Issue 56: Growing Challenges in Antarctica

Issue 56
January/February – 2001
Story Title: Growing Challenges in Antarctica

Emperor penguins huddling at Auster Rockery.

Managing the hydroponic facility at Mawson Station, Antarctica, seemed a fairly straight forward assignment for Australian National Antarctic Research Expeditions (ANARE) expeditioners GREG ROCKE and DAVID VINYCOMB – a chance to keep in touch with things green. However, the diesel mechanic and communications technical officer found maintaining a growing environment on this frozen continent a unique challenge.

According to David, the task of maintaining the Mawson hydroponics facility seemed fairly straightforward. “Or so we thought, as we raised our hands to take on this extra ‘station duty’ at a meeting in Hobart prior to our journey South. We were both keen gardeners who had left the rest of our lives behind in Melbourne to pursue the great white adventure. To us, this just seemed like a logical extension of our outdoor hobby and maybe a chance to keep in touch with things green.”

Aerial view of Mawson Station. The hydroponics building is the striped building (top right-hand corner).

David, Greg and their fellow crew sailed south after three months of specialised Antarctic training in Hobart, including six hours on hydroponics! After a month aboard Australia’s icebreaker, the RSV Aurora Australis, they arrived at Mawson Station at the beginning of summer. Mawson Station is located on a rocky outcrop in the Australian Antarctic Territory at the edge of the polar ice cap. Its latitude is just within the Antarctic Circle, and its longitude is roughly the same as Pakistan. The climate is characterised by almost continuous strong winds, frequent blizzards, and temperatures ranging from slightly above 0 degrees Celsius in summer to 30 degrees below in winter. The landscape can only be described as a barren white desert. Spectacular. The only living plant life is some mosses and lichen, hidden in rock crevices on the coast, sheltered by grounded icebergs thousands of years old.

The Australian Antarctic Division administers Mawson. The Division maintains three continental stations and a fourth station on sub Antarctic Macquarie Island.

The stations are a basis for scientific research and are staffed throughout the year. However, the stations can only be reached by ship three times a year, and only over the short summer period. Therefore, all stations have small hydroponic facilities to supply fresh vegetables and herbs throughout the year to supplement imported fresh, frozen and dehydrated fruit and vegetables. David agrees that the delight in having a fresh salad in the middle of the long Antarctic winter is always greatly appreciated. They grew a variety of salad ingredients, vegetables and herbs. Three types of lettuce were grown – Cos, Mignonette and Iceberg.

“Lettuce is the most important in the wintertime because it helps station morale to have some green on our plates,” said David. “It grows quickly in the ‘perfect’ hydroponic environment, and has a relatively short turnaround time of four weeks for mature lush lettuce.”

According to David, they increased their lettuce growing capacity throughout the year to cope with demand.

“The chef’s warm rare beef salad on a bed of Cos lettuce was superb,” recalls Greg. “We also grew capsicums, silver beet, spring onions, cucumbers, dozens of snow peas, baby beets, radishes, butter beans, and numerous herbs.”

David said the herb collection was very popular, where a little goes a long way. Basil, chives, marjoram, dill, sage and mint were grown, along with radishes and spring onions.

The set up
Having only a few days changeover with the outgoing “Winterers”, David and Greg found the hydroponics building empty and in the process of having its annual fumigation. They quickly learned about CF, the importance of correct pH, and the rooms microclimate.

“The one thing that quickly dawned on us was that this was to be more than just a way to pass a few leisurely hours on a Sunday. This ‘hobby’ shared time with our formal jobs and other station responsibilities – not to mention pressing penguin research!”

Christmas dinner started with a delicious tomato, bacon and basil soup.

The Mawson hydroponics building is a detached, fully insulated, plywood building that has seen previous days as sleeping accommodation and, more recently, a sauna and gym. Appearance wise, it had seen its best years some time ago. The main growing room measures eight by three metres and has a small storeroom and sealed entrance porch at one end. The growing room is lined with thermal reflective foil and has ten small double-glazed windows with internal shutters. This is an old-style building sitting on timber bearers, and guyed to the rock to cope with the fierce Antarctic winds.

Bits and pieces
On arrival in early summer, Greg soon realised that hydroponics stocks he had ordered weren’t amongst the supplies that came with the crew. A particular requirement was the perlite and vermiculite, one of the growing mediums used at Mawson.

“We wound up hand sifting and washing 25 ten-inch pots worth of the old stuff so we could start replanting,” Greg remembers.

Another growing system was the NFT system used for cultivating tomatoes. Fortunately, there were just enough remaining supplies of clay balls to last until the major resupply ship arrived at the end of summer.

One of the most precious resources in Antarctica is, believe it or not, water. Even though the continent is mostly covered with ice and snow, actually melting and keeping it that way consumes a lot of energy. It takes about one litre of distillate to make 25 litres of water. Because of this, water conservation in the hydroponics facility is paramount. At that time there was no reticulated water into the hydroponics building so there was a weekly roster to cart 400 litres in a huge drum on the back of the 4WD Ute.

“It was always a battle to pump all the water into the building to be stored in the internal tanks before the pumping hose and couplings froze up,” recalls David.

The only consolation was that the exact consumption of water could be monitored. Since their departure, a connection of flowing, heated water was available on tap, which now saves considerable labour.

They used commercially available two-part powder nutrients. These were mixed in separate plastic bins for later dosing by hand. Two types of nutrient were kept, one general purpose and one for flowering plants. Five nutrient tanks were used; three were made up on station out of sheet ABS plastic ranging from 200 to 400 litres, and two were 240 litre plastic “wheelie bins”. Nutrient tanks were heated to 25 degrees by fish tank heaters, and the solution kept oxygenated by fish-tank-type air pumps and airstones. Mains powered submersible pumps supplied liquid nutrient to the plants via spray bars improvised from electrical conduit.

“After all, we couldn’t just pop down to the local hydroponic shop for replacement parts,” quips David.

The solution CF was regularly tested for strength using a commercially available metering wand. The pH, which started at 5.5, rose steadily, requiring constant additions of acid. The nutrient was recycled as much as possible by first supplying it to the tomato and lettuce plants. After a month it was transferred to the other less demanding plants such as capsicums and silver beet. This method of circulating the liquid nutrient solution virtually eliminated any water discharge from the hydroponics facility. Due to ecological considerations and Australia’s commitment to preserving the Antarctic environment, the small amount of liquid waste was stored in drums and then passed through the waste treatment plant. All excess plant matter was burnt in our high temperature incinerator, and all ash returned to Australia.

In Antarctica there is virtually no useable natural light for much of the year, and little solar heat, so the growing room required both. Light was supplied by 13 Son-T Agro 400 watt grow lamps and 20 Osram “Fluora” fluorescent lamps. During the daytime growing cycle of 9am to 9pm, the grow lamps supplied sufficient heat to keep the room warm. An electric fan heater came on automatically when the room temperature fell below 15 degrees Celsius, usually at night, and an exhaust fan came on if the temperature rose above 25 degrees Celsius.

“A natural flow of air was maintained by having vents in the entrance doors and the exhaust fan cowl in the roof,” says Greg. “The conflict of too much cold air versus too little fresh air didn’t become an issue.”

A CO2 generator in the room was not used, as the excess heat it generated would have kept the exhaust fan on, thus, constantly extracting the freshly produced CO2 gas. Four oscillating electric fans kept air moving internally and prevented stratification.

Trial and error
“We had plenty of offers of ‘specialist help’ from other willing expeditioners,” recalls Greg. “One of our carpenters showed a talent for pruning and maintaining the capsicum plants. Although the plants were heavily laden with fruit after six months, we didn’t seem to be harvesting many. Our suspicions were confirmed when the said carpenter was caught unable to speak because his mouth was full!”

Help was certainly needed with the tomatoes.

“What are laterals? ” they asked the upper atmospheric engineer, as the 18 lush plants reached the roof and consumed half a tank of nutrient every day with not a tomato in sight. The next planting was followed with labour intensive, vigorous pruning, which produced a healthy crop. In total there were three crops of tomatoes throughout the year of both Grosse Lisse and Romas, after sacrificing the first crop to the incinerator.

In the interests of efficiency, there was experimentation in growing Cos and mignonette lettuce in clay balls. After altering the watering cycle from three 40 minute bursts a day in perlite/vermiculite, to seven-hour on/one-hour off cycles in the clay balls, they produced a successful crop. Best of all, the mature plants could be removed from the clay balls roots and all with little disturbance.

A close shave
Winter was, of course, the most testing time for the hydroponics venture. The wildlife had departed. The days were growing short and the last ship had been and gone, taking the last of the summer expeditioners with it. Twenty one of us (one female) were left to battle alone until the arrival of the next ship in late October. With the temperatures plummeting, Greg and David had their first building freeze up – well, almost.

A themed dinner in the machine shop of pan fried trout with hydroponic capsicum, basil and blanched string beans.

“A vigilant expeditioner noticed one morning that there was not the familiar glow coming from the hydroponics building,” David recalls. “Entire crops can freeze within hours after power failures, and with the outside temp at minus 15 degrees, we entered with a sense of dread. To our great relief, we found the inside temperature at just above freezing.”

Electrical timers revealed the power had been off for several hours. The main earth leakage breaker had tripped, cutting all the power. With over 40 plug-in items in the growing room, the task of finding the faulty culprit was daunting. Could it be a damp light transformer, a leaking pump, a short circuit in a heater? Some clear thinking saved the day.

“Over the next week we rewired the switchboard to incorporate separate breakers for each circuit, with one circuit especially for the main heater. This was by no means the end to our electrical problems, but it was our last freeze-up scare. Last year’s team weren’t so lucky. They had several fatal freeze ups, losing everything.”

The seed stock also became critical in Antarctica, as the older seeds were now becoming useless. All the imported seeds have to be vacuum packed to ensure no contamination from erroneous sources, but the shelf life of the seeds was becoming very short. Perhaps this was due to the cold environment or very dry atmosphere. Whatever the cause, the seeds failed to germinate before their expiry date.

“We’d like to think that our hydroponic efforts and experiments are now part of a growing trend to successfully produce fresh food in hostile environments, even outer space,” Greg commented, and David agreed.

“What we did discover were the differences between Antarctic and Australian hydroponics,” continued David. “Minimal solar energy is available in Antarctica, so all heating and lighting is artificial. All ingredients are imported, particularly seeds, and must be strictly controlled to avoid contamination to the environment. All waste products must be disposed of properly or returned to Australia, and conservation of water and energy is critical.”

But funnily enough, this isn’t the first question that local experts have asked them. What they’re really curious about is whether they’re allowed to grow ‘anything’ down there in Antarctica.

“Well put it this way, when it comes to growing ‘anything’, we’re covered by Australian laws, just like everyone else!