Hydroponics (redirected from hydroponically)

hydroponics, growing of plants without soil in water to which nutrients have been added. Hydroponics has been used for over a century as a research technique, but not until 1929 were experiments conducted solely to determine its feasibility for growing commercial crops. There are now hydroponic home gardens and commercial cropping operations in the United States and many other countries. Under hydroponics, plants can be grown closer together than in the field, thereby increasing yields, and multiple cropping (the growing of several crops in the same tank) can be practiced. In addition to conserving space, hydroponics almost eliminates weed and pest problems. The cost of equipment is high and personnel must be trained. Although hydroponics is possible for most plant species, a limiting factor is the amount of physical support required. Usually the plants are held upright by wire supports or are rooted in a sterile medium, e.g., pure sand or gravel. The nutrient solutions must supply, in optimum concentrations and in correct balance, the elements, such as nitrogen, phosphorus, potassium, and other essential nutrients normally found in soil. Other names for hydroponics are soilless gardening, soilless culture, chemiculture, and water gardening.

Bibliography

See R. Bridwell, Hydroponic Gardening (rev. ed. 1990); R. E. Nicholls, Beginning Hydroponics (1990).

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hydroponics

Cultivation of plants in nutrient-enriched water, with or without the mechanical support of an inert medium such as sand or gravel. Fertilizer solution is pumped through the system periodically. As the plants grow, concentration of the solution and frequency of pumping are increased. A wide variety of vegetables and florist crops can be grown satisfactorily in gravel. Automatic watering and fertilizing saves on labor, but installation costs are high and fertilizer solution must be tested frequently. Yields are about the same as for soil-grown crops.

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hydroponics [‚hī·drə′pän·iks]

(botany)

Growing of plants in a nutrient solution with the mechanical support of an inert medium such as sand.

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Hydroponics 

growing plants without soil in artificial mediums. In this process the root systems of the plants grow in solid substrata (without nutritive significance), in water, or in moist air (aeroponics). The plants receive nutrients from a food solution surrounding the roots.

Hydroponics permits the regulation of plant growth conditions and the creation of a feeding regimen for a root system that fulfills all the nutritional requirements of the plant. It is also possible to create the concentration of carbon dioxide gas in the air that is most beneficial for photosynthesis, as well as to regulate the air temperature and the temperature of the space around the roots, the humidity, and the intensity and prolongation of illumination.

Creating optimal conditions for the growth and development of plants helps obtain very high yields and better quality in a shorter period of time. Growing plants by the hydroponic method is less labor-consuming than soil cultivation, and the water and nutritive substances are used more economically. Application of the nutritive solution is easily automated. In hydroponics there is practically no problem with weeds.

In the USSR hydroponics is used mainly to grow cucumbers, tomatoes, and flowers and to obtain the vitamin-rich foliage of corn plants, which is used as additional fodder for young animals during the winter. The process is also used in scientific research. Of great importance for the successful growth of plants in hydroponic systems is the composition of the nutrient solution, which is varied depending on the species of the plants, their age, and the basic factors of the external environment (such as the temperature of the air and the root-medium layer and the relative humidity of the air).

The nutritive solution consists of the salts of nitrogen, phosphorus, potassium, and other elements (Ca, Mg, Fe, B, Mn, Zn, Cu, Mo). The concentration of the food solution for water cultures is about 6 millimoles per liter, for gravel cultures, about 30 millimoles per liter. For aeroponics the concentration of the solution is a little higher.

Large areas of greenhouses are used for hydroponics in the suburban areas of many cities, including Moscow, Leningrad, Kiev, and Sverdlovsk. Hydroponics is done on open ground in Armenia and Azerbaijan. Abroad hydroponics has been widely developed in Great Britain, Japan, France, Italy, and the Antilles.

REFERENCES

Vyrashchivanie rastenii bez pochvy. Leningrad, 1960.
Aliev, E. A., Iu. A. Diukarev, and B. V. Latenko. Vyrashchivanie ovoshchei v teplitsakh bez pochvy. Kiev, 1964.
Bentley, M. Promyshlennaia gidroponika. Moscow, 1965. (Translated from English.)
Zhurbitskii, Z. I. Teoriia i praktika vegetatsionnogo metoda. Moscow, 1968.

Z. I. ZHURBITSKII