Aeroponic Gardening - An Airy Concept

You might have heard of aeroponics before and may not have known what the term meant. The word aeroponic is derived from the Greek words aero (air) and ponic (labor) and is applied to the practice of plant propagation in air. That's right, you heard correctly. No soil, no liquid mediums or aggregates. Just air and mist.

Impossible you say? Well, not only is it possible, but also a highly effective and viable method of growing plants as diverse as lettuce and wheat. The amazing thing about aeroponics systems is that they are not just the product of some fevered scientific mind, but occur frequently in nature. In tropical climates, for instance, there are several orchid species that grow freely in trees without the support of any growth medium at all!

So how does this miraculous system work?

Aeroponics relies on plant roots natural ability to absorb nutrients from exposure to water without the presence of soil. Plants can absorb these nutrients from immersion in a nutrient rich liquid solution as in hydroponics or from exposure to a spray mist solution as applied in aeroponics.

In practice smaller plant varieties are suspended by their stems in closed cell foam with the root system exposed in an aeroponics chamber. These exposed roots are then sprayed or misted with a hydro-atomized water/nutrient solution for short periods at regular intervals. This exposure to the nutrient mixture allows the plant to absorb all its food requirements without the need for any growth medium. Larger plants are suspended on trellises to achieve the same effect.

OK, so aeroponics works. The question is, why go to so much effort when you can just plant them in the back yard?

The answer is quite simple. Aeroponics allows the healthy, natural growth of plants in a cost and labor effective, ecologically sound manner. Cost and labor effective due to the fact that, once installed, the system requires very little maintenance and uses far less additional supplements such as fertilizers and pesticides. Ecologically sound because these systems use less energy and water.

There are several different types of aeroponics systems, including small scale examples suitable for residential use, the AeroFlo system being one such example. Several large scale systems use combination techniques such as aero-hydroponic systems where the plant's roots are partially submerged in a growing chamber or canal filled with a liquid nutrient solution.

The rest of the root system is then exposed to an oxygen/nutrient rich spray. One of the economical and ecological benefits of these, and indeed all aeroponics systems, is that the mist only coats the plant roots in a layer of solution, the rest settles in the chamber or canal and is re-used.

Controlling the nutrient intake of the plants is also surprisingly simple. In the AeroFlo aeroponics example, the system has a simple dosing mechanism that automatically maintains a ph level of 5.5 to 6.5 as well as keeping nutrient concentrations at 800 to 1200 ppm.

The same principles are also applied in larger commercial aeroponics examples. Although aeroponics systems are not entirely closed to all common pests, the incidence of infestation is far lower than conventional methods due to the absence of an open soil environment. This means less maintenance and less exposure to pesticides.

Aeroponics as a common cultivation method has been slow to find favour due to the initial setup costs and licensing requirements. However, with ever increasing demands on space and natural resources, it won't be long before aeroponics and other low impact plant growth methods gain popularity both as a large scale commercial option and as an attractive solution for weekend warrior gardeners.

Sources:
Wiki-Aeroponics http://en.wikipedia.org/wiki/Aeroponics