Hydroponics is the growing of plants without the use of a traditional substrate such as soil, in which the required nutrients are usually contained. Instead, a specific nutrient solution is added, enabling rapid growth and increased efficiency. Because the nutrient solution is more readily available, plants require a smaller root network and consequently are able to use more energy for growth.
Like aquaponics, you will theoretically be successful growing just about any plants using hydroponics. However, as is the case with most gardening some will perform better than others. Fruiting crops such as lettuces, tomatoes or even strawberries are examples that do very well.
Like aquaponics, hydroponics is based on soil-less plant growing to produce a more sustainable and efficient loop system.
A huge advantage of hydroponics is space efficiency, making it an ideal candidate for urban and indoor farming as well as polytunnels and greenhouses.
- zero risk of food contamination e.g. from heavy metals
- little or no need for pesticides
- reduced pollution resulting from run-off
- year round production
- space efficiency is increased between three and tenfold!
Like aquaponics 60% less space is required than soil production and 75% less energy is required than traditional mechanical farming.
- Wick – A passive system in which the solution containing nutrients are drawn into a grow substrate e.g. coconut Fibre from a reservoir
- Deep water culture – A floating raft structure e.g. polystyrene is placed on top of a nutrient rich reservoir, into which the crop is planted
- Flood and drain – Usually used in conjunction with a media bed, a timer floods and then allows the bed to drain. This flow allows nutrient exchange in times of flood and oxygen exchange as the bed drains
- Drip system – A submersible pump located in a reservoir pumps nutrient solution directly onto the base of the plant, this can then be recovered and re-used for increased efficiency
- Aeroponics – Where nutrient-rich water is sprayed directly onto the root structure of the plants. This allows the required nutrient uptake as well as extremely efficient oxygen exchange through the root networks (not usually used in aquaponics due to presence of solid waste)
- Kratky – A passive system where plants are suspended above a nutrient reservoir. Although not considered a “best example” of permaculture good practices in an ideal environment (due to the requirement for often in-organic nutrient input).
Hydroponics does provide a space efficient solution to home food growing and therefore is a valuable tool in increased food sustainability in urban environments.
Like fungiculture, hydroponics has been practiced since before official records began. However, the concept as we recognise it today has slowly developed since the middle ages and was even described by Leonardo Da Vinci in the 15th century! The term hydroponics originates from the Greek hydros (water) and ponos (work).