PLANT PRODUCTION IN HYDROPONIC COMPONENT

Many types of vegetables have been grown in aquaponic system. However, the goal is to culture a vegetable that will generate the highest level of income per unit area per unit time. With this criterion, culinary herbs are the best choice. They grow very rapidly and command high market prices. The income from herbs such as basil, cilantro, chives, parsley, portulaca and mint is much higher than that from fruiting crops such as tomatoes, cucumbers, eggplant and okra. Traditional medicine plants and plants used for extraction of modern pharmaceuticals have not been cultivated in aquaponic systems, but there may be potential for growing some of these plants.

Pesticide should not be used to control insect on aquaponic plant crops. Even pesticides that are registered would pose a threat to fish and would not be permitted in a fish culture system.Similarly, therapeutants for threating fish parasites and disease should not be used because vegetables may absorb and concentrate them. The common practice of adding salt to treat fish diseases or reduce nitrite toxicity is detrimental to plant crops.Non chemical methodes of integrated pest management must be used. These include biological control (resistant cultivars, predators, pathogens and antagonist organism), physical barriers, traps, and manipulation of the physical environtment. There are more opportunities to use biological control methode in enclosed greenhouse environtments than in exterior installations. Parasitic wasps and ladybugs can use to control white flies and aphids.The prohibition on the use of pesticides makes crop production in aquaponic systems more difficult. However, this restriction ensures that crops from aquaponic system will be raised in an enviromentally sound manner and be free of pesticide residues. A major advantage of aquaponic systems is that crops are less susceptible to attack from soilborne diseases. Plants grown in aquaponic systems may be more resistant to diseases to that affect plants grown in standard hydroponic. This esistance may be due to the presence of some organic matter in the culture water that creates a stable growing environtment with a wide diversity of microorganisms, some of which may be antagonistic to plant root pathogens.

 

 

 

 

Iklan

FISH PRODUCTION IN RAS (RECIRCULATING AQUACULTURE SYSTEM) COMPONENT

Tilapia is the fish species most commonly cultured in aquaponic system. Although some aquaponic systems have used channel catfish, largemouth bass, crappies, rainbow trout, paccu, common carp, coi carp, goldfish (Carassius auratus),asian sea bass (barramundi) and murray cod, most commercial systems are used to raise  tilapia. Most fresh water species, which can tolerate crowding, will do well in aquaponic systems (including ornamental fish).

Goldfish are popular pond fish, since they are small , inexpensive, colorfull and very hardy. In an outdoorpond or water garden, they may even survive for brief periode of ice forms on the surface, as long as there is enough oxygen remaining in the water and the pond doesn’t freeze solid. Common goldfish, London and Bristol shubunkins, jikin, wakin, comet and some hardier fantail goldfish can be kept in a pond all year  round in temperate and subtropical clomates. Moor, veiltail, oranda and lionhead can be kept safely in outdoor ponds year round only in more tropical climates and only in summer elsewhere.

Koi are domestically common carp  (Cyprinus carpio) that are selected or culled for color, they are not a different species, and will revert to the original coloration within a few generations if allowed to breed freely. In general, goldfish tend to be smaller than koi, and have a greater variety body shapes and fin and tail configurations. Koi varieties tend to have common body shape, but they have greater variety of coloration and color patterns. They also have prominent barbels on the lip.

Some goldfish varieties, such as the common goldfish, comet goldfish, and shubunkin have body shapes and coloration  that are similar to koi and can be difficult to tell apart from koi when immature. Since goldfish and koi were developed from different species of carp, eventhough they can interbreed, their offspring is sterile. To recover high capital cost and operating expenses of aquaponic systems and earn a profit, both the fish rearing and the hydroponic vegetable components must be operated continuosly near maximum production capacity. The maximum biomass of fish a system can support without restricting fish growth is called the critical standing crop. Operating a system near its critical standing crop uses space efficiently, maximize production and reduces variation in the daily feed input to the system, an important factor in sizing the hydroponic component.

AQUAPONIC SYSTEM

Aquaponic system are recirculating aquaculture systems (RAS) that incorporate the production of plants without soil. Recirculating system are designed to raise large quantities of fish in relatively small volume of water by treating the water to remove toxic waste products and reusing the water many times. The accumulated metabolic by products, like non toxic nutrients and organic matter, need not be wasted if they are channeled into use as secondary crops, terrestrial plants grown in conjunction with fish. This integrated system is referred to as an aquaponic system. The goal is to culture as vegetable that will generate the highest level of income per unit area per unit time. Culinary herbs are the best choice.

In aquaponic systems plants grow rapidly with dissolved nutrients that are excreted directly by fish or generated from the microbial breakdown of fish wastes. In closed recirculating systems with very little daily water exchange, dissolved nutrients accumulate in concentrations similar to those in hydroponic nutrient solutions.

Dissolved nitrogen, in particular, can occur  at very high levels in recirculating systems.

  1. Fish excrete waste nitrogen, in the form of ammonia, directly into the water through their gills.
  2. Bacteria convert ammonia to nitrite and then to nitrate.

Ammonia and nitrite are toxic to fish, but nitrate relatively harmless  and is the preffered form of nitrogen for growing higher plants such as fruiting vegetables.

Aquaponic systems offer several benefits:

  1. Dissolved waste nutrients are recovered by the plants, reducing discharge to the environtment and extending water use (by removing dissolved nutrients through plant uptake, the water exchange rate can be reduced)
  2. Minimizing water exchange  reduces the costs of operating aquaponic systems in arid climates and heated greenhouses where water or heated water is a significant expense.
  3. Having a secondary plant crop that receives most of its required nutrients at no cost improves a system’s profit potential. The daily application of fish feed provides a steady supply of nutrients to plants and thereby elimates the need to discharge and replace depleted nutrient solution or adjust nutrient solutions as in hydrophonics.
  4. The plants remove nutrients from the culture water and eliminate the need for separate and expensive biofilters.
  5. Aquaphonic systems require substantially less water quality monitoring than separate hydrophonic or RAS.
  6. Savings are also realized by sharing operational and infrastructural cost such as pumps, reservoirs, heaters and alarm system.
  7. In addition, the intensive, integrated production of fish and plants require less land than ponds and gardens. Aquaponic system do require a large capital investment, moderate energy inputs and skilled management.
  8. Niche markets may be required for profitability

AQUAPONICS

In light of increasing populations and dwindling natural resources are playing a crucial role in ensuring people  understand and commit to more sustainable lifestyles. Climate change, growing pressures on global fisheries, and the harmfull effect in traditional agriculture methods exacerbate this call. Coupled with this emphasis is the need for career preparation that equips the next generation with 21st-century skills required to support sustainable practices.

Aquaponics is a symbiotic system that combines raising fish in tanks with cultivating plants in a recirculating ecosystem. Natural bacterial cycles convert fish waste into nutrients for the plants, and they in turn filter the water for the fish. Both large and small scale systems can impact our movement toward a more sustainable way of feeding the world’s population.

The themes of sustainability, ocean literacy, and ecological cycles are woven throughout the session as people employ 21st-century thingking and learning skills to address the following guiding question:

  1.  What the natural resources do fish and plants need to survive?
  2.  How can humans reduce their impacts on those resources?
  3.  How is sustainable agriculture important for the long term survival of humans?