Greenhouse Canada

Features Handling Systems Structures & Equipment
Inside View: March-April 2013

March 20, 2013
By Gary Jones


Early editions of “Inside View” had the same monthly themes as they do now.

Early editions of “Inside View” had the same monthly themes as they do now. Looking back at those earlier articles, the themes of “Innovation, Environmental Control, and Structures” brought some attention to new and old technology.

In February 2008, we looked at technologies, ideas or products that were being newly publicized or marketed then:

  • Upgrades to environmental control systems (Argus “Titan”).
  • Plant sensor equipment (Hoogendoorn “Stomata Sensor”).
  • “Smart” (i.e., “chipped”) greenhouse equipment.
  • Labour supervisory control (Argus “Supervisory Control Guardian”).
  • Wireless study groups.

In January 2010, we looked back to horticultural equipment that growers and others had noted as being milestone items for advancing the industry technology. These included the dilutor/proportional injector, greenhouse screens, environmental control computers, automated transplanters and heat-dump tanks.

So, it’s time to be looking ahead. I was chatting with an old colleague, who mentioned that research was developing “self-constructing” greenhouses that can be easily transported to the moon or Mars and be simply pulled out concertina-style to make a pop-up structure complete with hydroponic channels. (Google this and Gene Giacomelli at University of Arizona for great YouTube clips).
Think of those quick-erect, two-man tents that have become so standard for campers nowadays.


Also, I came across a BBC article describing work developing an inflatable structure that could be easily transported into space, popped up and “covered with a shell built by 3D printers. The printers, operated by robots, would use soil from the moon” (or Mars), “known as regolith, to build the layered cover.”1 Initially big enough for four people, these structures could be extended.

“In 2010, a team of researchers from Washington State University found that artificial regolith containing silicon, aluminum, calcium, iron and magnesium oxide could be used by 3D printers to create solid objects. The latest plans are the result of collaboration among a number of organizations including the European Space Agency. The consortium tested the practicalities of using a printer on the moon by setting up a D-shape 3D printer, used to print very large house-sized structures, in a vacuum chamber with simulated lunar material.”1

But what about the plants? Having the building technology is one thing, but it’s no good if the plants cannot grow. Apart from the obvious lack of gravity on the moon, there is a significantly lower air pressure.


Rob Ferl, director of Space Agriculture Biotechnology Research and Education at the University of Florida, found that “low pressure makes plants act as if they’re drying out.”2 Working with NASA’s Office of Biological and Physical research, researchers exposed young plants to low pressures (about one-tenth Earth’s normal) for 24 hours.

In such a low-pressure environment, water is pulled out through the leaves very quickly, and so extra water is needed to replenish it. But, says Ferl, the plants were given all the water they needed. Even the relative humidity was kept at nearly 100 per cent.

Nevertheless, the plants’ genes that sensed drought were still being activated. Apparently, says Ferl, the plants interpreted the accelerated water movement as drought stress, even though there was no drought at all.2 Understanding plant biology is just as critical a part of the equation as amazing future structures.

For the last couple of years, I’ve been watching closely the development of a rooftop greenhouse in Vancouver. Believed to be the first commercially sized vertical-style greenhouse in North America, it is located on a disused parking lot in the heart of the city, providing fresh leafy salad crops to local Vancouverites.

Project developers Alterrus Systems, have been using the “VertiCrop” movable stacked-tray hydroponic production system and harvested their first crops just before Christmas 2012, marketed under their “Local Garden” label. Alterrus claims that while yields can be up to 20 times higher than for similar field crops, their system uses only eight per cent of the water used for those crops.

Greenhouses on Mars are the stuff of the future. Rooftop greenhouses could be the stuff of the future now.

1 “3D printed moon building designs revealed,” BBC.CO.UK/News, Feb. 1, 2013.
2 “Greenhouses for Mars,” NASA Science News, 2004.