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Economics student’s research helps get plastic out of our food, water

Morris, arms crossed, standing in front of flowering trees.
Kevin Morris, undergraduate researcher at WSU’s School of Economic Sciences, is exploring the forces behind more sustainable plastic use in agriculture.

Protecting our oceans, rivers, fields, and food supply from a flood of plastic pollution means changing the way we use plastic, as well as the types that we use.

Through his discoveries at Washington State University’s School of Economic Sciences, student Kevin Morris is helping reveal how that change can happen.

A senior from Chelan, Wash., Morris studies the economics of a specific kind of plastic—the sheets of plastic used as ground cover in farming, referred to as plastic mulch.

A rising tide of plastic

U.S. agriculture uses about a billion pounds of plastic annually, and much of that material ends up in landfills, rivers, and oceans, and even our food, beverages, and bodies.

Farmers who grow crops like tomatoes, peppers, melons, squash, and cucumbers rely on large spreads of plastic mulches to block weeds and conserve water. Mulch is the second most used agricultural plastic in the world, with an estimated 700,000 tons, and rising, spread annually.

“We’re using more plastic, but there has to be somewhere for it to go,” said Morris. “It ends up in our oceans and our soil,” ground down into ever-smaller particles that can wind up in the food chain.

Fishing for answers

Most summers, Morris spends profitable months aboard his family’s Alaskan fishing boat, helping bring in the crab catch.

But in 2018, Morris swapped the Fishing Vessel Sandra Five for an academic conference in Spokane, Wash., on the topic of biodegradable plastic mulch, a sustainable replacement for typical plastic made from fossil fuels.

Biodegradable plastic mulch, or BDM, is broken down by bacteria and fungi and eliminated from the environment much faster than non-degradable mulch.

Farmers, however, have been slow to adopt it, as it’s often more expensive to purchase than non-biodegradable plastic. But that lower cost doesn’t reflect the time and labor to remove and dispose of the plastic, once it’s used, or its costs to the environment.

Meeting and talking with scientists from across the U.S., Morris was inspired to study the economic challenge of adoption. Advised by WSU Economics Professor Tom Marsh, his undergraduate research explores the policies that drive supply and demand for BDMs.

Demand for better products, practices

The more people understand the costs from plastic pollution to the environment and our food, the more demand will rise for BDMs, says Morris. Policies that insist on improved products and downstream responsibility by farmers and agricultural corporations could also spur acceptance, as could a higher minimum wage.

“States like Washington, with a higher minimum wage, offer an incentive to switch to biodegradable mulches,” says Morris. “Growers can avoid labor costs involved in removing and disposing plastic from the soil. By going biodegradable, it costs less for them to protect their crops.

“At the end of the day, what will bring change is supply and demand,” he added. “Farmers and society need economic as well as environmental incentives to switch.”

This summer, Morris is finishing a research paper on BDMs and preparing for graduate school. He is on track to receive his bachelor’s degree in economic sciences this fall.