Even a garden has a carbon footprint.Here’s how to reduce the climate impact of urban farming | CBC News

Urban gardening may seem pretty harmless when it comes to its overall carbon footprint, but when compared to traditional farming, a study released earlier this year suggests otherwise.

The study, published in the scientific journal Nature in January, found that urban food farming has a carbon footprint six times greater than conventional farming.

But there are ways gardeners can reduce their impact. Let’s see what that does.

Research overview

The study used citizen science at 73 urban farming sites (think cooperatives or collective gardens, not necessarily your backyard garden) in Europe and the United States.

It compared food from large conventional agricultural farms to urban farming sites including professionally managed urban farms, individual gardens and collective gardens.

“The major contributor to the carbon footprint of the sites we studied was actually investments in the infrastructure to grow food,” said Jason Hawes, a doctoral student in the University of Michigan School of Environment and Sustainability and the paper’s lead author.

While some previous studies have looked at high-tech gardens such as vertical farms, the researchers looked at low-tech urban farms.

Hawes says there is an embedded carbon footprint in the materials used in home gardens, such as raised flower beds, trellises and tools.

WATCH | Your garden’s carbon footprint may be higher than you think:

“It’s really important to try and find reused or recycled materials to invest in your garden because that becomes a very important part of your carbon footprint,” Hawes said.

“Whatever you put in at the beginning usually has a real long-term impact.”

But if you already have the device, don’t throw it away, Hawes said.

“If it’s already there, keep using it because you’re going to keep using these materials to produce more food and more social products.”

A different kind of community garden

Some collective gardens in Alberta have taken steps to reduce their environmental impact.

It’s still early in the season, but the folks behind Star Gardens in St. Albert are getting ready for the growing season.

The garden is located behind the Northern Star Retreat Center and is land borrowed by the Oblates.

A variety of vegetables are grown in the garden for volunteers to take home. All additional produce is donated to the St. Albert Food Bank.

Gardeners use techniques they believe contribute to sustainability.

“We’re kind of going back to old-school gardening practices, so it’s a deep mulch, no-till garden,” Star Gardens coordinator Clint Porritt said.

“Part of the deep mulch is the idea of ​​nourishing the soil in a natural way.”

But how do you start a garden on congested land without tilling it?

It starts with cardboard.

“What we do is put down cardboard, which is free for this type of gardening. We look for cardboard in dumpsters,” Porritt said.

Once you have sourced the cardboard, just make a bed on the grass.

“We lay it down. We soak it. We put wood chips on top. On top of the wood chips, we just put straw, leaves, grass clippings, any type of organic material that we can get for free.”

Almost everything in the garden is donated, including the wood and toilet paper rolls they use to make their seedling trays, so they don’t add to their carbon footprint by purchasing new materials.

cover tillage

The Star Garden was inspired by gardening pioneer Ruth Stout, who popularized deep mulch gardening in the 1950s, a method often referred to as “lazy gardening.”

As an amateur gardener, Stout had to compete with conventional farmers to cultivate her garden, Porritt said. One year, she got tired of waiting and decided to try something new.

“She just went to a farmer and got bales of hay that were no longer suitable for feeding the cows,” Porritt said.

“She took them out into her yard and spread them out six to eight inches deep, and then she planted the garden on top of that hay that was going bad because she was tired of waiting for the garden to be cultivated.”

It works.

A major benefit of this type of gardening is that it is very effective at keeping the soil moist.

Porritt said the garden was watered about 10 times the year it was established.

Last year’s record dry year meant the garden needed more water, but Porritt estimates they only watered the garden 20 times throughout the year.

“When you dig up soil, you’re actually drying it out, and you’re destroying all of the microbial networks that are working in the soil to keep it healthy and diverse,” he said.

Tips for reducing your garden’s carbon footprint

Hawes doesn’t want his research to stop people from growing their own food.

Instead, he wants to encourage people to pay attention to the way they garden.

Research shows that maintaining infrastructure for as long as possible and utilizing urban waste streams, such as using rainwater to manage your own compost, can significantly improve a garden’s carbon footprint.

Hawes said that goal is easily achievable with the city’s support.

“If cities can produce recyclable inputs, such as construction waste or reused wood, recycled windows and more that can be used by gardeners, then if we compare them to traditional agriculture, we study The location may be climate friendly.

Overall, he says the social benefits of gardening outweigh the carbon footprint.

“Whether that means giving your neighbor some tomatoes or inviting people over for a garden party, all of those things matter.”

It’s also important to pay attention to the vegetables you grow. Some conventionally grown vegetables have a larger carbon footprint, Hawes said.

“For urban farmers and gardeners, growing tomatoes is a really good thing because they have a relatively high carbon footprint in the traditional supply chain,” Hawes said.

He said asparagus is another vegetable with a larger carbon footprint, in part because of the long distances it takes to transport the product to grocery stores.

For Porritt, growing vegetables is a way to reconnect with nature.

“When you grow your own things, you interact with the environment and you gain a deeper appreciation of the natural world,” he said.

“You start to think of yourself as [nature]not to surpass it or be better than it, but to actually be something [you] You can work side by side with it, or you can become a partner with nature.