German scientists have succeeded in growing fruits and vegetables in the Antarctic in a closed greenhouse. Their success could address the challenges of global food production. Barbara Barkhausen reports from Sydney.
Fruits and vegetables in the Antarctic? On the driest, coldest and windiest continent on the planet? Where polar night temperatures drop to minus 45 degrees Celsius and the continent is dark for six months of the year?
The idea sounds farfetched, and yet scientists from the German Aerospace Center (DLR) in Bremen have succeeded in accomplishing what many would consider the impossible.
Strawberries difficult to care for
The scientists are harvesting an average of 740 grams of tomatoes, 1.8 kilograms of cucumbers and 400 grams of kohlrabi from their greenhouse every week, in addition to various herbs, lettuce and radish varieties.
“Cucumbers thrive particularly well,” said project manager Daniel Schubert. “Peppers, and particularly strawberries, are more difficult to care for.”
But even the hardy cucumber would challenge the greatest of gardeners in a place like the Antarctic.
“I spend about half my time sowing, caring for the plants and harvesting,” said Paul Zabel, who has been operating the greenhouse on his own. “The other half of the time I care for the greenhouse technical systems and conduct the approximately 40 experiments.”
Daylight at the touch of a button
The greenhouse, which has a cultivation area of around 13 square metres, uses a new technology called aeroponics, which can cultivate plants in a sterile environment without soil. A computer system controls when the plants are sprayed with a special blend of water and nutrients. The day/night rhythm is also artificially controlled: light is shone on the plants for 16 hours, after which they are left to rest light-free for eight hours.
As the greenhouse is 400 metres away from the German Neumayer Station III, the weather can sometimes prove an outright challenge.
“In mid-June we had a storm that lasted for days. During that time we had to control and monitor the greenhouse from Bremen for three days,” said Daniel Schubert.
The control centre for the Antarctic greenhouse is located at the DLR Institute of Space Systems in Bremen. From there, the researchers can speak with Paul Zabel at the greenhouse via video conference and receive images and technical data for all plants growing in the greenhouse.
Model for future food production
The experiment doesn’t simply provide fresh fruits and vegetables for the 10 crew members spending the winter at the Antarctic station. It also provides valuable insights into future food production in harsh climates across the globe or on the Moon and Mars.
The greenhouse has a completely closed circulation system, in which all water not contained within the fruits and plants is recycled, which could be used in deserts on Earth or for eventual space travel.
A service to science
Testing the greenhouse technology’s durability throughout the harsh Antarctic winter is also an essential part of the vegetable cultivation experiment. In past weeks, for example, Paul Zabel had to overcome several technical problems, including the outage of a regulation vent in the cooling system, the outage of an LED lamp, and inconsistencies in the complex control system.
But Zabel sees these challenges as a service to science. “A future greenhouse or on another planet should also be in continuous operation, so technical failures and their repair provide us with valuable findings.”