HYDROPONICS

HYDROPONICS, a method of growing plants in nutrient solutions, without soil. Under normal conditions, soil captures and stores nitrogen, potassium, and other mineral nutrients, which plant roots absorb gradually. Hydroponics, in contrast, immerses roots directly in liquid nutrient solutions. Plants are either suspended above water with their roots submerged, or they are placed in sand or in sterile growing mediums and regularly flooded with liquid nutrients. Proponents say this minimizes nutrient loss and allows more precise control over the nutrients the plants receive.

The principles of hydroponic gardening have been used since ancient times. They were brought to popular attention in the United States in 1937 by Dr. W. F. Gericke, who introduced the word "hydroponic" (from the Greek words for "water" and "work") and publicly displayed immense tomato plants cultivated by this method. Hydroponics became a brief fad. Although popular interest subsided, hydroponic methods continued to be developed and studied. In World War II, soldiers on Pacific islands grew their vegetables hydroponically, and in the 1960s large commercial hydroponic greenhouses and multiacre hydroponic farms were established in many locations around the United States.

In the early 2000s hydroponic systems ranged from small home setups to large enterprises. Advocates saw hydroponics as a way to increase the world's food supply and as a form of cultivation suitable for the confines of spacecraft. However, most people viewed hydroponics as a supplement to traditional growing methods rather than as a replacement. It is not suitable for all plants, must be done carefully, and can require large amounts of water.

BIBLIOGRAPHY

Nicholls, Richard. Beginning Hydroponics: Soilless Gardening. Philadelphia: Running Press, 1990.

Resh, Howard M. Hydroponic Food Production: A Definitive Guidebook of Soilless Food-Growing Methods. 5th ed. Santa Barbara, Calif.: Woodbridge Press, 1995.

JohnTownes/c. w.

See alsoAgriculture ; Gardening ; Organic Farming .