Building Agricultural Knowledge of Soil-biodegradable Plastic Mulch

The use of polyethylene (PE) mulch causes environmental pollution where incomplete removal leaves fragments susceptible to escape to ecosystems, such as the ocean, where they can cause ecological harm. PE mulch is generally nonrecyclable due to contamination with soil and crop debris after use, leaving growers with few end-of-life options for used PE mulch. Research studies have shown that soil-biodegradable plastic mulch (BDM) is comparable to PE mulch in terms of performance, soil health, and overall economics and is preferred from an environmental perspective, but the adoption of BDM by producers is still low. Previous research has shown that the primary barriers to BDM adoption are insufficient knowledge about BDM, high purchase cost, and unpredictable breakdown of BDM in the soil. The high purchase cost of BDM compared with PE mulch is offset by the costs for PE mulch removal, transport, and disposal fees. This project was conducted to develop BDM training materials, to educate and assess BDM knowledge gained by extension personnel and other agricultural professionals through trainings and webinars, and to educate producers about BDM through hands-on experience. Thirty-six research and extension publication outputs from two previous US Department of Agriculture Specialty Crop Research Initiative BDM projects were reviewed and transcribed into 45 new extension publications that included 11 slide presentations, 5 lecture slides, 10 fact sheets, and 3 videos. All the training materials are posted on a public university website. Professional development trainings were conducted at local, regional, national, and international levels to provide agricultural professionals the current, science-based information on BDM and resources for information. Survey results showed that at a local level, the greatest change of knowledge among participants was observed for "BDM use in organic production" (60%), and the lowest reported change of knowledge was observed for "limitations to PE mulch disposal" (19%). At a regional level, out of 58 participants, 23% to 35% of participants learned "a lot" and 35% to 51% learned "some new information" regarding BDM from the webinar. At the national level, out of 30 participants, 48% responded that they learned "a lot" and another 48% learned "some new information" on BDM from the training. Growers were trained about BDM via field days and on-farm demonstrations where five strawberry (Fragaria xananassa) growers volunteered to participate in BDM trials. The participant growers observed no difference in weed control and fruit yield between the PE mulch and the BDM. Growers expressed concerns about slow biodegradation of BDM after soil incorporation, potential impacts on soil biological activity, food safety concerns with BDM fragments and that BDM is not currently permitted for use in organic production.