How the natural world can be replicated to grow plants.
To grow, plants generally need a combination of water, sunlight, carbon dioxide and nutrients. Through photosynthesis they convert these four basic elements into sugars and oxygen, allowing them to survive, grow and reproduce. Hydroponics is the practice of growing plants by artificially supplying them with these four things in the absence of natural sources.
This process means the plants can be grown in an interior environment with neither sunlight nor soil. Artificial lights are often used instead of the Sun to enable the plants to produce chlorophyll, while oxygen, water and minerals are transported to the roots directly through a series of tubes.
Hydroponics is very useful as it enables different plants to be grown en masse in adverse conditions where they would otherwise perish, such as in hot or cold climates.
The absence of soil also largely removes the intrusion of insects and weeds, which can hamper growth. This artificial growing technique has also been considered for use on other planets.