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Organic food has a plastic problem

Analysis by Dr. Joseph Mercola Fact Checked

organic food plastic problem

Story at-a-glance -

  • Black plastic, sometimes referred to as plastic mulch, is a primary method of weed control for many organic farms, particularly those growing tomato, pepper and melon plants
  • Many grass and perennial weeds are unable to penetrate the plastic, which also prevents sunlight from hitting the ground and stimulating the growth of weeds
  • Most of the plastic ends up in landfills, which represents a massive amount of plastic waste, as it’s not unusual for large organic farms to spread plastic over thousands of acres
  • Biodynamic farming, which goes even beyond organic in terms of regeneration and protecting biodiversity, suggests that mulching materials should come from off the farm and be chosen with care
  • According to biodynamics, imported synthetic mulch materials that restrict oxygen to the soil below should “be used with caution”

The No. 1 reason why people choose to purchase organic products instead of conventional is to avoid pesticides and other chemicals not allowed in organics.1 Indeed, just by often or always eating organic, you may have significantly lower levels of pesticide residues in your body compared to someone who rarely does so.2

The benefits of not using chemical pesticides can't be overstated, especially as such chemicals are leading environmental pollutants. Worldwide, an estimated 7.7 billion pounds of pesticides are applied to crops each year, and that number is steadily increasing,3,4 even as related problems, like herbicide resistance and widespread water pollution, rise.

Still, farming without chemical pesticides isn't necessarily easy. "The hardest part about organic [farming] is weed control," Larry Tse, farm manager at Dig Inn Farm in New York, told NPR.5 As such, many use a barrier method instead, laying down row upon row of plastic sheeting to keep weeds in check. While this doesn't pose the risks inherent to chemicals, it's not without controversy and environmental risks of its own.

Plastic weed control used by organic farmers is a source of pollution

Black plastic, sometimes referred to as plastic mulch, is a primary method of weed control for many organic farmers, particularly for tomato, pepper and melon plants. Many grass and perennial weeds are unable to penetrate the plastic, which also prevents sunlight from hitting the ground and stimulating the growth of weeds.

Holes are added that allow the desired plants to flourish, while weeds are kept to a minimum. As an added benefit, the plastic warms the soil, which can speed up plant growth and harvest.

There are irrigation benefits, too, as drip irrigation, which delivers water directly to roots of the plants, acting as a much more efficient form of watering than sprinklers, can easily be used underneath the plastic sheeting. Meanwhile, the plastic sheeting also helps to minimize soil erosion.6

However, there is one glaring problem: What becomes of all that plastic when the growing season ends? Unfortunately, most of it ends up in landfills. This represents a massive amount of plastic waste, as it's not unusual for large organic farms to spread plastic over thousands of acres. While some have had success with recycling programs, they didn't last long, leaving landfills as the primary landing point for the plastic.7

Why biodegradable plastic isn't the answer

It would seem like using biodegradable plastic, which would simply break down over the course of the growing season and become integrated back into the soil, would be an environmentally friendly solution, but biodegradable plastic isn't allowed under organic rules, because it typically contains petroleum-based materials.

It's unknown what effects massive amounts of plastic breaking down over agricultural lands would have, but if adverse effects being observed from plastic pollution in marine environments are any indication, the outcome doesn't look good.

Not surprisingly, representatives from agrochemical giants like BASF, which produces one biodegradable plastic mulch called Ecovio, are regular attendees at the U.S. Department of Agriculture's National Organic Program (NOP) meetings, hoping to gain approval.

At least one study has shown that biodegradable plastics not only biodegrade in the environment, but also that "Carbon from each monomer unit of PBAT [poly(butylene adipate-co-terephthalate)] was used by soil microorganisms, including filamentous fungi, to gain energy and to form biomass."8

Research from the University of Tennessee's Institute of Agriculture also revealed that biodegradable mulches did not appear to have major implications on soil health, noting, "soil properties, soil health indicators and soil functions were affected more by site and time than by the mulch treatments."9

The study evaluated the effects of four biodegradable plastic mulches on soil health at two sites growing pie pumpkins. That being said, some differences were noted, although they weren't consistent among the biodegradable plastic mulches or the two sites. According to the study:

"[W]e did observe significant effects of some of the mulch treatments on six soil properties (aggregate stability, infiltration, soil pH, electrical conductivity, nitrate-N, and exchangeable potassium), four soil health indicators (hydraulic, biological, fertility, and salinity & sodicity), and one soil function (nutrient cycling)."

The study was only two years, which means it may have been too soon to know what effects plastic breakdown products could have on the environment, and ultimately the impacts of biodegradable plastic mulches on soil health remain completely unknown.

A healthier alternative would be a film made from 100% plant materials — and right now this is the only type of biodegradable mulch allowed under the NOP. Unfortunately, such a solution isn't widely available, while other natural mulches, such as straw or paper, are often too expensive or labor intensive for farmers.10

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Why I'm supporting the expansion of biodynamics

The issue of plastic pollution from organic farming is one reason why I support the expansion of biodynamics, which is superior to organic. While a biodynamic farm could be certified organic, an organic farm would not automatically be classified as biodynamic, as biodynamic has stricter rules and additional requirements.

Biodynamic farming is organic by nature, but it goes even further, operating on the premise that the farm be entirely self-sustaining. In the U.S., biodynamic farms use the USDA organic standard as a foundation but have additional requirements, encompassing the principles of regenerative agriculture and more.

For instance, biodynamic farms must produce at least 50 percent of their own organic animal feed, and 100 percent of the farm must be biodynamic (on the contrary, an organic farmer may raise only one crop as organic). In addition:11

  • Crops and livestock are integrated
  • Animals are treated humanely, and all have access to the outdoors, free range forage and plenty of space to move around
  • At least 10 percent of farm acreage is set aside for biodiversity
  • The farm must uphold standards of social responsibility

One of the key differences even between organic and biodynamic farms is that organic farms may raise only one type of crop, or only crops or livestock. But biodynamic farming brings animals and plants together to form a living web of life, a self-sustaining ecosystem.

"Each biodynamic farm or garden is an integrated, whole, living organism. This organism is made up of many interdependent elements: fields, forests, plants, animals, soils, compost, people and the spirit of the place," the Biodynamic Association explains, adding:12

"Biodynamic farmers and gardeners work to nurture and harmonize these elements, managing them in a holistic and dynamic way to support the health and vitality of the whole. Biodynamic practitioners also endeavor to listen to the land, to sense what may want to emerge through it, and to develop and evolve their farm as a unique individuality."

What do biodynamic farms use for weed control?

Biodynamic farms are, by nature, grass fed farms, but the American Grassfed Association (AGA) logo is another tool you can use to find grass fed products. The AGA logo on a product lets you know the animals were fed a lifetime diet of 100 percent forage, were raised on pasture (not in confinement) and were not treated with hormones or antibiotics.13

In the U.S., Demeter USA is the only certifier for biodynamic farms and products. While largely unknown in the U.S., Demeter is well-recognized within Central Europe.

In Germany, 10 percent of the organic farmland is biodynamic, and there are even Demeter stores. At this time, most Demeter members are small family farms that only sell locally or regionally. As for weed control, according to the Demeter biodynamic farm standard:14

"The foundation of weed control needs to be based on strategies that emphasize prevention located within the life of the farm. When applicable, the following techniques need to be demonstrably utilized to their maximum potential before allowed weed control materials (including petroleum to run tractors) may be imported.

Understanding of weed species life cycle/ timing of planting

Adjusting fertility conditions that promote certain weed species

Shade/ crop canopy


Crop rotation

Identifying and avoiding the spread of invasive weed species



Understanding the life cycle of a weed species is a very important tool in controlling a weed species. By knowing when a weed species is the most virulent, loss can be avoided by the timing of planting and also by breaking the life cycle of the weed."

As for plastic mulch, in particular, biodynamic farming suggests that mulching materials should come from the farm and be chosen with care. Demeter states that imported synthetic mulch materials that restrict oxygen to the soil below should "be used with caution," adding:15

"If synthetic mulch materials are used, they must be pulled up annually and not allowed to break down into the soil. In this case, it is preferable that the materials are durable enough to be reused annually. The materials must not inhibit the biological dynamics of the soil below."

Supporting biodynamic agriculture

The vision of Demeter is to heal the planet through agriculture, and we can do that by transitioning farming from conventional to not only organic but ultimately to biodynamic. This is why is increasingly introducing biodynamic products. We started with Moringa powder and are releasing a full line of biodynamics under Solspring, including biodynamic vinegar, Kalamata olives, extra-virgin olive oil and more.

In addition, we're partnering with Marci Zaroff, founder of the first organically certified textile mill in the U.S., to create biodynamic cotton for our SITO line of clothing. SITO stands for Soil, Integrity, Textile and Organic, and its mission is to take a stand for organic cotton and regenerative agriculture.

If you want to learn more about biodynamic farming and why it's a step above organic, be sure to watch my interview with Elizabeth Candelario, managing director for Demeter USA, which discusses the history of biodynamic farming and why biodynamic certification is the mark of a superior product.