May/June – 1993
Story Title: Hydroponics in Antarctica
Author: Dr Brian Hanger
The Australian Antarctic Division has three manned stations – Casey, Davis and Mawson. Hydroponics has been tried at all three stations with mixed success. Interest in hydroponics by the National Antarctic Research Expeditions (ANARE) extends back to the late 1970’s, and over the years vegetables and flowers have been grown. Dr Brian Hanger chronicles the history of Australian hydroponic efforts in the Antarctic.
The primary aim of hydroponics in Antarctica was to provide fresh vegetables to the expeditioners during the long dark winters. The availability of fresh vegetables for meals, and flowers in the dining/recreation areas, has a good effect on morale for the expeditioners.
I first became involved with the Antarctic hydroponic venture in the early 1980’s when a number of the expeditioners would spend at least a half day each year with me, having a crash course in hydroponic crop production. Many of the people on these courses were tradesmen, such as carpenters, who happened to have an interest in gardening and were thus selected to look after hydroponic units at the stations. They were to take over the hydroponic operation from the expeditioners returning to Australia.
This was a great challenge because not only did they have to quickly acquire the skills of growing plants under artificial lights in a room, but they also had to learn how to manage the hydroponics systems. If they had any problems it was a long way to get help.
I received many cablegrams and telephone calls from the expeditioners over the years. One cablegram had its humourous side with an invitation which read: “Perhaps you would consider attending our midwinter dinner . . . Dress is formal, and a dog-sled will be picking up at the ice-edge.” There is also a story from one of the stations that the hydroponic unit managed to produce one small tomato fruit in time for the midwinter dinner. This was carefully sliced and divided amongst the 24 expeditioners.
One of the earliest reports I have was from an expeditioner who looked after the hydroponic growing room at Casey Station in 1980. The small room was only 3m x 2.2m in area. In the room were growing modules (1.2 x 0.06 x 10m). These were lined with plastic and filled with scoria. All the modules were on tables, and the excess solution drained back into a 200 litre insulated tank from which it was recirculated. The modules were irrigated for 10 minutes every hour. Above each module was a bank of 7-8 fluorescent tubes to give light for 16 hours each day. The height of the tubes was adjustable so that they could be raised or lowered according to plant growth.
This expeditioner experienced a series of problems. One was the shortage of available water, and he had to install a second 200 litre tank for storage. Another problem was that the fluorescent plant tubes aged with time, and lighting for the plants became inadequate. Reflective aluminium sheets were hung over the tubes to direct more light towards the plants, and the lights were lowered to within 20 cm of the plant tops.
“An unexpected problem was that salad vegetables froze while being taken to the kitchen . . .”
High humidity of around 100% in the room was a serious problem. Water condensed on the insulated walls and drained to the outside around the doorway where it froze. On many occasions the door had to be prised open.
Initially, there were no pH or conductivity meters available to monitor nutrition in the scoria and the nutrient solution. Problems with plant growth were encountered from salt build-up in the media, but regular flushing with water overcame this problem. They ultimately built their own conductivity meter.
Another problem was the large temperature gradient of 15°C in the room from floor to ceiling. An oscillating fan was introduced to reduce this gradient to less than 5°C, and it also helped with pollination of the tomatoes and capsicums. An unexpected problem was that salad vegetables froze while being taken to the kitchen and had to be carried in a humidifier to prevent this from happening.
Over the year a range of plants were grown. Those most productive were silverbeet, endive [the greatest success], radish, cucumber, parsley, cos lettuce, and petunias. Those plants that had little success included tomatoes [few fruit], capsicum [no fruit], chives, winter lettuce and spinach. Nonetheless, from early July to late January, 60kg of edible vegetables was produced from the small hydroponic room.
The second report I received was in 1984 from the Davis Station unit which used an insulated shipping container (6 x 2.4 x 2.3m). This was located close to the water supply. One hundred litres of water had to be carried weekly to the container.
A major problem was again the large fluctuation in temperature from top to bottom, and between day and night. The floor was always below zero. Three fans set in the ceiling were needed to keep the air well mixed and a uniform temperature throughout the container. The container temperature ranged from 18-22°C, with an outside temperature of -20°C, and 20-35°C when the outside temperature was -10°C.
Better lighting was used at Davis Station. Wooden shelves (2.7 x 0.7m) were set under a bank of 10-12 full spectrum, long-life fluorescent tubes. The lights were 30-45 cm above the top of the shelves, and a 20-24 hour light cycle was used.
The growing system consisted of styrene boxes filled with 3cm of perlite on which was placed a rockwool slab cut down to fit. Seeds were germinated in rockwool propagation blocks. Fresh nutrient was made up weekly and the plants in the rockwool were fed every 2-3 days. The drainage water was collected but not recycled. All of the stations used premixed hydroponic nutrient powders from Australia.
The water at Davis Station came from melted snow and had a pH of 5.5-6.5 [Casey pH was 5.0-5.5]. The nutrient solution and water were stored in elevated 50 litre black plastic drums to ensure the solution temperature was good and did not inhibit root growth. Unlike the hydroponic unit at Casey Station, humidity tended to be very low and plants were sprayed daily with a fine mist, and a humidifier was set at 70% humidity. When the humidifier was first introduced, plant growth and health noticeably improved.
“It is an environmentally sensitive area and all care has to be taken . . .”
From May to October a wide range of vegetables were grown. Lettuce took about 6-7 weeks to grow large leaves suitable for the table. Radishes did not root well. Chinese cabbage was used in salads and was highly recommended, along with silverbeet. Spring onions were slow growing but popular for soups, salads and dumplings. Curled cress, water cress and mustard took about three weeks to grow to a size ready for the kitchen.
Tomatoes were pressed for space and took four months to reach the fruiting stage, and few fruit were produced in the time period. Capsicums and chillies grew well and flowered, but failed to produce any fruit in the time period. Zucchinis began to produce small fruit after 5 weeks.
The Davis Station operator concluded that once the hydroponic room was up and running, it could be easily maintained by one or two interested expeditioners, spending only 15 minutes per day. There was the knowledge that any vegetables produced in winter were always welcomed by the cooks.
The great advantage of hydroponics in the Antarctic is freedom from the natural diseases and insects pests of the plants grown. It is an environmentally sensitive area and all care has to be taken to ensure that it remains free of these problems and does not become polluted from man’s activities.
My discussions with the expeditioners on their way to the Antarctic have always stressed the need to be very careful with plant material taken to the stations. All plants must be grown from treated seed, and these should come from reputable seed suppliers. No bulbs, tubers, cuttings, etc. should be brought in. If plant material is required which can not be supplied as seed, then correctly prepared tissue-cultured plant material with a health clearance should be satisfactory. By growing all the vegetables required by the expeditioners hydroponically, it means that fresh vegetables will not have to be brought in by ship or aircraft. This would further reduce the risk of introducing plant disease organisms or pests into the Antarctic.
Currently, hydroponic crop production at the Australian Antarctic stations has stopped as new environmental guidelines are drawn up for the region. Let us hope that in the near future hydroponics returns to the Australian stations.
In the past, the true potential of vegetable growing has bever been realised because of the sub-optimal environmental conditions in the growing room. With correctly constructed rooms, output of vegetables and flowers will be substantially increased to meet the requirement of the stations. A functional hydroponic garden could become a recreational activity for many expeditioners, particularly during the dark winter months.
The Australian Anarctic Division is currently in the process of assessing the potential environmental impacts of hydroponics and, subject to a favourable assessment, hydroponics may be re-introduced to Antarctic stations under strict guidelines and with new equipment and appropriate training for operators. It was originally stopped following indications that hydroponic activities may have led to the introduction of invertebrates at Mawson and Macquarie Island.
A study has already been carried out by Ms Clare Green, a student of the Institute of Antarctic and Southern Ocean Studies (IASOS), who prepared a draft environmental assessment as part of her thesis work. It is expected that this and other relevant work will be drawn upon by the Division in conducting its own assessment, which it hopes to complete later this year. athesis.
Meanwhile, at the American Antarctic Station, plans are afoot to develop a vegetable production unit, as part of a joint venture between NASA and the National Science Foundation. Called the Controlled Ecological Life Support System (CELSS) Antarctic Analog Project – the CAAP – it was conceived as a joint project to develop and demonstrate advanced life support technology under the extreme conditions of the US South Pole Station.
According to NASA, the environment serves as an appropriate space base analog, for the development of technologies required for future space exploration. The implementation of CELSS technologies should also improve the quality of life for the people stationed there, and reduce environmental impact of the South Pole Station, through food production and waste recycling. NASA’s objectives for the project are numerous, and include validating the predicted performance of their life support system components; characterizing the effect of living plants and the availability of fresh vegetables on human mental and physical well being; quantifying the amount of crew time required to operate CELSS; determining training levels necessary for operation and maintenance of remote systems; and conducting scientific evaluation of process, system and crew interactions. Clearly, the project will establish an early demonstration of advanced life support technologies and systems needed for future space exploration.
About the Author
Dr Brian Hanger is a horticultural consultant specialising in hydroponic crop production and physiological disorders of plants. Prior to this, he was a research scientist with the Department of Agriculture in Victoria for 31 years, during which time he conducted research into plant nutritional disorders and became recognized as a world authority on the calcium nutrition of plants. He also specialised in the elimination of viruses from economically important plants, using tissue culture procedures. Brian is currently editor of the Australian Hydroponic Association’s newsletter.