Ever heard of growing food without soil? That’s hydroponics: a method of growing crops entirely in water, without the use of soil. It’s a closed system where all environmental elements are fully controlled to produce an optimal growing environment. Roots are fed nutrient-rich water in an indoor space such as a greenhouse or even a shipping container where elements such as temperature, moisture and light are controlled to reduce the time it takes to grow crops and to enable a year-round growing season. Fresh grown tomatoes in the middle of November? With hydroponics, it’s possible!
Hydroponics Versus Traditional Farming
Hydroponics can be used to grow many of the foods we eat. Tomatoes, cucumbers, peppers, eggplants, strawberries, leafy vegetables such as kale and spinach and many herbs can all be grown using hydroponics. There are many advantages of hydroponics over traditional farming. For one, it uses less water than traditional farming. It also has faster growing cycles and a year-round growing season, which translates into a greater quantity of food produced. Growing plants without soil also means that food can be produced in areas where farmland is scarce.
However, the main shortcoming of hydroponically grown produce is its energy use. Hydroponics uses significantly more energy than traditional agriculture. High amounts of energy are needed to power water pumps, artificial lighting, and the heating or cooling required to create the controlled growing environment. In comparison, traditional agriculture’s main energy inputs are for powering agricultural equipment, while elements such as light and climate are left to nature.
What Is the Role of Soil?
While some might point to hydroponic farming as the future of agriculture, one might wonder about the impacts of removing soil from the agriculture process. According to hydroponic farming principles, plants don’t really need the soil to grow; they just need the nutrients in it. Put those nutrients into the water and plants can grow just as well without soil.
Does that mean soil no longer has a purpose when it comes to growing plants? Well, in order to understand the value of soil we need to remember that for countless centuries, plants and the soil evolved together. To suddenly disconnect plants from the soil is to ignore the collective work of evolution. Also, given that hydroponic crops are grown using artificial light and a manufactured solution of nutrients, hydroponic farming removes plants from access to the earth, sunlight and the atmosphere; basically, their entire ecosystem.
Are Hydroponics Organic?
According to the Canadian Organic Standard, hydroponics can’t be certified organic because organic certification in Canada requires that organic crops must be grown in organic matter, namely soil. So, even though a hydroponic farm may avoid pesticides and synthetic fertilizers it would not be allowed to certify its crops as organic.
The main goal of organic agriculture is to maintain the health of the soil. Healthier soil means healthier plants and greater biodiversity. Hydroponics, on the other hand, is more focused on rapid crop growth and higher crop yields.
The Future of Farming
As an indoor system, hydroponics can be very beneficial for large cities. Fresh fruits and vegetables can be grown right within the urban centre, eliminating the need for produce to be transported from farmland located thousands of miles away. With hydroponics it’s not hard to imagine that one day we’ll be able to buy vegetables and herbs that have been grown right in the grocery store.
Yet, there can be unintended consequences for changing the way we grow food. No one can truly say what a surge in hydroponic farming might mean for the nutritional value of our fruits and vegetables. Or whether we may lose access to helpful microbes that plants are exposed to via the soil. As hydroponic farming becomes more mainstream, we also must consider how the biodiversity of our food will be impacted. Finally, we must face practical considerations around sustaining the world’s growing population. Unfortunately, soil farming alone may not be enough. For more information, check the list of articles and resources at the end of this article.
At Karma, we currently don’t stock hydroponically grown produce, but we do sell aquaponically grown microgreens from the Toronto supplier Aqua Greens. Like hydroponics, aquaponics grows crops in water. The main difference between the two is the source of the nutrients that are added to the water. While hydroponics uses a mixture of synthetic nutrients, aquaponics uses the nutrients from fish manure that are raised alongside the aquaponic produce. Aquaponic produce can be certified organic in Canada, albeit controversially. Despite the lack of soil as a growing medium, fish manure is considered organic matter.
So, here’s the dilemma: is it better to support locally grown, hydroponic or aquaponic produce that otherwise follows organic practices but may have unknown impacts on our health and ecosystems? Or, is it better to choose organic, soil-grown produce that may need to travel far and wide to reach us? How do we manage these different agricultural approaches while still being holistic and sustainable? What do you think? Share your thoughts with us!
“What is Hydroponics?” by Agriculture and Agri-Food Canada (March 29, 2017)
“Benefits of Hydroponics” by Green Our Planet.org.
“Are Hydroponic Vegetables as Nutritious as Those Grown in Soil?” by Sophie Egan. The New York Times Well Blog (December 23, 2016)
“The Organic Hydroponics Dichotomy: Can a Soil-Less Growing System Be Organic?” Cornucopia Institute White Paper (March 5, 2015)
“Are Hydroponics and Organics a Good Fit?” by Rupert Jannasch. The Canadian Organic Grower. (January 2009)
“Hydroponics Could Make Farming Flourish in UAE Desert” by Daniel Bardsley. The National.ae. (July 19, 2014)
“Comparison of Land, Water, and Energy Requirements of Lettuce Grown Using Hydroponic vs. Conventional Agricultural Methods” by Guilherme Lages Barbosa, Francisca Daiane Almeida Gadelha, Natalya Kublik, Alan Proctor, Lucas Reichelm, Emily Weissinger, Gregory M. Wohlleb, and Rolf U. Halden. National Center for Biotechnology Information (NCBI). (June 16, 2015)
“Something Fishy About Aquaponics” by Will Baigent & Cecilia Stuart. The Organic Council of Ontario. (September 19, 2018)
Submitted by Christine Dias