Aeroponics is a technique of growing plants without

Soil
Aeroponics is the process of growing plants in an air or mist environment without the use of soil or an aggregate medium (known as geoponics). Aeroponic culture differs from both conventional hydroponics, aquaponics, and in-vitro (plant tissue culture) growing. Unlike hydroponics, which uses a liquid nutrient solution as a growing medium and essential minerals to sustain plant growth; or aquaponics which uses water and fish waste, aeroponics is conducted without a growing medium.