Hydroponics

hydroponics

[‚hī·drə′pän·iks]

(botany)

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

McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.

The following article is from The Great Soviet Encyclopedia (1979). It might be outdated or ideologically biased.

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

The Great Soviet Encyclopedia, 3rd Edition (1970-1979). © 2010 The Gale Group, Inc. All rights reserved.