Hydroponics

Hydroponics is a method of growing plants without soil by delivering a nutrient-rich water solution directly to the roots. Plants are supported by an inert medium such as rock wool, perlite, expanded clay, or coco coir, while nutrients reach the roots in the solution. The system allows precise control of nutrients, water, oxygen, and pH, enabling faster growth and often higher yields in controlled environments.

History: Modern hydroponics developed in the 20th century, with early work by William Gericke in the 1930s and later growth in greenhouse production. The technique has since expanded with urban farming and research, and continues to be adapted for spaceflight and resource-limited settings.

Mechanism: Nutrient solutions supply macronutrients and micronutrients. Systems may be open or closed, draining or recirculating. Core components include a reservoir, a pump or air delivery, channels or beds, and a growing area. pH and electrical conductivity are routinely monitored; most crops prefer a pH roughly between 5.5 and 6.5, depending on species.

Common methods: Deep water culture holds plant roots directly in aerated solution; nutrient film technique runs a thin film of solution over roots; drip systems deliver nutrient solution through emitters; ebb-and-flow systems periodically flood and drain the root zone. Related approaches such as aeroponics use nutrient mist.

Advantages and challenges: Benefits include water-use efficiency, year-round production, and precise control; drawbacks include higher setup costs, reliance on electricity and equipment, and management of nutrients and pests.

Applications: Used in commercial greenhouses, urban farms, research facilities, and educational settings.