Excerpt:
Hydroponics, the growing of plants without soil, has developed from the findings of experiments carried out to determine what substances make plants grow and the composition of plants. Such work on plant constituents dates back as early as the 1600s. However, plants were being grown in a soilless culture far earlier than this. Hydroponics is at least as ancient as the pyramids. A primitive form has been carried on in Kashmir for centuries.
The process of hydroponics growing in our oceans goes back to about the time the earth was created. Hydroponic growing preceded soil growing. But as a farming tool, many believe it started in the ancient city of Babylon with it's famous hanging gardens, which are listed as one of the Seven Wonders of the Ancient World, and was probably one of the first successful attempts to grow plants hydroponically.