Opinion

Let’s Make Use of Our Fresh Water for Fish Farming

By Nicholas Lokuya Emmanuel

Aquaponics is a system of rearing fish and growing of plants whereby the waste produced by farmed fish or other aquatic creatures supplies the nutrients for plants which in turn purify the water. Aquaponics is a very lucrative business today that entrepreneurs and farmers should venture in. Farmers can be able to harvest fish and vegetables at the same time earning huge amount of money.

The cost of operation of aquaponics is much cheaper because the farmer only has to purchase feeds for the fish, the plants do not require fertilizers thus making it cost effective. Fish farming can also reduce over exploitation and extinction of valuable fish from our fresh water.

How the system works:

Fish are raised in a tank; water from the fish tank containing nitrogenous wastes is pumped to the plant’s growth bed that contains useful bacteria. The bacteria convert the wastes – ammonia and nitrite to nitrate which is required by the plants for growth and development. Plants absorb the nutrients from the water making the water less polluted and then the filtered water is returned to the fish tank clean.

South Sudan is one of the blessed countries in the world with good climate, fresh water bodies like River Nile and its tributaries, swamps, streams among others all this gives South Sudan an absolute advantage to venture into aquaponics so that we can be able to feed ourselves and export to feed the rest of the world earning us huge foreign income for development.

The main components of an aquaponic system include; a fish tank, plant grow bed, water pump, air pump, irrigation tubing, biofilter, fish and plants. The system includes bacteria which convert the toxic ammonia-rich waste, nitrites and the suspended solid waste into useful nitrates that can be easily utilized by plants.  A biofilter provides addition surface area for the beneficial bacterial to work and live in while the water pump is required for pumping the nutrient-rich water from the fish tank to the growth bed for the plants to absorb and remove excessive bio-nutrients. Nile tilapia and African cat fish are the best fish for aquaponics in South Sudan because they are warm water fish and are therefore suitable for environments with high temperatures like Juba. The system also requires a media (a piece of mattress) to fill in the growth bed.  The objective of the media is to provide good root support to the plants and increase the surface area on which the beneficial bacteria cling to and live, and the most commonly used media are expanded clay pellets, gravel (smooth river stones) and a piece of mattress.

The type of plants that can perform well in an aquaponics system in South Sudan  include; most varieties of lettuce, most varieties of herbs, tomatoes, maize, yams, sukuma-wiki, beans, dodo, cucumber, cabbage,  squash, peppers, broccoli, melons, and strawberries. However, the density of the plants must increase with the density of fish. Increased density of fish means an increased amount of wastes and thus increased nutrients for plants.

There are three major types of the aquaponic system which include; the Media Beds that consists of garden beds filled with small porous rocks – typically clay pellets or gravel – into which the vegetables are planted; the Nutrient Film Technique which involves sitting a series of pipes adjacent to the fish tank and pumping the nutrient rich water through them as a very thin film; and the Deep Water Culture system which involves sitting the plants on rafts through which their roots protrude and hang in the nutrient-rich water from the fish tank. A farmer has a choice of which system to employ basing his/ her capabilities and resources.  It doesn’t matter of the how far the farmer is from the main water source but rather his ability to embrace improves scientific technologies for high production and productivity at a reduced cost.

 

The writer is an Agriculturist and can be reached through: 0924648973, Email: lokuyanicholas19@gmail.com

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