Degradable Mulch Evaluation: A Field Study - Year 1

Degradable Mulch for Agriculture: Year 1 Evaluation Of A Field Study Karen K. Leonas1, Hang Liu1, Jeremy Cowan1, Douglas G. Hayes2, Larry Wadsworth2, Russell Wallace3, Carol Miles4, Annette Wszelaki2 and Debra Inglis4 1Washington State University, Pullman, WA, 2 University of Tennessee, Knoxville, TN, 3Texas A&M University, Lubbock, TX, 4Washington State University, Mount Vernon, WA The use of mulch in specialty crop production is critical to increasing and improving yields. The conventional mulch used by growers is a black polyethylene film product that does not biodegrade in the field; as a result, resources for removal and disposal are required. There is a critical need for mulch that can be tilled into the soil after a planting-growth-harvesting cycle to then fully biodegrade without negatively impacting the soil ecosystem. A three-year, multistate and multidisciplinary research project, funded by NIFA Specialty Crops Research Initiative, is now focused on the evaluation of experimental and currently available biodegradable mulch (BDM) products, in both high tunnel and open field tomato production. One experimental mulch material was developed for the study by using fibers of poly(lactic acid) (PLA) and nonwoven fabric production techniques, and is helping to determine if the fibrous structure of the biopolymer with its corresponding higher surface area and porosity will result in an accelerated rate of biodegradation. Year 1 field experiments in western Washington, eastern Tennessee and central Texas are nearly completed. Five mulches, including the experimental spun-bond PLA product, two commercially available BDM products, a cellulose-based product and conventional black polyethylene film, have been evaluated. Changes in breaking strength, elongation, tear strength, scanning electron microscopy, pore size, and molecular weight have been evaluated, and other observations made. This presentation will focus on the degradation of the mulch products during the Year 1 time period.