How Canada’s plan to curb farm emissions could make plastic pollution worse

Jul 05, 2022

Slow-release nitrogen fertilizers, central to Canada's plan to reduce greenhouse gas emissions on farms, are filling fields with microscopic plastic pollution, environmentalists warn.

The high-tech granular fertilizers are coated in a thin layer of plastic designed to slow down the release of nitrogen into the soil, making it easier for plants to absorb. Excess nitrogen in the soil is the main source of nitrous oxide, a potent greenhouse gas responsible for over a third of emissions from Canadian farms.

Plastic-coated fertilizers are part of a larger group of so-called "enhanced efficiency" fertilizers the federal government estimates could reduce emissions by 15 to 35 per cent. Fertilizer and farming industry groups have pitched them as a key tool in meeting Canada's climate goals — a perspective recently embraced by the federal government.

However, once the nitrogen has been absorbed or dissolved, the fertilizer's plastic coating stays in the soil. These tiny plastic particles can then accumulate in the ground or leach into waterways, absorbing other chemicals along the way that can harm people and the environment.

Studies show microplastics can travel widely through the ocean and air and in human bodies; they act like sponges, absorbing harmful chemicals from the environment before releasing them into people or animals. While there is a rapidly growing body of research that highlights microplastics' harmful effects on oceans, little research has been done on their impact on soil or on human health if they are absorbed by crops.

That worries Carroll Muffett, president of the Center for International Environmental Law. The environmental organization recently published a report, which was not peer-reviewed, calling for greater scrutiny of the use of agrochemicals.

Unlike loose trash, plastic mulches and other sources of microplastic pollution, the use of plastic-coated fertilizers is an "intentional" decision to put irretrievable plastic pollution in the soil, Muffett said.

The UN Food and Agriculture Organization (FAO) estimates fertilizer companies use about 100,000 tonnes of plastic to make about 400,000 tonnes of fertilizers each year, but public sales data from major fertilizer companies suggests the true amount of plastic-coated fertilizers used each year could be far higher.

Microplastics can also travel into or onto crops, eventually making their way into human food. Because plastic-coated fertilizers and pesticides put microplastic "in direct and sustained contact with highly toxic materials," they pose an extra health and environmental risk, Muffett said.

"The convergence of microplastics with pesticides and fertilizers essentially takes two enormous problems and combines them into one."

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Video: The 15-Year Bet Behind Every New Variety!

Canada is trying to decide how much agricultural research capacity it can afford to lose. Brian Rossnagel believes the better question is whether the country can afford to rebuild it.

The longtime barley and oat breeder makes the case with a simple fact about his profession: the consequences of today’s decisions may not become visible for 10 or 15 years.

“Pick the right parents. That’s the biggest thing,” Rossnagel says. “If you pick the wrong parents, you’re not going to get anywhere—and you don’t know that until 10 years, 15 years later.”

That warning carries particular weight as Agriculture and Agri-Food Canada moves to reduce spending and streamline parts of its science operations. The department’s 2026–27 plan anticipates the loss of approximately 665 positions by 2028–29 and says some research will be reduced where capacity exists in academia or industry. AAFC says the changes will make its science operations more cost-effective over the long term.

For Canada’s seed industry, Rossnagel’s career illustrates what is at stake.

This fall, the retired University of Saskatchewan breeder will be inducted into the Canadian Agricultural Hall of Fame. During his 35-year career at the Crop Development Centre, he helped develop more than 100 barley and oat varieties, including CDC Austenson—one of Western Canada’s most widely grown feed barleys. His induction recognizes not only those varieties, but the collaboration and research system that made them possible.

Rossnagel is quick to emphasize that none of it was the work of one person.

“The first thing I thought about was all the other people who contributed to whatever success I and my program had over the years,” he says. “We know that it’s not an individual who does this. It’s a group—a team.”

That team extends well beyond the breeder whose name appears beside a variety. It includes technicians, pathologists, quality specialists, statisticians, regional testing sites, seed growers and industry partners. It also includes the breeders who came before and those who will carry the germplasm forward.

CDC Fraser barley, for example, moved through three breeding careers. Its parents came from Brian Harvey’s program. Rossnagel advanced the material after Harvey retired, and Aaron Beattie later guided it through registration and release.

That kind of handoff is normal in plant breeding. The person who makes the original cross may never see the resulting variety reach farmers.

It also explains why lost research capacity cannot simply be switched back on when budgets improve.

“If you shut it off, it’s very, very difficult—and particularly costly—to start it up again,” Rossnagel says. “If you have to start from scratch, it’s going to be at least 10 years before anybody notices whether you’re getting anything done or not.”

The concern is not simply how many experimental lines Canada can process. Modern equipment, statistical tools and genetic technologies allow today’s breeding programs to evaluate tens of thousands of lines—far more than Rossnagel could handle when he entered the field in the early 1970s.

But efficiency and automation do not generate every idea.

“If you pare back down, and instead of having six or seven individual scientists concentrating on wheat breeding, you go down and say three people could handle all this, well, that’s half the ideas gone,” he says. “Particularly if you happen to lose the three people who had the really neat and innovative ideas, boy, that’s a problem.”

It is a timely distinction for Canadian agriculture. Consolidating programs may preserve the volume of material moving through a system, at least initially. It may not preserve the diversity of thinking, regional knowledge or willingness to pursue unconventional crosses.

That regional knowledge matters because Canadian agriculture is not one uniform production environment. A variety suited to southern Alberta may face different disease, moisture and maturity pressures than one grown in Manitoba, Ontario or Atlantic Canada.

“Agriculture is applied biology,” Rossnagel says. “Biology, all around the Earth, moves from the poles to the equator. It does not move from Newfoundland to B.C. like politics do.”