Recycled shipping containers have been used for many things in their second life, from swimming pools and restaurants to classrooms and emergency hospitals. Now, with a global population hurtling towards almost 10 billion people by 2050, they may also be the farms of the future.
Founded by Francisco Caffarena and Michael Harder in 2016, Sprout Stack is Australia's only commercial vertical farm. The Brookvale-based start-up utilises shipping containers to grow greens for independent grocers using methods more productive than traditional farming, says chief executive Hugh McGilligan.
"Vertical farming is also called controlled environment agriculture," he says. "Lighting in the containers is designed to optimise plant growth in vertical stacks, and we have sensors constantly measuring temperature, humidity and carbon dioxide levels which can be adjusted as needed. Because there's no birds, pests or fungus, we don't need to use herbicides or pesticides either."
Instead of soil, Sprout Stack uses the husk byproduct of commercial coconut production to hydroponically grow salad greens such as lettuce, kale, mizuna and pea tendrils. One shipping container can produce 2500 head of lettuce a week, which is a rate about 30 per cent faster than traditional agriculture.
"Carbon footprint wise, we use 95 per cent less water than traditional farming, too," says McGilligan. "By only selling to local businesses, our food miles are also reduced. We're not carbon neutral yet, but we will be at scale."
Sprout Stack supplies Harris Farm Markets and independent grocers including Manly Food Co-Op and Harbord Growers. With an aim to double output by the end of summer, the company moved to a larger warehouse in October and increased its container count from three to five.
McGilligan says Sprout Stack is now on track to ship its first container farm to Melbourne in 2021.
"We've spent the past 18 months honing our production techniques so we can clone the business and shift it to other cities around Australia," he says. "We will always be about local food for local communities."
To assist in its expansion, Sprout Stack has partnered with the University of New South Wales. Both are members of the Future Food Systems Co-operative Research Centre, a partially government-funded body which aims to optimise the productivity of food systems.
"The university is helping us look at ways we can introduce robotics and boost production by four to five times over the next year or so," says McGilligan.
Professor Sami Kara of the UNSW school of mechanical and manufacturing engineering says he was excited to work with Sprout Stack after seeing similar farms in Singapore and recognising their potential to feed a growing population.
"By 2050, 70 per cent of the world's population will be living in an urban area," he says. "We will also need to produce 70 per cent more food to feed that population.
"We can keep producing food in large quantities, far away from the majority of people, and shipping it with a massive transportation footprint. Or, we can grow food in the cities where the yield is high, environmental footprint is low, and customers receive food that's fresher, more nutritious and delicious."
Kara stresses that vertical farming is not trying to compete with traditional farming, but offers an additional solution to the population problem. "In order to provide the world's food requirements by 2050, we're going to need many different types of production models," he says.
McGilligan supports this view and recognises the importance of Australia's agricultural economy.
"We're not short on arable land in this country, so I understand this kind of venture may look a little bit threatening and odd compared to traditional farming," he says. "However, I firmly believe many more people will be eating vertically grown food in the future."