In two recent blogs, we\u2019ve explored how the climate in southern Africa is expected to change in the coming century and the ecological pros and cons of fish farming. The two are somewhat connected. Due to droughts becoming more frequent our water supply is expected to drop significantly, which will have a huge impact on our food supply. Aquaponics \u2013 the combination of aquaculture (fish farming) with hydroponics \u2013 offers a glimmer of hope. Farmers around the world in countries such as Australia, Costa Rica, Netherlands, Uganda, Namibia and USA have embraced aquaponics as a viable solution to our broken food chain and changing climate.
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Waste from fish ponds is collected and run through a biological filter, which turns the waste into a form of plant fertilizer. The plants absorb the nutrients, after which the now clean water returns to the fish. So it\u2019s a closed-loop system that feeds itself (mostly) and allows for the year-round production of protein and vegetables. Fancy, right?<\/p>\n\n\n\n
1. It can use up to 90% less water than normal agriculture.<\/strong><\/p>\n\n\n\n \u2018The largest loss of water in agriculture is through infiltration, water percolating into the ground that\u2019s not used by the plants\u2019 roots,\u2019 says Martin Niwinski, an aquaponics technician. \u2018This isn\u2019t the case with aquaponics because 95% of the water is reused. The closed-loop system recycles the water so it\u2019s particularly useful during a drought \u2013 the only losses that you should have are evaporative losses.<\/p>\n\n\n\n <\/p>\n\n\n\n 2. Pesticides can be avoided<\/strong><\/p>\n\n\n\n Some aquaponics farmers do use pesticides but the systems can be set up to avoid them. <\/p>\n\n\n\n <\/p>\n\n\n\n 3. It\u2019s top of the crops<\/strong><\/p>\n\n\n\n According to Niwinski, since nutrients are constantly available to plants\u2019 roots, plants can grow up to 25 percent faster than in soil, the produce is amazing and many of the plants that thrive in aquaponics are very easy to cultivate. Systems grow greens such as lettuces, watercress, sorrel, celery, fennel, and bok choy. And, of course, fish can be harvested as an additional food or revenue source.<\/p>\n\n\n\n <\/p>\n\n\n\n 4. Urban environments <\/p>\n\n\n\n One wonders what this could mean for townships in South Africa where there\u2019s a lack of arable land and a low number of entrepreneurial ventures. Could aquaponics be a possible solution to both these issues?<\/p>\n\n\n\n Starting an aquaponics project has a higher initial cost than other production methods, such as home gardens. Giving an exact figure is difficult as it depends on the size of the system and its technological level. Keep in mind that pumps and plumbing items are required.<\/p>\n\n\n\n 2. It requires large amounts of electricity (well that\u2019s an Eskom-shaped curveball) <\/strong><\/p>\n\n\n\n Aquaponics uses significantly more energy than conventional agriculture in terms of heating, cooling and supplemental lighting systems. Niwinski reports that the highest daily costs at his centre are from heating the fish pond to accommodate warm water for the tilapia, one of the most commonly used fish in aquaponics. <\/p>\n\n\n\n A local expert, Oliver Dawson, maintains that it depends very much on how you build the system. \u2018Aquaponics is about moving water. If you set your system up cleverly, you won\u2019t need to pump the water too far and you can cut down on your electricity fees.\u2019<\/p>\n\n\n\n 3<\/strong>. Things can get complicated<\/strong><\/p>\n\n\n\n Aquaponics is relatively more complex than other production systems as you need to have a simultaneous understanding of two different agricultural ecosystems; morphological and physiological. Basically, this means there are more chances for the system to fail. <\/p>\n\n\n\n Another challenge facing agriculture is the need for well-trained, knowledgeable farmers. To successfully master aquaponics\u2019 symbiotic system, Niwinski has been training and studying for four years and he still has much to learn. <\/p>\n\n\n\n 4. The cost of fish food<\/strong><\/p>\n\n\n\n The cost of food for the fish has the potential to make the system economically unsustainable. It can become the most expensive factor in the entire system. <\/p>\n\n\n\n 5. It demands 24\/7 care<\/strong><\/p>\n\n\n\n If you take your eye off the system for a weekend, the pump can break or the pipes can get clogged and you arrive home to a broken, irreparable system. <\/p>\n\n\n\n <\/p>\n\n\n\n Farmers in Uganda have been spurred into shifting their farming methods due to changes in rainfall, temperature and other patterns in weather. The Water Governance Institute<\/a>, a Ugandan NGO that has been looking into a number of ways to improve agricultural efficiency in the face of these climate challenges, has found that aquaponics is one of the most promising options. <\/p>\n\n\n\n Farmers in the Adjumani district of northern Uganda started adopting aquaponics due to the high market demand for both fish and crops in the area. The introduction of aquaponics has improved child nutrition, food security, land quality and family cash access. Despite the success stories, there have been many challenges. Continuous production means a farmer needs greater access to seedlings, fish feeds, fingerlings, water and knowledge about how to maintain and market the produce. <\/p>\n\n\n\n <\/p>\n\n\n\n
<\/strong>Entrepreneurs in Europe see aquaponics\u2019 potential as most useful in dense urban environments. They believe it can reduce food transportation costs and provide more equitable access to healthy food. The systems can be built vertically, horizontally or stacked on top of one another \u2013 with some farmers reporting growing six times more per square foot than traditional farming. <\/p>\n\n\n\nThat\u2019s unlikely at this stage, as there are also SOME DISTINCT DISADVANTAGES <\/strong>TO AQUAPONICS:<\/h2>\n\n\n\n
But wait! Don\u2019t be put off just yet, there are a growing number of success stories worldwide…<\/strong><\/h2>\n\n\n\n
It\u2019s helped in drought-ravaged Uganda
<\/strong><\/h2>\n\n\n\nSolar Aquaponics Greenhouses<\/strong><\/h2>\n\n\n\n