Benefits of a closed-loop system paying off for RuLIV’s Food Garden
23 March 2016
Awhile ago RuLIV decided to try their hand at farming tilapia fish and using the fish waste to irrigate the food garden.
As the season changes gear late in March 2016, some 1 500 tiny fingerlings are approaching adulthood and constantly race around the 30 000 litre pond in almost perfect fish formation.
Vincent Heathcote who is responsible for RuLIV’s agroecological garden and fish operation explained that the whole system is run on harvested rainwater from surrounding rooftops and is thus totally sustainable.
“All our indicators are telling us we are doing the right thing, our water temperature has been constant with no artificial heating and the water quality is regularly tested and proved good.”
Once a month the fish waste which settles at the bottom of the extensive multi-tank system is pumped into a holding tank and tapped off to irrigate the garden beds in RuLIV’s back yard.
“Our garden is a closed-loop system, meaning nothing gets wasted. The fish waste which looks like a kind of greenish sludge is full of beneficial bacteria and living organisms which feed and enrich the soil and ultimately benefits the growing fruit and vegetables,” says Heathcote.
There are two filtration systems, a mechanical one using stones and a biofiltration system which converts the ammonia in the fish waste into nitrates through nitrification, explains Heathcote.
“Our pH levels are good and our quality testing shows very low ammonia levels, so we are pleased with the outcome.”
The next hurdle is to look at ways to power the fish pond sustainably as power outages play havoc with the system and there are also cost considerations as electricity becomes more expensive.
“Luckily we haven’t had power outages for a quite a long while, but a solar powered system would be the way to go ideally,” adds Heathcote.
As the current batch of tilapia are nearing adulthood, the plan is to harvest them around November this year.
“Some locals have expressed an interest,” says Heathcote, “but we’re not a commercial operation yet so we will probably harvest and use this first batch ourselves.”
RuLIV food garden bearing fruit
RuLIV’s food garden is bearing fruit with our first harvest of bananas ripening and our tilapia fish coming along nicely.
Winter plantings in the garden will include: beetroot, carrots, celery, cabbage, lettuces, peas, runner beans, spinach or swiss chard. Please note chillies and herbs tend to die back in winter.
Not only was the RuLIV food garden featured in an article in the Saturday Dispatch on 20 June 2015 but garden manager, Vincent Heathcote also hosted East London’s Green Living Group together with some representatives from the community food garden at the city’s IDZ in the afternoon.
Members of the group were impressed with the garden with many expressing amazement that this large urban ‘agter plot’ had previously been one big car park. Now it’s full of vegetables growing in raised beds together with areas for making compost and an active worm farm. Bananas, avocado pears, citrus and kei apples are also planted on the boundaries.
The RuLIV garden grew out of RuLIV’s concerns around widespread malnutrition in southern Africa and the wider world. Malnutrition in Africa results in more deaths than from TB, Malaria and HIV combined and poverty in South African urban areas is critically high with one in three people being nutritionally insecure.
RuLIV takes the position that urban green spaces should be productive, to address nutrition needs and add to the basket of community’s livelihood opportunities.
As part of this ethos, RuLIV has established an agro-ecological-based food garden at its premises in Southernwood, East London. This followed an earlier study tour to Cuba in which RuLIV and community representatives visited Cuban urban agriculture projects and co-operatives.
This Cuba inspired learning and research and development site will be of particular value to impoverished urban communities, surrounding schools and Government institutions, in showing the mechanics of a ‘closed’ food production system (i.e. a system which feeds itself and you don’t have to buy in expensive inputs).
Moreover, it will show surrounding communities, the various aspects necessary to achieve a ‘closed’ food production system, through exposure, knowledge exchange, formal on-site training and extension mentoring. In addition, the site will make competitively priced organic produce available to the historically indigent white population and large youth student community of the area.
Over the next few months we will bring you more news on the garden and its produce together with tips, features about the people working in the garden and what we are learning.
We are also working on updating and revamping our Facebook page so we can bring you updates on a more regular basis.
For more information regarding the garden and what produce is available, contact Vincent on firstname.lastname@example.org