Plastic in agriculture a growing problem

An early winter storm left Suzanne Long and Tim Sanford with enough snow to use a plastic sled instead of a wheelbarrow for their morning chores on Luna Bleu Farm.

growing problem

In the short, cold days of December, little grows on the 43 acres of rocky hills where the married couple has farmed minutes outside the village for nearly thirty years. In one of their organic vegetable farm’s beds, heads of frozen kale look like a line of lollipops dipped in white.

But long after the frost hardens their land, Long and Sanford continue to farm — indoors.

Long led the way inside a greenhouse, where fresh greens were almost ready to harvest. The greenhouse’s plastic roof and sides trapped the sunlight, warming the air without burning any fuel. The ground of the 92-foot-long greenhouse is covered by polyethylene blankets as white as the snow outside.

Long lifted a corner of a row cover. Dark green spinach grew in a dense bed kept warm under the plastic’s insulating weight.

It is a relatively inexpensive and highly effective tool that can help a small farm achieve economic viability. And it’s critical for organic farmers who shun herbicides and pesticides.

It “just makes things grow a lot better,” Sanford said.

Still, like many Upper Valley farmers, Sanford and Long would prefer they weren’t so dependent on plastic for their livelihood.

Earlier this month, the Food and Agricultural Organization, an agency of the United Nations known as the FAO, issued a “call to action” on agricultural. The report acknowledged the reasons why plastic has become so ubiquitous over the last 70 years: It increases productivity and efficiency, reduces the need for labor and limits food loss and waste.

But agricultural plastic comes with serious trade-offs, argues the FAO. “Most agricultural plastic products are single use and can persist in the environment long after their intended use,” wrote FAO Deputy Director-General Maria Helena Semedo. “Degrading into microplastics, they can transfer and accumulate in food chains, threatening food security, food safety and potentially human health.”

John Wesley Hyatt, an engineer, invented plastic in 1869, after a billiards ball manufacturer offered $10,000 to anyone who could find a substitute for ivory. The new material was lauded as the elephants’ savior.

During World War II, American plastic production increased three fold as nylon and plexiglass took the place of natural fabric and glass. Industry no longer had to keep production within the limits of naturally-sourced materials.

The war ended, but the plastic revolution accelerated.

In the 1950s, E. M. Emmert, a Kentucky horticulturist, sparked plastic’s boom on farms. The story goes that he had no money for a glass greenhouse, and so he wrapped plastic around a wooden frame. Soon, he upgraded to polyethylene, a durable polymer that withstands the wear and tear of a farm better than most. He discovered that plastic greenhouses, mulches and row covers could increase yields and reduce labor.

Farmers were quick to catch on. In the Upper Valley, It became widespread, especially on the small organic farms that took root in the 1970s and 1980s. Many farmers with small operations couldn’t afford glass or other natural materials, and plastic reduces the need for toxic chemicals.

But agricultural plastic is also a “major source of contamination” that is energy intensive to produce and transport, and difficult to recycle, warns the FAO. The FAO estimates that nearly 14 million tons of agricultural plastic is used each year worldwide, with the majority in crop and livestock operations.

Dirtied with clumps of soil and manure, agricultural plastic usually sells for little or nothing on the recycling market.

Truckloads pile up in landfills. Farmers who are either unable or unwilling to drive to a landfill and pay for its disposal often store plastic that’s no longer usable on their land. Others burn or bury it, even though doing so violates environmental laws.

“We would like to get away from plastic, but when we’re thinking about something like greenhouse structures — we wouldn’t be able to do any of that,” Long said. “Our margins are already so thin.”

Long, 60, and Sanford, 69, use plastic in a multitude of ways. Outdoors, they plant vegetables in holes cut out of a layer of black plastic mulch — a dark sheet not unlike a garbage bag. Plastic keeps down weeds, warms the soil for crops adapted to warmer climates and keeps moisture in the ground to help withstand droughts.

To grow 100,000 pounds of produce a year, Long and Sanford would struggle without plastic. The plant trays that hold seedlings are made of plastic, and so are the drip tape irrigation lines that conserve water. It row covers protect against insects. Plastic crates hold vegetables over winter.

In the 1990s, Long and Sanford built their first greenhouse to start seedlings ahead Vermont’s natural growing season. They added additional greenhouses to grow tomatoes in the summer and then vegetables in winter. They now have a row of seven — all built largely of plastic.

With the help of plastic, spinach and arugula can be harvested all year long. It enables Long and Sanford to provide customers with more than just storage crops such as potatoes and cabbage during the winter.

Luna Bleu Farm has about 45 year-round customers in its community-supported agriculture program, or CSA for short. Before the COVID-19 pandemic, Long and Sanford also sold their produce at indoor winter farmers markets.

Along with the benefits of plastic, however, Long and Sanford recognize its downsides.

With outdoor crops sheathed in black plastic, water run offs without seeping into the soil. Plastic mulch is cheaper and less labor-intensive than organic mulches, like wood chips or hay, which Luna Bleu Farm also uses. But plastic cannot replicate the organic activity between soil and the organic mulches, Long said.

In their fields, Sanford and Long use plastic silage tarps to smother weeds. It allows them to avoid having to turn over the soil by tilling, which can accelerate erosion and surface runoff. Minimal tillage, as it’s called, is a farming practice designed to build organic matter and trap carbon from the atmosphere. But minimal tillage increases farmers’ dependence on plastic tarps.

“Plasticulture,” as it’s known, has taken off over the last 50 years, said Rebecca Sideman, a professor at the University of New Hampshire Cooperative Extension. It typically describes vegetable operations that use plastic far more intensely than Luna Bleu Farm. It’s become an academic cottage industry, where researchers search for new ways that plastic can increase yields and profits.

In the Northeast, farmers rely on plastic to reduce the risk of crop failure, Sideman said. “We have a super variable climate,” she said. “We have rainfall and inclement weather, which can cause really devastating problems on crops and hurt crop quality.”

“High-tunnels” – plastic draped over metal hoops planted across crops that intense rain would batter — buffer farmers from the dangers of heavy storms on fragile crops.

Feeding livestock with plastic
On dairy farms up and down the Upper Valley, old wooden barns that were once packed with square bales of dry hay stand mostly empty.

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Many farmers now store their cow’s winter feed outdoors. Large, round bales wrapped in shiny plastic appear on the horizon like giant white marshmallows. Concrete silage bunkers with plastic covers also preserve cows’ forage. Farmers moved away from storing hay in barns with good reason, said Steve Taylor, a Meriden farmer and a former New Hampshire agriculture commissioner.

Drying hay requires hands-on labor and a stretch of sunny days. But sealing forage in a white plastic roll or covering it with multiple layers of plastic takes only a day, and machines do much of the work.

Working fast is a necessity during wet summers, which seem to be coming with increasing regularity in the Northeast as the climate changes, Taylor said.

“When I was a teenager, we could count on three straight sunny days in June and July to cure hay, to get it dry and put it into the barns, and have it retain its feed value and do it safely,” he said. “But we don’t get that kind of weather in the summers now.”

The plastic rounds “cost a Dickens,” taking a bite out of a small farm’s slim profits, Taylor said, and chances are they will be discarded in a landfill.

But round bales wrapped in as many as six layers of plastic seal out oxygen so the forage ferments. By keeping the feed wrapped in plastic, it lasts all winter, and so far, no other material measures up, said Carl Majewski at the University of New Hampshire Cooperative Extension.

“If someone could come up with a better way, it would be great. But I don’t see it right off,” said Pat McNamara, whose family has been farming in Plainfield for 70 years and now takes a truckload of plastic to a landfill each year.

An environmental contaminant
Like McNamara, Long and Sanford also haul plastic that has outlived its use to a landfill. They recognize that getting it “off the landscape” helps protect their farmland from contamination.

Agricultural plastics’ “widespread and long-term use, coupled with lack of systematic collection and sustainable management, leads to their accumulation in soils and aquatic environments,” the FAO reported.

When left on farmland to disintegrate, agricultural plastics contaminate soil. They break down into microplastics and nanoplastics — highly mobile, small fragments of plastic that accumulate in soil and waterways.

Earthworms and other soil organisms eat microplastics. When a bird, for example, eats an earthworm, the microplastics then move up the food chain in higher concentrations. Some fragments are so small that they can cross cell walls.

Plastic disrupts the nutrient cycling and microorganisms that make soil fertile. When spread over soil, plastic blocks sunlight and the natural movement of water, and decreases the populations of microorganisms.

How “organic” is plastic?
Geo Honigford used plastic to grow tomatoes, peppers, eggplants, melons and sweet potatoes on his organic vegetable farm in South Royalton before he sold his farm this fall.

Without plastic, these crops would have diminished yields or no yields at all in Vermont’s climate, he said. He didn’t like paying thousands of dollars to the plastic industry, and then paying to dispose of the material. But plastic also meant that he didn’t have to depend on hard-to-find labor to weed his crops.

Honigford could never get all of the plastic mulch out of his soil at Hurricane Flats after he pulled it up at the end of the season. “I’ll be walking around my farm finding these little shards of plastics,” he said.

Using plastic didn’t settle well with how he understood organic agriculture. He saw organic organizations and farmers embrace plastic. They hosted workshops on how to use it and constantly promoted new ways to incorporate it into organic practices.

Just months before the COVID-19 pandemic struck in early 2020, Honigford voiced his concerns at a meeting of the Vermont chapter of the Northeast Organic Farming Association.

“As an organic farming community, we’re running to plastics faster than we’re running away from them,” he told the room of farmers and organic advocates. “And we pat ourselves on the back and say, ‘aren’t we better than the conventional guys?’ And yet we’re filling up dumpsters with the stuff at the end of the season.”

Nicole Dehne, the certification director at NOFA-VT, said Honigford had pointed to an area where organic farmers could do better. NOFA-VT helped set up a task force that brought together farmers, state and NOFA-VT officials and municipal waste managers. But then the pandemic brought more pressing problems, and nothing came of it.

Looking for alternatives
Mary Beth Kirkham, a Kansas State University professor who researches microplastic contamination and co-edited a book on the subject, argues that farmers need to end their dependency on plastic.

“We just can’t keep adding more and more microplastics as we’re doing,” she said.

She proposes using ceramic pipes to irrigate fields and returning to glass greenhouses. Bags made from hemp can hold seeds, and organic mulches were used before plastic was ever introduced.

“We could go back to some of these earlier methods,” she said.

At Luna Bleu, Sanford and Long try new materials and farming methods each year with a goal of using less and more durable plastic.

Long demonstrated how a Japanese planter removes the need for plastic pots. Every opening in the collapsible paper honeycomb holds a seedling that they unravel into a chain and plant in the soil. Given a year or two, it biodegrades.

But it’s a “fiddly” product, especially in their rocky soil, Sanford said. He held up firm, durable black plastic trays for plants that they had bought to displace the flimsy, already fractured trays piled along a wall of their shed.

Glass is out of their price range and prone to break, but plastic that can be used for many years is a step up from single-use plastic.

Standing among the plastic crates in their wooden barn stocked with storage vegetables, Long and Sanford weighed the pros and cons of using plastic.

Organic mulches, like wood chips or hay, keep the weeds down and retain moisture. “But it’s a bigger expense and it’s more labor. So that’s that trade off,” Long said.

Like many small organic farmers, Long and Sanford struggle to compete with larger conventional vegetable farms. “Part of the issue does still come down to cost of food,” she said. “So many of the environmental impacts are externalized.”

Source: vnews

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