From: National Science Foundation
Posted: Wednesday, February 25, 2004
Image: Greenhouse technician Rob Taylor relaxes in a hammock at the McMurdo greenhouse.
By Kris Kuenning
Antarctic Sun staff
There is a place in Antarctica where, even in the dead of winter, you can lie back in a hammock and bask in bright light. You can pluck pansies for a light snack, smell the fresh herbs or just hang out with a tiny forest of lettuce or a small jungle of tomato plants.
It's the McMurdo greenhouse and though it's only 200 square meters, it's some of the most valuable real estate on station for the people who live and work on the barren shores of Ross Island.
Greenhouse technician Rob Taylor knows the greenhouse is more than just a place to grow food, especially in winter.
"Winter is when the greenhouse is most effective," Taylor said. "Not only does it grow food for the winter population, but the people are also more deprived."
The McMurdo greenhouse generates up to 140 kg of food each month. From lettuce for salads to mint for Cuban cocktails, Taylor supplies both the central kitchen and individual requests for greenhouse produce.
In winter, when the station is cut off from resupply flights, the greenhouse is the only source of fresh food for the 200-odd residents. Harvesting 250 heads of lettuce every 10 days means winterers have salad a couple times a week.
In summer, when the number of people rises to more than 1,000, the greenhouse supplements the regular shipments of fresh food from New Zealand.
To comply with the Antarctic Conservation Act, everything is grown hydroponically.
"Soil contains microbes and microbial colonies," Taylor said, "so it would be theoretically possible for the microbes to escape into the environment."
Instead, the plant roots are either directly suspended in the liquid nutrients or supported by a non-soil agricultural mixture.
Signs outside the greenhouse warn smokers not to touch the plants. There are two reasons for this, Taylor said.
Not only is nicotine toxic to a lot of plants, but processed tobacco can carry the tobacco mosaic virus, which is devastating for plants like tomatoes, cucumbers and peppers.
"Because it's a linked system, if you touch one plant, it is transferred to the whole rung," Taylor said.
To combat a virus, all the plants have to be destroyed and the greenhouse started from scratch.
In early October, a subtropical insect found its way to the greenhouse. Taylor noticed specs of moving dust on the surface of the water. It turned out to be a non-native springtail.
"There are native Antarctic springtail, but this turned out to be a non-native, subtropical variety," Taylor said.
Springtail live only on live plants, so it's arrival is still a mystery. Rob first tried to combat it with soap, which breaks the surface of the water and drowns the insect.
Though springtail is not harmful to the plants, its existence was a potential threat to the delicate Antarctic environment and eventually the plants were destroyed, the greenhouse emptied and frozen out.
The only thing that survived was a lemon tree planted from seed several years ago by previous greenhouse technician Chris Wilt.
The McMurdo greenhouse has no glass. In a continent with only one long summer day and one long winter night in a year, the greenhouse's artificial lights create night and day every 24 hours for the plants.
"Plants do most of their respiration at night, so keeping them in constant sunlight means they're unable to exhale," Taylor said.
The artificial lights provide different spectrums of light for 16-17 hours a day but Taylor said it still doesn't approach the level of sunlight. And while most plants like a humidity level of 60-70 percent, Taylor says he's lucky to maintain 20 percent humidity in the dry Antarctic conditions.
Still, the plants thrive. They are lush, green and good producers.
"You have to force the plants to become accustomed to different growing environments. You don't want to make it super cushy for them."
But the plants make life just a little more cushy for McMurdo residents - in the dining hall and at the greenhouse itself. Taylor believes the greenhouse is a popular hangout because it allows people to re-connect with plants.
"Humans have evolved with plants, but in this area of Antarctica, you have humans without plants and I believe that when you take people out of their evolutionary background, it does something to the psyche ÷ Even if they haven't realized they've missed it. That's how I feel, anyway. I like the fact that I grow food for people but it's more than that," Taylor said.
There's no greenhouse at Palmer Station. Monthly supply ships from Chile alleviate the pressure to grow fresh vegetables at the tiny station on the Antarctic Peninsula.
"Space is the biggest issue right now for Palmer Station," said station manager Joe Pettit, "We don't have quite the motivation to create a greenhouse."
Nibbling on nasturtium leaves at one end of the tiny South Pole greenhouse, Jack Giacalone is enjoying the last season in the greenhouse under the dome before it is replaced by a high-tech growth facility in the new station in February.
Giacalone and his girlfriend Theresa "Tree" Menke are the volunteer caretakers for the greenhouse. They and 14 others pitch in to produce lettuce, fresh herbs, tomatoes, cucumbers and even avocados in the
coldest, driest place on earth.
Giacalone said the current greenhouse is very labor intensive. Keeping the plants alive requires daily checks of nutrient levels, acid levels and water temperature. There is also misting, planting and harvesting to be done. The 30 square meter greenhouse under the dome can produce up to four to five pounds of fresh vegetables a week.
Giacalone and Menke spend about 15 hours a week working in the greenhouse.
"It's quite a workload but there's not a lot else going on," Giacalone said, "And I'd rather be busy."
The biggest challenge is the dry air. A humidifier keeps the greenhouse between 47 and 58 percent humidity.
But, in many ways, running a greenhouse is easier at the South Pole than it would be back home.
"There are no insects, no aphids, no parasites ÷ almost," Giacalone said.
Like McMurdo, the biggest threat to the South Pole greenhouse is the tobacco mosaic virus.
Working in the greenhouse gives Giacalone the same kind of satisfaction of growing and producing that he gets at the vegetable garden he cultivates at his home in Hawaii.
"The conditions are ultra harsh here. To have stuff growing is very unique," he said.
Space age greenhouse
The empty South Pole landscape is often compared to outer space. Now an indoor growth chamber at the Pole may be a forerunner to supporting a base on Mars.
The automated growth chamber has been designed for the National Science Foundation by the University of Arizona.
"It's like no other growth chamber in the world," said Gene Giacomelli, director of the Controlled Environment Agriculture program at UA.
Though the 1,000-watt lamps pump out enough light to emulate 40 percent of a Tucson summer day, they are cool enough to touch. The water-cooled bulbs, designed by former South Pole worker Phil Sadler, mean plants can grow closer to the lamps, making more use of the growing space.
"It's going to be bright," Giacomelli said. "And that will make the plants grow faster."
All the water and nutrients are reused in the system. Carbon dioxide is pumped in for the plants' respiration. The environment inside the growth chamber will be computer controlled and monitored, but plant care and harvest will still require a human hand.
The 45 square meter space in the almost-completed wing of the new South Pole station includes twice as much growing room as the smaller greenhouse under the old dome. There's also more room for the people.
The growth chamber will be separated from a lounge area by a glass wall. In the so-called "enviroroom," people will be able to see the plants, enjoy the intense light, increased humidity and even smell the more pungent herb plants. A small "recreational" hydroponic system in the enviroroom will be accessible to everyone, Giacomelli said.
The equipment is scheduled to arrive at the South Pole a few weeks before the station closes for winter in mid-February. The growth chamber should be up and producing for this winter, but the official dedication of the greenhouse won't be until November 2004, after the station re-opens for the following summer season.
A Webcam in the growth chamber will allow the university professors and students to watch the plants grow. It could also be used as a diagnostic tool if there are problems with plant health.
Giacomelli said this system demonstrates the potential for growing in a closed system on a Mars base.
"It would not work on a space station because there is no gravity, but it could function on Mars."
The design would be lighter, though. Giacomelli said the South Pole growth chamber has been built for "heavy, long-term use."
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