Introduction to aquaponics
Hydroponics and soil-less culture
Soil-less culture is the method of growing agricultural crops without the use of soil. Instead of soil, various inert growing media, also called substrates, are used. These media provide plant support and moisture retention. Irrigation systems are integrated within these media, thereby introducing a nutrient solution to the plants’ root zones. This solution provides all of the necessary nutrients for plant growth. The most common method of soil-less culture is hydroponics, which includes growing plants either on a substrate or in an aqueous medium with bare roots.
· Food and Agriculture Organization of the United NationsCurrent applications of aquaponics
This final section briefly discusses some of the major applications of aquaponics seen around the world. This list is by no means exhaustive, but rather a small window into activities that are using the aquaponic concept. Appendix 6 includes further explanation as to where and in what contexts aquaponics is most applicable. Domestic/small-scale aquaponics Aquaponic units with a fish tank size of about 1 000 litres and growing space of about 3 m2 are considered small-scale, and are appropriate for domestic production for a family household (Figure 1.
· Food and Agriculture Organization of the United NationsAquaponics
Aquaponics is the integration of recirculating aquaculture and hydroponics in one production system. In an aquaponic unit, water from the fish tank cycles through filters, plant grow beds and then back to the fish (Figure 1.5). In the filters, the fish wastes is removed from the water, first using a mechanical filter that removes the solid waste and then through a biofilter that processes the dissolved wastes. The biofilter provides a location for bacteria to convert ammonia, which is toxic for fish, into nitrate, a more accessible nutrient for plants.
· Food and Agriculture Organization of the United NationsAquaculture
Aquaculture is the captive rearing and production of fish and other aquatic animal and plant species under controlled conditions. Many aquatic species have been cultured, especially fish, crustaceans and molluscs and aquatic plants and algae. Aquaculture production methods have been developed in various regions of the world, and have thus been adapted to the specific environmental and climatic conditions in those regions. The four major categories of aquaculture include open water systems (e.
· Food and Agriculture Organization of the United NationsApplicability of aquaponics
Aquaponics combines two of the most productive systems in their respective fields. Recirculating aquaculture systems and hydroponics have experienced widespread expansion in the world not only for their higher yields, but also for their better use of land and water, simpler methods of pollution control, improved management of productive factors, their higher quality of products and greater food safety (Box 1). However, aquaponics can be overly complicated and expensive, and requires consistent access to some inputs.
· Food and Agriculture Organization of the United NationsA brief history of modern aquaponic technology
The concept of using faecal waste and overall excrements from fish to fertilize plants has existed for millennia, with early civilizations in both Asia and South America applying this method. Through the pioneering work of the New Alchemy Institute and other North American and European academic institutions in the late 1970s, and further research in the following decades, this basic form of aquaponics evolved into the modern food production systems of today.
· Food and Agriculture Organization of the United Nations