericke’s formula to show soil-less agriculture is inferior to traditional soil variety.   And yet, Gericke came through. He published his works via a book called Complete Guide to Soilless Gardening - but not before leaving the walls of the university.   Not to be outdone however, Daniel I. Arnon and Dennis R. Hoagland wrote an agricultural bulletin in 1838. Entitled The Water Culture Method for Growing Plants Without Soil the bulletin claimed that Gericke’s hydroponic plant yields were not superior to plants cultivated in good old traditional soil.   Arnon’s and Hoagland’s research, however, was biased right from the onset. It failed to mention the essential advantages of hydroponics. For instance, their study never cited the fact that plants had greater access to vital oxygen. Its Commercial and Technological Use Today Today, hydroponic gardens are spreading by leaps and bounds. NASA in its quest for space conquest, for one, is doing extensive research on the topic. Currently, the government body is looking into growing plants using an LED-lighted set-up to mimic the environment on planet Mars.   True to Gericke’s vision, businesses are increasingly pitching in. In 2007, Eurofresh Farms, a company in Arizona, sold over 200 million pounds of fresh hydroponically-cultured tomatoes - pesticide-free. So great are their results that the company has dedicated over  318 acres under glass for this purpose alone.   The science itself is inspiring other ideas, giving way to aeroponic farming for instance.  hand holding soil and plant Benefits of an Indoor Hydroponic Garden for You   With more and more people converging, population density is highest in the cities. Added to that, there is an uptick in people traveling - riding their caravans to the ends of the Earth for instance. Such trends provide an ideal scenario for you for hydroponic gardening. And along with these reasons are:   Space maximization. It has to be remembered that plants grow differently in a soilless environment. In a hydroponic environment, for instance, they grow smaller roots. That means you can actually grow plants much closer to each other than in soil conditions. That is perfect for you should you be finding your space cramped. This is also ideal for greenhouses. It only means greater yield for the crop under glass.     Water Saver. Don’t get us wrong. Hydroponic gardens use water as a solution. So you may ask, how can you save water more in this method? Take note that in a hydroponic set-up, you may recycle water and the nutrients used. This way, it is able to save as much as 95% percent of water compared to traditional methods.   SuperiorQuality Yields. Gericke was right all along. Credit it to greater access to nutrients, plants grown hydroponically are superior in nutritional content. That may sound surprising. But truly, this could be your greatest reason to start growing fruits and vegetables this way. Studies show vegetables grown in a hydroponic setup had 50 percent more vitamins when compared to produce from traditional means. We’re talking about vitamins A and B complexes. Add vitamins C and E to that list and you know these are top-of-the-line produce.   Greater Control.Think about it. Unlike soil, you can easily manipulate the water used to nourish your indoor hydroponic garden. That only means you can easily addnutrients when found wanting, something you can hardly check in the soil. Indeed, this is a better-controlled environment.   Lighter Labor. The best part for you? You won’t have to work your butt off just to get the products you need. And that’s precisely because you won’t have to tend to a seemingly endless list of soil problems. Right? You need not pull weeds for instance. You need not shovel. Or for that matter, push a wheelbarrow. Imagine all the tedious labor you’re doing away. It’s a no brainer.  Hydroponic garden on a table in a bedroom Hydroponic Gardening: Helping You Live Life to the Fullest   By allowing yourself access to better yield via hydroponic gardening, you promote better health. But that’s not all.   Now you won’t have the convenient excuse of a cramped space for not gardening. And by such bliss, you put your health a notch higher.   By giving you the chance to garden, hydroponic gardening is giving you greater access to healthy produce. In addition two distinct studies reveal people in their prime age (i.e., the 60s to 70s) who garden regularly had 36 percent to 47 percent lesser chance of getting dementia compared to people who don’t, CNN health reports.   Add stress relief and exercise and you know getting hydroponic gardens in your abode is like breathing fresh morning air in a polluted city. Hydroponics[1] is a type of horticulture and a subset of hydroculture which involves growing plants (usually crops) without soil, by using mineral nutrient solutions in an aqueous solvent.[2] Terrestrial plants may grow with their roots exposed to the nutritious liquid, or, in addition, the roots may be physically supported by an inert medium such as perlite, gravel, or other substrates.[3] Despite inert media, roots can cause changes of the rhizosphere pH[4] and root exudates can affect rhizosphere biology.[5] The nutrients used in hydroponic systems can come from many different sources, including fish excrement, duck manure, purchased chemical fertilizers, or artificial nutrient solutions.[6] Plants commonly grown hydroponically, on inert media, include tomatoes, peppers, cucumbers, strawberries, lettuces, cannabis, and model plants like Arabidopsis thaliana.[7] 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 400 liters (88 imp gal; 110 U.S. gal) of water;[citation needed] 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.[8] Since hydroponics takes much less water to grow produce, it could be possible in the future for people in harsh environments with little accessible water to grow their own food.[9] Contents 1 History 2 Techniques 2.1 Static solution culture 2.2 Continuous-flow solution culture 2.3 Aeroponics 2.4 Fogponics 2.5 Passive sub-irrigation 2.6 Ebb and flow (flood and drain) sub-irrigation 2.7 Run-to-waste 2.8 Deep water culture 2.9 Rotary 3 Substrates (growing support materials) 3.1 Expanded clay aggregate 3.2 Growstones 3.3 Coconut Coir 3.4 Rice husks 3.5 Perlite 3.6 Vermiculite 3.7 Pumice 3.8 Sand 3.9 Gravel 3.10 Wood fiber 3.11 Sheep wool 3.12 Rock wool 3.13 Brick shards 3.14 Polystyrene packing peanuts 4 Nutrient solutions 4.1 Inorganic hydroponic solutions 4.2 Organic hydroponic solutions 4.3 Additives 4.4 Tools 4.5 Mixing solutions 5 Additional improvements 5.1 Growrooms 5.2 CO2 enrichment 6 See also 7 References History Further information: Historical hydroculture 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. Water culture became a popular research technique after that. In 1699 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.[10] Growth of terrestrial plants without soil in mineral nutrient solutions was called solution culture.[11] It quickly became a standard research and teaching technique and is still widely used. Solution culture is now considered a type of hydroponics where there is an inert medium. Around the 1930s plant scientists investigated diseases of certain plants, and thereby, observed symptoms related to existing soil conditions. In this context, water culture experiments were undertaken with the hope of delivering similar symptoms under controlled conditions.[12] This approach forced by Dennis Robert Hoagland led to model systems playing an increasingly important role in plant science.[13] In 1929, William Frederick Gericke of the University of California at Berkeley began publicly promoting that solution culture be used for agricultural crop production.[14][15][16] He first termed it aquaculture but later found that aquaculture was already applied to culture of aquatic organisms. Gericke created a sensation by growing tomato vines twenty-five feet (7.6 metres) high in his back yard in mineral nutrient solutions rather than soil.[17] He introduced the term hydroponics, water culture, in 1937, proposed to him by W. A. Setchell, a phycologist with an extensive education in the classics.[18] 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),[19] geoponica, that which concerns agriculture, replacing, γεω-, earth, with ὑδρο-, water.[10] Unfortunately, Gericke underestimated that the time was not yet ripe for the general technical application and commercial use of hydroponics for producing crops. 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 greenhouses 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 Hoagland and Arnon to re-evaluate Gericke's claims and show his formula held no benefit over soil grown plant yields, a view held by Hoagland. In 1940, Gericke published the book, Complete Guide to Soilless Gardening, after leaving his academic position in 1937 in a climate that was politically unfavorable. Therein, for the first time, he published his basic formula involving the macro- and micronutrient salts for hydroponically-grown plants.[20] As a result of research of Gericke's claims by order of the University of California, Dennis Robert Hoagland and Daniel Israel Arnon wrote a classic 1938 agricultural bulletin, The Water Culture Method for Growing Plants Without Soil, which made the claim that hydroponic crop yields were no better than crop yields obtained with good-quality soils.[21] Ultimately, crop yields would be limited by factors other than mineral nutrients, especially light.[22] However, this study did not adequately appreciate that hydroponics has other key benefits 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 as they need.[23] This is important as one of the most common errors when cultivating plants is overwatering and underwatering; and 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, thus, eliminating anoxic conditions in the root area. In soil, a grower needs to be very experienced to know exactly with how much water to feed the plant. Too much and the plant will be unable to access oxygen because the air in the soil pores is displaced; too little and the plant will lose the ability to absorb nutrients, which are typically moved into the roots while dissolved, leading to nutrient deficiency symptoms such as chlorosis. Hoagland's views and helpful support by the University prompted these two researchers to develop several new formulas for mineral nutrient solutions, universally known as Hoagland solution. Modified Hoagland solutions will continue to be used, as will the hydroponic techniques proposed by Gericke.[24] 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.[25] 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 by growing crops in gravel and nutrient-rich water because there was no arable land available.[26] In the 1960s, Allen Cooper of England developed the nutrient film technique.[27] 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. 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.[28] In 2007, Eurofresh Farms in Willcox, Arizona, sold more than 200 million pounds of hydroponically grown tomatoes.[29] Eurofresh has 318 acres (1.3 km2) under glass and represents about a third of the commercial hydroponic greenhouse area in the U.S.[30] Eurofresh tomatoes were pesticide-free, grown in rockwool with top irrigation. Eurofresh declared bankruptcy, and the greenhouses were acquired by NatureSweet Ltd. in 2013.[31] As of 2017, Canada had hundreds of acres of large-scale commercial hydroponic greenhouses, producing tomatoes, peppers and cucumbers.[32] Due to technological advancements within the industry and numerous economic factors, the global hydroponics market is forecast to grow from US$226.45 million in 2016 to US$724.87 million by 2023.[33] Techniques There are two main variations for each medium: sub-irrigation and top irrigation[specify]. For all techniques, most hydroponic reservoirs are now built of plastic, but other materials have been used including concrete, glass, metal, vegetable solids, and wood. The containers should exclude light to prevent algae and fungal growth in the nutrient solution. Static solution culture The deep water raft tank at the Crop Diversification Centre (CDC) South Aquaponics greenhouse in Brooks, Alberta In static solution culture, plants are grown in containers of nutrient solution, such as glass Mason jars (typically, in-home applications), pots, buckets, tubs, or tanks. The solution is usually gently aerated but may be un-aerated. If un-aerated, the solution level is kept low enough that enough roots are above the solution so they get adequate oxygen. A hole is cut (or drilled) in the top of the reservoir for each plant; if it a jar or tub, it may be its lid, but otherwise, cardboard, foil, paper, wood or metal may be put on top. A single reservoir can be dedicated to a single plant, or to various plants. Reservoir size can be increased as plant size increases. A home-made system can be constructed from food containers or glass canning jars with aeration provided by an aquarium pump, aquarium airline tubing and aquarium valves. Clear containers are covered with aluminium foil, butcher paper, black plastic, or other material to exclude light, thus helping to eliminate the formation of algae. The nutrient solution is changed either on a schedule, such as once per week, or when the concentration drops below a certain level as determined with an electrical conductivity meter. Whenever the solution is depleted below a certain level, either water or fresh nutrient solution is added. A Mariotte's bottle, or a float valve, can be used to automatically maintain the solution level. In raft solution culture, plants are placed in a sheet of buoyant plastic that is floated on the surface of the nutrient solution. That way, the solution level never drops below the roots. Continuous-flow solution culture The nutrient film technique (NFT) being used to grow various salad greens In continuous-flow solution culture, the nutrient solution constantly flows past the roots. It is much easier to automate than the static solution culture because sampling and adjustments to the temperature, pH, and nutrient concentrations can be made in a large storage tank that has potential to serve thousands of plants. A popular variation is the nutrient film technique or NFT, whereby a very shallow stream of water containing all the dissolved nutrients required for plant growth is recirculated in a thin layer past a bare root mat of plants in a watertight channel, with an upper surface exposed to air. As a consequence, an abundant supply of oxygen is provided to the roots of the plants. A properly designed NFT system is based on using the right channel slope, the right flow rate, and the right channel length. The main advantage of the NFT system over other forms of hydroponics is that the plant roots are exposed to adequate supplies of water, oxygen, and nutrients. In all other forms of production, there is a conflict between the supply of these requirements, since excessive or deficient amounts of one results in an imbalance of one or both of the others. NFT, because of its design, provides a system where all three requirements for healthy plant growth can be met at the same time, provided that the simple concept of NFT is always remembered and practised. The result of these advantages is that higher yields of high-quality produce are obtained over an extended period of cropping. A downside of NFT is that it has very little buffering against interruptions in the flow (e.g., power outages). But, overall, it is probably one of the more productive techniques.[citation needed] The same design characteristics apply to all conventional NFT systems. While slopes along channels of 1:100 have been recommended, in practice it is difficult to build a base for channels that is sufficiently true to enable nutrient films to flow without ponding in locally depressed areas. As a consequence, it is recommended that slopes of 1:30 to 1:40 are used.[34] This allows for minor irregularities in the surface, but, even with these slopes, ponding and water logging may occur. The slope may be provided by the floor, benches or racks may hold the channels and provide the required slope. Both methods are used and depend on local requirements, often determined by the site and crop requirements. As a general guide, flow rates for each gully should be one liter per minute.[35] At planting, rates may be half this and the upper limit of 2 L/min appears about the maximum. Flow rates beyond these extremes are often associated with nutritional problems. Depressed growth rates of many crops have been observed when channels exceed 12 meters in length. On rapidly growing crops, tests have indicated that, while oxygen levels remain adequate, nitrogen may be depleted over the length of the gully. As a consequence, channel length should not exceed 10–15 meters. In situations where this is not possible, the reductions in growth can be eliminated by placing another nutrient feed halfway along the gully and halving the flow rates through each outlet.[citation needed] Aeroponics Main article: Aeroponics Aeroponics is a system wherein roots are continuously or discontinuously kept in an environment saturated with fine drops (a mist or aerosol) of nutrient solution. The method requires no substrate and entails growing plants with their roots suspended in a deep air or growth chamber with the roots periodically wetted with a fine mist of atomized nutrients. Excellent aeration is the main advantage of aeroponics. A diagram of the aeroponic technique Aeroponic techniques have proven to be commercially successful for propagation, seed germination, seed potato production, tomato production, leaf crops, and micro-greens.[36] Since inventor Richard Stoner commercialized aeroponic technology in 1983, aeroponics has been implemented as an alternative to water intensive hydroponic systems worldwide.[37] The limitation of hydroponics is the fact that 1 kilogram (2.2 lb) of water can only hold 8 milligrams (0.12 gr) of air, no matter whether aerators are utilized or not. Another distinct advantage of aeroponics over hydroponics is that any species of plants can be grown in a true aeroponic system because the microenvironment of an aeroponic can be finely controlled. The limitation of hydroponics is that certain species of plants can only survive for so long in water before they become waterlogged. The advantage of aeroponics is that suspended aeroponic plants receive 100% of the available oxygen and carbon dioxide to the roots zone, stems, and leaves,[38] thus accelerating biomass growth and reducing rooting times. NASA research has shown that aeroponically grown plants have an 80% increase in dry weight biomass (essential minerals) compared to hydroponically grown plants. Aeroponics used 65% less water than hydroponics. NASA also concluded that aeroponically grown plants require ¼ the nutrient input compared to hydroponics.[39][40] Unlike hydroponically grown plants, aeroponically grown plants will not suffer transplant shock when transplanted to soil, and offers growers the ability to reduce the spread of disease and pathogens. Aeroponics is also widely used in laboratory studies of plant physiology and plant pathology. Aeroponic techniques have been given special attention from NASA since a mist is easier to handle than a liquid in a zero-gravity environment.[39] Fogponics Main article: Fogponics Fogponics is a derivation of aeroponics wherein the nutrient solution is aerosolized by a diaphragm vibrating at ultrasonic frequencies. Solution droplets produced by this method tend to be 5–10 µm in diameter, smaller than those produced by forcing a nutrient solution through pressurized nozzles, as in aeroponics. The smaller size of the droplets allows them to diffuse through the air more easily, and deliver nutrients to the roots without limiting their access to oxygen.[41][42] Passive sub-irrigation Main article: Passive hydroponics Water plant-cultivated crocus Passive sub-irrigation, also known as passive hydroponics, semi-hydroponics, or hydroculture,[43] is a method wherein plants are grown in an inert porous medium that transports water and fertilizer to the roots by capillary action from a separate reservoir as necessary, reducing labor and providing a constant supply of water to the roots. In the simplest method, the pot sits in a shallow solution of fertilizer and water or on a capillary mat saturated with nutrient solution. The various hydroponic media available, such as expanded clay and coconut husk, contain more air space than more traditional potting mixes, delivering increased oxygen to the roots, which is important in epiphytic plants such as orchids and bromeliads, whose roots are exposed to the air in nature. Additional advantages of passive hydroponics are the reduction of root rot and the additional ambient humidity provided through evaporations. Hydroculture compared to traditional farming in terms of crops yield per area in a controlled environment was roughly 10 times more efficient than traditional farming, uses 13 times less water in one crop cycle than traditional farming, but on average uses 100 times more kilojoules per kilogram of energy than traditional farming.[44] Ebb and flow (flood and drain) sub-irrigation An ebb and flow, or flood and drain, hydroponics system Main article: Ebb and flow In its simplest form, there is a tray above a reservoir of nutrient solution. Either the tray is filled with growing medium (clay granules being the most common) and then plant directly or place the pot over medium, stand in the tray. At regular intervals, a simple timer causes a pump to fill the upper tray with nutrient solution, after which the solution drains back down into the reservoir. This keeps the medium regularly flushed with nutrients and air. Once the upper tray fills past the drain stop, it begins recirculating the water until the timer turns the pump off, and the water in the upper tray drains back into the reservoirs.[45] Run-to-waste In a run-to-waste system, nutrient and water solution is periodically applied to the medium surface. The method was invented in Bengal in 1946; for this reason it is sometimes referred to as "The Bengal System".[46] A run-to-waste hydroponics system, referred to as "The Bengal System" after the region in eastern India where it was invented (circa 1946) This method can be set up in various configurations. In its simplest form, a nutrient-and-water solution is manually applied one or more times per day to a container of inert growing media, such as rockwool, perlite, vermiculite, coco fibre, or sand. In a slightly more complex system, it is automated with a delivery pump, a timer and irrigation tubing to deliver nutrient solution with a delivery frequency that is governed by the key parameters of plant size, plant growing stage, climate, substrate, and substrate conductivity, pH, and water content. In a commercial setting, watering frequency is multi-factorial and governed by computers or PLCs. Commercial hydroponics production of large plants like tomatoes, cucumber, and peppers uses one form or another of run-to-waste hydroponics. In environmentally responsible uses, the nutrient-rich waste is collected and processed through an on-site filtration system to be used many times, making the system very productive.[47] Some bonsai are also grown in soil-free substrates (typically consisting of akadama, grit, diatomaceous earth and other inorganic components) and have their water and nutrients provided in a run-to-waste form. Deep water culture The deep water culture technique being used to grow Hungarian wax peppers Main article: Deep water culture The hydroponic method of plant production by means of suspending the plant roots in a solution of nutrient-rich, oxygenated water. Traditional methods favor the use of plastic buckets and large containers with the plant contained in a net pot suspended from the centre of the lid and the roots suspended in the nutrient solution. The solution is oxygen saturated by an air pump combined with porous stones. With this method, the plants grow much faster because of the high amount of oxygen that the roots receive.[48] The Kratky Method is similar to deep water culture, but uses a non-circulating water reservoir. Top-fed deep water culture Top-fed deep water culture is a technique involving delivering highly oxygenated nutrient solution direct to the root zone of plants. While deep water culture involves the plant roots hanging down into a reservoir of nutrient solution, in top-fed deep water culture the solution is pumped from the reservoir up to the roots (top feeding). The water is released over the plant's roots and then runs back into the reservoir below in a constantly recirculating system. As with deep water culture, there is an airstone in the reservoir that pumps air into the water via a hose from outside the reservoir. The airstone helps add oxygen to the water. Both the airstone and the water pump run 24 hours a day. The biggest advantage of top-fed deep water culture over standard deep water culture is increased growth during the first few weeks.[citation needed] With deep water culture, there is a time when the roots have not reached the water yet. With top-fed deep water culture, the roots get easy access to water from the beginning and will grow to the reservoir below much more quickly than with a deep water culture system. Once the roots have reached the reservoir below, there is not a huge advantage with top-fed deep water culture over standard deep water culture. However, due to the quicker growth in the beginning, grow time can be reduced by a few weeks.[citation needed] Rotary A rotary hydroponic cultivation demonstration at the Belgian Pavilion Expo in 2015 Question book-new.svg This section relies too much on references to primary sources. Please improve this section by adding secondary or tertiary sources. (July 2018) (Learn how and when to remove this template message) A rotary hydroponic garden is a style of commercial hydroponics created within a circular frame which rotates continuously during the entire growth cycle of whatever plant is being grown. While system specifics vary, systems typically rotate once per hour, giving a plant 24 full turns within the circle each 24-hour period. Within the center of each rotary hydroponic garden can be a high intensity grow light, designed to simulate sunlight, often with the assistance of a mechanized timer. Each day, as the plants rotate, they are periodically watered with a hydroponic growth solution to provide all nutrients necessary for robust growth. Due to the plants continuous fight against gravity, plants typically mature much more quickly than when grown in soil or other traditional hydroponic growing systems.[citation needed] Because rotary hydroponic systems have a small size, it allows for more plant material to be grown per area of floor space than other traditional hydroponic systems.[49] Substrates (growing support materials) One of the most obvious decisions hydroponic farmers have to make is which medium they should use. Different media are appropriate for different growing techniques. Expanded clay aggregate Main article: Expanded clay aggregate Expanded clay aggregate Baked clay pellets are suitable for hydroponic systems in which all nutrients are carefully controlled in water solution. The clay pellets are inert, pH-neutral, and do not contain any nutrient value. The clay is formed into round pellets and fired in rotary kilns at 1,200 °C (2,190 °F). This causes the clay to expand, like popcorn, and become porous. It is light in weight, and does not compact over time. The shape of an individual pellet can be irregular or uniform depending on brand and manufacturing process. The manufacturers consider expanded clay to be an ecologically sustainable and re-usable growing medium because of its ability to be cleaned and sterilized, typically by washing in solutions of white vinegar, chlorine bleach, or hydrogen peroxide (H 2O 2), and rinsing completely. Another view is that clay pebbles are best not re-used even when they are cleaned, due to root growth that may enter the medium. Breaking open a clay pebble after a crop has been shown to reveal this growth. Growstones Growstones, made from glass waste, have both more air and water retention space than perlite and peat. This aggregate holds more water than parboiled rice hulls.[50] Growstones by volume consist of 0.5 to 5% calcium carbonate[51] – for a standard 5.1 kg bag of Growstones that corresponds to 25.8 to 258 grams of calcium carbonate. The remainder is soda-lime glass.[51] Coconut Coir Regardless of hydroponic demand, coconut coir is a natural byproduct derived from coconut processes. The outer husk of a coconut consists of fibers which are commonly used to make a myriad of items ranging from floor mats to brushes. After the long fibers are used for those applications, the dust and short fibers are merged to create coir. Coconuts absorb high levels of nutrients throughout their life cycle, so the coir must undergo a maturation process before it becomes a viable growth medium.[52] This process removes salt, tannins and phenolic compounds through substantial water washing. Contaminated water is a byproduct of this process, as three hundred to six hundred liters of water per one cubic meter of coir is needed.[53] Additionally, this maturation can take up to six months and one study concluded the working conditions during the maturation process are dangerous and would be illegal in North America and Europe.[54] Despite requiring attention, posing health risks and environmental impacts, coconut coir has impressive material properties. When exposed to water, the brown, dry, chunky and fibrous material expands nearly three-four times its original size. This characteristic combined with coconut coir's water retention capacity and resistance to pests and diseases make it an effective growth medium. Used as an alternative to rock wool, coconut coir, also known as coir peat, offers optimized growing conditions.[55] Rice husks Rice husks Parboiled rice husks (PBH) are an agricultural byproduct that would otherwise have little use. They decay over time, and allow drainage,[56] and even retain less water than growstones.[50] A study showed that rice husks did not affect the effects of plant growth regulators.[56][non-primary source needed] Perlite Perlite Perlite is a volcanic rock that has been superheated into very lightweight expanded glass pebbles. It is used loose or in plastic sleeves immersed in the water. It is also used in potting soil mixes to decrease soil density. Perlite has similar properties and uses to vermiculite but, in general, holds more air and less water and is buoyant. Vermiculite Vermiculite Like perlite, vermiculite is a mineral that has been superheated until it has expanded into light pebbles. Vermiculite holds more water than perlite and has a natural "wicking" property that can draw water and nutrients in a passive hydroponic system. If too much water and not enough air surrounds the plants roots, it is possible to gradually lower the medium's water-retention capability by mixing in increasing quantities of perlite. Pumice Pumice stone Like perlite, pumice is a lightweight, mined volcanic rock that finds application in hydroponics. Sand Sand is cheap and easily available. However, it is heavy, does not hold water very well, and it must be sterilized between uses.[57] Due to sand being easily available and in high demand sand shortages are on our horizon as we are running out. [58] Gravel The same type that is used in aquariums, though any small gravel can be used, provided it is washed first. Indeed, plants growing in a typical traditional gravel filter bed, with water circulated using electric powerhead pumps, are in effect being grown using gravel hydroponics. Gravel is inexpensive, easy to keep clean, drains well and will not become waterlogged. However, it is also heavy, and, if the system does not provide continuous water, the plant roots may dry out. Wood fiber Excelsior, or wood wool Wood fibre, produced from steam friction of wood, is a very efficient organic substrate for hydroponics. It has the advantage that it keeps its structure for a very long time. Wood wool (i.e. wood slivers) have been used since the earliest days of the hydroponics research.[20] However, more recent research suggests that wood fibre may have detrimental effects on "plant growth regulators".[56][non-primary source needed] Sheep wool Wool from shearing sheep is a little-used yet promising renewable growing medium. In a study comparing wool with peat slabs, coconut fibre slabs, perlite and rockwool slabs to grow cucumber plants, sheep wool had a greater air capacity of 70%, which decreased with use to a comparable 43%, and water capacity that increased from 23% to 44% with use.[59] Using sheep wool resulted in the greatest yield out of the tested substrates, while application of a biostimulator consisting of humic acid, lactic acid and Bacillus subtilis improved yields in all substrates.[59] Rock wool Rock wool Rock wool (mineral wool) is the most widely used medium in hydroponics. Rock wool is an inert substrate suitable for both run-to-waste and recirculating systems. Rock wool is made from molten rock, basalt or 'slag' that is spun into bundles of single filament fibres, and bonded into a medium capable of capillary action, and is, in effect, protected from most common microbiological degradation. Rock wool is typically used only for the seedling stage, or with newly cut clones, but can remain with the plant base for its lifetime. Rock wool has many advantages and some disadvantages. The latter being the possible skin irritancy (mechanical) whilst handling (1:1000).[citation needed] Flushing with cold water usually brings relief. Advantages include its proven efficiency and effectiveness as a commercial hydroponic substrate. Most of the rock wool sold to date is a non-hazardous, non-carcinogenic material, falling under Note Q of the European Union Classification Packaging and Labeling Regulation (CLP).[citation needed] Mineral wool products can be engineered to hold large quantities of water and air that aid root growth and nutrient uptake in hydroponics; their fibrous nature also provides a good mechanical structure to hold the plant stable. The naturally high pH of mineral wool makes them initially unsuitable to plant growth and requires "conditioning" to produce a wool with an appropriate, stable pH.[60] Brick shards Brick shards have similar properties to gravel. They have the added disadvantages of possibly altering the pH and requiring extra cleaning before reuse.[61] Polystyrene packing peanuts Polystyrene foam peanuts Polystyrene packing peanuts are inexpensive, readily available, and have excellent drainage. However, they can be too lightweight for some uses. They are used mainly in closed-tube systems. Note that non-biodegradable polystyrene peanuts must be used; biodegradable packing peanuts will decompose into a sludge. Plants may absorb styrene and pass it to their consumers; this is a possible health risk.[61] Nutrient solutions Inorganic hydroponic solutions The formulation of hydroponic solutions is an application of plant nutrition, with nutrient deficiency symptoms mirroring those found in traditional soil based agriculture. However, the underlying chemistry of hydroponic solutions can differ from soil chemistry in many significant ways. Important differences include: Unlike soil, hydroponic nutrient solutions do not have cation-exchange capacity (CEC) from clay particles or organic matter. The absence of CEC and soil pores means the pH, oxygen saturation, and nutrient concentrations can change much more rapidly in hydroponic setups than is possible in soil. Selective absorption of nutrients by plants often imbalances the amount of counterions in solution.[20][62][63] This imbalance can rapidly affect solution pH and the ability of plants to absorb nutrients of similar ionic charge (see article membrane potential). For instance, nitrate anions are often consumed rapidly by plants to form proteins, leaving an excess of cations in solution.[20] This cation imbalance can lead to deficiency symptoms in other cation based nutrients (e.g. Mg2+) even when an ideal quantity of those nutrients are dissolved in the solution.[62][63] Depending on the pH or on the presence of water contaminants, nutrients such as iron can precipitate from the solution and become unavailable to plants. Routine adjustments to pH, buffering the solution, or the use of chelating agents is often necessary. Unlike soil types, which can vary greatly in their composition, hydroponic solutions are often standardized and require routine maintenance for plant cultivation.[64] Hydroponic solutions are periodically pH adjusted to near neutral (pH ≈ 6.0) and are aerated with oxygen. Also, water levels must be refilled to account for transpiration losses and nutrient solutions require re-fortification to correct the nutrient imbalances that occur as plants grow and deplete nutrient reserves. Sometimes the regular measurement of nitrate ions is used as a parameter to estimate the remaining proportions and concentrations of other nutrient ions in a solution.[65] As in conventional agriculture, nutrients should be adjusted to satisfy Liebig's law of the minimum for each specific plant variety.[62] Nevertheless, generally acceptable concentrations for nutrient solutions exist, with minimum and maximum concentration ranges for most plants being somewhat similar. Most nutrient solutions are mixed to have concentrations between 1,000 and 2,500 ppm.[20] Acceptable concentrations for the individual nutrient ions, which comprise that total ppm figure, are summarized in the following table. For essential nutrients, concentrations below these ranges often lead to nutrient deficiencies while exceeding these ranges can lead to nutrient toxicity. Optimum nutrition concentrations for plant varieties are found empirically by experience or by plant tissue tests.[62] Element Role Ionic form(s) Low range (ppm) High range (ppm) Common Sources Comment Nitrogen Essential macronutrient NO− 3 or NH+ 4 100[63] 1000[62] KNO3, NH4NO3, Ca(NO3)2, HNO3, (NH4)2SO4, and (NH4)2HPO4 NH+ 4 interferes with Ca2+ uptake and can be toxic to plants if used as a major nitrogen source. A 3:1 ratio of NO− 3-N to NH+ 4-N (wt%) is sometimes recommended to balance pH during nitrogen absorption.[63] Plants respond differently depending on the form of nitrogen, e.g., ammonium has a positive charge, and thus, the plant expels one proton (H+ ) for every NH+ 4 taken up resulting in a reduction in rhizosphere pH. When supplied with NO− 3, the opposite can occur where the plant releases bicarbonate (HCO− 3) which increases rhizosphere pH. These changes in pH can influence the availability of other plant essential micronutrients (e.g., Zn, Ca, Mg).[66] Potassium Essential macronutrient K+ 100[62] 400[62] KNO3, K2SO4, KCl, KOH, K2CO3, K2HPO4, and K2SiO3 High concentrations interfere with the function Fe, Mn, and Zn. Zinc deficiencies often are the most apparent.[63] Phosphorus Essential macronutrient PO3− 4 30[63] 100[62] K2HPO4, KH2PO4, NH4H2PO4, H3PO4, and Ca(H2PO4)2 Excess NO− 3 tends to inhibit PO3− 4 absorption. The ratio of iron to PO3− 4 can affect co-precipitation reactions.[62] Calcium Essential macronutrient Ca2+ 200[63] 500[62] Ca(NO3)2, Ca(H2PO4)2, CaSO4, CaCl2 Excess Ca2+ inhibits Mg2+ uptake.[63] Magnesium Essential macronutrient Mg2+ 50[62] 100[62] MgSO4 and MgCl2 Should not exceed Ca2+ concentration due to competitive uptake.[63] Sulfur Essential macronutrient SO2− 4 50[63] 1000[62] MgSO4, K2SO4, CaSO4, H2SO4, (NH4)2SO4, ZnSO4, CuSO4, FeSO4, and MnSO4 Unlike most nutrients, plants can tolerate a high concentration of the SO2− 4, selectively absorbing the nutrient as needed.[20][62][63] Undesirable counterion effects still apply however. Iron Essential micronutrient Fe3+ and Fe2+ 2[63] 5[62] FeDTPA, FeEDTA, iron citrate, iron tartrate, FeCl3, Ferric EDTA, and FeSO4 pH values above 6.5 greatly decreases iron solubility. Chelating agents (e.g. DTPA, citric acid, or EDTA) are often added to increase iron solubility over a greater pH range.[63] Zinc Essential micronutrient Zn2+ 0.05[63] 1[62] ZnSO4 Excess zinc is highly toxic to plants but is essential for plants at low concentrations. Copper Essential micronutrient Cu2+ 0.01[63] 1[62] CuSO4 Plant sensitivity to copper is highly variable. 0.1 ppm can be toxic to some plants[63] while a concentration up to 0.5 ppm for many plants is often considered ideal.[62] Manganese Essential micronutrient Mn2+ 0.5[62][63] 1[62] MnSO4 and MnCl2 Uptake is enhanced by high PO3− 4 concentrations.[63] Boron Essential micronutrient B(OH)− 4 0.3[63] 10[62] H3BO3, and Na2B4O7 An essential nutrient, however, some plants are highly sensitive to boron (e.g. toxic effects are apparent in citrus trees at 0.5 ppm).[62] Molybdenum Essential micronutrient MoO− 4 0.001[62] 0.05[63] (NH4)6Mo7O24 and Na2MoO4 A component of the enzyme nitrate reductase and required by rhizobia for nitrogen fixation.[63] Nickel Essential micronutrient Ni2+ 0.057[63] 1.5[62] NiSO4 and NiCO3 Essential to many plants (e.g. legumes and some grain crops).[63] Also used in the enzyme urease. Chlorine Variable micronutrient Cl− 0 Highly variable KCl, CaCl2, MgCl2, and NaCl Can interfere with NO− 3 uptake in some plants but can be beneficial in some plants (e.g. in asparagus at 5 ppm). Absent in conifers, ferns, and most bryophytes.[62] Aluminum Variable micronutrient Al3+ 0 10[62] Al2(SO4)3 Essential for some plants (e.g. peas, maize, sunflowers, and cereals). Can be toxic to some plants below 10 ppm.[62] Sometimes used to produce flower pigments (e.g. by Hydrangeas). Silicon Variable micronutrient SiO2− 3 0 140[63] K2SiO3, Na2SiO3, and H2SiO3 Present in most plants, abundant in cereal crops, grasses, and tree bark. Evidence that SiO2− 3 improves plant disease resistance exists.[62] Titanium Variable micronutrient Ti3+ 0 5[62] H4TiO4 Might be essential but trace Ti3+ is so ubiquitous that its addition is rarely warranted.[63] At 5 ppm favorable growth effects in some crops are notable (e.g. pineapple and peas).[62] Cobalt Non-essential micronutrient Co2+ 0 0.1[62] CoSO4 Required by rhizobia, important for legume root nodulation.[63] Sodium Non-essential micronutrient Na+ 0 Highly variable Na2SiO3, Na2SO4, NaCl, NaHCO3, and NaOH Na+ can partially replace K+ in some plant functions but K+ is still an essential nutrient.[62] Vanadium Non-essential micronutrient VO2+ 0 Trace, undetermined VOSO4 Beneficial for rhizobial N2 fixation.[63] Lithium Non-essential micronutrient Li+ 0 Undetermined Li2SO4, LiCl, and LiOH Li+ can increase the chlorophyll content of some plants (e.g. potato and pepper plants).[63] Organic hydroponic solutions Main article: Organic hydroponics Organic fertilizers can be used to supplement or entirely replace the inorganic compounds used in conventional hydroponic solutions.[62][63] However, using organic fertilizers introduces a number of challenges that are not easily resolved. Examples include: organic fertilizers are highly variable in their nutritional compositions in terms of minerals and different chemical species. Even similar materials can differ significantly based on their source (e.g. the quality of manure varies based on an animal's diet). organic fertilizers are often sourced from animal byproducts, making disease transmission a serious concern for plants grown for human consumption or animal forage. organic fertilizers are often particulate and can clog substrates or other growing equipment. Sieving or milling the organic materials to fine dusts is often necessary. some organic materials (i.e. particularly manures and offal) can further degrade to emit foul odors under anaerobic conditions. many organic molecules (i.e. sugars) demand additional oxygen during aerobic degradation, which is essential for cellular respiration in the plant roots. organic compounds are not necessary for normal plant nutrition.[67] Nevertheless, if precautions are taken, organic fertilizers can be used successfully in hydroponics.[62][63] Organically sourced macronutrients Examples of suitable materials, with their average nutritional contents tabulated in terms of percent dried mass, are listed in the following table.[62] Organic material N P2O5 K2O CaO MgO SO2 Comment Bloodmeal 13.0% 2.0% 1.0% 0.5% – – Bone ashes – 35.0% – 46.0% 1.0% 0.5% Bonemeal 4.0% 22.5% – 33.0% 0.5% 0.5% Hoof / Horn meal 14.0% 1.0% – 2.5% – 2.0% Fishmeal 9.5% 7.0% – 0.5% – – Wool waste 3.5% 0.5% 2.0% 0.5% – – Wood ashes – 2.0% 5.0% 33.0% 3.5% 1.0% Cottonseed ashes – 5.5% 27.0% 9.5% 5.0% 2.5% Cottonseed meal 7.0% 3.0% 2.0% 0.5% 0.5% – Dried locust or grasshopper 10.0% 1.5% 0.5% 0.5% – – Leather waste 5.5% to 22% – – – – – Milled to a fine dust.[63] Kelp meal, liquid seaweed 1% – 12% – – – Commercial products available. Poultry manure 2% to 5% 2.5% to 3% 1.3% to 3% 4.0% 1.0% 2.0% A liquid compost which is sieved to remove solids and checked for pathogens.[62] Sheep manure 2.0% 1.5% 3.0% 4.0% 2.0% 1.5% Same as poultry manure. Goat manure 1.5% 1.5% 3.0% 2.0% – – Same as poultry manure. Horse manure 3% to 6% 1.5% 2% to 5% 1.5% 1.0% 0.5% Same as poultry manure. Cow manure 2.0% 1.5% 2.0% 4.0% 1.1% 0.5% Same as poultry manure. Bat guano 8.0% 40% 29% Trace Trace Trace High in micronutrients.[63] Commercially available. Bird guano 13% 8% 20% Trace Trace Trace High in micronutrients. Commercially available. Organically sourced micronutrients Micronutrients can be sourced from organic fertilizers as well. For example, composted pine bark is high in manganese and is sometimes used to fulfill that mineral requirement in hydroponic solutions.[63] To satisfy requirements for National Organic Programs, pulverized, unrefined minerals (e.g. Gypsum, Calcite, and glauconite) can also be added to satisfy a plant's nutritional needs. Additives In addition to chelating agents, humic acids can be added to increase nutrient uptake.[63][68] Tools Common equipment Managing nutrient concentrations, oxygen saturation, and pH values within acceptable ranges is essential for successful hydroponic horticulture. Common tools used to manage hydroponic solutions include: Electrical conductivity meters, a tool which estimates nutrient ppm by measuring how well a solution transmits an electric current. pH meter, a tool that uses an electric current to determine the concentration of hydrogen ions in solution. Oxygen electrode, an electrochemical sensor for determining the oxygen concentration in solution. Litmus paper, disposable pH indicator strips that determine hydrogen ion concentrations by color changing chemical reaction. Graduated cylinders or measuring spoons to measure out premixed, commercial hydroponic solutions. Equipment Chemical equipment can also be used to perform accurate chemical analyses of nutrient solutions. Examples include:[62] Balances for accurately measuring materials. Laboratory glassware, such as burettes and pipettes, for performing titrations. Colorimeters for solution tests which apply the Beer–Lambert law. Spectrophotometer to measure the concentrations of the lead parameter nitrate and other nutrients, such as phosphate, sulfate or iron. Using chemical equipment for hydroponic solutions can be beneficial to growers of any background because nutrient solutions are often reusable.[69] Because nutrient solutions are virtually never completely depleted, and should never be due to the unacceptably low osmotic pressure that would result, re-fortification of old solutions with new nutrients can save growers money and can control point source pollution, a common source for the eutrophication of nearby lakes and streams.[69] Software Although pre-mixed concentrated nutrient solutions are generally purchased from commercial nutrient manufacturers by hydroponic hobbyists and small commercial growers, several tools exist to help anyone prepare their own solutions without extensive knowledge about chemistry. The free and open source tools HydroBuddy[70] and HydroCal[71] have been created by professional chemists to help any hydroponics grower prepare their own nutrient solutions. The first program is available for Windows, Mac and Linux while the second one can be used through a simple JavaScript interface. Both programs allow for basic nutrient solution preparation although HydroBuddy provides added functionality to use and save custom substances, save formulations and predict electrical conductivity values. Mixing solutions Often mixing hydroponic solutions using individual salts is impractical for hobbyists or small-scale commercial growers because commercial products are available at reasonable prices. However, even when buying commercial products, multi-component fertilizers are popular. Often these products are bought as three part formulas which emphasize certain nutritional roles. For example, solutions for vegetative growth (i.e. high in nitrogen), flowering (i.e. high in potassium and phosphorus), and micronutrient solutions (i.e. with trace minerals) are popular. The timing and application of these multi-part fertilizers should coincide with a plant's growth stage. For example, at the end of an annual plant's life cycle, a plant should be restricted from high nitrogen fertilizers. In most plants, nitrogen restriction inhibits vegetative growth and helps induce flowering.[63] Additional improvements This section may contain material unrelated or insufficiently related to its topic, which is the topic of another article, Growroom. Please help improve this section or discuss this issue on the talk page. (April 2016) (Learn how and when to remove this template message) Growrooms With pest problems reduced and nutrients constantly fed to the roots, productivity in hydroponics is high; however, growers can further increase yield by manipulating a plant's environment by constructing sophisticated growrooms [Citation needed]. CO2 enrichment Main article: Carbon dioxide § Agricultural and biological applications To increase yield further, some sealed greenhouses inject CO2 into their environment to help improve growth and plant fertility. See also icon Agriculture portal icon Gardening portal Aeroponics Anthroponics Aquaponics Fogponics Folkewall Grow box Growroom Organoponics Passive hydroponics Plant factory Plant nutrition Plant pathology Regrowing vegetable Root rot Vertical farming Xeriscaping Progress regarding the water culture method of growing plants, i.e. “hydroponics,” was slow during the late 19th century. Much of the limited research conducted during that time used to further refine the list of necessary elements required for soilless plant growth, basically through the time-consuming process of trial, error, and elimination. At the turn of the century, however, science was on the march. Many inventions and discoveries were popularized during this period including radio, the automobile, the camera, moving pictures, and many others. Research into water culture techniques was gaining steam as well. Burton Edward Livingston published “A Simple Method For Experiments With Water Cultures” in Volume 9, No. 1 of The Plant World, wherein he describes a “… simpler method to study the nutrient or stimulating value of various substances.” Also in 1906, J.F. Breazeale of the University of Chicago, published in Volume 41, No. 1 of the Botanical Gazette, an article entitled “Effect Of Certain Solids Upon The Growth Of Seedlings In Water Cultures.” Most of these papers were not written for the layperson, however, and a review of Breazeale’s paper contained the ending caveat “…the paper shows very little consideration for the reader.” Research techniques were advancing as well. In November 1908, J.J. Skinner published a paper in Volume 11, No. 11 of The Plant World entitled “Water Culture Method For Experimenting With Potatoes.” In 1913, Conrad Hoffman of the University of Wisconsin published in Volume 55, No. 3 of the Botanical Gazette, his research on using paraffin blocks for growing seedlings in liquid culture solutions, since the cork used in experiments to date tended to add soluble compounds to the nutrient solution, potentially corrupting scientific results. And in 1914, W.E. Tottingham, also from the University of Wisconsin, published in Physiological Researches “A quantitative chemical and physiological study of nutrient solutions for plant cultures,” wherein it is described that “…it is the selective absorption of ions rather than complete salts that is indicated … ” and describing the importance of balance between the various elements in a nutritive solution. In 1915, John W. Shive published “A Three-Salt Nutrient Solution For Plants,” where the writer tested 84 differently proportioned nutrient solutions, and showing that Tottingham’s formula indeed was superior to the four salt nutrient solution devised earlier by Knop. Research into nutrient solutions continued however, and in fact B.E. Livingston and W.E. Tottingham together published “A New Three-Salt Nutrient Solution for Plant Cultures” in July of 1918. Studies were also being conducted on areas separate from the composition of nutrient solutions. In November of 1917, a paper by Walter Stiles and Ingvar Jorgensen appeared in The New Phytologist, “Observations On The Influence Of Aeration Of The Nutrient Solution In Water Culture Experiments, With Some Remarks On The Water Culture Method.” In 1916, Orton L. Clark published in Science Volume 44, No 1146 “A Method for Maintaining a Constant Volume of Nutrient Solutions,” recognizing the implications to solution strength and balance the effects of evaporation and transpiration have. Dennis Robert Hoagland | Hydroponics HistoryDennis Robert Hoagland At the University of California at Berkeley’s Agricultural Research Station were several scientists engaged in the active research of water culture and nutrient solutions. These included Dennis Robert Hoagland, who began his career at UC in 1913, and who later served as Professor of Plant Nutrition from 1927 until his death in 1949. Hoagland’s primary focus was initially soil based, yet his studies of kelp led to an extended period of investigation into exactly how plants absorb nutrients. This work definitively established that absorption of minerals by plants is a metabolic process and not just a physical one defined by permeability, osmosis, and the like. In the course of these studies, Hoagland successfully grew many different types of plants with a nutrient solution formula he developed that would be used worldwide as the standard for decades to come. However, he also emphasized that the solution formula that bore his name was not the end of the matter. He was often quoted as saying that there is no such thing as the “best” nutrient solution and that adjustments would always be necessary based on such things as plant variety and environment. Hoagland also contributed much knowledge in understanding the relationship of pH to plants grown in nutrient solutions as well as showing how important free oxygen around the root system is. As well he played an important part in identifying the further plant nutrient elements necessary above and beyond the ten known by 1920, particularly molybdenum. Also on the staff at UC, beginning in 1912, was a Nebraska born associate plant physiologist by the name of William Frederick Gericke. Educated at the University of Nebraska, Iowa State College of Agriculture, John Hopkins University in Baltimore, and the University of California, Gericke research entitled “On the physiological balance in nutrient solutions for plant cultures,” was published in the April, 1922 issue of the American Journal of Botany. In the October 13, 1922 issue of the publication Science, Gericke had published a Special Article on “Water Culture Experimentation” outlining his research growing wheat using single salt solutions during different phases of plant growth versus well-balanced nutrient solutions throughout. William F. Gericke | Father of HydroponicsWilliam F. Gericke Gericke continued his research at the university over the next decade, primarily engaged in studying grains including wheat and rice. Examples of his papers published during the last half of the 1920’s include “Salt Requirements of Wheat at Different Growth Phases”, “Adaptation of Rice to Forty Centuries of Agriculture,” and perhaps tellingly, in 1930, a paper entitled “Excessive Tax on Soil Fertility by Crop Production on Poor Land.” Much attention and credit is given to a short 200 word article by Gericke, published in the December, 1929 issue of the American Journal of Botany entitled “Aquaculture: A means of Crop-production,” wherein he describes, in the simplest of terms, the successful construction of growing reservoirs in which cartridges of plant food were added, and several different kinds “… of floral, vegetables, and field plants were grown. Results obtained called for serious consideration of this method for production of certain crops grown on an intensive scale.” This article is often credited as being the first to draw attention to the commercial potential of soilless crop production. However, further research shows that public announcements of his work with the soilless growth of plants actually came earlier than previously thought. Not only was Gericke a gifted scientist, he was keenly attuned to the power the press had in helping to promote ideas. His first experiments on the commercial potential of soilless culture began simultaneously at his home in Berkeley and in the campus greenhouse, a fact that would ultimately come back to haunt him later in his career. On April 1st, 1928, The San Bernadino County Sun published a short article entitled “Food Pills to Grow Plants in Water, Is Professor’s Claim.” In the article, Gericke says that the future gardener could grow his vegetables and flowers in simple jars of water in which “food pills,” bound cylindrical capsules containing combinations of seven essential plant nutrients are added to the water. These food pills would come also to be known as “plant pills” in future articles. In late April of that year, several short articles distributed throughout the country by the Associated Press, clearly state that on April 25, 1928, “In announcing his discovery today, Gericke said flowers produced by the soilless method are sturdier, more delicately colored, and less subject to mildew than those grown under ordinary conditions.” Headlines included “Grows Plants In Water: Chemicals Better Than Soil, Expert Says” and “Can Grow Plants Without Soil!” Plants Grow Without Sun or Soil; Chemicals Replace Earth in Test | Hydroponics HistoryHeadline from The Anniston Star, May 27, 1928 A few days later, on May 27th and June 3rd respectively, major stories published in Alabama’s The Anniston Star and California’s Santa Ana Register delved deeper into his research on soilless farming, and in fact highlighted the work Gericke was conducting by growing plants under artificial light. Under the Anniston Star headline “Plants Grow Without Sun or Soil; Chemicals Replace Earth In Test,” the article not only talks about the plant food pills, it also goes into how a battery of 300-candlepower argon-filled lamps are used by Gericke to grow wheat. The lighting remained on for 16 hours per day, generating rapid growth, and doubling the number of lights quadrupled the growth rate, the article claimed. “The experiment proved that all the sun rays essential to plant growth were present in the electric glares.” On June 29, Gericke announced that he would be demonstrating his methods of raising plants without soil while on a European tour with lectures being given in France, Sweden, England, Germany, Austria and Holland. On December 13, reports tell that he had returned to the Berkeley campus after his tour of research stations throughout Europe, and that he “…plans to continue his work on artificial plant nutrition until every phase of the investigation is completed and the adoption of the system by commercial growers made easy.” By 1929, it seemed that Gericke’s spat of publicity was waning. Save for a few recycled articles about plant pills that appeared late in the year, Gericke’s work received very little press until October, when a four page feature article entitled “Plant ‘Pills’ Grow Bumper Crops” authored by H.H. Dunn appeared in Popular Science Monthly, a hugely popular magazine at the time. Plant Pills Grow Bumper Crops, Popular Science Monthly, October, 1929 | Hydroponics HistoryHeadline from October, 1929 Popular Science Monthly The article opens with the proclamation that “…through the use of a chemical “plant pill,” administered to plants grown in shallow tanks of water, cereal and vegetable crops now are made to thrive under desert conditions of heat, arid soil, and lack of humidity.” It goes on to point out that five thousand experiments over the past five years have resulted in this discovery. The same article gives specific examples of his experiment results, saying that the size of asparagus stalks grown with the method increased nearly 100 percent; that potatoes increased in size by half again, and that the yield of tomato plants could be increased by 40 percent. Experiments with wheat, cotton, tobacco, and cabbage showed similar results. Cotton cultivated in water could be harvested sooner. The article further states, “…from these results, Dr. Gericke and his assistants, with the backing of the University of California, started experiments with tank production of food crops, to figure costs of such production on a commercial scale.” Many examples are given of the economic and production benefits achieved and offers convincing thoughts on the potential for farming food in areas of the world where it was not now achievable. The article ends with Dr. Gericke quoted as follows, “… an area less than one-fourth that which, in my boyhood days, supplied the ‘garden truck’ for the family, will produce foodstuffs of variety, quality, quantity and value never dreamed of by the home gardener. Incidentally, the labor required will be only a small fraction of that needed for proper tilling of the soil. This, it seems to me, is the greatest value of the five years of experiments we have been conducting — that millions may be fed from water, on soils that hitherto have produced nothing but an occasional clump of cacti, or a few fig trees.” Despite the publicity generated by the Popular Science Monthly article, Gericke still had a lot of work to do to bring his ideas to fruition. Gericke had decided to focus his efforts on the practical application of what he had learned to date and on June 27, 1933, W.F. Gericke obtained a U.S. patent (No. 1,915,884) for a “Fertilizing unit for growing plants in water.” Soon afterwards, he was installing his equipment in California greenhouses and arranging for agriculture research stations in other parts of the country to try it as well. In early 1936, famous inventor Arthur Pillsbury, an early water culture enthusiast in his own right, and an expert in photography, particularly time-lapse photography, visited Dr. Gericke in California to take many high-quality photos of Gericke’s phenomenal results, and Gericke was then able to distribute to the press and other interested parties for publication with their articles about his work. In addition, Mr. Pillsbury created a motion picuture featuring his time lapse photography and the photogenic results of Gerickes efforts. Gericke also embarked on a publicity campaign that included live demonstrations and speaking engagements where he showed his moving pictures to generate further interest in his discoveries, which he believed would revolutionize age-old concepts of agriculture. On September 24th of that same year, the Corvallis Gazette-Times in Oregon reported that Dr. Gericke had installed a tank farming system on the roof of the canning plant of George Brehm of Seattle. In the same article is the quote, “…this culture tank is designated a hydroponicum.” This is one of, if not the first printed reference to a variation of the term ‘hydroponics,’ ultimately adopted by Gericke. William F. Gericke and his wife show off greenhouse tomato crop grown with hydroponics.William F. Gericke and his wife show off greenhouse hydroponic tomato crop. Thanks to the power of the image and exaggerated claims the press was all too willing to spread, articles with pictures of Gericke’s work began appearing across the country, and spreading around the world, as far away as Australia and Japan. Along with these press reports came a slew of requests for further information on this exciting new method of farming. Gericke, however, initially discouraged these requests, stating that such queries distracted him from his work and do little, because he was not in a place at the time to share this information, and in fact “…resolutely declines to permit his system to be promoted and handled on a large scale by strangers.” Yet, during this same period, Gericke was searching for a unique, relevant and memorable name for his new farming technique and, referring to his 1929 first paper on the topic, he fancied the term “aquaculture.” Quoted in Science, Gericke says his work “…may be considered as the birth of a new art and perchance a new science which should be designated by a distinctive name.” Dr. William Albert Setchell | Suggested the term 'hydroponics' to William F. GerickeDr. William Albert Setchell However, the American-Fish Cultural Association had used that term to describe the breeding of fish as far back as the late 1800’s. And while Dr. Gericke is widely credited with adopting the term “hydroponics” as an alternative, he did not actually come up with it himself. That honor went to his associate, Dr. William Albert Setchell, a Professor of Botany at UC, who suggested the term met Gericke’s requirements. “Hydroponics is from the Greek “hydro,” or water, and “ponos,” or labor, and is comparable to geoponics, by which agriculture was once designated. It meets the requirements of the philologers; it is easily pronounceable.” And so, on February 12th, 1937, the term “hydroponics” was first introduced to the public in a Science magazine article, “…to mean the raising of vegetables, flowers, and fruit without soil, in tanks of warmed, fertilized water. The new name is proposed by the originator of this system, hitherto known by the colloquial nickname of “dirtless farming,” Prof. W. F. Gericke of the University of California.” The next installment of The History of Hydroponics will cover the explosive growth, application, and misrepresentation of Gericke’s ‘hydroponics’, including the application of hydroponics by state Agricultural Research Stations, Pan American Airways, and the United States military.
  • Condition: Used
  • Type: Photograph
  • Year of Production: 1940
  • Original/Licensed Reprint: Original

PicClick Insights - 1940 Original Scientist Hydroponics Photo Fantastic Vintage PicClick Exclusive

  •  Popularity - 0 watchers, 0.0 new watchers per day, 25 days for sale on eBay. 0 sold, 1 available.
  •  Best Price -
  •  Seller - 808+ items sold. 0% negative feedback. Great seller with very good positive feedback and over 50 ratings.

People Also Loved PicClick Exclusive