Vernon, CT- Updated Assessment Examines Progress and Challenges of Soil-Biodegradable Plastic Mulches in Sustainable Agriculture
Plastic mulch has become an essential tool in modern crop production, helping growers conserve moisture, suppress weeds, regulate soil temperature, and improve yields. However, the widespread use of conventional polyethylene mulch has created a significant environmental challenge: disposal of plastic waste after harvest. A new assessment published by the University of Connecticut provides an updated look at soil-biodegradable plastic mulches (BDMs) and their potential role in creating more sustainable agricultural systems.
The review, led by Dr. Shuresh Ghimire, Associate Extension Educator and Vegetable Specialist at University of Connecticut, brings together researchers from Washington State University and the University of Tennessee. It updates a 2017 review by synthesizing new research on BDM feedstocks, material design and additives, field performance, deterioration and biodegradation in soil, residue fate, standards and certification, economics, and requirements for organic production.
According to Dr. Ghimire, “Despite decades of generally positive research findings, BDMs still represent less than 1% of the mulch market, while conventional polyethylene mulches account for more than 99%. Growers and agricultural service providers need current, science-based information on BDM performance, degradation, and effects on soil health to make informed decisions about adopting or recommending these materials.”
The assessment highlights that biodegradable mulches generally provide crop production benefits comparable to conventional plastic mulches, including weed suppression, moisture conservation, and crop yield support. Research conducted across a range of specialty crops has shown that yields achieved with biodegradable mulches are often similar to those obtained with polyethylene mulch, making them a promising alternative for growers seeking more sustainable production practices.
Co-author Dr. Carol Miles of Washington State University, stated, “I have evaluated BDMs for over two decades, and it is encouraging to see continued improvements in material design as well as the development of standards and certification programs that help ensure products are truly biodegradable in soil.”
The article also notes that questions remain regarding long-term environmental impacts and performance of BDM under diverse field conditions. Rates of degradation can vary depending on climate, soil characteristics, and mulch composition. Cooler or drier soils, including those common in parts of the northern United States, may slow biodegradation. As BDM deteriorates, it can also form transient micro- and nanoplastic fragments before those fragments are further biodegraded. The authors emphasize the need to investigate how such transient BDM fragments interact with soil ecosystems, microbial communities, and soil health.
Dr. Ghimire recommends pairing standardized laboratory biodegradation tests with field-based monitoring. “Laboratory methods are essential for evaluating a material’s inherent biodegradability and ensuring it does not contain harmful substances. Field studies are equally important because they show how a mulch performs and breaks down under the soils, climates, and management practices where growers use it.”
The article also addresses the unique challenges facing organic agriculture. Although biodegradable plastic mulches have attracted considerable interest among organic growers, regulatory requirements concerning feedstock composition and manufacturing processes have limited their approval and adoption in certified organic production systems. Ongoing research and policy discussions are expected to play an important role in determining how these materials fit within future organic farming standards.
As agriculture seeks practical solutions to reduce plastic pollution while maintaining productivity, soil-biodegradable mulches continue to emerge as a promising technology. The updated assessment emphasizes that successful adoption will depend on continued advances in material design, standardized evaluation methods, and a deeper understanding of environmental impacts across diverse agricultural systems.
The full article can be found on the Journal of the American Society for Horticultural Science electronic journal website at: https://doi.org/10.21273/JASHS05596-26
Established in 1903, the American Society for Horticultural Science is recognized around the world as one of the most respected and influential professional societies for horticultural scientists. ASHS is committed to promoting and encouraging national and international interest in scientific research and education in all branches of horticulture.
Comprised of thousands of members worldwide, ASHS represents a broad cross-section of the horticultural community – scientists, educators, students, landscape and turf managers, government, extension agents and industry professionals. ASHS members focus on practices and problems in horticulture: breeding, propagation, production and management, harvesting, handling and storage, processing, marketing and use of horticultural plants and products. To learn more, visit ashs.org.
