“The plastic footprint of U.S. agriculture” By Julie Peller Ph.D.

Green Junction

In the late 1950s, plastic films began to replace paper and other natural-based materials in agriculture and landscaping. Mostly classified as mulch, these materials are applied directly on soils for different purposes: protection of seedlings and young plants, reduction of soil moisture, control of weed growth, and prevention of soil erosion. For many years, landscaping practices have routinely used plastic netting during seeding to promote grass growth. However, these practices pollute the soil, air, and nearby water as the plastic breaks into smaller pieces (microplastics) over time. A recent scientific study reports, “Plastic mulch films are one of the main sources of microplastic pollution in agroecosystems.”  

Numerous scientific studies have evaluated the effects of microplastics in soil. Plastic particles affect soil texture, and I have witnessed this change in my backyard garden, which is contaminated with microplastics. I found that the soil clumped around pieces of plastic. In addition, microbial communities are different in soils contaminated with plastic. In the presence of plastics, the soil’s ability to hold water and exchange air changes. Overall, plant growth can be disrupted, and a recent study measured a reduction in photosynthesis.

A 2025 study titled “The plastic footprint of U.S. agriculture” estimated that the industry uses 1.56 million tons of plastic each year, which is 2.7% of total domestic plastic use. While the farming practice of using thin films to improve crop yield by inhibiting weed growth has benefits for food production, many plastics in planting and landscaping are not critical, just convenient. Plants are mostly sold in plastic containers, but some businesses have programs to collect and reuse them. Growing grass can be done without plastic netting; natural materials can replace plastics in landscaping; and consumers can choose sturdier metal gardening tools. Non-plastic pots are an option, and large volumes of soil and mulch can be purchased in bulk rather than in plastic bags. Our earth and the health of its soil depend on choices that reduce plastic pollution. 

Julie Peller, Ph.D., is an environmental chemist (Professor of Chemistry at Valparaiso University). She has been writing a weekly column, The Green Junction, for the past seven years and is helping to move the call of Laudato Si to action. Her research interests include advanced oxidation for aqueous solutions, water quality analyses, emerging contaminants, air quality analyses, challenges along the Lake Michigan shoreline (such as Cladophora, water, and sediment contaminants), and student and citizen participation in environmental work.