Hydroponics: http://www.simplyhydro.com/whatis.htm

With hydroponics the plants are grown in an inert growing medium and a perfectly balanced, pH adjusted nutrient solution is delivered to the roots in a highly soluble form. This allows the plant to uptake its food with very little effort as opposed to soil where the roots must search out the nutrients and extract them. This is true even when using rich, organic soil and top of the line nutrients. The energy expended by the roots in this process is energy better spent on vegetative growth and fruit and flower production.

HYDROPONICS