Greenhouses, Container Gardening, Hydroponics 

One way of describing ‘hydroponics’ is that it is a method involving plants that are being grown using certain kinds of nutrients and water but without the use of soil. By certain means, water must be sent to the area of the plant root. The system may be surrounded by a particular container or trough that is crammed with substrate; the substrate is an alternative to soil. Some materials that can be found in this soil substitute are wood chips, pebbles, sand and perlite, among others. The substrate should have enough capacity for holding adequate amounts of water but still adequately absorbent for gas to be exchanged in an efficient manner. This book provides some useful information about hydroponics. This system involves a lot of methods that are utilized for sending the water to the root section of the soilless plant. For every plant which is cultivated in such a manner, there is a certain kind of water emitter provided as a part of a drip irrigation system. One method of recycling the water in this arrangement is through what is called the ebb and flow method. Another technique involves watering from the underside by allowing the tray to fill up totally with water and then draining the extra water. - from Amzon