Extreme Greenhouses: Growing Food in Crazy Places
Can food crops be grown in extreme environments? Novel research projects are looking at whether food plants can be grown in the desert, in the polar regions, and in space. As humanity migrates to harsher climates—or “unearthly” ones—fresh produce will be a requirement.
Growing Plants in Space
The global space sector has begun to investigate whether current space operations in the Earth’s orbit can be expanded to include longer expeditions, beyond the moon, and particularly to Mars. This idea is fairly controversial with regard to its technical feasibility, although the debate has become serious enough for NASA to actively consider how astronauts undertaking such a voyage might sustain themselves.
The main focus of research in this area is to determine alternatives to the present system of packaged foods and vitamins that currently sustain astronauts engaged in space operations—on board the International Space Station (ISS), for example. Packaged foods are certainly suitable for near-Earth operations, but they will degrade as astronauts travel further into space. For this reason, a number of projects, many of them directly run by NASA, are investigating methods of growing fresh produce in space.
Two major challenges to cultivating fresh food in space are low gravity and the lack of sunlight. Aboard the space station, the Vegetable Production System (Veggie) consists of a plant-growth facility. It utilizes two low-powered units with 70 watts of electricity to power lights, fans and electronic controls supporting basic hydroponic systems. The seeds are glued into wicks using water-soluble guar gum. Plant pillows, consisting of black Kevlar with a heat-resistant fiber bottom, contain growth media of calcined clay and controlled-release fertilizer. Water is introduced through a quick-disconnect valve.
The Veggie project operates alongside a more sophisticated growth chamber called the Advanced Plant Habitat while, back on Earth, projects such as the NASA-sponsored Biological Research in Canisters (BRIC) and Fairchild Tropical Botanic Garden’s Growing Beyond Earth (GBE) complement those in space. BRIC acts as a control group.
Growing plants in microgravity is complicated by the fluid physics involved and lack of convective flow. This issue is addressed by the calcined clay media, which ensures that the roots of the plants in the space station’s Veggie project have air and water at the same time, while a fan system ensures the plants do not get trapped within a bubble.
Although the Advanced Plant Habitat (APH) is located on the space station, it is an enclosed and automated project equipped with cameras and sensors that provide constant interactive contact with researchers at Kennedy Space Center. This means that the crew members of the space station have little direct interaction with the project other than to harvest samples and send them back to Earth for further study.
APH looks at what happens to plant genetics, proteins, and metabolites in space, particularly with regard to what happens to plant lignin when in microgravity. Lignin supports vertical plant growth in gravity, and lignification can be slowed in microgravity. The aim is to assess whether or not plants that are genetically engineered to have less lignin can survive in space.
"Advanced Plant Habitat (APH) on ISS is an automated project equipped with cameras and sensors that provide constant contact with researchers at Kennedy Space Center, meaning that the crew members have little interaction with the plants."
The Biological Research in Canisters (BRIC) project focuses on small organisms grown in petri dishes, such as yeast and microbes. Its findings have included the observation that plants in space suffer increased stress from oxidation while some genes that are associated with the plant’s immune system turn on in space while others switch off. Plants in space also find it more difficult to fight off pathogens.
Growing Plants in the Desert
The challenges of growing food in deserts have led to plant-growth research projects that may prove applicable in space. On February 19, 2022, as reported by Jewish News Syndicate (JNS), Israeli chickpea seeds were scheduled to be delivered as part of the cargo of Northrop Grumman’s 17th commercial resupply voyage to the ISS. The seeds are to be grown in “miniature greenhouses” using hydroponic technology for scientific research. The chickpea project has been named Space Hummus—fast-growing chickpeas are a main ingredient of the popular dish and may hold potential for feeding space travellers on longer voyages.
Here on Earth, a conceptual project run by King Abdullah University of Science and Technology (KAUST) in Thuwal, Saudi Arabia, is looking at growing plants in hot desert regions using technologies already in development at the school. The KAUST project envisions facilities with large greenhouse complexes supported by solar panels, low-energy cooling systems, and salt-tolerant agriculture. This area of research is known as controlled environment agriculture (CEA), a technology-driven approach to food production in which the use of scarce commodities, such as fresh water and labor, are optimized. Research on salt-tolerant edible plants is aimed at using seawater or diluted seawater to water plants in arid coastal climates in the Middle East Region.
KAUST research is also being conducted on the benefits of algal biotechnology as well as the cultivation of plants using liquid desiccants—concentrated substances that absorb water from the air. This research, if successful, could help reduce the demand on municipal water supplies in arid areas. Semi-transparent solar panels—used as glazing in greenhouses—could convert infrared energy into electricity while simultaneously allowing light through to aid plant growth and mitigate the problem of excessive heat adversely affecting plant growth.
Some of this research has already delivered interesting and useful results, with Red Sea Farms, a spin-off of KAUST, having grown varieties of tomatoes that contain higher levels of vitamins and antioxidants while using seawater that is only 30% diluted.
Growing Plants in Polar Regions
While some projects investigating the growing of plants in polar regions have supported space research, such as the nearly-autonomous Arthur Clarke Mars Greenhouse in the Canadian Arctic, most polar projects focus on tackling food insecurity in cold regions. One such project is Nauvik (an Inuit word meaning “growing place”), which consists of a greenhouse run by the Arctic Research Foundation (ARF), located in Gjoa Haven, Nunavut, Canada. Nauvik is equipped with two shipping containers, two wind turbines and a 14.4-kilowatt solar array with a diesel generator for backup power. The facility harvests microgreens and tomatoes chosen by and distributed to community elders and residents.
"Temperatures in Gjoa Haven can fall below -40 °F, while inside the greenhouse the temperature often reaches 100 °F in summer, aided by the region’s constant summer daylight."
The project is a collaboration with the Hamlet of Gjoa Haven, ARF, Agriculture and Agri-Food Canada, the National Research Council and the Canadian Space Agency.
A similar project is the Inuvik Community Greenhouse, a polycarbonate dome on the site of a former hockey arena, beneath which vegetables and flowers are grown. Inuvik is a town in Canada located 120 miles north of the Arctic Circle, with a population of 3,200. Temperatures there can fall below -40 °F, while inside the greenhouse the temperature often reaches 100 °F in summer, aided by the region’s constant summer daylight. Constant daylight and warmth accelerate growth, resulting in a plentiful harvest, including leafy greens, squash, tomatoes, and flowers.
Community greenhouses like Inuvik are now popular in northern Canada, with at least sixteen in the Yukon and twenty-four in the Northwest Territories.
Another Arctic food project of note is The Institute of Arctic Biology Greenhouse in Alaska, run by the University of Alaska Fairbanks (UAF). The institute, completed in 1994, was designed as a facility for research and education. The greenhouse is computer-controlled and focuses on plant genetics, physiology, ecology, evolution, and systematics. There are four computer-controlled zones within the greenhouse—where research is conducted—which also house plant collections. Alongside these zones are three climate-controlled growth chambers. An onsite teaching classroom can accommodate sixteen students and there is also an outdoor growing space. Projects have included a study on whether pollinators are abandoning native plants in favor of invasive species, a plant genome project and a project seeking to understand controls over nitrogen fixation by native and invasive plants.
Future requirements for fresh produce in extreme climates may one day be greater than we can imagine. Though most projects in harsh environments have already delivered benefits for area communities, the research in extreme-climate growing is still very much ongoing and developing. Whether or not it will deliver hoped-for, enhanced benefits and new discoveries remains to be seen.
*Robin Whitlock is an England-based freelance journalist specializing in environmental issues, climate change, and renewable energy, with a variety of other professional interests including green transportation.