Hydroponics is a method of growing plants in a nutrient solution without soil. The plants, which are usually grown in shallow trays, are supported by an inert growing medium such as gravel, mineral wool, or perlite. Greenhouse is an ideal place for hydroponic gardening.
Temperature and humidity can be maintained in the growing range that is best for plants, creating a nearly perfect environment.
Hydroponic gardens can be located almost anywhere, as long as there’s electricity to run the equipment. The trays take up little space. And since nutrients are delivered to the roots, rather than the roots ranging through the soil to find nutriment, less space is needed for a hydroponic garden than a conventional garden.
A few basic pieces of equipment are necessary to start your hydroponic garden: trays, growing medium, pipes, valves, and a storage tank for the solution. To have an automatic system, you’ll also need a pump and a timer. The equipment can be purchased a s a kit; instructions are generally included. Once the equipment is set up, you’re ready to plant. Almost any plant that can be cultivated can be grown hydroponically — vegetables, annuals, and even bulbs. There are 3 methods for getting plants started in a hydroponic garden — planting seeds directly in the medium, starting seeds in compressed peat pellets, and buying nursery seedlings.
It is best to use just plain water (without nutrients) in your grow tray until the plants established and growing. Then, introduce the nutrient solution gradually so plants won’t be shocked. The solution should be circulated through the grow tank twice a day — NEVER at night and preferably not during the hottest part of the day, because plants can’t use nutrients efficiently at these times. After the tank is filled, the solution slowly drains back into the storage tank, allowing the roots to breathe again.
Some of the reasons why hydroponics
is being adapted around the world for food production are the following:
• No soil is needed for hydroponics. The water stays in the system and can be reused - thus, a lower water requirement.
• It is possible to control the nutrition levels in their entirety - thus, lower nutrition requirements.
• No nutrition pollution is released into the environment because of the controlled system.
• Stable and high yields.
• Pests and diseases are easier to get rid of than in soil because of the container's mobility.
• Ease of harvesting
• No pesticide damage
• Plants grow healthier
• It is better for consumption
Aquaponics, is a food production system that combines conventional aquaculture, (raising aquatic animals such as snails, fish, crayfish or prawns in tanks), with hydroponics (cultivating plants in water) in a symbioticenvironment.
In normal aquaculture, excretions from the animals being raised can accumulate in the water, increasing toxicity. In an aquaponic system, water from an aquaculture system is fed to a hydroponic system where the by-productsare broken down by nitrogen-fixing bacteria into nitrates and nitrites, which are utilized by the plants as nutrients.
The water is then recirculated back to the aquaculture system.
Aquaponics has ancient roots, although there is some debate on its first occurrence:
•Aztec cultivated agricultural islands known as chinampas in a system considered by some to be the first form of aquaponics for agricultural use where plants were raised on stationary (and sometime movable) islands in lake shallows and waste materials dredged from the Chinampa canals and surrounding cities were used to manually irrigate the plants.
•South China and Thailand who cultivated and farmed rice in paddy fields in combination with fish are cited as examples of early aquaponics systems.
Thesepolycultural farming systems existed in many Far Eastern countries and raised fish such as the oriental loach, swamp eel, Common and crucian carp as well as pond snails in the paddies.
Aquaponics consists of two main parts, with the aquaculture part for raising aquatic animals and the hydroponics part for growing plants.
Aquatic effluents, resulting from uneaten feed or raising animals like fish, accumulate in water due to the closed-system recirculation of most aquaculture systems.
The effluent-rich water becomes toxic to the aquatic animal in high concentrations but these effluents are nutrients essential for plant growth.
Although consisting primarily of these two parts, aquaponics systems are usually grouped into several components or subsystems responsible for the effective removal of solid wastes, for adding bases to neutralize acids, or for maintaining water oxygenation.
are grown as in hydroponics systems, with their roots immersed in the nutrient-rich effluent water.
This enables them to filter out the ammonia that is toxic to the aquatic animals, or its metabolites.
After the water has passed through the hydroponic subsystem, it is cleaned and oxygenated, and can return to the aquaculture vessels.
This cycle is continuous.
Common aquaponic applications of hydroponic systems include:
• Deep-water raft aquaponics: styrofoam rafts floating in a relatively deep aquaculture basin in troughs.
• Recirculating aquaponics: solid media such as gravel or clay beads, held in a container that is flooded with water from the aquaculture. This type of aquaponics is also known as closed-loop aquaponics.
• Reciprocating aquaponics: solid media in a container that is alternately flooded and drained utilizing different types of siphon drains. This type of aquaponics is also known as flood-and-drain aquaponics or ebb-and-flow aquaponics.
• Other systems use towers that are trickle-fed from the top, nutrient film technique channels, horizontal PVC pipes with holes for the pots, plastic barrels cut in half with gravel or rafts in them. Each approach has its own benefits.
Most green leaf vegetables grow well in the hydroponic subsystem, although most profitable are varieties of chinese cabbage,lettuce, basil, roses, tomatoes, okra, cantaloupe and bell peppers.
Other species of vegetables that grow well in an aquaponic system include beans, peas, kohlrabi, watercress, taro, radishes, strawberries, melons, onions, turnips, parsnips,sweet potato and herbs.
Since plants at different growth stages require different amounts of minerals and nutrients, plant harvesting is staggered with seedings growing at the same time as mature plants.
This ensures stable nutrient content in the water because of continuous symbiotic cleansing of toxins from the water.