Roots in space

Most of us have heard of hydroponics, a system for growing plants in solution rather than soil, but when Peter VanderZaag, potato breeder from Alliston, Ontario and President of the World Potato Congress, first mentioned aeroponics I did a double-take. “What’s that?”

You can’t grow tubers in solution, so hydroponics isn’t an option for crops like potatoes. In aeroponics, the roots of plants grow in air and are misted at regular intervals with a solution that provides nutrients and hormones adapted to the physiological age of the plant.

Twenty-three years after NASA started developing aeroponics, Dr. He Wei at the Crops Research Institute of the Sichuan Academy of Agricultural Sciences along with Dr. Xie Kaiyun of the International Potato Center (CIP) were testing aeroponics in China when an earthquake devastated part of the Sichuan province.

The 2008 earthquake came in the middle of the potato harvest. Over 68,000 people died with hundreds of thousands more injured and millions displaced. It was “a terrible situation,” remembers VanderZaag. Sichuan’s population, ReliefWeb reported at the time, was “critically dependent on agriculture for their livelihoods” and every part of the agriculture sector was disrupted. The World Bank offered funding to the CIP to restore the potato seed supply to the province. VanderZaag was on the Board of Trustees. At the time, no one had attempted to scale aeroponics to the level Sichuan needed. “Everything was lined up – not to solve it – but at least to alleviate some of the crisis of seed supply through this very rapid way of doing aeroponics. That’s how it all took off.”

Today VanderZaag estimates that ten aeroponic organisations in China are still “doing very well.” More than that, this small community around the world is crowdsourcing their approaches to developing aeroponics. One of the key members of that community is in Quebec.

Aeroponics around the world

André LaChance, of Maxi-Plant Inc. in Quebec, traveled to Chengdu to see aeroponics and then enlisted faculty and students at Laval University to help him research further. “He’s an amazing scientist,” VanderZaag enthuses. “He’s been the main teacher, I would say, in the whole world in how to do this exactly right.”

With that high recommendation, I watched LaChance present on a World Potato Congress webinar. He built his greenhouse in 2014. It’s 234 square metres and produces two cycles of seed potato a year, approximating 475,000 minitubers a year, with about 100 tubers per plant. His temperature and lights are controlled through propane and electricity backup. Is the yield high enough to offset the costs? I wondered. “Absolutely,” says VanderZaag.

LaChance explained the four physiological stages of the potato: acclimatation (rooting), vegetative (the upper part of the plant grows), initiation (the tubers grow) and harvesting. Each stage comes with its own nutrient requirements.

Aeroponics systems vary depending on the climate they’re set in. Sichuan is cheaper in energy costs because it’s closer to the equator and Rwanda is even cheaper, but Rwanda has other problems, says VanderZaag, mainly water quality and lack of sunlight. “Every place has its challenges.” That’s why the webinar gathered people from very different parts of the world to share their strategies: China, Quebec, Chile and Rwanda. “This is by popular demand; there is really no society or organisation that supports aeroponics research and development. We’re sort of doing our own thing.”

A unique community

Is crowd-sourcing solutions normal in most agriculture sectors? I ask. “I think the aeroponics community is unique – it’s a small group,” VanderZaag said. Sometimes, people – or global companies – take hours of time and expertise from people like VanderZaag and LaChance without reciprocating. “Some of these things you laugh at, what kind of nonsense is this? You want all this free information and you’re a company that then won’t give us a good price for our potatoes?”

“It depends on the leadership of the people involved, and what they’re willing to share. Xie Kaiyun who passed away, sadly, did a lot of this work in Asia, in the Middle East, he was tirelessly promoting and selflessly sharing his knowledge on aeroponics.”

People glean information from these webinars to make their business profitable, VanderZaag says. “[We are] innovators who work together, yes. Third world countries, developed countries, doesn’t matter, we’re all working together towards the same goal.”

Farming in the future

Aeroponics requires scientific precision in controlling temperature, photoperiod, plant hormones or nitrogen shocks, pathogen control and oxygen levels. It’s a closed system, with zero nutrient waste. And it’s a system that can be run from the phone in your hand.

“I think for urban farming, down the road, aeroponics will be a key player,” says VanderZaag. At the moment, it’s used for growing seed potatoes, not the ones we put on the table. “I was just in Sichuan and I visited an urban farm. A seven-story building, with mostly hydroponics. It’s robots doing all the sowing of the seeds, the transplanting, the growing, the harvesting, the packaging. It’s an unbelievable farm!” The same urban farm is creating forty-foot shipping container farms: “You can place them in your backyard and have your own hydroponic or aeroponic farming, if you wanted to. As China moves ahead they’re saying, high-rise buildings for people, for pigs and for plants.” In Japan, rice and wheat are already farmed in high-rise buildings. “This is a sustainable system that is closed. Where there’s high population densities and wealth, this is all going to happen.”