Aquaponics: Farming for the future
Aquaponics — a combination of aquaculture and hydroponics — produces more food with less water than traditional agriculture, and requires far less land. But the hi-tech operation doesn’t come cheap
Just outside Pretoria, a 1ha farm is producing 5t of fish using just 1% of the fresh water a traditional farming operation would need. And it’s growing vegetables, using the ammonia-rich water from the fish tanks for irrigation, then distilling the run-off and piping it back to the fish tanks in a never-ending cycle.
It’s a sophisticated operation, with technology that allows sensors to be activated remotely to monitor the fish and plants, turn water pumps on and off, and alert farmworkers if the fish are in danger or distress.
"It’s a completely self-sustainable turnkey model," says Leon van Deventer, agricultural engineer at technology company Matsei, which runs the pilot farm alongside Swedish enterprise software company IFS. "You can put it in the middle of the desert because all you need is solar energy and satellite communication to monitor sensors on the plants and fish tanks, and you use so little water."
It may be difficult to get one’s head around the idea of farming in a desert, but Sundrop Farms has proved it’s possible in south Australia. Since 2016 the company has been producing 17,000t of tomatoes a year using just sunlight and seawater.
While Sundrop’s system involves hydroponics — growing plants using a nutrient-rich, water-based solution rather than soil — IFS and Matsei are using aquaponics. A hi-tech version, at that.
Aquaponics brings together conventional aquaculture, such as raising fish in tanks, and hydroponics. Popular with missions and government aid initiatives, it produces more food using less water than traditional agriculture. And it uses just 1% of the land to produce the same amount of protein as a herd of cattle. Aquaponics farmers source fingerlings — juveniles of resilient species such as catfish — and feed them in a controlled environment until they reach the right weight for consumption.
"You can put it in the middle of the desert because all you need is solar energy, and satellite communicationLeon van Deventer
Despite its efficiencies, it hasn’t gained traction in SA — just a few farmers are doing it, and then on a small scale. Van Deventer believes this is because aquaponics needs the entire production ecosystem — farming, processing, storage and transportation — to be in place in the community where the farm is.
However, agricultural economist Wandile Sihlobo says the issue is one of cost: because there’s ample open land still available for growing produce in SA, the cost of aquaponics counts against it. "If competition for land toughened, you would see aquaponics take off," he says.
Sihlobo believes concerns around climate change — and resultant concerns around food security — will drive the adoption of new agricultural methods, including aquaponics. "But the cost has to come down first, and I expect that it will in coming years."
Food security is at the heart of the IFS/Matsei project. The joint venture will focus specifically on rural communities, with the aim of promoting sustainable food production in poor communities, while offering a cheaper source of protein.
"It’s easy for communities in Africa to cultivate starch such as maize," says Van Deventer. "The problem lies in getting meat-based protein, and we know red meat is costly for many, even the middle class."
There is a business motive as well. While the smallest farm is expected to produce 40t of fish a year once it’s up and running, the largest will produce 160t. At this scale, there will be excess supply that can be sold in nearby urban areas. The companies also plan to export their product: they estimate that a 160t farm will export most of its product, adding to the 103,457t of fish and aquatic invertebrates SA exports a year, according to 2016 figures from the department of agriculture, forestry & fisheries. It’s a R6.4bn market, with take-up in Italy, Spain, China and Hong Kong.
What it means
A pilot project which focuses on rural communities offers a solution to the food security issue
Then there’s the employment angle. The companies estimate that a 40t operation will create 120 jobs through the value chain, while operations on large farms could create about 400, ranging from low-level farm work to jobs for engineers and electricians.
The plan is for farms to be set up on tribal and communal land — mostly in Mpumalanga — so that the communities will own the operations, while IFS and Matsei will retain a stake in return for the infrastructure. They will also manage the regional depots, certify the fish and fresh produce, and bulk-buy inputs for the farms.
It is probably the safest way to enter the agriculture industry in SA, given fears around how expropriation of land without compensation might affect farming operations. Though President Cyril Ramaphosa has stressed that food production will not be compromised by expropriation, farming organisations such as Grain SA believe the opposite.
For Matsei director Bertus van Niekerk, however, the aquaponics joint venture offers the perfect solution to the food security issue because of how little land it requires, and the fact that the companies are targeting community-owned and mining land — land that would fall outside the scope of expropriation.