Plastic mulch is widely used in specialty crop production to improve weed control, conserve soil moisture, and increase crop yields. Approximately 2.5 million metric tons of plastic mulch films are used globally every year, with polyethylene (PE) being the most widely used polymer in mulch manufacturing (FAO 2021). This is because of the durability and flexibility, low cost, excellent mechanical strength, and barrier properties of PE that can prevent weed growth, optimize soil temperature, and conserve soil moisture for crop growth ( However, conventional polyethylene mulch creates significant disposal challenges because it must be removed from fields and sent to landfills after use.
Soil-biodegradable plastic mulches (BDMs) have emerged as a potential alternative that can be tilled into the soil after the growing season, where they are designed to biodegrade through microbial activity. Generally, BDM has agronomic performance similar to that of PE mulch; therefore, growers can achieve weed management, moderation of soil temperature and moisture, and enhancement of crop yield and quality The in situ disposal of BDM saves labor and end-of-season removal.
The article addresses many of the most common questions growers, educators, and agricultural professionals have about BDMs, including how they work, what they are made from, their environmental impacts, performance in the field, and current regulations surrounding their use.
Interest in biodegradable mulch technologies has increased as growers seek more sustainable production practices while reducing labor and disposal costs associated with conventional plastics. The publication explains that while BDMs offer promising advantages, successful adoption depends on understanding factors such as soil conditions, climate, crop management practices, and product selection.
According to the authors, additional research is needed to improve understanding and confidence in biodegradable mulch technologies while advancing new options that support organic production, soil health, nutrient delivery, and circular economies. At the same time, better recycling systems for polyethylene mulch are needed in situations where biodegradable mulches are not practical, including improved collection and processing methods that reduce soil contamination, transportation costs, and recycling challenges.
Additional research is needed to improve understanding and confidence in biodegradable mulch technologies while advancing new options that support organic production, soil health, nutrient delivery, and circular economies. At the same time, better recycling systems for polyethylene mulch are needed in situations where biodegradable mulches are not practical, including improved collection and processing methods that reduce soil contamination, transportation costs, and recycling challenges.
The article provides a comprehensive overview for growers, researchers, extension professionals, and others interested in sustainable specialty crop production practices.
Carol Miles has been investigating biodegradable plastic for agricultural applications for 25 years. The initial motivation was prompted by using nondegradable polyethylene mulch for organic crop production and feeling the waste and environmental pollution that comes from plastic inadvertently left in the field is counter to the principles of organic agriculture. Carol worked with a group of graduate students and a postdoc to write this article to address the questions that frequently come from growers and research and Extension colleagues regarding biodegradable plastic.
Carol Miles is Professor of Horticultural Crops Research and Extension Specialist at Washington State University.
The full article can be found on the ASHS HortTech electronic journal website at: https://doi.org/10.21273/HORTTECH05652-25
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.
