Soilless

Soilless refers to crop production systems that do not rely on soil as the primary growing medium. In soilless cultivation, plants receive water, nutrients, and support through inert or semi-inert substrates and carefully controlled nutrient solutions. The approach is widely used in horticulture and urban farming to optimize resource use and environmental control.

Hydroponics is the most common form, where plant roots access a nutrient solution directly. Subsystems include nutrient film technique (NFT), vertical towers, drip systems, and ebb-and-flow benches. Substrates may be inert media such as rockwool, perlite, vermiculite, coconut coir, or clay pellets. Aeroponics suspends roots in air and applies a fine mist, reducing media needs further. Aquaponics merges hydroponics with aquaculture, using fish waste to supply nutrients while maintaining water quality.

Advantages include efficient water use, increased control over nutrition, higher yields, and the ability to grow in places with poor or contaminated soil. Challenges include higher capital and energy costs, reliance on pumps and sensors, disease or nutrient imbalance propagation in circulating systems, salt accumulation in some media, and disposal concerns for used substrates.

Modern soilless methods emerged in the 20th century with advances in hydroponics; they are common in greenhouses for vegetables, herbs, and ornamentals, and are used in research and space or disaster-area projects.

While efficient in water use and land, the environmental footprint depends on energy sources and nutrient management. Proper design emphasizes closed-loop water and nutrient recovery to minimize waste.