ASHS 2025 Conference

Polyethylene (PE) mulch is a valuable tool that suppresses weeds, optimizes the soil and canopy microclimate, and enhances efficient production of quality fruits and vegetables. However, PE mulch is not biodegradable and limited cost-effective waste management options lead to large amounts of used PE mulch being annually landfilled, stockpiled on farms, burned, and sometimes buried in soil. The objective of this presentation is to review the status of alternative mulch technologies that have the potential to reduce plastic waste generation in strawberry (Fragaria × ananassa) cultivation with an emphasis on soil-biodegradable plastic mulch (BDM), hydromulch, and cellulose-based film. Several commercial BDM products have been available in the market since the 1990s and are made using a blend of fossil-fuel derived and biobased ingredients. Trials conducted in Washington State show strawberry yield and fruit quality are comparable when plants are grown with black PE mulch or BDM. Green BDM deteriorates rapidly depending on environmental conditions. Rapid deterioration may lead to increased weed pressure and reduced production similar to bare ground cultivation. Hydromulch is a sprayable mulch alternative that can be formulated with ingredients that meet the requirements for certified organic production in North America, whereas commercially available BDMs do not meet these requirements. Trials carried out in Washington State and North Dakota demonstrated hydromulch maintains strawberry yield and fruit quality. Hydromulch formulations with guar gum demonstrate superior mechanical properties relative to formulations without or with other tackifiers. Reduced weed suppression, the logistics of sourcing hydromulch feedstock, lack of specialized application equipment, and high material and application costs are current barriers to this emerging technology. Cellulose-based film, such as lignocellulose film, is another fully biodegradable and emerging alternative to PE mulch and can be made with ingredients suitable for certified organic production. Field trials with cellulose-based film are limited, but current findings show high levels of biodegradability and maintenance of crop growth. Growers, crop consultants, and marketers should consider biodegradable mulch alternatives to reduce plastic waste generation and persistent plastic pollution in agricultural and environmental settings, particularly if recycling is not available or a cost-effective option.