Physics isn't usually associated with gardening but it is now being used to help develop a new field of agriculture - aeroponics. In this method, plants are cultivated without any soil and receive nutrients from moist air instead. Paul Ammann from New Jersey has patented a new system for aeroponics (Patent 5724768).
In Ammann’s scheme the plants are grown in a vertical structure with their roots protruding into a central column. A nozzle at the top of the structure sprays nutrients into this column, wetting the roots of the plants. The plants are also able to breathe in nitrogen and carbon dioxide through their roots, as would happen in soil.
One drawback of aeroponic systems is that stagnant air can build up in the chamber. Ammann has overcome this problem by designing the system such that the falling droplets cause atmospheric turbulence, and by using an air induction manifold to establish a low pressure zone inside the system that draws in fresh air.
