Aeroponics is the process of growing
plants
Plants are predominantly Photosynthesis, photosynthetic eukaryotes of the Kingdom (biology), kingdom Plantae. Historically, the plant kingdom encompassed all living things that were not animals, and included algae and fungi; however, all curr ...
in the
air
The atmosphere of Earth is the layer of gases, known collectively as air, retained by Earth's gravity that surrounds the planet and forms its planetary atmosphere. The atmosphere of Earth protects life on Earth by creating pressure allowing for ...
or
mist
Mist is a phenomenon caused by small droplets of water suspended in the cold air, usually by condensation. Physically, it is an example of a dispersion. It is most commonly seen where water vapor in warm, moist air meets sudden cooling, such a ...
environment without
soil
Soil, also commonly referred to as earth or dirt, is a mixture of organic matter, minerals, gases, liquids, and organisms that together support life. Some scientific definitions distinguish ''dirt'' from ''soil'' by restricting the former te ...
or an
aggregate
Aggregate or aggregates may refer to:
Computing and mathematics
* collection of objects that are bound together by a root entity, otherwise known as an aggregate root. The aggregate root guarantees the consistency of changes being made within the ...
medium. The word "aeroponic" is derived from the
Greek
Greek may refer to:
Greece
Anything of, from, or related to Greece, a country in Southern Europe:
*Greeks, an ethnic group.
*Greek language, a branch of the Indo-European language family.
**Proto-Greek language, the assumed last common ancestor ...
meanings of ''aer'' ("air") and ''ponos'' ("labour"). It is a subset of
hydroponics
Hydroponics is a type of horticulture and a subset of hydroculture which involves growing plants, usually crops or medicinal plants, without soil, by using water-based mineral nutrient solutions in aqueous solvents. Terrestrial or aquatic plan ...
, since water is used in aeroponics to transmit nutrients.
Methods
The basic principle of aeroponic growing is to grow plants suspended in a closed or semi-closed environment by
spray
Spray or spraying commonly refer to:
* Spray (liquid drop)
** Aerosol spray
** Blood spray
** Hair spray
** Nasal spray
** Pepper spray
** PAVA spray
** Road spray or tire spray, road debris kicked up from a vehicle tire
** Sea spray, refers to ...
ing the plant's
dangling roots and lower
stem
Stem or STEM may refer to:
Plant structures
* Plant stem, a plant's aboveground axis, made of vascular tissue, off which leaves and flowers hang
* Stipe (botany), a stalk to support some other structure
* Stipe (mycology), the stem of a mushro ...
with an atomized or sprayed,
nutrient
A nutrient is a substance used by an organism to survive, grow, and reproduce. The requirement for dietary nutrient intake applies to animals, plants, fungi, and protists. Nutrients can be incorporated into cells for metabolic purposes or excret ...
-rich water solution.
[Stoner, R.J. and J.M. Clawson (1997-1998). ''A High Performance, Gravity Insensitive, Enclosed Aeroponic System for Food Production in Space.'' Principal Investigator, NASA SBIR NAS10-98030.] The leaves and
crown
A crown is a traditional form of head adornment, or hat, worn by monarchs as a symbol of their power and dignity. A crown is often, by extension, a symbol of the monarch's government or items endorsed by it. The word itself is used, partic ...
, often called the
canopy
Canopy may refer to:
Plants
* Canopy (biology), aboveground portion of plant community or crop (including forests)
* Canopy (grape), aboveground portion of grapes
Religion and ceremonies
* Baldachin or canopy of state, typically placed over an a ...
, extend above. The roots of the plant are separated by the plant support structure. Often,
closed-cell foam
Foams are materials formed by trapping pockets of gas in a liquid or solid.
A bath sponge and the head on a glass of beer are examples of foams. In most foams, the volume of gas is large, with thin films of liquid or solid separating the reg ...
is compressed around the lower stem and inserted into an opening in the aeroponic chamber, which decreases labor and expense; for larger plants,
trellising is used to suspend the weight of
vegetation
Vegetation is an assemblage of plant species and the ground cover they provide. It is a general term, without specific reference to particular taxa, life forms, structure, spatial extent, or any other specific botanical or geographic character ...
and
fruit
In botany, a fruit is the seed-bearing structure in flowering plants that is formed from the ovary after flowering.
Fruits are the means by which flowering plants (also known as angiosperms) disseminate their seeds. Edible fruits in particu ...
.
Ideally, the environment is kept free from
pests
PESTS was an anonymous American activist group formed in 1986 to critique racism, tokenism, and exclusion in the art world. PESTS produced newsletters, posters, and other print material highlighting examples of discrimination in gallery represent ...
and
disease
A disease is a particular abnormal condition that negatively affects the structure or function of all or part of an organism, and that is not immediately due to any external injury. Diseases are often known to be medical conditions that a ...
so that the plants may grow healthier and more quickly than plants grown in a
medium
Medium may refer to:
Science and technology
Aviation
*Medium bomber, a class of war plane
* Tecma Medium, a French hang glider design
Communication
* Media (communication), tools used to store and deliver information or data
* Medium of ...
. However, since most aeroponic environments are not perfectly closed off to the outside, pests and disease may still cause a threat. Controlled environments advance plant development, health, growth, flowering and fruiting for any given plant species and
cultivar
A cultivar is a type of cultivated plant that people have selected for desired traits and when propagated retain those traits. Methods used to propagate cultivars include: division, root and stem cuttings, offsets, grafting, tissue culture, ...
s.
Due to the sensitivity of root systems, aeroponics is often combined with conventional
hydroponics
Hydroponics is a type of horticulture and a subset of hydroculture which involves growing plants, usually crops or medicinal plants, without soil, by using water-based mineral nutrient solutions in aqueous solvents. Terrestrial or aquatic plan ...
, which is used as an emergency "crop saver" – backup nutrition and water supply – if the aeroponic apparatus fails.
High-pressure aeroponics is defined as delivering nutrients to the roots via 20–50 micrometre mist heads using a high-pressure ()
diaphragm pump
A diaphragm pump (also known as a Membrane pump) is a positive displacement pump that uses a combination of the reciprocating action of a rubber, thermoplastic or teflon diaphragm and suitable valves on either side of the diaphragm
( check valve ...
.
Benefits and drawbacks
Increased air exposure
Air cultures optimize access to air for successful plant growth. Materials and devices which hold and support the aeroponic grown plants must be devoid of disease or pathogens. A distinction of a true aeroponic culture and apparatus is that it provides plant support features that are minimal. Minimal contact between a plant and support structure allows for a maximal amount of air to reach the plant. Long-term aeroponic cultivation requires the root systems to be free of constraints surrounding the stem and root systems. Physical contact is minimized so that it does not hinder natural growth and root expansion or access to pure water, air exchange and disease-free conditions .
Benefits of oxygen in the root zone
Oxygen
Oxygen is the chemical element with the symbol O and atomic number 8. It is a member of the chalcogen group in the periodic table, a highly reactive nonmetal, and an oxidizing agent that readily forms oxides with most elements as wel ...
(O
2) in the
rhizosphere
The rhizosphere is the narrow region of soil or substrate that is directly influenced by root secretions and associated soil microorganisms known as the root microbiome. Soil pores in the rhizosphere can contain many bacteria and other microor ...
(root zone) is necessary for healthy plant growth. As aeroponics is conducted in air combined with micro-
droplets
A drop or droplet is a small column of liquid, bounded completely or almost completely by free surfaces. A drop may form when liquid accumulates at the lower end of a tube or other surface boundary, producing a hanging drop called a pendant d ...
of water, almost any plant can grow to maturity in air with a plentiful supply of oxygen, water and nutrients.
Some growers favor aeroponic systems over other methods of hydroponics because the increased
aeration
Aeration (also called aerification or aeriation) is the Systems engineering process, process by which air is circulated through, mixed with or solvation, dissolved in a liquid or other substances that act as a fluid (such as soil). Aeration proces ...
of nutrient solution delivers more oxygen to plant roots, stimulating growth and helping to prevent
pathogen
In biology, a pathogen ( el, πάθος, "suffering", "passion" and , "producer of") in the oldest and broadest sense, is any organism or agent that can produce disease. A pathogen may also be referred to as an infectious agent, or simply a germ ...
formation.
Clean air supplies oxygen which is an excellent purifier for plants and the aeroponic environment. For natural growth to occur, the plant must have unrestricted access to air. Plants must be allowed to grow in a natural manner for successful physiological development. If the natural growth of the plant is restricted by the support structure, the risk of damage to the plant and thereby disease increases .
Some researchers have used aeroponics to study the effects of root zone gas composition on plant performance. Soffer and Burger
offer et al., 1988studied the effects of dissolved oxygen concentrations on the formation of adventitious roots in what they termed "aero-hydroponics." They utilized a 3-tier hydro and aero system, in which three separate zones were formed within the root area. The ends of the roots were submerged in the nutrient reservoir, while the middle of the root section received nutrient mist and the upper portion was above the mist. Their results showed that dissolved O
2 is essential to root formation, but went on to show that for the three O
2 concentrations tested, the number of roots and root length were always greater in the central misted section than either the submersed section or the un-misted section. Even at the lowest concentration, the misted section rooted successfully.
Other benefits of air (CO2)
Aeroponics may also involve managing levels in the air within the system, which in turn affects the rate of photosynthesis within the plants.
Growing under artificial lights allows increased growth rates and reliability in comparison with solar lighting and can be used in combination with aeroponics .
Disease-free cultivation
Aeroponics can limit disease transmission since plant-to-plant contact is reduced and each spray pulse can be sterile. In the case of soil, aggregate, or other media, disease can spread throughout the growth media, infecting many plants. In most greenhouses, these solid media require sterilization after each crop and, in many cases, they are simply discarded and replaced with fresh, sterile media.
A distinct advantage of aeroponic technology is that if a particular
plant does become diseased, it can be quickly removed from the plant support structure without disrupting or infecting the other plants.
Due to the disease-free environment that is unique to aeroponics, many plants can grow at higher density (plants per square meter) when compared to more traditional forms of cultivation (
hydroponics
Hydroponics is a type of horticulture and a subset of hydroculture which involves growing plants, usually crops or medicinal plants, without soil, by using water-based mineral nutrient solutions in aqueous solvents. Terrestrial or aquatic plan ...
, soil and Nutrient Film Technique
FT. Commercial aeroponic systems incorporate hardware features that accommodate the crop's expanding root systems.
Researchers have described aeroponics as a "valuable, simple, and rapid method for preliminary screening of genotypes for resistance to specific seedling blight or root rot".
The isolating nature of the aeroponic system allowed them to avoid the complications encountered when studying these infections in soil culture.
Water and nutrient hydro-atomization
Aeroponic equipment involves the use of sprayers, misters, foggers, or other devices to create a fine mist of solution to deliver nutrients to plant roots. Aeroponic systems are normally closed-looped systems providing macro and micro-environments suitable to sustain a reliable, constant air culture. Numerous inventions have been developed to facilitate aeroponic spraying and misting. The key to root development in an aeroponic environment is the size of the water droplet. In commercial applications, a hydro-atomizing spray at 360° is employed to cover large areas of roots utilizing air pressure misting.
A variation of the mist technique, known as
fogponics
Fogponics, or atmoponics (from Ancient Greek ἀτμός (atmós), meaning ''"vapour"'' or ''"steam"''), is a subset of aeroponics. Fogponics uses a suspension of nutrient enriched water to deliver nutrients and oxygen to plant roots.
This is in ...
, employs the use of
ultrasonic foggers to mist nutrient solutions in low-pressure aeroponic devices.
Water droplet size is crucial for sustaining aeroponic growth. Too large a water droplet means less oxygen is available to the root system. Too fine a water droplet, such as those generated by the ultrasonic mister, produce excessive
root hair
Root hair, or absorbent hairs, are outgrowths of epidermal cells, specialized cells at the tip of a plant root. They are lateral extensions of a single cell and are only rarely branched. They are found in the region of maturation, of the root. Root ...
without developing a lateral root system for sustained growth in an aeroponic system.
Mineralization of the ultrasonic
transducers
A transducer is a device that converts energy from one form to another. Usually a transducer converts a signal in one form of energy to a signal in another.
Transducers are often employed at the boundaries of automation, measurement, and contro ...
requires maintenance and potential for component failure. This is also a shortcoming of metal spray jets and misters. Restricted access to the water causes the plant to lose turgidity and wilt.
Advanced materials
NASA
The National Aeronautics and Space Administration (NASA ) is an independent agency of the US federal government responsible for the civil space program, aeronautics research, and space research.
NASA was established in 1958, succeeding t ...
has funded research and development of new advanced materials to improve aeroponic reliability and maintenance reduction. It also has determined that high pressure hydro-atomized mist of 5–50 micrometres micro-droplets is necessary for long-term aeroponic growing.
For long-term growing, the mist system must have significant pressure to force the mist into the dense root system(s).
Repeatability
Repeatability or test–retest reliability is the closeness of the agreement between the results of successive measurements of the same measure, when carried out under the same conditions of measurement. In other words, the measurements are taken ...
is the key to aeroponics and includes the hydro-atomized droplet size. Degradation of the spray due to mineralization of mist heads inhibits the delivery of the water nutrient solution, leading to an environmental imbalance in the air culture environment.
Special low-mass
polymer
A polymer (; Greek '' poly-'', "many" + ''-mer'', "part")
is a substance or material consisting of very large molecules called macromolecules, composed of many repeating subunits. Due to their broad spectrum of properties, both synthetic a ...
materials were developed and are used to eliminate mineralization in next generation hydro-atomizing misting and spray jets.
Nutrient uptake
The discrete nature of interval and duration aeroponics allows the measurement of nutrient uptake over time under varying conditions. Barak et al. used an aeroponic system for non-destructive measurement of water and ion uptake rates for
cranberries
Cranberries are a group of evergreen dwarf shrubs or trailing vines in the subgenus ''Oxycoccus'' of the genus ''Vaccinium''. In Britain, cranberry may refer to the native species ''Vaccinium oxycoccos'', while in North America, cranberry m ...
(Barak, Smith et al. 1996).
In their study, these researchers found that by measuring the concentrations and volumes of input and
efflux solutions, they could accurately calculate the nutrient uptake rate (which was verified by comparing the results with N-
isotope
Isotopes are two or more types of atoms that have the same atomic number (number of protons in their nuclei) and position in the periodic table (and hence belong to the same chemical element), and that differ in nucleon numbers (mass numbers) ...
measurements). After verification of their analytical method, Barak et al. went on to generate additional data specific to the cranberry, such as
diurnal variation in nutrient uptake, correlation between
ammonium
The ammonium cation is a positively-charged polyatomic ion with the chemical formula or . It is formed by the protonation of ammonia (). Ammonium is also a general name for positively charged or protonated substituted amines and quaternary a ...
uptake and
proton
A proton is a stable subatomic particle, symbol , H+, or 1H+ with a positive electric charge of +1 ''e'' elementary charge. Its mass is slightly less than that of a neutron and 1,836 times the mass of an electron (the proton–electron mass ...
efflux, and the relationship between ion concentration and uptake. Work such as this not only shows the promise of aeroponics as a research tool for nutrient uptake, but also opens up possibilities for the monitoring of plant health and optimization of crops grown in closed environments.
Atomization (>), increases bioavailability of nutrients, consequently, nutrient strength must be significantly reduced or leaf and root burn will develop. Note the large water droplets in the photo to the right. This is caused by the feed cycle being too long or the pause cycle too short; either discourages both lateral root growth and root hair development. Plant growth and fruiting times are significantly shortened when feed cycles are as short as possible. Ideally, roots should never be more than slightly damp nor overly dry. A typical feed/pause cycle is < 2 seconds on, followed by ~1.5–2 minute pause- 24/7, however, when an accumulator system is incorporated, cycle times can be further reduced to < ~1 second on, ~1 minute pause.
As a research tool
Soon after its development, aeroponics took hold as a valuable research tool. Aeroponics offered researchers a noninvasive way to examine roots under development. This new technology also allowed researchers a larger number and a wider range of experimental parameters to use in their work.
[Stoner, R.J. (1983). ''Aeroponics Versus Bed and Hydroponic Propagation.'' Florists' Review Vol 1 173 (4477).]
The ability to precisely control the root zone moisture levels and the amount of water delivered makes aeroponics ideally suited for the study of water stress. K. Hubick evaluated aeroponics as a means to produce consistent, minimally water-stressed plants for use in drought or flood physiology experiments.
Aeroponics is the ideal tool for the study of root
morphology
Morphology, from the Greek and meaning "study of shape", may refer to:
Disciplines
*Morphology (archaeology), study of the shapes or forms of artifacts
*Morphology (astronomy), study of the shape of astronomical objects such as nebulae, galaxies, ...
. The absence of aggregates offers researchers easy access to the entire, intact root structure without the damage that can be caused by removal of roots from soils or aggregates. It's been noted that aeroponics produces more normal root systems than hydroponics.
Terminology
''Aeroponic growing'' refers to plants grown in an air culture that can develop and grow in a normal and natural manner.
''Aeroponic growth'' refers to growth achieved in an air culture.
''Aeroponic system'' refers to hardware and system components assembled to sustain plants in an air culture.
''Aeroponic greenhouse'' refers to a climate controlled glass or plastic structure with equipment to grow plants in air/
mist
Mist is a phenomenon caused by small droplets of water suspended in the cold air, usually by condensation. Physically, it is an example of a dispersion. It is most commonly seen where water vapor in warm, moist air meets sudden cooling, such a ...
environment.
''Aeroponic conditions'' refers to air culture environmental parameters for sustaining plant growth for a plant species.
''Aeroponic roots'' refers to a root system grown in an air culture.
Types of aeroponics
Low-pressure units
In most low-pressure aeroponic gardens, the plant roots are suspended above a
reservoir
A reservoir (; from French ''réservoir'' ) is an enlarged lake behind a dam. Such a dam may be either artificial, built to store fresh water or it may be a natural formation.
Reservoirs can be created in a number of ways, including contro ...
of nutrient solution or inside a channel connected to a reservoir. A low-pressure pump delivers nutrient solution via jets or by ultrasonic transducers, which then drips or drains back into the reservoir. As plants grow to maturity in these units they tend to have dry sections of the root systems, which prevent adequate nutrient uptake. These units, because of cost, lack features to purify the nutrient solution, and adequately remove incontinuities,
debris
Debris (, ) is rubble, wreckage, ruins, litter and discarded garbage/refuse/trash, scattered remains of something destroyed, or, as in geology, large rock fragments left by a melting glacier, etc. Depending on context, ''debris'' can refer to ...
, and unwanted
pathogens
In biology, a pathogen ( el, πάθος, "suffering", "passion" and , "producer of") in the oldest and broadest sense, is any organism or agent that can produce disease. A pathogen may also be referred to as an infectious agent, or simply a germ ...
. Such units are usually suitable for bench top growing and demonstrating the principles of aeroponics.
High-pressure devices
![Aeroponic roots nepal](https://upload.wikimedia.org/wikipedia/commons/4/42/Aeroponic_roots_nepal.jpg)
High-pressure aeroponic techniques, where the mist is generated by high-pressure pump(s), are typically used in the cultivation of high value crops and plant specimens that can offset the high setup costs associated with this method of
horticulture
Horticulture is the branch of agriculture that deals with the art, science, technology, and business of plant cultivation. It includes the cultivation of fruits, vegetables, nuts, seeds, herbs, sprouts, mushrooms, algae, flowers, seaweeds and no ...
.
High-pressure aeroponics systems include technologies for air and
water purification
Water purification is the process of removing undesirable chemicals, biological contaminants, suspended solids, and gases from water. The goal is to produce water that is fit for specific purposes. Most water is purified and disinfected for hu ...
,
nutrient sterilization,
low-mass polymers and
pressurized nutrient delivery systems.
Commercial systems
Commercial aeroponic systems consist of high-pressure device hardware and biological systems. The
biological systems matrix includes enhancements for extended plant life and crop maturation.
Biological subsystems and hardware components include
effluent
Effluent is wastewater from sewers or industrial outfalls that flows directly into surface waters either untreated or after being treated at a facility. The term has slightly different meanings in certain contexts, and may contain various pollut ...
controls systems, disease prevention, pathogen resistance features, precision timing and nutrient solution pressurization, heating and cooling
sensors
A sensor is a device that produces an output signal for the purpose of sensing a physical phenomenon.
In the broadest definition, a sensor is a device, module, machine, or subsystem that detects events or changes in its environment and sends ...
, thermal control of solutions, efficient photon-
flux
Flux describes any effect that appears to pass or travel (whether it actually moves or not) through a surface or substance. Flux is a concept in applied mathematics and vector calculus which has many applications to physics. For transport ph ...
light arrays, spectrum filtration spanning,
fail-safe
In engineering, a fail-safe is a design feature or practice that in the event of a specific type of failure, inherently responds in a way that will cause minimal or no harm to other equipment, to the environment or to people. Unlike inherent safe ...
sensors and protection, reduced maintenance & labor saving features, and
ergonomics
Human factors and ergonomics (commonly referred to as human factors) is the application of psychological and physiological principles to the engineering and design of products, processes, and systems. Four primary goals of human factors learnin ...
and long-term reliability features.
Commercial aeroponic systems, like the high-pressure devices, are used for the cultivation of high value crops where multiple
crop rotation
Crop rotation is the practice of growing a series of different types of crops in the same area across a sequence of growing seasons. It reduces reliance on one set of nutrients, pest and weed pressure, and the probability of developing resistant ...
s are achieved on an ongoing commercial basis.
Advanced commercial systems include data gathering, monitoring, analytical
feedback
Feedback occurs when outputs of a system are routed back as inputs as part of a chain of cause-and-effect that forms a circuit or loop. The system can then be said to ''feed back'' into itself. The notion of cause-and-effect has to be handled ...
and internet connections to various subsystems.
History
![Commercialaero35kathmandu](https://upload.wikimedia.org/wikipedia/commons/8/87/Commercialaero35kathmandu.gif)
In 1911,
V.M.Artsikhovski published in the journal "Experienced Agronomy" an article "On Air Plant Cultures", which talks about his method of physiological studies of root systems by spraying various substances in the surrounding air - the aeroponics method. He designed the first aeroponics and in practice showed their suitability for plant cultivation.
It was W. Carter in 1942 who first researched air culture growing and described a method of growing plants in water vapor to facilitate examination of roots.
As of 2006, aeroponics is used in agriculture around the globe.
[NASA Spinoff (2006) ''Progressive Plant Growing Has Business Blooming.'' Environmental and Agricultural Resources NASA Spinoff 2006, pp. 68–72.]
In 1944, L.J. Klotz was the first to discover vapor misted citrus plants in a facilitated research of his studies of diseases of citrus and avocado roots. In 1952, G.F. Trowel grew apple trees in a spray culture.
It was F. W. Went in 1957 who first coined the air-growing process as "aeroponics", growing coffee plants and tomatoes with air-suspended roots and applying a nutrient mist to the root section.
Genesis Machine, 1983
The first commercially available aeroponic apparatus was manufactured and marketed by GTi in 1983. It was known then as the ''Genesis Machine'' - taken from the movie
Star Trek II: The Wrath of Khan. The ''Genesis Machine'' was marketed as the "Genesis Rooting System".
[Stoner, R.J (1983). ''Rooting in Air.'' Greenhouse Grower Vol I No. 11]
GTi's device incorporated an open-loop water driven apparatus, controlled by a
microchip
An integrated circuit or monolithic integrated circuit (also referred to as an IC, a chip, or a microchip) is a set of electronic circuits on one small flat piece (or "chip") of semiconductor material, usually silicon. Large numbers of tiny M ...
, and delivered a high pressure, hydro-atomized nutrient spray inside an aeroponic chamber. The ''Genesis Machine'' connected to a
water faucet and an electrical outlet.
Aeroponic propagation (cloning)
Aeroponic culturing revolutionized cloning (vegetative propagation) from cuttings of plants. Numerous plants which were previously considered difficult, or impossible, became easier to propagate via stem cuttings in aeroponics, such as delicate hardwoods or cacti which were sensitive to bacterial infection in cuttings. The overall success of propagation with the use of aeroponics is that the system creates a highly aerated environment around the root, which causes good root hair development (Soffer and Burger, 1988). There is also more root and growth development due to the nutrients supplied to the plants through the aeroponics system (Santos and Fisher 2009). Since the roots are not grown in any rooting media, it minimizes the risk of the plants getting infected by root disease (Mehandru et al. 2014).
[Mehandru, P., N. S Shekhawat, M. K. Rai, V. Kataria, H. S. Gehlot. (2014). Evaluation of aeroponics for clonal propagation of Caralluma edulis, Leptadenia reticulata and Tylophora indica – three threatened medicinal Asclepiads. Physiology and Molecular Biology of Plants. 20(3):365–373.]
The use of aeroponic is important for helping to propagate plants with low rate of success in vegetative propagation, plants that have important medicinal uses, plants that are in high demand, and to create new cultivars of certain plant species. Leptadenia reticulata is an important plant used in medicines that also has a low reproduction rate through both seed and cuttings (Mehandru et al. 2014).
Aeroponics has made it easier to propagate some these important medicinal plants (Mehandru et al. 2014).
Ulmus Americana, which was almost completely wiped out by Dutch elm disease, along with other cultivars of the species have also shown some success through propagation with aeroponics allowing for elm trees to be more available on the market (Oakes et al. 2012).
Aeroponics is a more viable alternative to the traditionally used process of overhead misters (Peterson et al. 2018).
[Peterson, B. J., S. E. Burnett, O. Sanchez. (2018). Submist is effective for propagation of Korean lilac and inkberry by stem cuttings. HortTechnology. 28(3):378–381.] There is a higher success rate with the use of aeroponics compared to overhead misters, and with the overhead misters there are drawbacks such as needing to apply large volumes of water, having potentially unsanitary conditions, having irregular misting coverage, and potential leaching of foliar nutrients (Peterson et al. 2018).
In short, cloning became easier because the aeroponic apparatus initiated faster and cleaner root development through a sterile, nutrient rich, highly oxygenated, and moist environment (Hughes, 1983).
Air-rooted transplants
Aeroponics significantly advanced tissue culture technology. It cloned plants in less time and reduced numerous labor steps associated with tissue culture techniques. Aeroponics could eliminate stage I and stage II plantings into soil (the bane of all tissue culture growers). Tissue culture plants must be planted in a sterile media (stage-I) and expanded out for eventual transfer into sterile soil (stage-II). After they are strong enough they are transplanted directly to field soil. Besides being labor-intensive, the entire process of tissue culture is prone to disease, infection, and failure.
With the use of aeroponics, growers
cloned
Cloning is the process of producing individual organisms with identical or virtually identical DNA, either by natural or artificial means. In nature, some organisms produce clones through asexual reproduction. In the field of biotechnology, c ...
and transplanted air-rooted plants directly into field soil. Aeroponic roots were not susceptible to wilting and leaf loss, or loss due to transplant shock (something hydroponics can never overcome). Because of their healthiness, air-rooted plants were less likely to be infected with pathogens.
(If the RH of the root chamber gets above 70 degrees F, fungus gnats, algae, anaerobic bacteria are likely to develop.)
The efforts by GTi ushered in a new era of artificial life support for plants capable of growing naturally without the use of soil or hydroponics. GTi received a patent for an all-plastic aeroponic method and apparatus, controlled by a microprocessor in 1985.
Aeroponics became known as a time and cost saver. The
economic
An economy is an area of the Production (economics), production, Distribution (economics), distribution and trade, as well as Consumption (economics), consumption of Goods (economics), goods and Service (economics), services. In general, it is ...
factors of aeroponic's contributions to agriculture were taking shape.
Genesis Growing System, 1985
By 1985, GTi introduced second generation aeroponics hardware, known as the "Genesis Growing System". This second generation aeroponic apparatus was a closed-loop system. It utilized recycled effluent precisely controlled by a microprocessor. Aeroponics graduated to the capability of supporting seed germination, thus making GTi's the world's first plant and harvest aeroponic system.
Many of these open-loop unit and
closed-loop aeroponic systems are still in operation today.
Commercialization
Aeroponics eventually left the laboratories and entered into the commercial cultivation arena. In 1966, commercial aeroponic pioneer B. Briggs succeeded in inducing roots on hardwood cuttings by air-rooting. Briggs discovered that air-rooted cuttings were tougher and more hardened than those formed in soil and concluded that the basic principle of air-rooting is sound. He discovered air-rooted trees could be transplanted to soil without having transplant shock or setback to normal growth. Transplant shock is normally observed in
hydroponic
Hydroponics is a type of horticulture and a subset of hydroculture which involves growing plants, usually crops or medicinal plants, without soil, by using water-based mineral nutrient solutions in aqueous solvents. Terrestrial or aquatic plan ...
transplants.
In Israel in 1982, L. Nir developed a patent for an aeroponic apparatus using compressed low-pressure air to deliver a nutrient solution to suspended plants, held by
styrofoam
Styrofoam is a trademarked brand of closed-cell extruded polystyrene foam (XPS), commonly called "Blue Board", manufactured as foam continuous building insulation board used in walls, roofs, and foundations as thermal insulation and water barrie ...
, inside large metal containers.
In summer 1976, British researcher John Prewer carried out a series of aeroponic experiments near
Newport, Isle of Wight
Newport is the county town of the Isle of Wight, an island county off the south coast of England. The town is slightly north of the centre of the island, and is in the civil parish of Newport and Carisbrooke. It has a quay at the head of the nav ...
, U.K., in which
lettuce
Lettuce (''Lactuca sativa'') is an annual plant of the family Asteraceae. It is most often grown as a leaf vegetable, but sometimes for its stem and seeds. Lettuce is most often used for salads, although it is also seen in other kinds of food, ...
s (variety Tom Thumb) were grown from seed to maturity in 22 days in
polyethylene
Polyethylene or polythene (abbreviated PE; IUPAC name polyethene or poly(methylene)) is the most commonly produced plastic. It is a polymer, primarily used for packaging ( plastic bags, plastic films, geomembranes and containers including bo ...
film tubes made rigid by pressurized air supplied by ventilating
fans
Fan commonly refers to:
* Fan (machine), a machine for producing airflow, often used for cooling
** Hand fan, an implement held and waved by hand to move air for cooling
* Fan (person), short for fanatic; an enthusiast or supporter, especially wit ...
. The equipment used to convert the water-nutrient into fog droplets was supplied by Mee Industries of California. "In 1984 in association with John Prewer, a commercial grower on the Isle of Wight - Kings Nurseries - used a different design of aeroponics system to grow
strawberry
The garden strawberry (or simply strawberry; ''Fragaria × ananassa'') is a widely grown hybrid species of the genus '' Fragaria'', collectively known as the strawberries, which are cultivated worldwide for their fruit. The fruit is widely ap ...
plants. The plants flourished and produced a heavy crop of strawberries which were picked by the nursery's customers. The system proved particularly popular with
elderly
Old age refers to ages nearing or surpassing the life expectancy of human beings, and is thus the end of the human life cycle. Terms and euphemisms for people at this age include old people, the elderly (worldwide usage), OAPs (British usage ...
customers who appreciated the cleanliness, quality and flavor of the strawberries, and the fact they did not have to stoop when picking the fruit."
In 1983, R. Stoner filed a patent for the first
microprocessor
A microprocessor is a computer processor where the data processing logic and control is included on a single integrated circuit, or a small number of integrated circuits. The microprocessor contains the arithmetic, logic, and control circu ...
interface to deliver tap water and nutrients into an enclosed aeroponic chamber made of plastic. Stoner has gone on to develop numerous companies researching and advancing aeroponic hardware, interfaces, biocontrols and components for commercial aeroponic crop production.
In 1985, Stoner's company, GTi, was the first company to manufacture, market and apply large-scale closed-loop aeroponic systems into greenhouses for commercial crop production.
[Stoner, R.J. and J.M. Clawson (1999–2000). ''Low-mass, Inflatable Aeroponic System for High Performance Food Production''. Principal Investigator, NASA SBIR NAS10-00017]
In the 1990s, GHE or General Hydroponics
uropethought to try to introduce aeroponics to the hobby hydroponics market and finally produced the Aerogarden system. However, this could not be classed as 'true' aeroponics because the Aerogarden produced tiny droplets of solution rather than a fine mist of solution; the fine mist was meant to reproduce true Amazon rain. In any case, a product was introduced to the market and the grower could broadly claim to be growing their hydroponic produce aeroponically. A demand for aeroponic growing in the hobby market had been established and moreover it was thought of as the ultimate hydroponic growing technique. The difference between true aeroponic mist growing and aeroponic droplet growing had become very blurred in the eyes of many people. At the end of the nineties, a UK firm, Nutriculture, was encouraged enough by industry talk to trial true aeroponic growing; although these trials showed positive results compared with more traditional growing techniques such as Nutrient Film Technique (NFT) and Ebb & Flood there were drawbacks, namely cost and maintenance. To accomplish true mist aeroponics a special pump had to be used which also presented scalability problems. Droplet-aeroponics was easier to manufacture, and as it produced comparable results to mist-aeroponics, Nutriculture began development of a scalable, easy to use droplet-aeroponic system. Through trials they found that aeroponics was ideal for
plant propagation
Plant propagation is the process by which new plants grow from a variety of sources: seeds, cuttings, and other plant parts. Plant propagation can also refer to the man-made or natural dispersal of seeds.
Propagation typically occurs as a step i ...
; plants could be propagated without medium and could even be grown-on. In the end, Nutriculture acknowledged that better results could be achieved if the plant was propagated in their branded X-stream aeroponic propagator and moved on to a specially designed droplet-aeroponic growing system - the Amazon.
Aeroponically grown food
In 1986, Stoner became the first person to market fresh aeroponically grown food to a national grocery chain. He was interviewed on
NPR
National Public Radio (NPR, stylized in all lowercase) is an American privately and state funded nonprofit media organization headquartered in Washington, D.C., with its NPR West headquarters in Culver City, California. It differs from other ...
and discussed the importance of the water conservation features of aeroponics for both modern agriculture and space.
Aeroponics in space
Space plants
Plants were first taken into Earth's orbit in 1960 on two separate missions,
Sputnik 4
Korabl-Sputnik 1 (russian: Корабль Спутник 1 meaning ''Vessel Satellite 1''), also known as Sputnik 4 in the West, was the first test flight of the Soviet Vostok programme, and the first Vostok spacecraft. It was launched on May 15, 1 ...
and
Discoverer 17 (for a review of the first 30 years of plant growth in space, see Halstead and Scott 1990). On the former mission,
wheat
Wheat is a grass widely cultivated for its seed, a cereal grain that is a worldwide staple food. The many species of wheat together make up the genus ''Triticum'' ; the most widely grown is common wheat (''T. aestivum''). The archaeologi ...
,
pea
The pea is most commonly the small spherical seed or the seed-pod of the flowering plant species ''Pisum sativum''. Each pod contains several peas, which can be green or yellow. Botanically, pea pods are fruit, since they contain seeds and d ...
,
maize
Maize ( ; ''Zea mays'' subsp. ''mays'', from es, maíz after tnq, mahiz), also known as corn (North American and Australian English), is a cereal grain first domesticated by indigenous peoples in southern Mexico about 10,000 years ago. Th ...
, spring
onion
An onion (''Allium cepa'' L., from Latin ''cepa'' meaning "onion"), also known as the bulb onion or common onion, is a vegetable that is the most widely cultivated species of the genus ''Allium''. The shallot is a botanical variety of the onion ...
, and
Nigella damascena
''Nigella damascena'', love-in-a-mist, or devil in the bush, is an annual garden flowering plant, belonging to the buttercup family Ranunculaceae.
It is native to southern Europe (but adventive in more northern countries of Europe), north Afri ...
seeds were carried into space, and on the latter mission
Chlorella pyrenoidosa
''Auxenochlorella pyrenoidosa'', formerly ''Chlorella pyrenoidosa'', is a species of the freshwater green alga in the Division Chlorophyta. It occurs worldwide. The species name ''pyrenoidosa'' refers to the presence of a prominent pyrenoid withi ...
cells were brought into orbit.
Plant experiments were later performed on a variety of
Bangladesh
Bangladesh (}, ), officially the People's Republic of Bangladesh, is a country in South Asia. It is the eighth-most populous country in the world, with a population exceeding 165 million people in an area of . Bangladesh is among the mos ...
,
China
China, officially the People's Republic of China (PRC), is a country in East Asia. It is the world's most populous country, with a population exceeding 1.4 billion, slightly ahead of India. China spans the equivalent of five time zones and ...
, and joint Soviet-American missions, including Biosatellite II (
Biosatellite program
NASA's Biosatellite program was a series of three uncrewed artificial satellites to assess the effects of spaceflight, especially radiation and weightlessness, on living organisms. Each was designed to reenter Earth's atmosphere and be recovered ...
),
Skylab 3
Skylab 3 (also SL-3 and SLM-2) was the second crewed mission to the first American space station, Skylab. The mission began on July 28, 1973, with the launch of NASA astronauts Alan Bean, Owen Garriott, and Jack Lousma in the Apollo command ...
and
4,
Apollo–Soyuz
Apollo–Soyuz was the first crewed international space mission, carried out jointly by the United States and the Soviet Union in July 1975. Millions of people around the world watched on television as a United States Apollo spacecraft docked ...
,
Sputnik
Sputnik 1 (; see § Etymology) was the first artificial Earth satellite. It was launched into an elliptical low Earth orbit by the Soviet Union on 4 October 1957 as part of the Soviet space program. It sent a radio signal back to Earth for t ...
,
Vostok Vostok refers to east in Russian but may also refer to:
Spaceflight
* Vostok programme, Soviet human spaceflight project
* Vostok (spacecraft), a type of spacecraft built by the Soviet Union
* Vostok (rocket family), family of rockets derived from ...
, and
Zond. Some of the earliest research results showed the effect of low
gravity
In physics, gravity () is a fundamental interaction which causes mutual attraction between all things with mass or energy. Gravity is, by far, the weakest of the four fundamental interactions, approximately 1038 times weaker than the stro ...
on the orientation of roots and shoots (Halstead and Scott 1990).
Subsequent research went on to investigate the effect of low gravity on plants at the organismic, cellular, and subcellular levels. At the organismic level, for example, a variety of species, including
pine
A pine is any conifer tree or shrub in the genus ''Pinus'' () of the family Pinaceae. ''Pinus'' is the sole genus in the subfamily Pinoideae. The World Flora Online created by the Royal Botanic Gardens, Kew and Missouri Botanical Garden accep ...
,
oat
The oat (''Avena sativa''), sometimes called the common oat, is a species of cereal grain grown for its seed, which is known by the same name (usually in the plural, unlike other cereals and pseudocereals). While oats are suitable for human con ...
,
mung bean
The mung bean (''Vigna radiata''), alternatively known as the green gram, maash ( fa, ماش٫ )٫ mūng (), monggo, or munggo (Philippines), is a plant species in the legume family.Brief Introduction of Mung Bean. Vigna Radiata Extract G ...
, lettuce,
cress, and ''
Arabidopsis thaliana
''Arabidopsis thaliana'', the thale cress, mouse-ear cress or arabidopsis, is a small flowering plant native to Eurasia and Africa. ''A. thaliana'' is considered a weed; it is found along the shoulders of roads and in disturbed land.
A winter a ...
'', showed decreased seedling, root, and shoot growth in low gravity, whereas lettuce grown on Cosmos showed the opposite effect of growth in space (Halstead and Scott 1990). Mineral uptake seems also to be affected in plants grown in space. For example, peas grown in space exhibited increased levels of
phosphorus
Phosphorus is a chemical element with the symbol P and atomic number 15. Elemental phosphorus exists in two major forms, white phosphorus and red phosphorus, but because it is highly reactive, phosphorus is never found as a free element on Ear ...
and
potassium
Potassium is the chemical element with the symbol K (from Neo-Latin ''kalium'') and atomic number19. Potassium is a silvery-white metal that is soft enough to be cut with a knife with little force. Potassium metal reacts rapidly with atmosphe ...
and decreased levels of the
divalent
In chemistry, the valence (US spelling) or valency (British spelling) of an element is the measure of its combining capacity with other atoms when it forms chemical compounds or molecules.
Description
The combining capacity, or affinity of an ...
cations
An ion () is an atom or molecule with a net electrical charge.
The charge of an electron is considered to be negative by convention and this charge is equal and opposite to the charge of a proton, which is considered to be positive by convent ...
calcium
Calcium is a chemical element with the symbol Ca and atomic number 20. As an alkaline earth metal, calcium is a reactive metal that forms a dark oxide-nitride layer when exposed to air. Its physical and chemical properties are most similar to ...
,
magnesium
Magnesium is a chemical element with the symbol Mg and atomic number 12. It is a shiny gray metal having a low density, low melting point and high chemical reactivity. Like the other alkaline earth metals (group 2 of the periodic ta ...
,
manganese
Manganese is a chemical element with the symbol Mn and atomic number 25. It is a hard, brittle, silvery metal, often found in minerals in combination with iron. Manganese is a transition metal with a multifaceted array of industrial alloy use ...
,
zinc
Zinc is a chemical element with the symbol Zn and atomic number 30. Zinc is a slightly brittle metal at room temperature and has a shiny-greyish appearance when oxidation is removed. It is the first element in group 12 (IIB) of the periodi ...
, and
iron
Iron () is a chemical element with symbol Fe (from la, ferrum) and atomic number 26. It is a metal that belongs to the first transition series and group 8 of the periodic table. It is, by mass, the most common element on Earth, right in f ...
(Halstead and Scott 1990).
Biocontrols in space
In 1996, NASA funded Richard Stoner's research to develop a natural liquid biocontrol, known then as organic disease control (ODC), to prevent plant diseases and increase yields without the use of pesticides for closed-loop hydroponic systems. By 1997, Stoner's biocontrol experiments were conducted by NASA. BioServe Space Technologies's GAP technology (miniature growth chambers) delivered the ODC solution unto bean seeds. Triplicate ODC experiments were conducted in GAP's flown to the MIR by the space shuttle; at the
Kennedy Space Center
The John F. Kennedy Space Center (KSC, originally known as the NASA Launch Operations Center), located on Merritt Island, Florida, is one of the National Aeronautics and Space Administration's (NASA) ten field centers. Since December 1968 ...
; and at
Colorado State University
Colorado State University (Colorado State or CSU) is a public land-grant research university in Fort Collins, Colorado. It is the flagship university of the Colorado State University System. Colorado State University is classified among "R1: ...
(J. Linden). All GAPS were housed in total darkness to eliminate light as an experiment variable. The NASA experiment was to study only the benefits of the biocontrol.
NASA's enclosed environment bean experiments aboard the MIR space station and shuttle confirmed that ODC elicited increased germination rate, better sprouting, increased growth and natural plant disease mechanisms. Though originally developed with NASA, ODC is not just for space. Soil and hydroponics growers can benefit by incorporating ODC into their planting techniques, as ODC meets
USDA
The United States Department of Agriculture (USDA) is the federal executive department responsible for developing and executing federal laws related to farming, forestry, rural economic development, and food. It aims to meet the needs of com ...
NOP standards for organic farms.
One example of ODC's expansion in agriculture is the ODC product line, which caters to emerging agricultural crops, such as cannabis. The active ingredients in the ODC cannabis line contain the original active ingredient chitosan at 0.25%, as well as 0.28% colloidal nitrogen, and 0.05% calcium.
In order to make hydroponic and aeroponic systems inherently more resilient to plant disease and less reliant upon chemical supplementation, NASA investigates environmental biocontrols integrated into the system's design. For example, NASA's Advanced Plant Habitat (APA) has been in operation on the ISS since 2018. The APA is equipped with more than 180 sensors which allows for the optimization of plant growth, health, and monitoring in space, while decreasing reliance upon chemical additive biocontrols. These environmental controls and sensors include lighting (intensity, spectrum, and photoperiod), temperature, CO
2, relative humidity, irrigation, as well as plant-derived ethylene and
volatile organic compound
Volatile organic compounds (VOCs) are organic compounds that have a high vapour pressure at room temperature. High vapor pressure correlates with a low boiling point, which relates to the number of the sample's molecules in the surrounding air, a ...
(VOC) scrubbing. Additionally, APA is equipped with leaf temperature sensors, root zone temperature, root zone moisture sensors, as well as oxygen concentration meters.
These environmental controls typically inhibit plant diseases through two methods. The first method is to maintain environmental conditions that directly impact and inhibit diseases, fungus, and pests. For example, by monitoring and controlling environmental conditions such as temperature and humidity, the risk of botrytis infection in leaves are reduced as the environment is not conducive for disease proliferation. The second method is to provide environmental conditions that promote the plant's natural disease prevention mechanisms, whereby indirectly inhibiting the effects of plant diseases. This method has been explored through light experiments with peppers. For example, peppers grown under blue light conditions showed more resilience to powdery mildew.
Aeroponics for Earth and space
In 1998, Stoner received NASA funding to develop a high performance aeroponic system for use on earth and in space. Stoner demonstrated significantly increased growth rates of dry biomass in lettuce plants grown in aeroponic systems compared to other cultivation techniques. NASA subsequently utilized numerous aeroponic advancements developed by Stoner.
Research was conducted to identify and develop technologies for rapid plant growth in a variety of gravitational environments. Low-gravity environments pose problems like effectively delivering water and nutrients to plants and recovering the effluents. Food production in space faces other challenges including water handling, minimization of water use, and minimization of the systems weight. Food production on planetary bodies like the Moon and Mars will also require dealing with reduced gravity environments. Because of the different fluid dynamics present at differing levels of gravity a major focus in developing plant growth systems has been optimizing nutrient delivery systems.
There are a number of nutrient delivery methods currently utilized (both on Earth and in low gravity). Substrate dependent methods include traditional soil cultivation, zeoponics, agar, and nutrient-loaded ion exchange resins. In addition to substrate dependent cultivation, many methods that don't use soil have been developed including the nutrient film technique, ebb and flow, aeroponics, and many others. Because of their high nutrient solution throughput hydroponic systems can produce rapid plant growth. This necessitates large water volumes and substantial recycling of the solution which makes controlling solutions more difficult in microgravity conditions.
To deliver nutrients aeroponic systems use hydro-atomized sprays that minimize water use, increase root oxygenation, and produce excellent plant growth. The nutrient solution throughput of aeroponic systems is higher than in other systems developed to operate in low gravity. Aeroponics' elimination of substrates and the need for large nutrient stockpiles reduce the amount of waste material that needs to be processed by other life support systems. The removal of the need for a substrate also simplifies planting and harvesting (making automation easier), decreases the weight and volume of expendable materials, and eliminates a potential pathogen transmission pathway. These advantages demonstrate the potential of aeroponic production in microgravity and the efficient production of food in outer space.
NASA inflatable aeroponics
In 1999, NASA funded development of an inflatable low-mass aeroponic system (AIS) for space and Earth high performance food production. AIS is a self-contained, self-supporting, inflatable aeroponic crop production system capable of controlling nutrient/mist delivery to the plant roots. Being an inflatable structure, AIS is lightweight, and can be deflated to take up less volume during transportation and storage. The current iteration of AIS improved upon the previous design that used rigid structures, which are more expensive to manufacture and transport.
On Earth, expensive materials and transportation may hinder the economic feasibility of aeroponic systems for commercial growers. However, such obstacles become magnified when considering payload mass for space transportation.
Due to the mass and volume restraints, NASA developed specialized materials for inflatable habitats and structures to withstand the space environment. These aramid-like materials are currently being used to develop Bigelow Aerospace's expandible habitats. One of Bigelow's Expandable Activity Modules has been successfully tested in space.
Benefits of aeroponics for earth and space
Aeroponics possesses many characteristics that make it an effective and efficient means of growing plants.
Less nutrient solution throughout
Plants grown using aeroponics spend 99.98% of their time in air and 0.02% in direct contact with hydro-atomized nutrient solution. The time spent without water allows the roots to capture oxygen more efficiently. Furthermore, the hydro-atomized mist also significantly contributes to the effective oxygenation of the roots. For example, Nutrient Film Technique (NFT) has a nutrient throughput of 1 liter per minute compared to aeroponics' throughput of 1.5 milliliters per minute.
The reduced volume of nutrient throughput results in reduced amounts of nutrients required for plant development.
Another benefit of the reduced throughput, of major significance for space-based use, is the reduction in water volume used. This reduction in water volume throughput corresponds with a reduced buffer volume, both of which significantly lighten the weight needed to maintain plant growth. In addition, the volume of effluent from the plants is also reduced with aeroponics, reducing the amount of water that needs to be treated before reuse.
The relatively low solution volumes used in aeroponics, coupled with the minimal amount of time that the roots are exposed to the hydro-atomized mist, minimizes root-to-root contact and spread of pathogens between plants.
Greater control of plant environment
Aeroponics allows more control of the environment around the root zone, as, unlike other plant growth systems, the plant roots are not constantly surrounded by some medium (as, for example, with hydroponics, where the roots are constantly immersed in water).
Improved nutrient feeding
A variety of different nutrient solutions can be administered to the root zone using aeroponics without needing to flush out any solution or matrix in which the roots had previously been immersed. This elevated level of control would be useful when researching the effect of a varied regimen of nutrient application to the roots of a plant species of interest.
In a similar manner, aeroponics allows a greater range of growth conditions than other nutrient delivery systems. The interval and duration of the nutrient spray, for example, can be very finely attuned to the needs of a specific plant species.
The aerial tissue can be subjected to a completely different environment from that of the roots.
More user-friendly
The design of an aeroponic system allows ease of working with the plants. This results from the separation of the plants from each other, and the fact that the plants are suspended in air and the roots are not entrapped in any kind of matrix. Consequently, the harvesting of individual plants is quite simple and straightforward. Likewise, removal of any plant that may be infected with some type of pathogen is easily accomplished without risk of uprooting or contaminating nearby plants.
More cost effective
Aeroponic systems are more cost effective than other systems. Because of the reduced volume of solution throughput (discussed above), less water and fewer nutrients are needed in the system at any given time compared to other nutrient delivery systems. The need for substrates is also eliminated, as is the need for many moving parts .
Use of seed stocks
With aeroponics, the deleterious effects of seed stocks that are infected with pathogens can be minimized. As discussed above, this is due to the separation of the plants and the lack of shared growth matrix. In addition, due to the enclosed, controlled environment, aeroponics can be an ideal growth system in which to grow seed stocks that are pathogen-free. The enclosing of the growth chamber, in addition to the isolation of the plants from each other discussed above, helps to both prevent initial contamination from pathogens introduced from the external environment and minimize the spread from one plant to others of any pathogens that may exist.
21st century aeroponics
Aeroponics is an improvement in artificial life support for non-damaging plant support, seed germination, environmental control and rapid unrestricted growth when compared with hydroponics and drip irrigation techniques that have been used for decades by traditional agriculturalists.
Contemporary aeroponics
Contemporary aeroponic techniques have been researched at NASA's research and commercialization cente
BioServe Space Technologies( ) located on the campus of the University of Colorado in Boulder, Colorado. Other research includes enclosed loop system research at
Ames Research Center
The Ames Research Center (ARC), also known as NASA Ames, is a major NASA research center at Moffett Federal Airfield in California's Silicon Valley. It was founded in 1939 as the second National Advisory Committee for Aeronautics (NACA) laborat ...
, where scientists were studying methods of growing
food crop
A crop is a plant that can be grown and harvested extensively for profit or subsistence. When the plants of the same kind are cultivated at one place on a large scale, it is called a crop. Most crops are cultivated in agriculture or hydroponics ...
s in
low gravity
Weightlessness is the complete or near-complete absence of the sensation of weight. It is also termed zero gravity, zero G-force, or zero-G.
Weight is a measurement of the force on an object at rest in a relatively strong gravitational fie ...
situations for future
space colonization
Space colonization (also called space settlement or extraterrestrial colonization) is the use of outer space or celestial bodies other than Earth for permanent habitation or as extraterrestrial territory.
The inhabitation and territori ...
.
In 2000, Stoner was granted a patent for an organic disease control biocontrol technology that allows for pesticide-free natural growing in an aeroponic systems.
In 2004, Ed Harwood, founder of
AeroFarms, invented an aeroponic system that grows lettuces on micro fleece cloth.
AeroFarms, utilizing Harwood's patented aeroponic technology, is now operating the largest indoor vertical farm in the world based on annual growing capacity in Newark, New Jersey. By using aeroponic technology the farm is able to produce and sell up to two million pounds of pesticide-free leafy greens per year.
Aeroponic bio-pharming
Aeroponic bio-pharming is used to grow pharmaceutical medicine inside of plants. The technology allows for completed containment of allow effluents and by-products of biopharma crops to remain inside a closed-loop facility.
As recently as 2005,
GMO
A genetically modified organism (GMO) is any organism whose genetic material has been altered using genetic engineering techniques. The exact definition of a genetically modified organism and what constitutes genetic engineering varies, with ...
research at
South Dakota State University
South Dakota State University is a public land-grant research university in Brookings, South Dakota. Founded in 1881, it is the state's largest and most comprehensive university and the oldest continually-operating university in South Dakota. The ...
by Dr. Neil Reese applied aeroponics to grow
genetically modified corn.
According to Reese it is a historical feat to grow corn in an aeroponic apparatus for
bio-massing. The university's past attempts to grow all types of corn using hydroponics ended in failure.
Using advanced aeroponics techniques to grow genetically modified corn Reese harvested full ears of corn, while containing the corn pollen and spent effluent water and preventing them from entering the environment. Containment of these by-products ensures the environment remains safe from GMO contamination.
Reese says, aeroponics offers the ability to make bio-pharming economically practical.
Large scale integration of aeroponics
In 2006, the Institute of Biotechnology at
Vietnam National University of Agriculture
Vietnam National University of Agriculture (or ''VNUA'') ( vi, Học viện Nông nghiệp Việt Nam), until 2014 ''Hanoi University of Agriculture (HUA)'', is an education and research university specializing in the agricultural sector. The un ...
, in joint efforts with Stoner, established a postgraduate doctoral program in aeroponics. The university's Agrobiotech Research Center, under the direction of Professor
Nguyen Quang Thach, is using aeroponic laboratories to advance
Vietnam
Vietnam or Viet Nam ( vi, Việt Nam, ), officially the Socialist Republic of Vietnam,., group="n" is a country in Southeast Asia, at the eastern edge of mainland Southeast Asia, with an area of and population of 96 million, making i ...
's minituber potato production for certified seed potato production.
The historical significance for aeroponics is that it is the first time a nation has specifically called out for aeroponics to further an agricultural sector, stimulate farm economic goals, meet increased demands, improve food quality and increase production.
"We have shown that aeroponics, more than any other form of agricultural technology, will significantly improve Vietnam's potato production. We have very little tillable land, aeroponics makes complete economic sense to us", attested Thach.
Vietnam joined the
World Trade Organization
The World Trade Organization (WTO) is an intergovernmental organization that regulates and facilitates international trade. With effective cooperation
in the United Nations System, governments use the organization to establish, revise, and e ...
(WTO) in January 2007.
Aeroponic integration in Vietnamese agriculture begins by producing a low cost certified disease-free organic minitubers, which in turn supplies local farmers for their field plantings of seed potatoes and commercial potatoes. Potato farmers will benefit from aeroponics because their seed potatoes will be disease-free and grown without pesticides. Most importantly for the Vietnamese farmer, it will lower their cost of operation and increase their yields, says Thach.
See also
*
Aerial root
Aerial roots are roots above the ground. They are almost always adventitious. They are found in diverse plant species, including epiphytes such as orchids (''Orchidaceae''), tropical coastal swamp trees such as mangroves, banyan figs ('' F ...
*
Plant nutrition
Plant nutrition is the study of the chemical elements and compounds necessary for plant growth and reproduction, plant metabolism and their external supply. In its absence the plant is unable to complete a normal life cycle, or that the element i ...
References
External links
NASA Web Site: Aeroponic Plants"Re-examining Aeroponics for Spaceflight Plant Growth"AeroFarms (paywall)Aerogarden- home aeroponic plant growing system.
Aeroponics 101- History of Aeroponics and components of aeroponic system
{{Hydroculture
Agricultural soil science
Horticultural techniques
Hydroculture
NASA spin-off technologies