In Okahandja, 70km north of Windhoek, Namibia’s newest aquaponics facility has just started supplying Freshmark’s Namibian DCs with all of their pillowpack and mixed lettuce requirements and other leafy greens for sale at Checkers stores across the country.
“When you look at aerial photos, you can see how dry Okahandja is,” explains Ryno Postma, a chartered accountant and commercial director of Oribi Aquaponics, a Namibian trust.
Aquaponics – like hydroponics – uses only 10% of the water employed in soil-based vegetable production and, therefore, is a no-brainer for a place like central Namibia, Ryno maintains.
Natural hedge keeps it green
The recirculating system was supplied by Justin Hess of Ichthys Aquaponics, the largest aquaponics system supplier in Africa with projects on many continents.
Right: Red 6 Mozambique tilapia.
Ryno credits Colin Bremner of Kleinskuur Aquaponics for clarifying the principles when Ryno and his cousin Heindré van Zyl started investigating the concept: fish excrete nutrients that are made available to plants, which, in turn, purify the water.
“You produce crops with no chemical fertilizers or pesticides. If you use chemical pesticides, your fish will die. That is a natural hedge in your aquaponics system to ensure that you deliver quality produce that is safe for human consumption.”
Apart from the salad ranges grown by Oribi Aquaponics grows, Ryno says they’d like to do baby cabbage as well as expand their herb selection.
The facility will consist of six modular and independent units by next year (Vegtech’s OptiGrow greenhouse structure with aluminium shade screens). Phase 1a comprises three modular units in which a newly installed misting unit has remarkably revived plants struggling in the harsh afternoon sun. “The heat is terrible,” Ryno remarks.
Another aspect that sets Oribi apart from other production units in Namibia, he says, is its high-care facility, where leaves are washed, dried, placed into pillow packs with modified atmosphere packaging (MAP), and kept cool.
Fundraising for seedling facility & fish hatchery
Oribi is currently fundraising for the remainder of the aquaponics production system, which will include a rainwater catchment on the greenhouse roof (they’re aiming to eventually move from borehole-dependent to being rainfed), a plant seedling facility and a fish hatchery.
They use the Red 6 Mozambique tilapia bred by the well-regarded Rivendell Hatchery in the Eastern Cape, which they also plan to multiply in their own hatchery.
“Namibia is extremely strict on the fish species one may use. Mozambique tilapia is an indigenous species, which made it the logical choice that authorities would approve. In the future, we want to add trout to deliver as fish protein to formal and semi-formal markets.”
Their water temperature, always maintained between 19 and 22°C, is ideal for trout; the Mozambique tilapia excels in higher temperatures, but the Red 6 strain is more cold-resistant than its wild African cousins.
Ryno considers the cool water temperatures, plus now the misting system, as key to pulling plants through the hot Namibian days. Water is cooled by dropping two meters in vertical towers. Reversible heat pumps help and could, conversely, heat up the water in winter.
Photovoltaic cells will be placed on the high care facility’s roof – a solar energy company is a shareholder in the Oribi Aquaponics Namibia Trust – but not to save power in batteries; their large number and diversity of pumps render that unaffordably expensive.
“Our cost per kilowatt [of solar power] would be almost double what we’re currently paying,” he notes; they are on the Namibian national electricity grid.
Attention to the numbers
Ryno recounts that together with his cousin Heindré van Zyl, who has a background in engineering and filmmaking, they were looking for opportunities where they could feel they were making a positive and tangible contribution.
“We started investigating aquaponics, which is an organic process. It’s different from hydroponics, which is a chemical process. We like that it’s a natural ecosystem.”
Synergy is created through their service level agreement with mushroom grower Jan Conradie of Agricon Mushrooms in Okahandja, with whom they share administrative resources, cooled transport, and storage facility.
Ryno points out that the beguilingly simple process of aquaponics has tended to attract hobbyists with a technical bent, often people less interested in how the business end would look.
Hydroponics, on the other hand, tends to draw more “business-savvy” people, he observes.
“Most people don’t pay enough attention to the business side of aquaponics, while I think that’s most important. To succeed, the same energy needs to go into the business side of things, like finding an offtake, as into the technical side of it.”
Investments flowing into Namibia
Namibia attracts among the most foreign direct investment in Africa at the moment. The government’s stability and commitment to agriculture work in its favour.
“We’re active in other crops with an eye on follow-up projects. Namibia has a very large drive to reduce food imports and to promote local production,” he says.
The country closes its borders to imports (primarily from South Africa) at times to bolster local supply, but in this sellers’ market, affordability is sometimes sacrificed. Ryno emphasises Oribi Aquaponics Namibia Trust's intention to improve food affordability in Namibia.
“The end consumer and the general populace need to benefit from increased access to food if you want to make a difference.”
To do that, he sets forth, they intend to bring crops to areas that have long relied on imports and doing it at a fraction of the water cost of conventional cropping.
“It’s about providing produce where water is a problem and not shying away from environmental concerns.”
The aquaponics facility in the thornbush savannah of central Namibia (photos supplied by Oribi Aquaponics).
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