Hydroponics is the growing of plants without soil. It was developed from the findings of experiments carried out to determine what substances make plants grow and the composition of plants. This dates back as early as the 1600s. Plants were being grown in a soil less culture far earlier than this. There were hanging gardens in Babylon, floating gardens of the Aztecs of Mexico, and the Chinese also had methods that were examples of "hydroponics" …showed first 75 words of 2540 total…

…showed last 75 words of 2540 total…CAN MATURE FASTER UNDER A SILLESS SYSTEM THAN UNDER SOIL. 12. PERMANENCE OF MEDIUM (SOIL) SOIL IN A GREENHOUSE MUST BE CHANGED REGULARLY EVERY SEVERAL YEARS SINCE FERTILITY AND STRUCTURE BREAK DOWN. UNDER FIELD CONDITIONS MUST FALLOW. (SOILLESS) NO NEED TO CHANGE MEDIUM IN GRAVEL, SAND OR WATER CULTURES; NO NEED TO FALLOW. SAWDUST, PEAT, VERMICULITE MAY LAST FOR SEVERAL YEARS BETWEEN CHANGES. 13. YIELDS (SOIL) GREENHOUSE TOMATOES 15-20 LB/YEAR/PLANT. (SOILLESS) 25-35 LB/YEAR/PLANT.