Berlin start-up pioneers fish-farm veggie garden
By Mathilde Richter, AFP
May 19, 2014, 12:02 am TWN
BERLIN -- The ancient Aztecs and Chinese did it millennia ago, and now a Berlin start-up hopes it will feed 21st-century city dwellers using aquaponics, a combination of rearing fish and growing vegetables.
Set up inside the brick walls of an old brewery, the company ECF, short for Efficient City Farming, is using an age-old technique to grow tomatoes, peppers and greens in a miniature container farm, fertilized with fish excretions.
"Our vision is to give city dwellers access to agricultural goods produced in a sustainable way," said Nicolas Leschke, who founded ECF two years ago with a business partner.
Aquaponics, as the method is known, combines the techniques of hydroponics, or cultivating plants in water, with aquaculture — or the rearing of fish in tanks.
Because it allows food to be produced directly in cities, not the distant countryside, "the environmental and financial costs of conserving and transporting the goods are greatly reduced," Leschke told AFP.
"And last but not least, it guarantees access to fresh products," he added, snacking on a home-grown swiss chard, a leafy green vegetable popular in Mediterranean cuisine.
The business has set up a prototype container farm on two levels, with a fish tank at the bottom and a small greenhouse at the top where vegetables are grown.
Separate to the aquarium is a tank with a special filter that uses bacteria to transform the ammonium of the fish excretions into nitrates.
The nitrate-enriched water is then pumped to irrigate a greenhouse where the plants grow, not in soil but in a hydroponic bath of flowing water enriched with mineral nutrients.
It is ideal for farming in crowded population centers — an important point at times of growing urbanization, with half of the world's population now living in cities.