CHAPTER 1 INTRODUCTION
Desertification is the process of soil degradation in arid and semi-arid areas and caused by human and climatic activities (European Environment Agency, 2013). As a result of this areas like Bucharest, the capital city of Romania have been forced to take up irrigation in order to present constant water supply for their crops. Irrigation is the artificial supply of water to farm crops and livestock. Irrigation for agriculture consumes 70% of the global water supply (Abdul-Rahman et al., 2011). Procedures of applying water to the soil are various, such as drip irrigation, which makes use of tubes or stripes for watering plants (irrigation). With drip irrigation, the water coming out of the tubes or strips is dispensed in little drops, directly into the roots of the plants.
Aside from drip irrigation, scientists and agricultural specialists are working on new techniques to improve crop production by using less water and conserving aquatic organisms. One such technique is using water from fish ponds.
Fish farming is a type of aquaculture, which is the farming of fishes under controlled conditions (Helfrich & Libey, 1991). Approximately 46,000 fish ponds produce 1.1 Gg of fish every year in Africa (Meso et al., 2004). During the harvesting process, the fish ponds are drained, leading to the discharge of fish waste. Before the invention of aquaponics (the combination of aquaculture and hydroponics), the fish wastes are poured on the soil and were allowed to flow into the waterways from the
soil; since the fish waste is nutrient-rich those that remain makes the soil become nutritious.
Aquaculture is a sector of agriculture that is growing rapidly all over the world because of the demand for fish as food and other uses. Aquaculture includes the farming of finfishes, mollusks, crustaceans, amphibians (frogs), aquatic reptiles (except crocodiles), and other aquatic animals, such as sea urchins, sea squirts, and jellyfishes (Boison & Turnipseed, 2015). Aquaculture farmers are restricted to the farming of newly hatched, algae and also aquatic items needed for fashion and cosmetic, like shell buttons and pearls. The United Nations’ Food and Agricultural Organization defines aquaculture as the farming of aquatic organisms including fish, molluscs, crustaceans, and aquatic plants (Boison & Turnipseed, 2015). Historically, the water used for fish farming in aquaculture was disposed of, but this has changed in recent years, as fish pond water has been shown to be potentially beneficial to plant growth. Aquaculture depends on the constant supply of freshwater from rivers and other water sources, but discharging waste water from the fish pond to the freshwater sources degrades water quality of the source and may also affect the fishes reared in the aquaculture system (Trang & Brix, 2014). Fish ponds have begun to serve as reservoir for the irrigation of plants because the effluent of fishes deposited in the water is important for the growth of plants (Fernando & Halwart, 2000). As a result, integrating aquaculture and hydroponics (planting of crops in water and not soil) has become popular globally.
Around the 80s and 90s, the urban style of agriculture has experienced an explosion in terms of creativity and innovation. Living in the city where education, nightlife,
and culture have become the day to day worries of the various individuals. With all the creativity and innovations, scientists came up with ways to access fresh food without importing from other places. Scientists came up with a technique which involves the integration of aquaculture and hydroponics is the best way to do it.
However, the process of integrating aquaculture and hydroponics gives rise to aquaponics.
Aquaponics
Aquaponics combines aquaculture and hydroponics. Hydroponics is the process of planting crops in nutrient-rich water rather than in soil. It was developed during the 1980s became more popular in subsequent years (Elia, Popa, & Nicolae, 2014). As a result, others scientist are now researching about, developing, and diversifying the method. The combination of the two methods is known as a close-loop food production system, which results in little or no waste. The close-loop means that the waste obtained from one method becomes the nutrients, or input, for the other method. This is possible because aquaponics takes advantage of the natural nitrification process that is carried out by bacteria (Nicolae et al., 2015). Basically, in aquaponics, the waste obtainedfrom fish water in aquaculture serves as fertilizer for plants that are grown in hydroponics.
