Source: UNIVERSITY OF TENNESSEE submitted to
PERFORMANCE AND ADOPTABILITY OF BIODEGRADABLE PLASTIC MULCH FOR SUSTAINABLE SPECIALTY CROP PRODUCTION
Sponsoring Institution
National Institute of Food and Agriculture
Project Status
TERMINATED
Funding Source
Reporting Frequency
Annual
Accession No.
1004366
Grant No.
2014-51181-22382
Project No.
TEN2014-07894
Proposal No.
2014-07894
Multistate No.
(N/A)
Program Code
SCRI
Project Start Date
Sep 1, 2014
Project End Date
Aug 31, 2019
Grant Year
2016
Project Director
Hayes, D.
Recipient Organization
UNIVERSITY OF TENNESSEE
2621 MORGAN CIR
KNOXVILLE,TN 37996-4540
Performing Department
Biosystems Engr & Soil Science
Non Technical Summary
Mulching with plastic materials is standard practice for specialty crop growers throughout the U.S. to reduce weeds and conserve water and soil, among many benefits.Unfortunately, most plastic mulch after use is stockpiled or burned illegally due to poor biodegradability of conventional plastic mulch materials, and limited recycling options, releasing harmful residues into the environment. Biodegradable plastic mulches (BDMs) have been developed to address the environmental deficiencies. However, concerns by growers and key intermediaries (e.g., suppliers and county extension agents) have limited the widespread use of BDMs based on perceived barriers: lack of knowledge, high cost, and unpredictable breakdown. To overcome these hurdles, we will implement an integrated and transdisciplinary science- and application-based research design to improve crop production, reduce post-harvest and environmental costs, and increase economic vitality for growers and consumers by using BDMs. Specifically, we will address multiple objectives: 1) evaluate the impacts of long-term BDM deployment (diverse scales of operation and climates) and environmentally-friendly disposal options(tilling into the soil vs. retrieving followed by composting) on soil quality, microbial communities, pests, diseases, and crop production; 2) assess the economic feasibility of BDM utilization(cost and benefits) for growers and consumers; and 3) engage with relevant stakeholders to increase interest in sustainable deployment and disposal of BDMs leading to increased adoption and economic and environmental benefits for growers and consumers.
Animal Health Component
0%
Research Effort Categories
Basic
65%
Applied
30%
Developmental
5%
Classification

Knowledge Area (KA)Subject of Investigation (SOI)Field of Science (FOS)Percent
1331199107015%
1020110110310%
1121499111010%
2035299202010%
2046199200010%
2057410209010%
2164099301010%
4036030308010%
6015299106015%
Goals / Objectives
A. Evaluate the impacts of long-term use of BDMs on 1) the soil ecosystem (i.e., soil quality, microbial communities, and long-term storage of carbon); and 2) on a specialty crop production system along with its associated growers and consumers. B. Identify BDM degradation mechanisms (e.g., changes at the macroscopic and molecular levels) and interrelationships among the life stages of BDMs: their origin (fossil fuel-derived vs. biobased), service life (role of weathering), and potentially sustainable end-of-life outcomes (ambient soil degradation vs. retrieval followed by composting). C. Compare diverse scales of operation (field vs. laboratory studies), climate regions, and methodology for evaluating the soil degradation of BDMs to improve performance regulations. D. Identify steps along the supply chain for BDMs to better understand the bridges and barriers to BDM adoption by growers and intermediaries (e.g., extension agents, agricultural input suppliers, and crop consultants,) as related to economic relevance and regulation; and educate growers, intermediaries, consumers, and the general public on BDMs and biobased mulches and plastics, especially as related to sustainable and organic agriculture. E. Assess the economic feasibility of agricultural products grown with BDM technologies through the entire supply chain to consumers, and identify potential BDM-associated disease and pest problems. F. Interact with a community of stakeholders (consumers, growers, intermediaries, regulators, composters, and scientists) to increase interest in sustainable deployment of BDMs throughout the U.S. and worldwide. G. Educate and train undergraduate and graduate students, postdoctoral research assistants, and principal investigators on skills needed to work on transdisciplinary research problems.
Project Methods
Methods: field and laboratory studies; surveys, focus groups, grower case studies, extension and outreach activities, elaborate team communications.(via teleconferencing and project annual meetings);and project assessment (including input from Advisory Committee). All project outputs will be peer-reviewed by a statistics expert and project team members prior to dissemination.Efforts:Dissemination of new knowledgewill occur via extension and outreach products, field days, scientific publications(including a seminal edited book), and presentations and organized symposia at international conferencesEvaluation: In addition to tracking progress toward completing project tasks, deliverables, and milestones (as described above), project assessment will evaluate this CAP on a larger scale in two major areas: (1) to assess changes in knowledge for key participants and stakeholders (via entrance and exit surveys, and surveys throughout the project duration) as well as changes in action; and (2) to evaluate the overall impact of the research program.(via collection ofprogress metrics such as the number of scholarly outputs, undergraduate students supported, services provided.To assess and quantify the project's impacts in terms of change in actions or practice, we will identify progress metrics to be evaluated, such as crop production costs with different soil types and BDMs, crop yield, reduced or avoided input costs, etc. [4]. We will develop a specific benefit-cost analysis (BCA) framework as a mechanism to evaluate the progress metrics and establish assumptions for the analysis. Throughout the project, we will engage stakeholders via individual consultations and focus groups to accomplish this task. The primary objectives of BCA are to assess the overall feasibility of the project for growers and investors (i.e., USDA), and to provide a basis for comparing the total expected cost against total expected benefits, with and without the project (i.e., evaluate if benefits outweigh the costs and estimate the magnitude).

Progress 09/01/14 to 08/31/19

Outputs
Target Audience:Target audiences reached during the project are specialty crop growers and intermediaries, including Extension specialists and agents; agricultural plastic film and mulch manufacturers; scientists in several different disciplines; agricultural standards committees and regulators; and undergraduate and graduate students. Our efforts extended beyond our traditional audiences and reflect our transdisciplinary approach as we addressed agricultural sustainability and biodegradable plastics with audiences ranging from social scientists to marketing executives in the personal care products industry to specialty crop growers. The project's 24-member Advisory Committee (AC) included specialty crop growers and representatives of grower organizations; Extension specialists; and experts in food safety, polymer science, mulch manufacturing, composting, materials standards, government policy, sociology, agricultural economics, soil microbiology, climate science, various horticultural specialties, and transdisciplinary research. Engaging the AC was paramount for our transdisciplinary project and was accomplished through team-wide meetings and routine working group-level conference calls to review preliminary project research findings, new research protocols, and outreach plans. We reached all audiences through the project's website (http://biodegradablemulch.org), with the homepage having had more than 5,000 visits in the final year of the project. Specialty crop growers and intermediaries have been engaged interactively through their participation in growers' meetings and field days at which team members discussed biodegradable plastic mulches (BDMs) generally and the project specifically. Over the course of the project, the team held or participated in >50 outreach events, including numerous state and regional grower conventions. Assessment of participants at these events demonstrates that the events and information we provide increase participants' knowledge about BDM as an alternative to PE mulch and awareness of the benefits of BDM for specialty crop growers, consumers, and for the environment. Growers were also engaged through seven events hosted by the Technology Adoption (TA) Working Group's (WG's) including on-farm case study demonstrations and focus groups where we capture grower perceptions. We have collected and carefully reviewed the questions we have received from growers and other stakeholder groups in the past year at Extension and other types of events. We presented this information to the team members and the AC in Year 4 and developed a set of extension publications that specifically address our stakeholders' questions: Economic viability of adopting biodegradable plastic mulches (BDMs) at the farm level (Extension); Long term benefits of BDM use (e.g., topsoil conservation, long term productivity) (research and Extension); Explaining the concepts of nanoplastics, microplastics, and other related concepts (Extension); Potential methodologies for measuring BDM fragments remaining in the soil (Extension); Explaining the differences between biobased and biodegradable (Extension); Suitability of BDM for various crops (Extension); Relevance of standards to BDMs (Extension). Our extension publications, included those noted above, are indexed on our website's "Basic Information" page. This page had more than 1800 visits in the final year of the project. Our record of scientific publications and presentations demonstrates our success in reaching the scientific community. To date, our project results are published in 31 peer-reviewed articles across 24 professional journals. The journals have impact factors ranging from 0.474 to 7.149, and averaging 3.0. Just in the final year of the project, team members published journal articles addressing 1) the impacts of BDMs on soil microbial communities and ecosystem functions; 2) BDMs and farmers' perceptions of good farming practices; 3) the use of BDMs in sweet corn and pepper production; and 4) farmers' interest in adopting BDMs at various price points and for particular farm goals. The scientific outputs of the project are indexed through the project website; the page indexing our journal articles had 653 visits in the final year of the project. Students are another target audience. Engagement of students involved in the research and production of outreach products are discussed in the "Opportunities for Training and Professional Development" section. Team members, over the course of the project, have given >20 guest lectures reaching ~800 students in University graduate and undergraduate classes (including a community college, universities not represented on the project team, and university departments other than those of project team members, including one in China where residue from conventional plastic mulch has been labeled "white pollution"). Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?Interdisciplinary research between our project's working groups in the planning, conducting, and analysis of experiments significantly involved postdoc and graduate student trainees. The activities have equipped trainees to prepare Extension outputs and journal manuscripts that they and project scientists and Extension specialist co-wrote in interdisciplinary teams. Three of the project's PhD students each currently hold research or Extension specialist positions in their respective fields (soil science, horticulture, and agricultural economics) at U.S. universities. A fourth PhD student holds a relevant post-Doctoral research position, and another will soon complete her PhD program. Two MS graduates supported by the project are gainfully employed: one as a researcher at Washington State University and another an additional MS serving in a management position at a vegetable processing company. How have the results been disseminated to communities of interest?We have addressed our efforts to disseminate information about BDMs, including our research findings, in the "Target Audiences" Section. Here we share a list of the conferences and symposia at which we have presented and the journals in which our work has been published to demonstrate the breadth of the activity. We have presented results at several national and international scientific conferences, including the American Society for Microbiology; Organic Agriculture Soil Health Symposium; Geoscience Union; American Society for Horticultural Science; Agriculture, Food, and Human Values Society and Association for the Study of Food and Society; Agricultural and Applied Economic Association Meeting; Soil Science Society of America/American Society of Agronomy/ Crop Science Society of America; American Society for Microbiology; International Society for Microbial Ecology; BioEnvironmental Polymer Society; the NSF Food-Energy-Water Systems Research Network Symposium and Workshop; and the International Society of Bioplastics, Biocomposites and Biorefining. To date, our scientific publications appear in these journals: Agricultural Water Management, Agriculture and Human Values, Agriculture, Ecosystems and Environment, Applied Microbiology and Biotechnology, Applied Soil Ecology, Energy Economics, Environmental Science & Policy, Environmental Science & Technology, Food Research International, Frontiers in Microbiology, HortScience, HortTechnology, Journal of Agroecology and Sustainable Food Systems, Journal of the American Oil Chemists' Society, Journal of Engineered Fiber and Fabrics, Journal of Plant Pathology, Journal of Polym. Environment, Journal of Visual Experience, Journal of Science Food and Agriculture, Polymer Testing, Rural Sociology, Science of the Total Environment, and Textile Research Journal. We have disseminated our research findings and general information about BDMs at numerous Extension events in our home states (MT, TN, and WA), as well as many specialty crop grower events including: Pacific Northwest Vegetable Association, Ontario Fruit and Vegetable Convention, Hermiston Oregon Farm Fair, WA Tilth Conference, North Carolina Mountain Research Station Field Day, the Southern Sustainable Agriculture Conference (SAWG), and the North Mississippi Fruit and Vegetable Growers Conference. What do you plan to do during the next reporting period to accomplish the goals? Nothing Reported

Impacts
What was accomplished under these goals? This project showed that 4-years of continuous use of biodegradable plastic mulches (BDMs) in field trials produced no negative impact on soil health. However, complete biodegradation of BDMs in soil will take at least two years and degradation of BDMs during use and after soil incorporation depends on local climatic and soil conditions. We also found that during biodegradation, microparticles and poorly-degradable additives and residues will be released. The fate and transport of terrestrial microplastics and poorly degradable additives needs further study. We demonstrated that crop productivity, weed suppression, and water management did not differ significantly between polyethylene (PE) and biodegradable mulch use. U.S. farmers' employment of BDMs is influenced by product cost, farm size, environmental attitudes, and labor costs as well as farmers' perceptions of good farming practices. Consumers are willing to accept a price premium for food products grown on BDMs, suggesting profitability for growers and social and environmental benefits. Our results allow growers to make more informed decisions on specialty crop production and pricing strategies and demonstrate that BDMs are a viable alternative to PE mulch. Goal A. In western Washington and eastern Tennessee, we completed four years of field trials, comparing four BDMs versus controls: PE mulch, paper mulch, and bare soil. Crops used in the trials were pumpkin, sweet corn, and green peppers. We found that BDMs performed similarly to PE for crop yield, crop quality and control of weeds , soil temperature, and diseases ; and paper mulch was uniquely effective in controlling nutsedge. We found secondary issues--adhesion to vining fruit and unintended damage to mulches from extreme weather events and workers' actions--are more likely to occur for BDMs than PE mulch. We developed a field sampling protocol to assess the amount of visible BDM tilled into soil. We evaluated soil health from field trial plots prior to application of mulches and then every six months, by measuring 19 soil properties (physical, chemical, and biological). We showed that after 4-years of continuous use of BDMs, there was no negative impact of the BDMs on soil health. Overall, BDMs may be a viable alternative to PE mulch. However, long-term studies are needed to better understand the effects of poorly degradable additives and microparticles on soil health. Our studies found BDMs provide comparable soil moisture dynamics to PE mulch although BDMs' soil water conservation effectiveness was diminished as it disintegrated over the growing season. By studying earthworms in mesocosms, we found that earthworms ingested only soil-composted BDMs, and their actions redistributed macroscopic plastics in the soil profile and likely enhance the degradation of BDMs in soil. Goal B. We found no significant effects of BDMs on soil bacterial community structure and soil enzyme activity levels when compared to PE; however, microbial communities differed between seasons and locations. We also identified the type of bacterial and fungal taxa that degraded BDMs in both field-soils and laboratory microcosms and found them to vary between BDMs. We assessed the changes in soil organic carbon fractions between mulch treatments and locations. Soil C accumulation was greater for BDMs compared to PE mulch and bare soil treatments because the latter two did not involve mulches' soil incorporation. All BDM treatments were subject to seasonal effects in carbon fractions with high turnover rates likely due to drought and other factors. We found that 1) climate has a large influence over carbon cycling in mulched soils and 2) microplastic particles comprise a small, albeit increasing, fraction of particulate organic matter in BDM soils. Composting is a viable option for disposal of BDMs. We determined the biodegradation of two BDMs under composting conditions for 18 weeks was ≥97%. While the polymers in the BDMs degraded, micro- and nanoparticles--most likely carbon black--were released from the plastics. The long-term impact of terrestrial micro- and nanoparticles released from BDMs upon degradation warrants additional investigation to ensure that no long-term harm to the ecosystem is caused. Such future studies will be aided by an approach we developed to prepare micro- and nanoplastics from BDMs, consisting of three steps: 1) cryogenic exposure (to simulate environmental weathering), 2) mechanical milling (to simulate tillage of BDMs into soil) producing micro plastics having broad size distribution and irregular shapes, and 3) wet grinding and, which (to simulate low-energy impacts between terrestrial plastics and soil particles), resulting in nanoplastics. Goal C. Our work has shown that there is a direct link between the severity of environmental weathering experienced by a BDM during use and its biodegradability after soil incorporation. Environmental weathering to BDMs during field trial use decreased the BDMs' mechanical strength and increased its embrittlement. Effects of site, season, crop production and soil management practices were significant for all BDMs, and degradation of the plastics cannot be directly predicted based on BDMs' physical and chemical properties. Laboratory simulations showed that environmental weathering accelerated biodegradation of BDMs under both ambient soil and industrial composting conditions, with the less recalcitrant components of the BDMs preferably utilized by microorganisms. Also using laboratory studies, we learned that the addition of both inorganic and organic nitrogen decreased biodegradation rate of BDMs in soil compared to controls. An experimental mulch film prepared from a polylactic acid (PLA)/polyhydroxyalkanoate (PHA) blend underwent biodegradation in soil nearly as rapidly as commercially available BDMs under laboratory conditions, suggesting that the PLA content of BDMs can potentially be increased compared to levels employed in currently available BDMs, which would increase BDMs' biobased content . Goal D. We studied 1) specialty crop growers' experiences with and perceptions of BDMs generally and as related to aesthetics and soil health and 2) mulch manufacturers', organic certifiers', and growers' opinions about USDA National Organic Program (NOP) standards for BDMs. A survey of strawberry growers explored their experiences with and perceptions of PE mulch and BDMs. Significant research findings relate to the barriers and bridges to BDM adoption, tactile space and experiential learning, the role of plastic use in notions of 'good farming', the aesthetics of plastic mulch, growers' perceptions of plastic use and soil health, and the challenges associated with the NOP standards for BDMs. Goal E. We determined that consumers would be willing to pay 10.3% more for strawberries grown on BDMs compared to PE mulch. Consumers who are female, earn a higher income, have stronger environment-friendly attitudes, or receive scientific information about BDM benefits are those most willing to pay a price premium. We found growers' current and potential BDM use to be associated with farm size, attitudes toward products labeled as "environmentally friendly", and labor costs/potential labor savings. Our economic feasibility analysis of BDM use (no price premium for BDM-grown product) demonstrated that BDM use can be more profitable than using PE mulch if, while holding all else the same, marketable yield is 1.2% higher, or material cost of a 4-ft wide BDM is lower than $65 per 1000 linear feet, or hourly labor cost is $4 or more above the $14 and $15 baselines for manual and mechanical labor. Goal F. See "Target Audiences" Goal G. See "Opportunities for Training"

Publications

  • Type: Journal Articles Status: Submitted Year Published: 2020 Citation: Tymon, L., B. Gundersen, and D. Inglis. Potential of fungal endophytes as antagonists to Verticillium dahliae infecting pumpkin mulched with biodegradable plastic in western Washington. Applied Soil Ecology (submitted)
  • Type: Theses/Dissertations Status: Published Year Published: 2018 Citation: Microbial Degradation and Ecological Impacts of Biodegradable Plastic Mulch Films in Agricultural Soils. University of Tennessee, Knoxville, TN. Dissertation. August, 2018
  • Type: Conference Papers and Presentations Status: Published Year Published: 2019 Citation: DeBruyn J.M., S. Bandopadhyay, K. Bonifer, J. Liquet y Gonzalez, T. Reynolds. The agricultural plastisphere: Insights into soil microbes degrading biodegradable plastic mulch films. SSSA Meeting, San Diego, CA, Jan 6-9, 2019
  • Type: Conference Papers and Presentations Status: Published Year Published: 2019 Citation: Wszelaki A., M. Valendia, J.M. DeBruyn. Biodegradable Mulches: What are the effects on the ground, on the crop and on your pocketbook? Ohio Ecological Food and Farm Association Workshop, Dayton, OH, Feb 14-15, 2019
  • Type: Conference Papers and Presentations Status: Published Year Published: 2019 Citation: Hayes D.G., M.B. Anunciado, A.F. Astner, H.M. ONeill, B.R. Evans, S. Venkatesh Pingali, V.S. Urban, M. Flury, H. Sintim, J.M. DeBruyn, S.M. Schaeffer, S. Bandopadhyay, M. English, C. Miles, S. Ghimire, A. Wszelaki, and J. Moore. When Worlds Collide: Relationships Between the Life Cycle of Biodegradable Plastic Mulches and Ecosystems. Bioenvironmental Polymer Society Annual Meeting, Greenville, SC, Jun 5-7 2019
  • Type: Conference Papers and Presentations Status: Published Year Published: 2019 Citation: DeBruyn J.M., S. Bandopadhyay, K. Bonifer, M. Anunciado, H. Sintim, J.E. Liquet y Gonzalez, M. Flury, D. Hayes, T. Reynolds. Soil biodegradation of agricultural biodegradable mulch films. BIOPOL, Stockholm, Sweden, 17-19 Jun 2019
  • Type: Conference Papers and Presentations Status: Published Year Published: 2019 Citation: Liquet y Gonzalez J., S. Bandopadhyay, H. Serrano Ruiz, J.M. DeBruyn. Characterizing microbial communities established on plastic mulch films buried in soil. ASM Microbe, San Fransico, CA, 20-25 Jun 2019
  • Type: Conference Papers and Presentations Status: Published Year Published: 2019 Citation: Flury, M. 2019. Biodegradable Plastic Mulch and Organic Agriculture. National Organic Standards Board/USDA National Organic Program Meeting (Invited Presentation).
  • Type: Conference Papers and Presentations Status: Published Year Published: 2019 Citation: Sintim, H. Y., S. Bandopadhyay, M. English, A. Bary, J.M. DeBruyn, S. Schaeffer, M. Flury. 2019. Biodegradable plastic mulch effects on soil health . Soil Science Society of America International Meeting, San Diego, January 2019 (Presentation).
  • Type: Conference Papers and Presentations Status: Published Year Published: 2019 Citation: English, M., and S. Schaeffer. 2019. Isolation of biodegradable plastic mulch microparticles in soil and isotopic tracing of biodegradable plastic mulch carbon. Soil Science Society of America International Meeting, San Diego, January 2019 (Poster).
  • Type: Journal Articles Status: Published Year Published: 2018 Citation: Bandopadhyay, S., L. Martin-Closas, A. M. Pelacho, and J. DeBruyn. 2018. Biodegradable plastic mulch films: Impact on soil microbial communities and ecosystem functions. Frontiers in Mircobiology 26 April 2018. https://doi.org/10.3389/fmicb.2018.00819.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2019 Citation: Dentzman, K.E., and J.R. Goldberger. 2019. Plastic scraps: biodegradable mulch films and the aesthetics of good farming in U.S. specialty crops. Joint Meeting of the Agriculture, Food, and Human Values Society and Association for the Study of Food and Society, Anchorage, AK, June 26-29, 2019.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2018 Citation: Dentzman, K.E., J.R. Goldberger, C. Benedict, and J. Cowan. 2018. Perceptions of biodegradable mulch films: A case study of Boxx Berry Farm. Poster presentation. Tilth Producers of Washington Annual Conference, Spokane, WA, November 9-11, 2018
  • Type: Other Status: Published Year Published: 2018 Citation: Chen, K.J., S.P. Galinato, S. Ghimire, S. MacDonald, T.L. Marsh, C.A. Miles, P.R. Tozer, M.M. Velandia, M. M. (2018). Important Considerations for the Use of Biodegradable Mulch in Crop Production. WSU Extension FS304E. 2018 (August).
  • Type: Other Status: Published Year Published: 2019 Citation: Velandia, M., A. Smith, A. Wszelaki, and S. Galinato (2019). The Economic Feasibility of Adopting Plastic Biodegradable Mulches in Pumpkin Production. UT Extension publication W 822; University of Tennessee Institute of Agriculture.
  • Type: Other Status: Published Year Published: 2019 Citation: Moore, J. and A. Wszelaki (2019, August). Paper Mulch for Nutsedge Control in Vegetable Production. Performance and Adoptability of Biodegradable Mulch, Report No. FA-2019-02. https://ag.tennessee.edu/biodegradablemulch/Documents/Paper%20Mulch%20for%20Nutsedge%20Control%20in%20Vegetable%20Production_FINAL.pdf
  • Type: Other Status: Published Year Published: 2019 Citation: Hayes, D. (2019, April). Micro- and Nanoplastics in Soil: Should We Be Concerned? Performance and Adoptability of Biodegradable Mulch, Report No. PA-2019-01. https://ag.tennessee.edu/biodegradablemulch/Documents/Microplastics-soil-Factsheet-formatted.pdf
  • Type: Other Status: Published Year Published: 2019 Citation: Dentzman, K. and J. Goldberger (2019, April). On-Farm Biodegradable Mulch Case Study: Boxx Berry Farm - Washington State. Performance and Adoptability of Biodegradable Mulch, Report No. TA-2019-01. https://ag.tennessee.edu/biodegradablemulch/Documents/CaseStudy-Boxx%20Berry.pdf
  • Type: Other Status: Published Year Published: 2019 Citation: Dentzman, K. and D. Hayes (2019, January). The Role of Standards for Use of Biodegradable Plastic Mulches: Truths and Myths. Performance and Adoptability of Biodegradable Mulch, Report No. EXT-2019-01. https://ag.tennessee.edu/biodegradablemulch/Documents/Standards%20Factsheet%20Formatted%20revised%2015Jan2019.pdf
  • Type: Other Status: Published Year Published: 2018 Citation: Dentzman, K. and J. Goldberger (2018, Sept.) On-Farm Biodegradable Mulch Case Study: Cloudview Farm - Washington State. Performance and Adoptability of Biodegradable Mulch Report TA-2018-02. https://ag.tennessee.edu/biodegradablemulch/Documents/CaseStudyFactsheet-Cloudview-9-14-18FINAL.pdf
  • Type: Other Status: Published Year Published: 2018 Citation: Dentzman, K. and J. Goldberger (2019, Sept.) On-Farm Biodegradable Mulch Case Study: Omache Farm - Washington State. Performance and Adoptability of Biodegradable Mulch Report TA-2018-01. https://ag.tennessee.edu/biodegradablemulch/Documents/CaseStudyFactsheet-Omache-9-14-18FINAL.pdf
  • Type: Other Status: Published Year Published: 2018 Citation: Ghimire, S., E. Scheenstra, and C. Miles (2018, Oct.) Soil Sampling Method to Assess the Aount of Mulch Fragments in the Field after Tillage. Performance and Adoptability of Biodegradable Mulch Report FA-2018-02. https://ag.tennessee.edu/biodegradablemulch/Documents/SoilSamplingFactsheet10Oct2018.pdf
  • Type: Other Status: Published Year Published: 2018 Citation: Cowan, J. and C. Miles (2018, Sept.) Impact of Biodegradable Plastic Mulch on Specialty Crop Production. Performance and Adoptability of Biodegradable Mulch Report EXT-2018-02. https://ag.tennessee.edu/biodegradablemulch/Documents/BDM%20for%20crops-research%20summary.pdf
  • Type: Other Status: Published Year Published: 2019 Citation: Anunciado, M. and D. Hayes (2019, Nov.) Disparity between the Terms "Biodegradability" and "Biobased" Pertaining to Biodegradable Mulch Films. Performance and Adoptability of Biodegradable Mulch Report PA-2019-02. https://ag.tennessee.edu/biodegradablemulch/Documents/Biobased-and-biodegradable-Fact-Sheet-final.pdf
  • Type: Journal Articles Status: Published Year Published: 2019 Citation: Astner, A.F., D.G. Hayes, H. O'Neill, B.R. Evans, S.V. Pingali, V.S. Urban, T.M. Young. 2019. Mechanical formation of micro- and nano-plastic materials for environmental studies in agricultural ecosystems. Science of the Total Environment 685: 1097-1106. https://doi.org/10.1016/j.scitotenv.2019.06.241
  • Type: Journal Articles Status: Published Year Published: 2019 Citation: Dentzman, K. and J. Goldberger. 2019. Plastic scraps: biodegradable mulch films and the aesthetics of 'good farming' in US specialty crop production. Agriculture and Human Values. https://doi.org/10.1007/s10460-019-09970-x
  • Type: Book Chapters Status: Published Year Published: 2019 Citation: Hayes, D.G, M.B. Anunciado, J.M. DeBruyn, S. Bandopadhyay, S. Schaeffer, M. English, S. Ghimire, C. Miles, M. Flury, and H.Y. Sintim. 2019. Biodegradable plastic mulch films for sustainablespecialty crop production. In: Guti�rrez T. (eds) Polymers for Agri-Food Applications. Springer, Cham. https://doi.org/10.1007/978-3-030-19416-1_11
  • Type: Journal Articles Status: Published Year Published: 2019 Citation: Moore, J. and A. Wszelaki. 2019. The use of biodegradable mulches in pepper production in the southeastern United States. Horticultural Science 54(6):1031-1038. https://doi.org/10.21273/HORTSCI13942-19.
  • Type: Journal Articles Status: Published Year Published: 2019 Citation: Sintim, H.Y., A.I. Bary, D.G. Hayes, M.E. English, S.M. Schaeffer, C.A. Miles, A. Zelenyuk, K. Suski, and M. Flury. 2019. Release of micro- and nanoparticles from biodegradable plastic during in situ composting. Science of the Total Environment 675(2019): 686-693. https://doi.org/10.1016/j.scitotenv.2019.04.179.
  • Type: Journal Articles Status: Published Year Published: 2019 Citation: Sintim, H.Y., S. Bandopadhyay, M.E. English, A.I. Bary, J.M. DeBruyn, S.M. Schaeffer, C.A. Miles, J.P. Reganold, and M. Flury. 2019. Impacts of biodegradable plastic mulches on soil health. Agriculture, Ecosystems and Environment 273(2019): 36-49. https://doi.org/10.1016/j.agee.2018.12.002
  • Type: Journal Articles Status: Published Year Published: 2018 Citation: Goldberger, J.R. 2018. Agriculture in the plastic age. 2018 AFHVS presidential address. Agriculture and Human Values, https://doi.org/10.1007/s10460-018-9889-x
  • Type: Journal Articles Status: Published Year Published: 2019 Citation: Dentzman, K.E. and J.R. Goldberger. 2019. Organic standards, farmers' perceptions, and the contested case of biodegradable plastic mulch in the United States. Journal of Rural Studies. https://doi.org/10.1016/j.jrurstud.2019.11.002
  • Type: Journal Articles Status: Published Year Published: 2019 Citation: Goldberger, J.R., L.W. DeVetter, and K.E. Dentzman. 2019. Polyethylene and Biodegradable Plastic Mulches for Strawberry Production in the United States: Experiences and Opinions of Growers in Three Regions. HortTechnology 29(5):619-628. https://doi.org.10.21273/HORTTECH04303-19
  • Type: Journal Articles Status: Published Year Published: 2019 Citation: Ghimire, S., M. Flury, E.J. Scheenstra, and C.A. Miles. 2019. Sampling and Degradation of Biodegradable Plastic and Paper Mulches in Field after Tillage Incorporation. Science of the Total Environment. https://doi.org/10.1016/j.scitotenv.2019.135577
  • Type: Journal Articles Status: Submitted Year Published: 2020 Citation: Tymon, L., K. Bophela, S. Martins, L. Ramos-Sepulveda, D. Inglis, and C. Bull. Fruit warts and leafspots of cucurbits caused by Pseudomonas syringae pv. brownii pv. nov. (submitted)
  • Type: Journal Articles Status: Submitted Year Published: 2020 Citation: Ghimire, S., E. Scheenstra and C. Miles. Biodegradable Mulches for growth and yield of sweet corn in Mediterranean-type climate. Agroecology and Sustainable Food Systems (submitted)


Progress 09/01/17 to 08/31/18

Outputs
Target Audience:Target audiences reached during the fourth year of the project (Yr 4) are specialty crop growers and intermediaries, including Extension specialists and agents; agricultural plastic film and mulch manufacturers; scientists in several different disciplines; agricultural standards committees and regulators; and undergraduate and graduate students. Our efforts extended beyond our traditional audiences and reflect our transdisciplinary approach as we addressed agricultural sustainability and biodegradable plastics with audiences ranging from social scientists to marketing executives in the personal care products industry to specialty crop growers. The project's 24-member Advisory Committee (AC) includes specialty crop growers and representatives of grower organizations; Extension specialists; and experts in food safety, polymer science, mulch manufacturing, composting, materials standards, government policy, sociology, agricultural economics, soil microbiology, climate science, various horticultural specialties, and transdisciplinary research. Engaging the AC is paramount for our transdisciplinary project and was accomplished through team-wide meetings and routine working group-level conference calls to review preliminary project research findings, new research protocols, and outreach plans. We reached all audiences through the project's website (http://biodegradablemulch.org), with the homepage having had more than 2,500 visits in Yr 4. Specialty crop growers and intermediaries have been engaged interactively through their participation in growers' meetings and field days at which team members discussed biodegradable plastic mulches (BDMs) generally and the project specifically. In Yr 4, the team held or participated in 11 outreach events, including seven state and regional grower conventions. Assessment of participants at these events demonstrates that the events and information we provide increase participants' knowledge about BDM as an alternative to PE mulch and awareness of the benefits of BDM for specialty crop growers, consumers, and for the environment. Growers were also engaged through seven events hosted by the Technology Adoption (TA) Working Group's (WG's) including on-farm case study demonstrations and focus groups where we capture grower perceptions. We have collected and carefully reviewed the questions we have received from growers and other stakeholder groups in the past year at Extension and other types of events. We presented this information to the team members and the AC to identify topics or needs not addressed with previous research/Extension publications or other project products. As a result of this process, we identified the following topics for Extension outputs and further research addressing these needs: Consumer willingness-to-pay for strawberries using BDMs (Extension); Economic viability of adopting biodegradable plastic mulches (BDMs) at the farm level (Extension); Long term benefits of BDM use (e.g., topsoil conservation, long term productivity) (research and Extension); Explaining the concepts of nanoplastics, microplastics, and other related concepts (Extension); Potential methodologies for measuring BDM fragments remaining in the soil (Extension); Explaining the differences between biobased and biodegradable (Extension); Suitability of BDM for various crops (Extension); White-on-black BDMs and the issues associated with titanium dioxide as white colorant (research and Extension); Summaries of case studies of farms experimenting with BDMs (Extension). Overall impact of BDMs on soil health (research); Economic and environmental value of using PE vs BDMs (Life Cycle Assessment; research); Relevance of standards to BDMs (Extension); and Creation of a label for BDM use (research and Extension). Our record of scientific publications and presentations demonstrates our success in reaching the scientific community. In Yr 4, team members presented 30 oral and poster presentations at professional conferences and symposia. Additionally, at our annual team meeting, members delivered 15 presentations documenting preliminary results for the team and AC. In Yr 4, team members published seven journal articles addressing 1) the impacts of BDMs on soil microbial communities and ecosystem functions; 2) BDMs and soil moisture dynamics; 3) the use of BDMs in pie pumpkin production; 4) sampling methods to asses BDM fragments remaining in the field after soil incorporation; 5) the interaction between earthworms and terrestrial BDM and PE mulch fragments; 6) consumer willingness-to-pay for products grown on BD; and 7) commentary about misuse of terminology associated with BDMs. The scientific outputs of the project are indexed through the project website. Students are another target audience. Engagement of students involved in the research and production of outreach products are discussed in the "Opportunities for Training and Professional Development" section. Team members have given eight guest lectures reaching 350 students in University graduate and undergraduate classes (including a community college, universities not represented on the project team, and university departments other than those of project team members, including one in China where residue from conventional plastic mulch has been labeled "white pollution"). Changes/Problems:No major changes in approach have occurred or are foreseen. In the summer of 2018, one project team member relocated from Washington State University to Kansas State University (KSU), and his portion of the research budget is being moved to KSU. His scope of work has not changed. What opportunities for training and professional development has the project provided?Interdisciplinary research between WGs in the planning, conducting, and analysis of experiments has significantly involved postdoc and graduate student trainees. The activities have equipped trainees to prepare Extension outputs and journal manuscripts that they and project scientists and Extension specialist co-write in interdisciplinary teams. How have the results been disseminated to communities of interest?We have addressed our efforts to disseminate information about BDMs, including our research findings, in the "Target Audiences" Section. Here we share a list of the conferences and symposia at which we have presented and the journals in which our work has been published to demonstrate the breadth of the activity. We have presented results at several national and international scientific conferences and meetings including the American Society for Microbiology; Organic Agriculture Soil Health Symposium; Geoscience Union; American Society for Horticultural Science; Agriculture, Food, and Human Values Society and Association for the Study of Food and Society; Agricultural and Applied Economic Association Meeting; Soil Science Society of America/American Society of Agronomy/ Crop Science Society of America; American Society for Microbiology; International Society for Microbial Ecology; BioEnvironmental Polymer Society; the NSF Food-Energy-Water Systems Research Network Symposium and Workshop; and the International Society of Bioplastics, Biocomposites and Biorefining. In Yr 4, ten journal articles were published or submitted for review. To date, our scientific publications appear in these journals: Agricultural Water Management, Environmental Science & Technology, Science of the Total Environment, Frontiers in Microbiology, Horticultural Science, Horticultural Technology, Journal of the American Oil Chemists' Society, Polymer Testing, Journal of Plant Pathology, Energy Economics, and Food Research International. We have disseminated our research findings and general information about BDMs at numerous Extension events in our home states (MT, TN, and WA), as well as the following symposia and specialty crop grower events in 2017-2018: Pacific Northwest Vegetable Association, Ontario Fruit and Vegetable Convention, Hermiston Oregon Farm Fair, WA Tilth Conference, North Carolina Mountain Research Station Field Day, the Southern Sustainable Agriculture Conference (SAWG), and the North Mississippi Fruit and Vegetable Growers Conference. What do you plan to do during the next reporting period to accomplish the goals?In the final project year, altogether we plan to produce eight Extension fact sheets and six case study reports, and complete more than twenty journal manuscripts that are in preparation or planned. In September 2018, the Soil Ecology WG will complete the final soil quality assessment. We will keep monitoring environmental variables (soil moisture, soil temperature, meteorological variables) until spring 2019. Our 4-year study of BDM biodegradation in soil will be completed after retrieval of BDM fragments buried mesh bags in fall 2018 and spring 2019. Soil lysimeter measurements will be done in fall 2018, and data from lysimeters will be analyzed and interpreted. Data from the soil quality assessments will be analyzed and disseminated in form of a technical manuscript. We will continue to analyze for C dynamics in soils and laboratory experiments. DNA sequence data analysis will be continued to determine microbial community structures and shifts over time. We have set up a lab experiment to test the effects of various Nitrogen amendments on mulch degradation; this coming year we will measure and analyze degradation rates, gas emissions and soil nutrient cycling dynamics. We will continue to analyze all data and write up scientific publications. To finalize assessment of the specialty crop production, the Field Activities WG will complete crop harvest in September 2018 and both locations will continue data analysis and draft papers documenting results. In WA, we will sample soil for mulch fragments in October. At both field locations we will collect mulch samples for testing, till in BDMs and remove PE mulch, and plant a winter cover crop. In late April 2019, we will kill the winter cover crop, and soil samples will be collected for quality analysis. In WA, soil will also be sampled for mulch fragments. A summer cover crop will be planted by late May at both sites. The Plastics Analysis WG will continue measuring the biodegradability of plastic mulches under industrial composting conditions. We will measure biodegradability (via carbon dioxide evolution) and physicochemical changes of the plastic mulch fragments in soil. Materials and soils scientists will collaboratively assess the effect of soil nitrogen sources and levels on biodegradability of plastic mulches. After completing the analysis of mulches retrieved from the field in September, 2018, after fruit harvest in both Knoxville and Mount Vernon, we will evaluate environmental data and the physicochemical properties of weathered mulches across four years to determine important linkages between the two datasets, and prepare a manuscript for publication. We will also prepare a manuscript for publication featuring the effect of agricultural weathering on biodegradability under soil and industrial composting conditions via standardized laboratory testing. To continue the assessment of economic considerations, the LCA-Supply Chain WG will complete the following tasks. First, we will conduct a grower willingness-to-pay survey, analyze the data, and prepare a report. The survey will focus on the factors that affect a grower's decision on purchasing BDM, particularly change in crop price, portion of mulch residue in field at end of season (before tilling into soil), soil health, and mulch cost. Second, we will conduct a Life Cycle Analysis of selected agricultural production scenarios with a manuscript for publication generated as output. Third, we will finalize and publish extension factsheets about the partial budget analyses of BDM adoption in pumpkins and sweet corn in Western WA, and pumpkins and peppers in TN. Labor hours involved in cleanup of the different types of mulches (both PE and BDMs) will be validated with growers. The Technology Adoption WG will engage in the following activities: (1) complete on-farm case studies in Tennessee and Washington State; (2) facilitate one experiential field day focused on till-down of BDMs at case study farm in western WS; (3) conduct two or more focus groups in Tennessee and Washington State focused on mulch aesthetics and soil health; (4) collaborate with the Supply Chain / Life Cycle Assessment WG on a survey of specialty crop growers; (5) present posters and oral talks at grower meetings and professional conferences; (6) prepare and submit multiple manuscripts (some in coordination with other working groups) to peer-reviewed journals; (7) complete (and post online) a two-page factsheet about each completed on-farm case study. The Project Evaluation WG will complete an assessment of the overall economic impact of the research project. In the final year of the project, we will produce a publication to document the results of the exit surveys between 2015 and 2018, particularly regarding changes in knowledge and practice of participants before and after the events related to BDM use.

Impacts
What was accomplished under these goals? Biodegradable plastic mulches (BDMs) contribute to sustainable farming practices by replacing polyethylene (PE) mulch which is associated with environmental deficiencies. This project involves 1) conducting laboratory and field studies to assess BDM degradation and effects on crops and soils, 2) studying the economic costs and benefits and growers' and consumers' perceptions of using BDM, and 3) increasing interest in sustainable deployment and disposal of BDMs. Our findings demonstrate that the performance of BDMs above and below the soil (i.e., for production of specialty crops and biodegradation in soil after incorporation) cannot be directly predicted based on BDMs' physical and chemical properties and adherence to internationally-recognized standards, but rather are impacted by various crop production practices and techniques for machine laying and plowing of mulches into soil. From a soil health perspective and based on analysis of two years of soil quality data, we conclude that BDM is a viable alternative to PE mulch; however additional attention is warranted on the poorly-degradable additives such as plasticizers, binders, and colorants, and their residues that are currently not directly addressed in testing and regulations. We have demonstrated that productivity, weed suppression, and water management does not differ significantly between PE mulch and BDM use; but, secondary issues such as BDM adhesion to vining fruit and unintended damage from extreme weather events, unintended actions by workers, and machinery can increase soil exposure and reduce weed control. Our research finds that U.S. consumers are willing to accept a price premium for food products grown on BDMs, suggesting profitability for growers and social and environmental benefits through increased replacement of PE mulches by BDMs. Interactions with growers have revealed perceptions of BDMs and operational factors that present challenges to adoption. By providing empirical evidence on the potential adoption of BDMs, our results allow growers to make more informed decisions on specialty crop production and pricing strategies. Goal A. We completed the 2017 field experiments and all preparations for the 2018 field experiments. We have collected data on mulch percent-soil-exposed, weeds, and crop growth. Preliminary data at WA field site indicates crop growth in 2018 was greater than in 2017, likely due to increased irrigation in 2018, a decision reached to address moisture stress that was observed in 2017. It is possible that different mulch products may require different irrigation regimens. New bell pepper transplants suffered from extreme heat and excessive rain at TN field site, and storms caused tears in BDMs early in the season, allowing weeds to proliferate. Nutsedge, a pernicious weed, was able to penetrate all mulches except for the cellulose mulch. Harvests in TN ended two weeks earlier in 2018 than in 2017. We have drafted a manuscript that evaluates the soil quality data from 2015 and 2016 in which we conclude that the use of BDMs did not have detrimental effects to soil quality compared to PE and bare soil controls. Based on these 2-year results, we conclude that BDMs are a viable alternative to conventional polyethylene (PE) plastic film. We have completed the soil quality assessments for fall 2017 and spring 2018 and continued our study of BDMs' biodegradation in soil through long-term burial of mulch pieces in mesh bags. A publication quantifies the soil moisture dynamics under different mulch treatments (Saglam et al. 2017) and another documents our experiments on the interactions of earthworms with BDM fragments in soil, which found that earthworms were able to ingest BDMs (Zhang et al. 2018).We assessed the changes in total and microbial carbon among treatments and locations observing no significant differences among mulch treatments. Carbon dynamics were quantified in different particle size fractions of the experimental soils. We also developed a protocol to extract BDM fragments (250 - 2000 micrometer) from soil samples. Goal B. Our investigation of soil community structure, function and microbial counts (bacterial and fungal gene copies) found that microbial communities differed between seasons and location, but not between BDM treatments. We identified microbial communities associated with BDMs in field-soils vs. enriched in laboratory microcosms. Fungi associated with BDMs incorporated into the soil differed between mulch treatments. We authored a publication to summarize current knowledge of the effects of biodegradable plastics on soil microbial communities (Bandopadhyay et al. 2018). Our assessment of biodegradation of BDM pieces contained within mesh bags in composting conditions was completed, and a manuscript documenting compost study results has been submitted for publication. Goal C. We completed data collection to assess the effect of agricultural weathering on BDMs' physicochemical properties and biodegradability in soil (via the standardized ASTM D5988 laboratory test) for the 2016 and 2017 field seasons. For all BDMs, agricultural weathering enhanced the rate of biodegradability during the first 3-4 months, but the effect was reduced at later times and varied between BDMs. We also completed assembly of the instrumentation for the testing of biodegradability under industrial composting conditions (per ASTM D5338); applied it to evaluate the effect of weathering on the compostability of two BDMs. Generally, the agricultural weathering factor that most significantly promoted changes in physicochemical properties of BDMs was sunlight. We found that a clear version of BDM underwent the greatest extent of weathering compared to a black and white-on-black version of BDM. We examined the physicochemical property changes of BDM fragments buried in soil in mesh bags and found that soil burial in TN (and less so in WA) led to depolymerization for the BDMs and to an increase of the polylactic acid content for PLA/PHA, the latter indicating the microorganisms' preference for PHA as a carbon source. We developed methodologies for isolating microplastic fragments from soil recovered from laboratory-based biodegradability experiments and for their analysis using Image J software, which included fitting mathematical models to the size distribution of microplastics. Goal D. We collected qualitative and observational data on specialty crop growers' experiences with and perceptions of BDMS via on-farm case studies, experiential field days in WA, focus groups related to BDM aesthetics and impacts on soil health, and interviews with mulch manufacturers, organic certifiers, and specialty crop growers. Emerging research themes include the role of aesthetics in BDM adoption/rejection, growers' perceptions of plastic use and soil health, and the challenges associated with the USDA National Organic Program (NOP) standards for BDMs. Goal E. Using a dichotomous-choice contingent valuation method, we surveyed 1,500 U.S. households with a randomized information treatment and found consumers are willing to pay 10.3% more for strawberries grown on BDM (Chen et al. 2018). Consumers who are female, earn a higher income, have stronger environment-friendly attitudes, or receive the information treatment on the benefits of BDM also expressed more willingness to pay a premium price. We conducted an economic feasibility analysis of BDM utilization in a case study of pumpkin production that did not involve a price premium for the BDM-grown product demonstrated that BDM use can be more profitable than using PE mulch if, while holding all else the same, marketable yield is 1.2% higher, or material cost of a 4-ft wide BDM is lower than $65 per linear foot, or hourly labor cost is $4 or more above baseline of $14 for manual labor and $15 for mechanical labor. Goal F. See "Target Audiences" Goal G. See "Opportunities for Training"

Publications

  • Type: Journal Articles Status: Published Year Published: 2018 Citation: Zhang, L., H.Y. Sintim, A.I.Bary, D.G. Hayes, L.C. Wadsworth, M.B. Anunciado, M. Flury. 2018. Interaction of Lumbricus terrestris with macroscopic polyethylene and biodegradable plastic mulch. Science of the Total Environment. 635 (2018): 1600-1608. https://doi.org/10.1016/j.scitotenv.2018.04.054.
  • Type: Journal Articles Status: Published Year Published: 2018 Citation: Bandopadhyay, S., L. Martin-Closas, A. M. Pelacho, and J. DeBruyn. 2018. Biodegradable plastic mulch films: Impact on soil microbial communities and ecosystem functions. Frontiers in Mircobiology 26 April 2018. https://doi.org/10.3389/fmicb.2018.00819.
  • Type: Journal Articles Status: Published Year Published: 2018 Citation: Ghimire, S., A.L. Wszelaki, J.C. Moore, D.A. Inglis, and C.A. Miles. 2018. Use of biodegradable mulches in pie pumpkin production in two diverse climates. Horticultural Science 53(3):288-294. doi:10.21273/hortsci12630-17.
  • Type: Journal Articles Status: Published Year Published: 2017 Citation: Ghimire, S., A. Saxton, A.L. Wszelaki, J.C. Moore, and C.A. Miles. 2017. Reliability of soil sampling method to assess visible biodegradable mulch fragments remaining in the field post soil-incorporation. HortTechnology 27(5):650-658.
  • Type: Journal Articles Status: Published Year Published: 2017 Citation: Saglam, M., Sintim, H.Y., Bary, A.I., Miles, C.A., Ghimire, S., Inglis, D.A., Flury, M. 2017. Modeling the effect of biodegradable paper and plastic mulch on soil moisture dynamics. Agric. Water Management 193(2017):240-250. http://dx.doi.org/10.106/j.agwat.2017.08.011
  • Type: Journal Articles Status: Published Year Published: 2017 Citation: Hayes, D.G. 2017. Commentary: The relationship between biobased, biodegradability and environmentally-friendliness (or the absence thereof). Editorial in J Am Oil Chem Soc 94:1329-1331. DOI 10.1007/s11746-017-3040-9.
  • Type: Journal Articles Status: Published Year Published: 2017 Citation: Tymon, L, and Inglis, D. 2017. Identification and pathogenicity of a Pseudomonas syringae genomospecies 1 phylogroup 2B causing leaf spots and fruit warts on cucurbits in western Washington, U.S. J. Plant Path 99(3). http://dx.doi.org/10.4454/jpp.v99i3.3956.
  • Type: Journal Articles Status: Published Year Published: 2017 Citation: Miles, C., L. DeVetter, S. Ghimire, and D.G. Hayes. 2017. Suitability of biodegradable plastic mulches for organic and sustainable agricultural production systems. HortScience 52(1):10-15. DOI: 10.21273/HORTSCI11249-16.
  • Type: Journal Articles Status: Submitted Year Published: 2018 Citation: Sintim, H.Y., A. Bary, D.G. Hayes, M. English, S. Schaeffer, C.A. Miles, A. Zelenyuk, D.M. Bell, and M. Flury, 2018. Release of carbon black micro- and nanoparticles from biodegradable plastic mulch during composting, submitted to Science.
  • Type: Journal Articles Status: Published Year Published: 2018 Citation: Chen, K. J., Marsh, T. L., Tozer, P. R., and Galinato, S. P. 2018. Biotechnology to sustainability: Consumer preferences for food products grown on biodegradable mulches. Food Research International. Online 10 August 2018. https://doi.org/10.1016/j.foodres.2018.08.013.
  • Type: Journal Articles Status: Under Review Year Published: 2018 Citation: Dentzman, K. and J.R. Goldberger. The standard organic: A case study of biodegradable plastic mulch films. Journal of Rural Studies (under review).
  • Type: Conference Papers and Presentations Status: Published Year Published: 2017 Citation: Schexnayder, S., J.R. Goldberger, and M. Flury. 2017. Specialty crop growers perceptions of soil health impacts from conventional and biodegradable plastic mulches. ASA-CCSA-SSSA Annual Meeting, Tampa, FL. Oct 22-26.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2018 Citation: Dentzman, K.E. and J.R Goldberger. The standard organic: A case study of biodegradable plastic mulch films." Annual Meeting of the Rural Sociological Society, Portland, OR. July 26-29, 2018.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2017 Citation: Dentzman, K.E., J.R. Goldberger and J.S. Cowan. 2017. Perceptions of biodegradable mulch films: A case study of Cloudview Farm. Poster presentation. WA Tilth Conference, Vancouver, WA, Nov 10-12.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2017 Citation: Liquet y Gonzalez J.E., X. Wen, K. Bonifer, S. Bandopadhyay, T. Reynolds, J.M. DeBruyn. Characterization of soil bacterial isolates capable of degrading biodegradable plastic mulch films. ASM TN-KY Regional Branch Meeting, Cookeville, TN, Nov 10-11, 2017
  • Type: Conference Papers and Presentations Status: Published Year Published: 2018 Citation: Bandopadhyay S., H. Sintim, M. Flury, J.M. DeBruyn. 2018. Structural and functional responses of soil microbial communities to biodegradable plastic film mulching in two agroecosystems. American Society for Microbiology, Atlanta, GA, June 2018. (Poster and Talk)
  • Type: Conference Papers and Presentations Status: Published Year Published: 2018 Citation: Liquet J, S Bandopadhyay, JM DeBruyn. 2018. Characterization of soil bacterial isolates capable of degrading biodegradable plastic mulch films. American Society for Microbiology, Atlanta, GA, June 2018. (Poster)
  • Type: Conference Papers and Presentations Status: Published Year Published: 2018 Citation: Goldberger, J.R. Agriculture in the plastic age. Presidential Address at the Joint Meeting of the Agriculture, Food, and Human Values Society and Association for the Study of Food and Society, Madison, WI. June 13-16, 2018. ~300 participants.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2018 Citation: Tymon, L.S., K. Bophela, L. Ramos-S�pulveda, S. Martins, D.A. Inglis, and C.T. Bull. 2018. Leaf lesions and fruit warts on pumpkin are caused by Pseudomonas syringae sensu stricto. American Phytopathological Society/ International Congress of Plant Pathology Meeting, Boston, MA, July 29-August 3.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2018 Citation: Moore, J.L., and A.L. Wszelaki. 2018. Does bell pepper growth, yield and quality differ among biodegradable mulch treatments? ASHS Annual Meeting, July 31 - Aug 3. Washington, DC. HortScience abstract (in press)
  • Type: Conference Papers and Presentations Status: Published Year Published: 2018 Citation: Hager, B. and A. Wszelaki. 2018. What should organic growers cover the soil with? Southern Sustainable Agriculture Working Group Conference, Chattanooga, TN, 17-20 Jan 2018.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2018 Citation: Chen, K. J., Marsh, T. L., & T. Fortenbery, R. 2018. The relationship between biomaterial and agricultural commodity markets. Selected Paper Presentation, Agricultural and Applied Economic Association Meeting, Washington DC.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2018 Citation: Cowan-Banker, C.D., M.B. Anunciado, L.C. Wadsworth, and D.G. Hayes. 2018. Effect of environmental weathering on microbial assimilation of biodegradable mulch films [poster], 25th BioEnvironmental Polymer Society (BEPS) Annual Meeting, August 15-17, 2018, Troy, NY.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2018 Citation: Cowan-Banker, C.D., M.B. Anunciado, L.C. Wadsworth, and D.G. Hayes. 2018. Effect of environmental weathering on microbial assimilation of biodegradable mulch films [poster], 15th International Symposium on Bioplastics, Biocomposites, and Biorefining (ISBBB), July 24  27, 2018, Guelph, Ontario, Canada.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2018 Citation: Hayes, D.G. [invited speaker], A.F. Astner, H. ONeill, B.R. Evans, S.V. Pingali, V.S. Urban. 2018. Formation of nanoplastics from biodegradable plastic mulch films and characterization of their behavior in soil, 15th International Symposium on Bioplastics, Biocomposites, and Biorefining, July 24  27, 2018, Guelph, Ontario, Canada.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2017 Citation: Hayes, D.G. [speaker], A. F. Astner, H. ONeill, B.R. Evans, S.V. Pingali, V.S. Urban. 2017. Formation of nanoplastics from biodegradable plastic mulch films and characterization of their behavior in soil, BioEnvironmental Polymer Society (BEPS) 24th Annual Meeting, Albany, CA, 20-22 September 2017.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2017 Citation: Anunciado, M., L.C. Wadsworth, C.D. Cowan-Banker, and D.G. Hayes. 2017. Effect of weathering on biodegradability of biodegradable mulch film, BioEnvironmental Polymer Society (BEPS) 24th Annual Meeting, Albany, CA, 20-22 September 2017.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2017 Citation: English, M. E, and S. M. Schaeffer. 2017. The role of biodegradable plastic mulches in soil organic carbon cycling. ASA-CCSA-SSSA Annual Meeting, Tampa, FL. Oct 22-26.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2017 Citation: English, M. E., S. Bandopadhyay, J. M. DeBruyn, D. G. Hayes, and S. M. Schaeffer. 2017. Temperature sensitivity of biodegradable plastic mulches to microbial decomposition. Southeastern Biogeochemistry Symposium, Athens GA.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2017 Citation: Bandopadhyay S, J Liquet y Gonzalez, L Tymon, D Inglis, DG Hayes, JM DeBruyn. 2017. Microbial communities associated with biodegradable plastic mulch films in two agroecosystems. ASA-CSSA-SSSA-Annual Meeting, Tampa, FL, Oct 22-26
  • Type: Conference Papers and Presentations Status: Published Year Published: 2017 Citation: Sintim, H.Y. S. Bandopadhyay, M.E. English, A. Bary, J.M. DeBruyn, S.M. Schaeffer, M. Flury. 2017. Degradation of biodegradable plastic mulches and impacts on soil health. ASA-CSSA-SSSA-Annual Meeting, Tampa, FL, Oct 22-26.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2017 Citation: Liquet y Gonzalez, J., X. Wen, K. Bonifer, S. Bandopadhyay, T. Reynolds, J.M. DeBruyn. 2017. Characterization of soil bacterial isolates capable of degrading biodegradable plastic mulch films. ASA-CSSA-SSSA-Annual Meeting, Tampa, FL, Oct 22-26.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2017 Citation: DeBruyn J.M, S. Bandopadhyay, H. Sintim, M.E. English, S.M. Schaeffer, M. Flury, A. Wszelaki, J. Moore, C.A. Miles, S. Ghimire, D.G. Hayes. 2017. Impact of biodegradable plastic mulches on soil health. Organic Agriculture Soil Health Symposium, Tampa, FL, Oct 24.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2017 Citation: DeBruyn J.M, S. Bandopadhyay, H. Sintim, M.E. English, X. Wen, J. Liquet y Gonzalez, S.M. Schaeffer, M. Flury, K. Bonifer, T. Reynolds, D.G. Hayes. 2017. Biodegradable plastic agricultural mulches: Microbial degradation and implications for soil health. ASA-CSSA-SSSA-Annual Meeting, Tampa, FL, Oct 22-26.
  • Type: Theses/Dissertations Status: Published Year Published: 2018 Citation: Ghimire, S. Biodegradable Mulch for Pumpkin and Sweet Corn Production: Crop Yield and Quality, and Mulch Degradation. Dissertation, Washington State University. Advisor, Carol Miles.
  • Type: Theses/Dissertations Status: Published Year Published: 2018 Citation: Sintim, H.Y. Biodegradable Plastic Mulch. Degradation and Impacts on Soil Health. Dissertation, Washington State University. Advisor, Markus Flury.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2018 Citation: Bonifer K.S, J.M. DeBruyn, T.R. Reynolds. 2018. Quantifying and characterizing poly-lactic acid degradation by the soil microbes Bacillus pumilus and Rhodococcus yunnanensis. International Society for Microbial Ecology Symposium, Leipzig, Germany, Aug 12-17, 2018
  • Type: Conference Papers and Presentations Status: Submitted Year Published: 2019 Citation: English, M., S.M. Schaeffer, Isolation and isotopic tracing of biodegradable plastic mulch microparticles in soil. Annual Meeting of the Soil Science Society of America, San Diego CA, January 2019 (poster presentation, submitted)
  • Type: Conference Papers and Presentations Status: Accepted Year Published: 2018 Citation: Dentzman, K.E., J.R. Goldberger, J.S. Cowan, and C. Benedict. Perceptions of biodegradable mulch films: A case study of Boxx Berry Farm. Poster presentation. Tilth Producers of Washington Annual Conference, Vancouver, WA. November 9-11, 2018. Accepted.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2017 Citation: Goldberger, J.R., C. Lyons, L. DeVetter, and K.E. Dentzman. Biodegradable plastic mulches for strawberry production: Experiences and opinions of growers in three regions of the United States. American Society for Horticultural Science (ASHS), Waikoloa, Hawaii. Sept. 19-22, 2017.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2017 Citation: Cowan, J.S. and J.R. Goldberger. Planning for tactile space to improve extension outreach activities. ASHS Annual Conference, Waikoloa, Hawaii. Sept. 19-22, 2017.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2018 Citation: Ghimire, S. and C.A. Miles. 2018. Yield and quality of sweet corn grown with biodegradable plastic mulches. ASHS Annual Conference, August 1-3. Washington, DC. HortScience (abstract in press)
  • Type: Conference Papers and Presentations Status: Published Year Published: 2018 Citation: Ghimire, S., A. Saxton, and C.A. Miles. 2018. Soil sampling to assess biodegradable plastic mulch fragments in soil. ASHS Annual Conference, August 1-3, Washington, DC. HortScience (abstract in press)


Progress 09/01/16 to 08/31/17

Outputs
Target Audience:Target audiences reached during the third year of the project (Yr 3) are specialty crop growers and intermediaries, including Extension specialists and agents; agricultural plastic film and mulch manufacturers; scientists in several different disciplines; agricultural standards committees and regulators; and undergraduate and graduate students. The project's 24-member Advisory Committee (AC) includes specialty crop growers and representatives of grower organizations; Extension specialists; and experts in food safety, polymer science, mulch manufacturing, composting, materials standards, government policy, sociology, agricultural economics, soil microbiology, climate science, various horticultural specialties, and transdisciplinary research. Engaging the AC is paramount for our transdisciplinary project and was accomplished through team-wide meetings and routine working group-level conference calls to review preliminary project research findings, new research protocols, and outreach plans. Specialty crop growers and intermediaries have been engaged interactively through team members' participation in local and regional growers' meetings and field days at which team members discussed biodegradable plastic mulches (BDMs) generally and the project specifically. In Yr 3, the team held or participated in 11 events that were attended by more than 525 farmers, Extension agents, and Co-op representatives. This number includes the Technology Adoption (TA) working group's (WG's) on-farm case study demonstrations. At the events, we address participants' questions relating to the function, efficacy, and end-of-life strategies of plastic mulches. The Supply Chain-Life Cycle Assessment (SC-LCA) WG is reaching growers and suppliers through personal in-depth interviews about economic aspects. We also reach growers through the project's website (http://biodegradablemulch.org) and the basic information provided in factsheets developed specifically for the website. The website was updated in Yr 3 with a "frequently asked questions" section, based on dialogues with stakeholders at our outreach events. The website also now features an "Ask a Question about Biodegradable Mulch" component. (Extension publications are addressed in the Accomplishments section.) Our scientific publications and presentations record demonstrates our efforts to reach the scientific community. In Yr 3, team members published four journal articles, and submitted five additional manuscripts which are in review or already accepted. The work presented in the Accomplishments section below is being documented in several additional manuscripts for submission in Yr 4. We presented 24 oral and poster presentations at professional conferences and 10 presentations at other (non-recurring scientific conferences). Additionally, at our annual meeting, the team delivered 16 presentations documenting preliminary results. The scientific outputs of the project are indexed through the project website. Extension products to educate growers and other stakeholders in Yr 3 include videos and Extension factsheets that highlight the mechanics of laying BDM, as well as the costs of BDM relative to PE mulch and challenges for disposal of PE mulch. Videos highlighting Soil WG activities and describing the process by which BDMs breakdown within the soil are being finalized. Industry stakeholders, particularly our AC members, review Extension products and manuscripts before publication, for example, the recently revised a WSU Extension publication 'Suitability of BDM for Sustainable and Organic Agriculture.' Our website continues to be a primary point for information dissemination. Students are another target audience, and the engagement of University of Tennessee (UT) and Washington State University (WSU) students involved in project research and outreach is discussed in the "Opportunities for Training and Professional Development" section. Team members have given guest lectures in University graduate and undergraduate classes (including a community college, universities not represented on the project team, and university departments other than those of project team members). One presentation was made to a school club at the K-12 level. These seven events reached 210 students. Changes/Problems:The anticipated change of test crop (reported as possible in Yr 2 report) occured, and new BDMs from the companies whose products were trialed in Yrs 1 and 2 were installed in Yr 3 and will be used for Yr 4. The original products are being trialed as well to test performance after storage. Changes to the experimental design for the field trial are the addition of clear plastic BDM at WA and white-on-black BDM at TN. The addition of a grower WTP study and the time needed to amass sufficient data to develop production budgets has slowed somewhat the development of products by the LCA and Supply Chain WG. Likewise, challenges in recruiting farms to host on-farm field days have slowed case study research in TN. To address this the Technolgy Adoption WG has scheduled two case studies for spring-summer 2018. What opportunities for training and professional development has the project provided?Postdoctoral, graduate and undergraduate students are engaged in project research, collaborating to conducting the experiments, and collecting and analyzing data. Authorship of several journal publications has been led by students, and students also are presenting their research at professional conferences. In Yr 3, two Post-docs, six PhD students, and two MS students are conducting research projects in support of the SCRI CAP research objectives (including one with outside funding). Several undergraduate students also are involved in research, especially data collection. More than 30 members of the team participated in three professional development sessions at the project annual meeting. The first was a presentation and Q/A session offered by project Advisors that explained the process for materials to be certified for use on U.S. organic farms and discussed the current status of biodegradable plastic mulches. The second was a transdisciplinary project training session led by AC member Dr. Doug Jackson-Smith, that led team members through activities to identify further linkages for research and opportunities to include others (beyond university researchers) in data collection, analysis, and product development. The third training session offered by the UT Libraries data curation librarian explained best practices for data management and opportunities and expectations for long-term data storage in public data repositories. How have the results been disseminated to communities of interest?Dissemination of results is related to project Goals D and F and is addressed in the Target Audiences section. Here we address dissemination of results and products built expressly to increase youth interest in science. Presentations about the project to K-12 and community college students (previously addressed) introduce students to applications of fundamental science. Also, PIs DeBruyn and Benedict are developing a video targeting youth that uses animation to explain the process by which soil microbes break down BDMs (to be completed in Yr 4). DeBruyn also developed in Yr 3 a set of youth science activities primarily for 4H clubs and accompany educator guides that focus on decomposition and biodegradation. Researchers and agricultural producers abroad are another community of interest and the team's outreach to and cooperation with international researchers was substantial in Yr 3.. Team members specializing in horticulture, soil microbiology, plastics, farm economics, and technology adoption participated in a tour of BDM use and research in Spain and Italy, and organized and attended an International Symposium on BDMs in Novara, Italy with colleagues at Novamont S.p.A. PIs Flury and DeBruyn each hosted visiting scientists from the Department of Soil Science and Plant Nutrition, Ondokuz May?s University, Samsun, Turkey, and Beijing Pharmaceutical Chemistry Institute, respectively, for year-long rotations in their laboratories. . PIs Flury and Schaeffer are building partnerships with agricultural technology universities in China--Shenyang Agricultural University, Liaoning Academy of Agricultural Sciences and Northwest Agriculture and Forestry University--and have collaborated with researchers of these institutes to establish field trials that parallel those we are conducting in the U.S. What do you plan to do during the next reporting period to accomplish the goals?Generating publications that documentproject findings and presenting results in various formats will continue to be a priority. We are holding a cross-disciplinary symposium on BDMs as they relate to soil at the Soil Science Society of America meeting in October 2017, presenting 2 talks in a Plasticulture Workshop and 4 presentations in general sessions at ASHS 2017. We were invited to present our work on BDMs at the Southern Sustainable Agriculture Working Group Conference in 2018. We are organizing a symposium at American Society for Horticultural Science in 2018 to provide current information on BDM research with a focus on crop productivity and soil quality and health. Presentation of economic and technology adoption results are scheduled for the Western Agricultural Economics Association, the International Sociological Association, Rural Sociological Society meetings in 2018. The Extension/Outreach WG will continue assist PIs in identifying content appropriate for and in writing Extension publications to disseminate scientific findings to a broader stakeholder community. We will continue to post new information on our website. New factsheets will focus on: the difference between 'biobased' and 'biodegradable', the pros and cons of in-place biodegradation (soil incorporation following cropping) vs biodegradation in compost, and field management practices to prevent wind and water erosion of BDM fragments. To underscore the transdisciplinary nature of the project, the Extension and Project Assessment WGs will develop a short video highlighting our AC's involvement in the project (interview them): why they are involved, how they have impacted the project, and what they gain from being part of the project. The Technology Adoption Working Group (TAWG) will continue to collect, analyze, present, and write up data related to farmers' perceptions of biodegradable plastic mulches. Teams in TN and WA will conclude data collection for the 2017 farmer case studies, organize one or two experiential field days, conduct additional focus groups, and conduct semi-structured interviews to explore specific areas of interest (e.g., organic standards, soil health, etc.). In early 2018, farmer case studies will be identified for the 2018 growing season. TA WG members will also work with other working groups on shared areas of interest (e.g., soil health, organic standards, field days, technology adoption). The Field Activities WG will continue data collection, and green pepper, pumpkin, and sweet corn harvest activities will be carried-out as planned, as well as being coordinated with other WG needs. Monthly conference calls with WG members and advisors will be re-initiated in September to review 2017 findings, and begin to plan for 2018 experimental field trials as based on 2017 results. In September 2017 and May 2018, the Soils WG will complete our next soil quality assessments. We will continue monitoring environmental parameters (soil moisture, soil temperature, meteorological measurements). Lysimetry measurements will also be continued, and data will be analyzed and interpreted. Data from the soil quality assessments will be analyzed and written up in form of a technical manuscript. We will continue to analyze for C dynamics in soils and laboratory experiments. DNA sequence data analysis will be continued to determine microbial community structures and shifts over time. Studies on interactions of BDMs with earthworms and microbes will be completed. In Fall 2017, we will complete a detailed analysis of mulch carbon accumulation in soils from Spring 2015 to Spring 2017 detailing the distribution of any undecomposed micro-sized mulch fragments, and estimates of mulch-derived carbon conversion into soil organic matter. The Plastics Analysis WG will continue BDM degradation studies in the lab and will assess changes in physiochemical properties due to weathering in the 2017 and 2018 field seasons. In 2018, we begin laboratory studies to assess the effect of nitrogen sources and nitrogen levels on biodegradation. To further the assessment of economic feasibility and supply chain impacts, the SC-LCA WG will test the producer WTP instrument and the experiment will be conducted in the 2017-18 year. An analysis of linkages of biomaterial input prices and commodities prices will continue in 2017-18

Impacts
What was accomplished under these goals? Biodegradable plastic mulches (BDMs) contribute to sustainable farming practices by replacing conventional plastic mulch which is associated with environmental deficiencies. However, growers, suppliers, and Extension agents' concerns and lack of knowledge about BDMs--costs relative to benefits, historically unpredictable breakdown, and unknown long-term impacts on soil and crops--have limited the widespread use of BDMs. This project is addressing these barriers by conducting laboratory and field studies to assess BDM degradation during deployment and in the soil after incorporation and effects on crops and soils; studying the economic costs and benefits and growers' and consumers' perceptions of using BDMs; and increasing interest in sustainable deployment and disposal of BDMs. Goal A. Multi-year, large-scale experimental field trials to assess the impact of four BDMs and controls on crops are being conducted at Knoxville, TN and Mount Vernon, WA. Pumpkin harvest and fruit storage assessments were completed for both locations. Results show that yield and quality of pumpkin grown on BDMs are comparable to those which employed PE mulch, and paper mulch can prevent nutsedge penetration in TN. However, when pumpkin fruit rest for a prolonged period of time on BDMs, adhesion of mulch fragments onto fruit occurred, which can reduce marketable yield. We continue to test various methods of soil sampling for "in field" assessment of visible BDM remnants. New field trial protocols for sweet corn (WA), green pepper (TN), rain splash/Pseudomonas spread on mulch (WA), and stored-mulch integrity (TN and WA) were produced. Data collection includes: % soil exposure; mulch deterioration; weed assessment; plant nitrate levels, fruit storage quality assessment (TN only), and plant height and SPAD readings (WA only). In WA, there are striking and consistent mulch treatment differences in Yr 3. Sweet corn plants in bare ground and paper mulch plots are smaller than those in other mulch plots. Plants under clear plastic, although initially the largest and most vigorous, matured and senesced earlier than plants in other mulch treatments. Additional plant, soil, and irrigation delivery analyses are being done to explain the differences. Soil quality assessments of soils at the field trial sites through Spring 2017 produced no observed change in soil quality parameters at either field site. Underpinning this statement are two completed Yr 3 samplings and data analyses. Goal B. The 4-year study of biodegradation of mulches under ambient soil conditions continues. Continuously collected environmental have been analyzed. The retrievable, soil-buried mulch pieces (in mesh bags) have been sampled for mulch characterization and microbial community studies. Field-weathered mulch was used for the second compost study and for characterization of plastic-degrading microbes. The 2016/2017 study of degradation of field-weathered mulch in compost has been completed. A set of analytical techniques (molecular, microscopic, macroscopic) has been used to characterize mulch fragments observed in mesh bags. We found that the field-weathered BDM decomposes almost completely in compost, but micro-and nanoparticles remained after the 4-month composting period. Experiments are testing earthworm interactions with different BDMs in Petri dishes and mesocosms. Earthworms were observed to pull field-weathered mulch pieces in to their burrows, but did not eat or swallow them, suggesting earthworm activity does not contribute to the BDM degradation. Microbial communities associated with plastics and soils in the field experiment were assessed using metagenomics: sequence libraries were prepared targeting taxonomically relevant genes for bacteria and fungi and sequenced on next gen platforms at the Hudson Alpha Genome Service lab. These data revealed the types of microbes associated with different plastic mulches. Laboratory measurements of film degradation by these strains are ongoing. Goal C. The impact of weathering on mulch deterioration during the TN and WA field trials was measured. In addition to ultraviolet radiation, several secondary environmental factors play a key role, such as temperature and moisture, leading to greater loss of mechanical strength for mulches in TN. Using simulated weathering as a control, results show that additional factors must play a role in mulch degradation, believed to be minor components in soil, water, and air that catalyze photodegradative reactions. Laboratory-scale studies demonstrate that agriculturally-weathered mulches undergo biodegradation much more rapidly than unweathered mulches. Un-weathered and weathered mulches from the field trials have been analyzed for C content and stable C isotopic composition. An interdisciplinary study using microcosm incubation experiments evaluated the effects of soil temperature on BDM degradation and soil properties. We found that mulch and soil properties changed to a greater extent with an increase of temperature for PLA/PHA mulch, and PHA was preferentially degraded relative to PLA. Goal D. We have collected and analyzed data related to farmers' perceptions of BDMs. Teams in TN and WA concluded their first round of farmer case studies and initiated their second round. Focus groups (with growers) were conducted in TN with an emphasis on perceptions of BDMs and soil health. Semi-structured interviews were conducted with growers, BDM manufacturers, researchers, and policymakers about the U.S. organic farming standards pertaining to BDMs. Results from these various activities indicate that specialty crop growers are interested in learning more about BDMs; however, they have concerns related to unpredictable breakdown, high purchase cost, and limited durability. Activities to educate stakeholders are summarized in the section "Target Audiences." Goal E. This effort considers all aspects of the supply chain, from material and energy inputs, to farm-level markets and enterprise budgets, to consumers. The consumer willingness-to-pay (WTP) study assessed consumer demographics, environmental attitudes, and other consumer characteristics to determine WTP for strawberries grown on BDMs, and survey results have important implications for grower revenue. Data analysis of the 1500 observations indicates that consumers' WTP is significantly more (by 8.3 - 10.3%) than average market price for strawberries grown with BDMs ($3.50/lb); 71% of respondents indicated they were at least somewhat likely to purchase strawberries grown on BDMs. However, 68% of respondents had little or no knowledge of BDMs. To assess farmer WTP, a survey-based choice experiment was designed to measure monetary values of biodegradable mulch attributes. Research to design the auction experiment to determine producers' WTP for BDM was conducted. Together these assessments will have implications for production costs. The assessment of the relationship among markets for biomaterials inputs (starch, lignin, etc.), regulations, and risks included amassing the data and testing the statistical model. Preliminary results show that lignin and agricultural commodity prices move together in the long run and the co-movement is stronger after the Energy Independence and Security Act (EISA) of 2007. The life cycle assessment focusing on BDM and PE-base mulches during service and at end-of-life was begun in June 2017 and all data have been collected. No results are yet available. Work to amass labor and other production data for the labor assessment and enterprise budgets for pumpkin, strawberry, and tomato production continues. A draft pumpkin enterprise budget for WA was produced. These products are tools for farmers to understand the economic feasibility of adopting BDMs. A draft mulch calculator was developed and is in review. Goal F. The "Target Audiences" section addresses our effort to reach the scientific and farm-community stakeholders.

Publications

  • Type: Conference Papers and Presentations Status: Published Year Published: 2017 Citation: Ghimire, S., A.M. Saxton and C. Miles. 2017. Is soil sampling with a soil core an accurate method to specify the amount of mulch remaining in the field? Southern Sustainable Agriculture Working Group Annual Conference. Lexington, KY, Jan 25-26.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2017 Citation: Wszelaki, A., J. Moore, S. Ghimire, and C. Miles. 2017. Where the rubber meets the road: Can biodegradable mulches produce comparable yields to black plastic mulch for pumpkin? Organic Agriculture Research Symposium, Southern Sustainable Agriculture Working Group Annual Conference. Lexington, KY, Jan 25-26.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2017 Citation: Ghimire, S., E. Scheenstra, J.S. Cowan, H. Sintim, M. Flury, D.A. Inglis and C.A. Miles. 2016. Deterioration of biodegradable plastic mulch in pumpkin production in northwest Washington. HortScience 51(9):S215.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2016 Citation: Wszelaki, A., J. Moore, S. Ghimire, and C. Miles. 2016. Adhesion of biodegradable mulches to pie pumpkins: a production and quality consideration. HortScience 51(9):S256.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2016 Citation: Ghimire, S., A.L. Wszelaki, J. Moore, H. Sintim, D.A. Inglis, M. Flury and C. A. Miles. 2016. Biodegradable plastic mulch provided weed control, yield, and quality of pie pumpkin comparable to polyethylene mulch. HortScience 51(9):S275.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2016 Citation: Benedict, C. and C. Miles. 2016. Designing and implementing multi-dimensional outreach activities. HortScience 51(9):S213.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2016 Citation: Cowan, J., S. Ghimire and C. Miles. 2016. Biodegradable mulch films: their constituents and suitability for organic agriculture. HortScience 51(9):S357.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2016 Citation: Faustich, C., L. DeVetter, C. Miles and S. Sablani. 2016. Application of biodegradable mulches in day-neutral strawberry grown in western Washington. HortScience 51(9):S330.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2016 Citation: Sintim, H., S. Bandopadhyay, S. Ghimire, M.Flury, A. Bary, S. Schaeffer, J. DeBruyn, C. Miles, and D. Inglis. 2016. Soil Quality and Colloid Transport under Biodegradable Mulches. EGU2016-18410, 2016 EGU General Assembly 2016, Geophysical Research Abstracts Vol. 18.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2016 Citation: Inglis, D.A., L.S. Tymon, and D.A. Wheeler. Alternative methods to managing Verticillium wilt in vegetables. 2016. Tilth Producers Meeting, Wenatchee, WA. Nov. 11-13.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2016 Citation: English, M., S. Bandopadhyay, D.G. Hayes, J.M. DeBruyn, L.C. Wadsworth, S.M. Schaeffer. 2016. Temperature sensitivity of biodegradable plastic mulches to microbial decomposition. ASA-CCSA-SSSA Annual Meeting, Phoenix, AZ, Nov 6-9.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2016 Citation: Sintim H., M. English, A. Barry, S. Schaeffer, M. Saglam, and M. Flury. 2016. Soil microclimate and degradation of biodegradable plastic mulches. ASA-CSSA-SSSA Annual Meeting, Phoenix, AZ, Nov 6-9.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2016 Citation: Bandopadhyay, S. et al. 2016. Effect of BDMs on Soil Microorganisms. ASA-CSSA-SSSA-Annual Meeting, Phoenix, AZ, Nov. 6-9.
  • Type: Conference Papers and Presentations Status: Accepted Year Published: 2017 Citation: Liquet y Gonzalez J., X. Wen, K. Bonifer, S. Bandopadhyay, T. Reynolds, J.M. DeBruyn. 2017. Characterization of soil bacterial isolates capable of degrading biodegradable plastic mulch films. ASA-CSSA-SSSA-Annual Meeting, Tampa, FL, Oct 22-26.
  • Type: Conference Papers and Presentations Status: Accepted Year Published: 2017 Citation: DeBruyn J.M., S. Bandopadhyay, H. Sintim, M. English, S. Schaeffer, M. Flury, A. Wszelaki, J. Moore, C. Miles, S. Ghimire, D. Hayes. 2017. Impact of biodegradable plastic mulches on soil health. Organic Agriculture Soil Health Symposium, Tampa, FL, Oct 24.
  • Type: Conference Papers and Presentations Status: Accepted Year Published: 2017 Citation: DeBruyn JM, S Bandopadhyay, H Sintim, M English, X Wen, J Liquet y Gonzalez, SM Schaeffer, M Flury, K Bonifer, T Reynolds, DG Hayes. 2017. Biodegradable Plastic Agricultural Mulches: Microbial degradation and implications for soil health. ASA-CSSA-SSSA-Annual Meeting, Tampa, FL, Oct 22-26.
  • Type: Conference Papers and Presentations Status: Accepted Year Published: 2017 Citation: Hager, B. and A. Wszelaki. 2017. What should growers cover the soil with? Southern Sustainable Agriculture Working Group Conference, Chattanooga, TN, 17-20 Jan 2018.
  • Type: Conference Papers and Presentations Status: Accepted Year Published: 2017 Citation: Goldberger, J.R., C. Lyons, L. DeVetter, and K. Dentzman. 2017. Biodegradable plastic mulches for strawberry production: experiences and opinions of growers in three regions of the United States. Poster presentation. Annual Meeting of the American Society for Horticultural Science (ASHS), Waikoloa, Hawaii, Sept 19-22. HortScience: in press.
  • Type: Conference Papers and Presentations Status: Accepted Year Published: 2017 Citation: Goldberger, J.R. 2017. Use of plastic mulches in strawberry production: growers experiences and opinions. Invited Speaker in Plasticulture Workshop. Annual Meeting of the American Society for Horticultural Science (ASHS), Waikoloa, Hawaii, Sept 19-22. HortScience: in press.
  • Type: Conference Papers and Presentations Status: Accepted Year Published: 2017 Citation: Cowan, J.S. and J.R. Goldberger. 2017. Planning for tactile space to improve Extension outreach activities. Annual Meeting of the American Society for Horticultural Science (ASHS), Waikoloa, Hawaii, Sept 19-22. HortScience: in press.
  • Type: Conference Papers and Presentations Status: Accepted Year Published: 2017 Citation: Ghimire, S., A.M. Saxton, A.L. Wszelaki, J.C. Moore, and C.A. Miles. 2017. Soil core sampling is not reliable for assessing biodegradable mulch fragments in soil. Annual Meeting of the American Society for Horticultural Science (ASHS), Waikoloa, Hawaii, Sept 19-22. HortScience: in press.
  • Type: Conference Papers and Presentations Status: Accepted Year Published: 2017 Citation: Ghimire, S., A. Wszelaki, J. Moore, and C. Miles. 2017. Biodegradable plastic and paper mulches produced pumpkin with similar quality as polyethylene mulch. Annual Meeting of the American Society for Horticultural Science (ASHS), Waikoloa, Hawaii, Sept 19-22. HortScience: in press.
  • Type: Conference Papers and Presentations Status: Accepted Year Published: 2017 Citation: Ghimire, S., A. Wszelaki, J. Moore, and C. Miles. 2017. Yield of pie pumpkin grown with biodegradable plastic and paper mulch. Annual Meeting of the American Society for Horticultural Science (ASHS), Waikoloa, Hawaii, Sept 19-22. HortScience: in press.
  • Type: Conference Papers and Presentations Status: Accepted Year Published: 2017 Citation: J.R. Goldberger, S. Schexnayder, and M. Flury. 2017. Specialty crop growers perceptions of soil health impacts from conventional and biodegradable plastic mulches. Annual Meeting of the Soil Science Society of America (SSSA), Tampa, FL, Oct 22-25.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2017 Citation: Chen, K., P. Tozer, and T.L. Marsh. 2017. Consumer Willingness to Pay for Strawberries Grown on Biodegradable Mulches. AAEA Selected Paper, Chicago.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2017 Citation: English, M., S. Bandopadhyay, D.G. Hayes, J.M. DeBruyn, L.C. Wadsworth, and S.M. Schaeffer. 2017. Temperature sensitivity of biodegradable plastic mulches to microbial decomposition. Southeastern Biogeochemistry Symposium, Athens, GA, March 31.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2017 Citation: DeBruyn JM, S Bandopadhyay, H Sintim, M English, X Wen, SM Schaeffer, M Flury, D Hayes. 2016. Biodegradable Plastic Agricultural Mulches: Microbial degradation and impacts on soil ecology. China-US Joint Symposium of Environmental Health and Ecological Safety, Yixin, China, Oct 26-29.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2017 Citation: Miles, C. and D.G. Hayes. 2017. The North American perspective: Biodegradable plastic mulch for agriculture. Biodegradable Mulch Films: Europe Meets USA (an international symposium), Novara, Italy, June 30.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2017 Citation: Wszelaki, A., J. Moore, S. Ghimire, and C. Miles. Biodegradable mulch use in vegetable crops. 2017. Biodegradable Mulch Films: Europe Meets USA (an international symposium), Novara, Italy, June 30.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2017 Citation: DeBruyn, J. Soil quality, ecology and mulch biodegradation. 2017. Biodegradable Mulch Films: Europe Meets USA (an international symposium), Novara, Italy, June 30.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2017 Citation: Velandia, M. Economic considerations for the adoption of biodegradable plastic mulch. 2017. Biodegradable Mulch Films: Europe Meets USA (an international symposium), Novara, Italy, June 30.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2017 Citation: Schexnayder, S. and J. Goldgerger. 2017. Producer perceptions, information needs, and social factors influencing the adoption of biodegradable plastic mulch in the United States. Biodegradable Mulch Films: Europe Meets USA (an international symposium), Novara, Italy, June 30.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2017 Citation: DeBruyn, J. and M. Flury. 2017. Soil Ecology Working Group Update: Performance and Adoptability of Biodegradable Plastic Mulch for Sustainable Specialty Crop Production. USDA SCRI Project Annual Meeting, Knoxville, TN. March 20-22.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2017 Citation: Bandopadhyah, S. 2017. Microbial degradation of biodegradable plastic mulch films: Enrichment cultures, lab and field metagenomics studies. USDA SCRI Project Annual Meeting, Knoxville, TN. March 20-22.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2017 Citation: Bonifer, K. 2017. Quantifiy and characterizing PLA degradation by soil microbes. USDA SCRI Project Annual Meeting, Knoxville, TN. March 20-22.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2017 Citation: Sintim, H. 2017. Biodegradable plastic mulch: Degradation and impacts on soil ecology. USDA SCRI Project Annual Meeting, Knoxville, TN. March 20-22.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2017 Citation: Saglam, M. 2017. Effects of biodegradable and polyethylene plastic mulch films on soil moisture. USDA SCRI Project Annual Meeting, Knoxville, TN. March 20-22.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2017 Citation: Marsh, T. 2017. Supply chain/LCA Working Group Update: Performance and Adoptability of Biodegradable Plastic Mulch for Sustainable Specialty Crop Production. USDA SCRI Project Annual Meeting, Knoxville, TN. March 20-22.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2017 Citation: Chen, K., and T. Marsh. 2017. Willingness to pay for strawberries grown on BDMs. USDA SCRI Project Annual Meeting, Knoxville, TN. March 20-22.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2017 Citation: Goldberger, J. 2017. Technology Adoption Working Group Update: Performance and Adoptability of Biodegradable Plastic Mulch for Sustainable Specialty Crop Production. USDA SCRI Project Annual Meeting, Knoxville, TN. March 20-22.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2017 Citation: Galinato, S. 2017. Project Assessment Working Group Update: Performance and Adoptability of Biodegradable Plastic Mulch for Sustainable Specialty Crop Production. USDA SCRI Project Annual Meeting, Knoxville, TN. March 20-22.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2017 Citation: Hayes, D. 2017. Plastics Analysis Working Group Update: Performance and Adoptability of Biodegradable Plastic Mulch for Sustainable Specialty Crop Production. USDA SCRI Project Annual Meeting, Knoxville, TN. March 20-22.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2017 Citation: Inglis, D., C. Miles, and A. Wszelaki. 2017. Field Activities Working Group Update: Performance and Adoptability of Biodegradable Plastic Mulch for Sustainable Specialty Crop Production. USDA SCRI Project Annual Meeting, Knoxville, TN. March 20-22.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2017 Citation: Ghimire, S., A. Wszelaki, J. Moore, D. Inglis, and C. Miles. 2017. Horticultural findings: Years 1 and 2 of Performance and Adoptability of Biodegradable Plastic Mulch for Sustainable Specialty Crop Production. USDA SCRI Project Annual Meeting, Knoxville, TN. March 20-22.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2017 Citation: Miles, C. 2017. Sweet corn trial with BDMs 2017 & 2018: Performance and Adoptability of Biodegradable Plastic Mulch for Sustainable Specialty Crop Production. USDA SCRI Project Annual Meeting, Knoxville, TN. March 20-22.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2017 Citation: Wszelaki, A. and J. Moore.2017. 2017 & 2018 Pepper trial protocol with BDMs: Performance and Adoptability of Biodegradable Plastic Mulch for Sustainable Specialty Crop Production. USDA SCRI Project Annual Meeting, Knoxville, TN. March 20-22.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2017 Citation: Tymon, L., P. Morgan, B. Gunderson, and D. Inglis. 2017. Plant pathology update: Performance and Adoptability of Biodegradable Plastic Mulch for Sustainable Specialty Crop Production. USDA SCRI Project Annual Meeting, Knoxville, TN. March 20-22.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2017 Citation: Miles, C. 2017. Extension and Outreach Working Group Update: Performance and Adoptability of Biodegradable Plastic Mulch for Sustainable Specialty Crop Production. USDA SCRI Project Annual Meeting, Knoxville, TN. March 20-22.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2017 Citation: Tymon, L.S., A. Salamone, and D.A. Inglis. 2017. Fungal endophytes isolated from pumpkin roots grown with agricultural mulches Annual WSU Mount Vernon NWREC Field Day. July 13.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2016 Citation: DeBruyn, J. 2016. Biodegradable Plastic Agricultural Mulches: Microbial degradation and impacts on soil ecology. China-US Symposium on Environmental Science and Pollution Control, Yixin, China, Oct 26-29.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2016 Citation: Schaeffer, S.M. 2016. Response of coupled C and N biogeochemical cycles to land management and climate change. China-US Center for Soil Productivity and Environmental Conservation (SPEC), Shenyang, China, Oct 24-25.
  • Type: Other Status: Published Year Published: 2016 Citation: Ghimire, S. and C.A. Miles. 2016. Dimensions of costs of paper, polyethylene, and biodegradable plastic mulch (Extension factsheet). Washington State University Extension.
  • Type: Other Status: Published Year Published: 2016 Citation: Ghimire, S. and C.A. Miles. 2016. Mechanically laying biodegradable paper and plastic mulch (Extension factsheet). Washington State University Extension.
  • Type: Other Status: Published Year Published: 2016 Citation: Moore, J. and A. Wszelaki. 2016. Plastic mulch in fruit and vegetable production: Challenges for disposal. University of Tennessee Extension Fact Sheet W410.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2017 Citation: Chen, K. 2017. Willingness to Pay for Biodegradable Mulches. Poster presentation at the Annual DuPont Pioneering Ideas in Agriculture Conference, Washington State University, March 17.
  • Type: Other Status: Published Year Published: 2017 Citation: Goldberger, J. and C. Lyons. Strawberry Growers Perceptions of Biodegradable Plastic Mulches: Results from a Multi-State Survey. Performance and Adoptability of Biodegradable Mulch Report No. TA-2017-01.
  • Type: Other Status: Published Year Published: 2016 Citation: Moore, J., and A. Wszelaki. 2016 (December). Plastic Mulch in Fruit and Vegetable Production: Challenges for Disposal. Performance and Adoptability of Biodegradable Mulch Report No. FA-2016-2.
  • Type: Other Status: Published Year Published: 2017 Citation: Goldberger, J. and C. Lyons. 2017, February. Use of Plastic Mulch Films in U.S. Strawberry Production: Results from a Multi-State Survey about U.S. Strawberry Growers Perceptions and Experiences with Plastic Mulch Films. Project report.
  • Type: Other Status: Published Year Published: 2016 Citation: D.G. Hayes, Preparing Big Grants: How to Lead a Team Effort, UTIA Office of Sponsored Programs Newsletter, July, 2016 (Part 1); October, 2016 (Part 2); in UT AgResearch Impacts | Fall 2016 eNewsletter, Sept, 2016; and in UTIA Common Ground, Sept 2016 eNewsletter.
  • Type: Other Status: Published Year Published: 2017 Citation: Wszelaki. 2017.Do Biodegradable Mulches Fit into Your Production System? Tennessee Tomato, Pepper and Biodegradable Mulch Field Day, Dayton, TN. Aug 9. (Field Day)
  • Type: Other Status: Published Year Published: 2017 Citation: Wszelaki. 2017. Mulches and Irrigation. UT New Extension Agent Hands-on Bootcamp In-service Training, Crossville, TN. Aug 9. (In-service training for Extension agents)
  • Type: Other Status: Published Year Published: 2017 Citation: Ghimire and Miles. 2017. Evaluating biodegradable plastic mulches for sweet corn production. WSU NWREC Field Day, WSU NWREC, Mount Vernon, WA. July 13. (Field Day presentation and demonstration)
  • Type: Other Status: Published Year Published: 2017 Citation: Tymon, L. 2017. Rain splash/mulch/Pseudomonas spread study. WSU NWREC Field Day, WSU NWREC, Mount Vernon, WA. July 13. (Field Day presentation and demonstration)
  • Type: Other Status: Published Year Published: 2017 Citation: Dentzman,K., J. Goldberger, J. Cowan, C. Benedict. 2017. Hands-on biodegradable plastic mulch field day, Cloudview Farm, Ephrata, WA. May 25. (Field Day)
  • Type: Other Status: Published Year Published: 2017 Citation: Tymon, L.S., P. Morgan, B. Gundersen, and D.A. Inglis. 2017. Pseudomonas on pumpkins, symptoms, and overview of the upcoming trials. Puyallup, WA. Mar 9. (Field Day presentation)
  • Type: Other Status: Published Year Published: 2017 Citation: Wszelaki, A. 2017. Vegetable production updates, UT Extension Bledsoe Co. Grower Meeting, Pikeville, TN. Mar 2. (presentation)
  • Type: Other Status: Published Year Published: 2017 Citation: Cowan-Banker, D. Effect of environmental weathering on biodegradation of plastics. University of Tennessee Exhibition of Undergraduate Research and Creative Achievement (EUReCA) undergraduate research competition (abstract and poster presentation). April.
  • Type: Other Status: Published Year Published: 2017 Citation: Wszelaki, A. 2017. Vegetable production updates, UT Extension Lawrence Co. Grower Meeting, Ethridge, TN. Feb 24. (presentation)
  • Type: Other Status: Published Year Published: 2017 Citation: Wzselaki, A. 2017. Biodegradable Mulches: Can they save you time and money? Pick Tennessee Conference, Franklin, TN. Jan 16. (presentation)
  • Type: Other Status: Published Year Published: 2016 Citation: Ghimire, S. 2016. Biodegradable mulches for organic and conventional vegetable production. Pacific Northwest Vegetable Association 29th annual conference. Three Rivers Convention Center, Kennewick WA. Nov 16. (presentation)
  • Type: Other Status: Published Year Published: 2016 Citation: Miles, C. and S. Ghimire. 2016. Showcase of biodegradable mulches. 10 year anniversary of NWREC facility. Dec 6. (Field Day presentation)
  • Type: Other Status: Published Year Published: 2016 Citation: Ghimire, G. 2016. There is no away: search for biodegradable alternatives to plastic mulch. WSU Horticulture 509 seminar. Dec 8.(Invited class lecture)
  • Type: Other Status: Published Year Published: 2017 Citation: Ghimire, S. 2017. Biodegradable plastic mulch for organic agriculture in the U.S. Lecture for: Western Washington University, Bellingham, WA. May 26. (Invited class lecture)
  • Type: Other Status: Published Year Published: 2017 Citation: Ghimire, S. 2017. Biodegradable vs non-biodegradable waste. Skagitonians To Preserve Farmland, WSU NWREC, Mount Vernon, WA. Apr 21. (Invited presentation)
  • Type: Other Status: Published Year Published: 2017 Citation: DeBruyn, J. 2017. Below ground impacts of biodegradable plastic agriculture mulches. University of Tennessee Department of Civil and Environmental Engineering Seminar Series, Knoxville, TN. Apr 13. (Invited class lecture)
  • Type: Other Status: Published Year Published: 2017 Citation: Miles, C. and S. Ghimire. 2017. There is no away: search for biodegradable alternatives to plastic mulch. Lecture in: Sustainable Plastics and Composite Materials College of Science and Engineering, Western Washington University, Bellingham, WA. Feb 17. (Invited class lecture)
  • Type: Other Status: Published Year Published: 2016 Citation: Ghimire, S. 2016. Quality of pumpkin fruit grown with biodegradable mulches. Skagit Valley Community College, Mount Vernon, WA. Nov 3. (Invited class lecture)
  • Type: Other Status: Published Year Published: 2016 Citation: Schaeffer, S. and M. English. 2016. ESS 442 Soil Genesis and Classification: Classifying soils at the BDM research plots in Tennessee. Oct 22. (Invited class lecture)
  • Type: Other Status: Published Year Published: 2017 Citation: Liquet y Gonazalez, J. 2017. Class Report (BCMB562): Evaluation of fixatives for SEM visualization of biodegradable mulch films.
  • Type: Journal Articles Status: Accepted Year Published: 2017 Citation: Tymon, L. and D. Inglis. 2017. Identification and pathogenicity of a Pseudomonas syringae pathovar causing leaf spots and fruit warts on cucurbits in western Washington, U.S. J. Plant Path. July 7.
  • Type: Journal Articles Status: Accepted Year Published: 2017 Citation: Saglam, M., H.Y. Sintim, A.I. Bary, A.I., C.A. Miles, S. Ghimire, D.A. Inglis, M. Flury 2017. Modeling the effect of biodegradable paper and plastic mulch on soil moisture dynamics. Agric. Water Dynamics. Jun 22.
  • Type: Journal Articles Status: Published Year Published: 2017 Citation: Hayes, D.G., L.C. Wadsworth, H.Y. Sintim, M. Flury, M. English, S. Schaeffer, A.M. Saxton. 2017. Effect of diverse weathering conditions on the physicochemical properties of biodegradable plastic mulches. Polymer Testing 62(2017): 454-467. DOI: 10.1016/j.polymertesting.2017.07.027.
  • Type: Journal Articles Status: Published Year Published: 2017 Citation: Sintim, H.Y. and M. Flury. 2017. Is biodegradable plastic mulch the solution to agricultures plastic problem? Environmental Science & Technology 51: 1068-1069. DOI: 10.1021/acs.est.6b06042.
  • Type: Journal Articles Status: Published Year Published: 2017 Citation: Brodhagen, M., J.R. Goldberger, D.G. Hayes, D.A. Inglis, T.L. Marsh, and C. Miles. 2017. Policy considerations for limiting unintended residual plastic in agricultural soils. Environmental Science & Policy 69(March): 81-84.
  • Type: Journal Articles Status: Published Year Published: 2017 Citation: Miles, C., L. DeVetter, S. Ghimire, and D.G. Hayes. 2017. Suitability of biodegradable plastic mulches for organic and sustainable agricultural production systems. HortScience 52(1):10-15. Doi: 10.21273/HORTSCI11249-16.
  • Type: Journal Articles Status: Accepted Year Published: 2017 Citation: Ghimire, S., A. Saxton, A.L. Wszelaki, J.C. Moore, and C.A. Miles. 2017. Reliability of soil sampling method to assess visible biodegradable mulch fragments remaining in the field post soil-incorporation. HortTechnology.
  • Type: Journal Articles Status: Submitted Year Published: 2017 Citation: Ghimire, S., A.L. Wszelaki, J.C. Moore, D.A. Inglis, and C.A. Miles. 2017. The use of biodegradable mulches in pie pumpkin crop production in two diverse climates. HortScience. Submitted July 24.
  • Type: Journal Articles Status: Submitted Year Published: 2017 Citation: Saglam, M., H.Y. Sintim, A.I. Bary, C.A. Miles, S. Ghimire, D.A. Inglis, and M. Flury. 2017. Modeling the effect of biodegradable paper and plastic mulch on soil moisture dynamics, Agric. Water Manage. Submitted.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2017 Citation: Sintim, H. , M. Flury, A. Bary, S.Schaeffer, M. English, D.G. Hayes. 2017. Nanoparticles from Degradation of Biodegradable Plastic Mulch. EGU General Assembly 2017, Vienna, Austria.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2017 Citation: Tymon, L., P. Morgan, B. Gundersen, and D.A. Inglis. 2017. Prospective endophyte antagonists of Verticillium dahliae isolated from three field-grown cucurbit cultivars in western Washington. Ann. Mtg. Amer. Phytopath. Soc., S10x:Sx.xxx, San Antonio, TX.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2017 Citation: Goldberger, J.R. and K. Dentzman. 2017. Are farmers interested in biodegradable plastic mulch films? Preliminary results from a mixed methods study of U.S. specialty crop growers. Joint Meeting of the Agriculture, Food, and Human Values Society and Association for the Study of Food and Society, Los Angeles, CA, June 14-17.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2017 Citation: Hayes, D.G., L.C. Wadsworth, C. Miles, and A.L. Wszelaki. 2017. Life cycle of biodegradable plastic mulches for specialty crop production. Organic Agriculture Research Symposium, Southern Sustainable Agriculture Working Group Annual Conference. Lexington, KY, Jan 25-26.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2017 Citation: DeBruyn, J.M., S. Bandopadhyay, X. Wen, H. Sintim, M. English, S.M. Schaeffer, M. Flury, D. Hayes. 2017. Impact of biodegradable plastic mulches on soil quality and ecology. Organic Agriculture Research Symposium, Southern Sustainable Agriculture Working Group Annual Conference. Lexington, KY, Jan 25-26.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2017 Citation: Miles, C., L. DeVetter, S. Ghimire, and D.G. Hayes. 2017. Suitability of biodegradable plastic mulches for organic and sustainable agriculture. Organic Agriculture Research Symposium, Southern Sustainable Agriculture Working Group Annual Conference. Lexington, KY, Jan 25-26.


Progress 09/01/15 to 08/31/16

Outputs
Target Audience:Target audiences reached during the second year of the project (Year 2) are specialty crop growers and intermediaries, including Extension specialists and agents; agricultural plastic film and mulch manufacturers; scientists in several different disciplines; agricultural standards committees and regulators; and undergraduate and graduate students. The project's 24-member Advisory Committee includes specialty crop growers and representatives of grower organizations; Extension specialists; and experts in food safety, polymer science, mulch manufacturing, composting, materials standards, government policy, sociology, agricultural economics, soil microbiology, climate science, various horticultural specialties, and transdisciplinary research. Engaging the AC is paramount for our transdisciplinary project and was accomplished through team-wide meetings to review project research protocols and outreach plans, informal consultations with members via email and telephone, and participation of AC members in project Working Group (WG) meetings and conference calls. Specialty crop growers and intermediaries have been engaged interactively through their participation in growers' meetings and field days at which team members discussed biodegradable plastic mulches (BDMs) generally and the project specifically (7 events with 168 participants; 3 additional field days are scheduled before the end of Year 2 (Yr2), Aug 28, 2016). The Technology Adoption (TA) WG engaged growers through the survey of strawberry growers' experience with and perspectives on BDMs (implemented Jan-March 2016) and on-farm case studies (spring and summer 2016). The Supply Chain-Life Cycle Assessment (SC-LCA) WG is reaching growers and suppliers through personal in-depth interviews about costs and supply (Sept 2015 - current), as well as its survey of farmers willingness-to-pay survey (draft; implementation in Yr3). We also reach growers through the project's website (http://biodegradablemulch.org) and the basic information provided in factsheets developed specifically for the website. Based on Advisory Committee feedback, the Extension-Outreach (EO) WG is adding interactive features to the website in summer 2016. We have reached the scientific community through the website, which is a gateway to scientific outputs of the project, and through our journal articles (4 in Yr2 and several more in development) and presentations delivered at professional conferences (13 abstracts and proceedings by the end Yr2; 3 more are accepted for presentation in Yr3). Postdoctoral, graduate and undergraduate students are engaged in project research, collaborating to design the research, conducting the experiments, and collecting and analyzing data. Two Post-docs, 4 PhD students, and 2 MS students are conducting research projects through support of the SCRI CAP. Several undergraduate students also are involved in research, especially data collection. One field tour hosted 25 Florida Future Farmers of America students. Changes/Problems:There are no significant changes in the research schedule, goals, or research compliance protocols in Yr2. The FA WG is considering a change of test crop for field trials in Yr3 and 4, to reflect typical crop rotation practices and minimize the disease and insect pressure, per advice from AC members. Candidate crops (sweet corn and cabbage) are being tested at both sites in summer 2016. Also, the team (especially SE, FA, and PA WGs) is considering a request by the AC to employ new rolls of BDMs for the Yr3 and 4 field trials, due to concern about deterioration of BDMs during long-term storage. (We have been monitoring BDM deterioration and have observed only minor deterioration to date, covering a 15 month period). This consideration is being weighed against effects on soil quality and BDM degradation research that may result from minor changes in chemical composition between original and new rolls of plastic mulch. To enhance our team's evaluation of the socioeconomic impact of BDMs on growers and other stakeholders, we have added to Task 4b of our research plan 1) an LCA and 2) a grower willingness to pay survey. To lead these new efforts, we have added Chi and Chouinard as co-PIs to our project team. PI Tozer retains some responsibility for supply chain assessment, but transitioned to a consultant role on the project after taking an academic position abroad. By leveraging additional funding provided by WSU, Post doc Tymon will use WA field trial data and new studies in controlled greenhouse conditions to examine the effect of selected mulch treatments on the occurrence of pumpkin root endophytes and Verticillium dahliae, a plant pathogen prominent in the production area of the WA trial, as well as on the survivability of microsclerotia of V. dahliae in mulched soil (Task 1b). What opportunities for training and professional development has the project provided?Project members provided and participated in training and professional development opportunities. PIs are currently mentoring 7 graduate students, 2 postdocs, and 10 undergraduate students. Team members, including the PIs, postdocs, and graduate students have led several workshops for Extension agents, provided field day demonstrations and presentations to growers about BDMs, and produced fact sheets and the first of a set of "how to" videos addressing the use of BDMs. (See products list for details.) Thirty-five team members participated in a transdisciplinary training session, designed by Advisor Jackson-Smith, a recognized leader in the field, at the project's second annual meeting. The purpose of the training was to encourage participants, including advisors, to understand and visually depict how various components of the research and outreach activities interrelate. Wszelaki and Schexnayder also participated in a day-long workshop on mentoring students. How have the results been disseminated to communities of interest?Dissemination of results is incorporated into Objectives D and F. We have shared our results with the scientific communities of interest through our project website, 4 published journal articles, 13 completed factsheets, and scientific/professional conference presentations (13 in the project year ending Aug 28, 2016 and 3 more accepted), and other conference and symposium presentations (6 in this project year). Miles, leader of the EO WG, works with all other WGs to identify opportunities to share research results and general information about BDMs. We disseminated results to growers and intermediaries at several growers' meetings, five field days, and one workshop for Extension agents (by end of Yr2). One field tour was hosted specifically for a Future Farmers of America high school group from Florida, and future efforts will target youth (through 4-H activities). UT team members are working currently to disseminate results through Eureka (news service for science writers). In addition to written works and oral presentations, the team developed three videos this project year as we aim to provide diverse content to reach growers and general audiences. What do you plan to do during the next reporting period to accomplish the goals?In the third year of the project, numerous activities are planned. First, to address adoption and economics issues (Obj. D and E), the TA WG will develop additional case studies, analyze the results of the strawberry producers' survey and begin developing manuscripts, and conduct three focus groups addressing special topics related to adopting BDMs (Task 4a of Research Plan). The SC-LCA WG will implement a consumer willingness-to-pay survey and conduct choice experiments to elicit produce tradeoffs in their willingness to pay for different products (Task 4b). The SC-LCA WG will also continue labor data collection through focus groups and interviews for the construction of enterprise budgets and a labor-needs assessment tool. Data collection for the life cycle inventory database for agricultural mulches will continue. To address Objs. A and C, the Field Activities, Soil Ecology, and Plastics Analysis WGs will collect and analyze crop, weed, disease, soil, and BDM data through the Year 2 field trials (Task 1, 2ac, and 3a; currently underway). The SE WG will continue its mesh bag study of BDM degradation and complete its composting study (Obj. B; Task 2b). Laboratory experiments are planned to measure the biodegradability of BDMs under ambient soil and industrial compost conditions, and better understand the underlying soil microbiology and abiotic factors involved with biodegradation (Objs. B and C; Task 3). The EO WG will continue outreach through the project website, factsheets, and video products and will identify outlets for all team members to disseminate results to all audiences (Objs. D and F; Task 5). The Project Assessment WG will continue to collect and analyze information from the change-in-knowledge surveys administered at project events. For all activities and across all project WGs, development and publication of conference presentations, journal manuscripts, project and Extension factsheets and videos will continue in Yr 3. In addition, the education of team members will be enhanced through transdisciplinary training during the 2017 annual team meeting in Knoxville. Also, several co-PIs will participate in a trip to Spain and Italy next year to obtain an international context for the use of BDMs in sustainable agriculture. The tour focuses on the manufacturing of bioplastics and differences between the U.S. and European Union with respect to BDM regulation, assessment methods, and growers' rates of adoption and perceptions of BDMs.

Impacts
What was accomplished under these goals? Impact Biodegradable plastic mulches (BDMs) contribute to sustainable farming practices by replacing conventional plastic mulch which is associated with environmental deficiencies. However, growers, suppliers, and Extension agents' concerns and lack of knowledge about BDMs--costs relative to benefits, and historically unpredictable breakdown--have limited the widespread use of BDMs. This project is working to address these barriers by conducting laboratory and field studies to assess BDM degradation and effects on crops and soils; studying the economic costs and benefits and growers' and consumers' perceptions of using BDMs; and increasing interest in sustainable deployment and disposal of BDMs. The impact of our project on Objectives A-G follows. A. Evaluate the impacts of long-term use of BDMs on 1) the soil ecosystem; and 2) on a specialty crop production system along with its associated growers and consumers. Our Team's Working Groups (WGs) successfully completed the large-scale, multi-disciplinary field trials in Tennessee (TN) and Washington (WA) in 2015 to explore the impact of four BDMs and positive and negative controls on crop yield and quality, weed and disease control, and soil quality (4 manuscripts in preparation). Results show that with the suppression of weeds by the BDMs and conventional polyethylene (PE) mulch, comparable pumpkin fruit yields between BDMs and PE were higher than achieved for the bare ground control. Also, there has been no change observed to date in soil quality parameters at either site. The 2016 trials are now successfully initiated. Consistency in experimental approaches between TN and WA, and coordination of multiple tasks among scientists of different disciplines was facilitated by completing a series of comprehensive protocols, a transdisciplinary exercise among the co-PIs and our advisors. The protocols have been slightly modified based on lessons learned from the 2015 studies, such as performing a more thorough evaluation of mulch adhesion to fruit, which occurred unexpectedly at 30-50% for BDM treatments in WA. B. Identify BDM degradation mechanisms and interrelationships among the life stages of BDMs: their origin (fossil fuel-derived vs. biobased), service life, and potentially sustainable end-of-life outcomes (ambient soil degradation vs. retrieval followed by composting). Changes in mulches' physico-chemical properties due to weather exposure during the 2015 field studies, simulated weathering, and in-laboratory storage (control), have been measured according to the Plastics Analysis (PA) protocol. Preliminary findings show that BDMs in the field underwent mechanical strength loss, embrittlement, and depolymerization to the greatest extent in TN, presumably due to higher air and soil temperatures in TN (manuscript in preparation). A 4-yr mesh bag study for biodegradation of mulches under ambient soil conditions at TN and WA was initiated at the end of the first growing season in Sept. 2015 (Soil Ecology (SE) protocol). Mesh bags will be retrieved every 6 month and mulch samples are being evaluated for changes in physicochemical properties, loss of surface area, and microbial communities. The first of three on-farm composting studies using mesh bag burial also has been completed. Initial results indicate that BDMs undergo size reduction and almost complete macroscopic disintegration after 4 months; however, nm to micron -scale particles still were observed on mesh bag fibers via scanning electron microscopy. Immediately after BDMs were tilled into the soil (Fall 2015) and 6 months later, BDM fragments were captured from soil samples, and mulch surface area was measured. An interdisciplinary experiment to examine the effect of soil temperature (10, 20, and 30oC) on the biodegradation process for two BDMs at 10 weeks is underway. C. Compare diverse scales of operation (field vs. laboratory studies), climate regions, and methodology for evaluating the soil degradation of BDMs to improve performance regulations. Lab-scale testing of biodegradability for weathered BDMs under ambient soil and composting conditions is in preparation. Specialty crop production in WA vs. TN in 2015 and weathering of BDMs at the field sites vs. simulated weathering is discussed under Objectives A and B. D. Identify steps along the supply chain for BDMs to better understand the bridges and barriers to BDM adoption by growers and intermediaries as related to economic relevance and regulation; and educate growers, intermediaries, consumers, and the general public on BDMs and biobased mulches and plastics, especially as related to sustainable and organic agriculture. Interviews with U.S. strawberry growers indicated low interest in BDM products. Options for recycling PE mulches (e.g., field-side pick-up) are increasing in a few locations, making removal and disposal of used plastic much easier and the higher cost of BDMs more difficult to justify for some growers. In Europe, strawberry growers may be much more interested in BDMs because BDMs are more compatible with local production practices and are closer in price to PE mulches. The survey of strawberry growers was completed in Jan-Apr 2016; data cleaning and analysis are underway. Three farms have been identified in WA and TN for the Farmer Case Studies. Repeated on-farm interviews began in in early 2016. During the first On-Farm Experiential Field Day in WA, participants were interested in BDMs for home gardening use. IRB approval has been given for development of crop enterprise budgets with growers in WA (pumpkin) and TN (pumpkin, tomato and strawberry). E. Assess the economic feasibility of agricultural products grown with BDMs through the entire supply chain to consumers, and identify potential BDM-associated disease and pest problems. Preliminary data for an enterprise budget of pumpkin production in western WA, evaluating the potential replacement of PE mulch with BDMs, were collected from two growers in Apr 2016, with three additional growers committed to assist. Additional feedback from growers will be collected in Nov-Dec 2016 to validate the preliminary data. Data collection for enterprise budgets in TN will begin in fall 2016. A survey on consumers' willingness to pay for strawberries grown with BDMs has been developed and will be fielded in 2016. An overview of the LCA for BDMs has been completed. F. Interact with a community of stakeholders to increase interest in sustainable deployment of BDMs throughout the U.S. and worldwide. A key component of stakeholder interaction has been the meaningful involvement of our Advisory Committee (AC), which spans several stakeholder groups (see Target Audiences). Field days and similar presentations have engaged 345 growers and intermediaries and 170 students. We have also engaged farmers, scientists, and other stakeholder groups through our project website, 13 completed factsheets, and scientific/professional conference presentations (12 to date and 9 accepted). G. Educate and train undergraduate and graduate students, postdoctoral research assistants, and principal investigators on skills needed to work on transdisciplinary research problems. This project has supported the training of post docs, graduate students and undergraduate students. Students, co-PIs, and AC members have participated in transdisciplinary training exercises (led by AC member Jackson-Smith) at both the 2015 and 2016 annual team meetings. The PD will give a presentation about the training at the 2016 SCRI PDs' Workshop (Aug. 2016). Transdisciplinary training has been augmented by participation in labor-intensive "all hands on deck" activities at the TN and WA field sites, such as soil quality assessments, BDM laying, pumpkin planting, and fruit harvesting, and attendance in quarterly meetings of other WGs. Statistics advice by co-PI Saxton has benefited the team greatly.

Publications

  • Type: Journal Articles Status: Published Year Published: 2015 Citation: Schaeffer, S., M. Flury, H.Y. Sintim, S. Bandopadhyay, A.I. Bary, J. and DeBruyn. 2015. Assessing soil quality as affected by different mulches. American Geophysical Union (AGU)-Annual Meeting, San Francisco, CA, 14-18 Dec 2015.
  • Type: Journal Articles Status: Accepted Year Published: 2016 Citation: Lyons, C. and J. Goldberger. U.S. strawberry growers experiences with and perceptions of biodegradable plastic mulch films. Rural Sociological Society Annual Meeting, Toronto, CA, Aug 7-10, 2016.
  • Type: Journal Articles Status: Accepted Year Published: 2016 Citation: Wszelaki, A., J. Moore, S. Ghimire, and C. Miles. 2016. Adhesion of biodegradable mulches to pie pumpkins: A production and quality consideration. ASHS National Conference, Atlanta, GA Aug 8-11 2016.
  • Type: Journal Articles Status: Accepted Year Published: 2016 Citation: Ghimire, S., E. Scheenstra, J. Cowan, H.Y. Sintim, M. Flury, D. Inglis and C. Miles. 2016. Deterioration of Biodegradable Plastic Mulch in Pumpkin Production in Northwest Washington. American Society of Horticultural Science (ASHS) Annual Conference, ASHS National Conference, Atlanta, GA, Aug 8-11 2016.
  • Type: Journal Articles Status: Accepted Year Published: 2016 Citation: Ghimire, S., A. Wszelaki, J. Moore, H.Y. Sintim, M. Flury, D. Inglis, and C. Miles. 2016. Biodegradable plastic mulch produced comparable yield and quality of pie pumpkin as polyethylene mulch. ASHS National Conference, Atlanta, GA, Aug 8-11 2016.
  • Type: Journal Articles Status: Accepted Year Published: 2016 Citation: Benedict, C. and C. Miles. 2016. Developing outreach materials for large SCRI project. ASHS National Conference, Atlanta, GA, Aug 8-11 2016.
  • Type: Journal Articles Status: Accepted Year Published: 2016 Citation: Hayes, D.G., L.C. Wadsworth , A.L. Wszelaki, H.Y. Sintim, M. Flury, and C. Miles. Comparison of weathering at two diverse geographic locations and simulated weathering on the physicochemical properties of biodegradable plastic mulches. ASHS National Conference, Atlanta, GA Aug 8-11 2016.
  • Type: Journal Articles Status: Accepted Year Published: 2016 Citation: Cowan, J. 2016. Biodegradable mulch films: Their constituents and suitability for organic agriculture. ASHS National Conference, Atlanta GA Aug 8-11 2016.
  • Type: Journal Articles Status: Submitted Year Published: 2016 Citation: English, M., S. Bandopadhyay, D.G. Hayes, J.M. DeBruyn, L.C. Wadsworth, S.M. Schaeffer. 2016. Temperature sensitivity of biodegradable plastic mulches to microbial decomposition. ASA-CCSA-SSSA Annual Meeting, Phoenix, AZ, Nov 6-9.
  • Type: Journal Articles Status: Published Year Published: 2016 Citation: Tymon, L., and Inglis, D.A. 2016. Pseudomonas syringae pv. Syringae causing lesions on pumpkin fruit in WA, U.S. Ann. Mtg. Pacific Division, American Phytopathological Society, La Conner, WA, Jun 28-30.
  • Type: Journal Articles Status: Published Year Published: 2015 Citation: Sintim, H.Y, S. Bandopadhyay, S. Ghimire, M. Flury, A. Bary, S. Schaeffer, J. DeBruyn, C. Miles, and D. Inglis. 2016. Soil Quality and Colloid Transport under Biodegradable Mulches. EGU2016-18410, EGU General Assembly 2016, Geophysical Research Abstracts, Vol. 18.
  • Type: Journal Articles Status: Submitted Year Published: 2016 Citation: Sintim H., et al. Degradation of BDMs in Compost. ASA-CSSA-SSSA-Annual Meeting, Phoenix, AZ, Nov. 6-9, 2016.
  • Type: Journal Articles Status: Submitted Year Published: 2016 Citation: Bandopadhyay, S. et al. Effect of BDMs on Soil Microorganisms. ASA-CSSA-SSSA-Annual Meeting, Phoenix, AZ, Nov. 6-9, 2016.
  • Type: Journal Articles Status: Published Year Published: 2015 Citation: Miles, C., and S. Ghimire. Biodegradable mulch films: their constituents and suitability for organic agriculture. 2015. New England Vegetable and Fruit Conference, Dec. 15-17 2015, Manchester NH, p. 204-206.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2016 Citation: Wszelaki, A., S. Ghimire, C. Miles and J. Moore. 2016. Biodegradable Mulches for Vegetable Production Systems, Pick TN Conference, Knoxville, TN, February 11-13, 2016.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2016 Citation: Tymon, L., A. Salamone, and D. Inglis. Mar 30, 2016. Fungal endophytes isolated from pumpkin roots grown with agricultural mulches. Year 2 SCRI CAP team meeting, Performance and Adaptability of Biodegradable Plastic Mulch for Sustainable Specialty Crop Production. Mount Vernon, WA (poster). March 30.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2016 Citation: Tymon, L. March 30, 2016. Biodegradable mulch project: Plant pathology update. Year 2 SCRI CAP team meeting, Performance and Adaptability of Biodegradable Plastic Mulch for Sustainable Specialty Crop Production. Mount Vernon, WA. Mar 30 (presentation).
  • Type: Conference Papers and Presentations Status: Published Year Published: 2016 Citation: Sintim, Henry. 2016, March. Biodegradable plastic mulches: Degradation and impacts on soil quality and soil microclimate. Proposal for PhD dissertation, Washington State University. (40 students, faculty, and technical staff participants)
  • Type: Other Status: Published Year Published: 2016 Citation: Ghimire, S. and C. Miles. 2016, April. Dimensions of costs of polyethylene, paper and biodegradable plastic mulch. Washington State University Extension. (Extension factsheet)
  • Type: Other Status: Published Year Published: 2016 Citation: Ghimire, S. and C. Miles. 2016. Mechanically laying biodegradable paper and plastic mulch. Washington State University Extension. (Extension factsheet)
  • Type: Other Status: Published Year Published: 2016 Citation: Tymon, L. and D. Inglis. 2016 (April). What Is an Endophyte? Performance and Adoptability of Biodegradable Mulch Report No. FA-2016-01. https://ag.tennessee.edu/biodegradablemulch/Documents/what_is_an_endophyte_formatted.pdf
  • Type: Other Status: Published Year Published: 2016 Citation: Lyons, C., and J. Golberger. 2016 (January). What Is the Technology Adoption Working Group and Why Is It Necessary? Performance and Adoptability of Biodegradable Mulch Report No. TA-2016-01. Online. https://ag.tennessee.edu/biodegradablemulch/Documents/Fact-sheet-TAWG-FINAL.pdf
  • Type: Other Status: Published Year Published: 2015 Citation: DeBruyn, J., S. Bandopadhyay, D.G. Hayes, D. Inglis, and C. Miles. 2015 (October). Biodegradation  Putting Biology to Work. University of Tennessee Institute of Agriculture (UTIA). Performance and Adoptability of Biodegradable Mulch Report No. SE-2015-02. October 2015. Online. https://ag.tennessee.edu/biodegradablemulch/Documents/biodegradation_factsheet.pdf
  • Type: Conference Papers and Presentations Status: Published Year Published: 2015 Citation: Ghimire, Shuresh. 2015, December. Biodegradable plastic mulch for pumpkin production: crop yield, quality and mulch biodegradation in northwest Washington. Presentation of proposal for PhD dissertation, Washington State University. (30 student, faculty, and technical staff participants present, and broadcast to WSU Pullman campus and other WSU research centers.
  • Type: Other Status: Published Year Published: 2015 Citation: Miles, C., S. Ghimire, A. Wszekaki, and J. Moore. 2015 (October). Biodegradable Plastic Mulch in Organic Vegetable Production Systems. 2015. PowerPoint slide presentation. Online. https://ag.tennessee.edu/biodegradablemulch/Documents/Miles_etal_BDM_organic_conference.pdf
  • Type: Other Status: Published Year Published: 2016 Citation: Weaver, Bill and Mary Weaver. 2016. Biodegradable mulch research. Country Folks Grower Western Region 9(4, March):5, 17. http://cfgrower.com/biodegradable-mulch-research/ (popular press article)
  • Type: Other Status: Published Year Published: 2016 Citation: Benedict, C. and V. Alvarez. Performance and Adoptability of Biodegradable Plastic Mulch for Sustainable Specialty Crop Production: Project Introduction (video). https://ag.tennessee.edu/biodegradablemulch/Pages/Videos-relating-to-Biodegradable-Mulch.aspx
  • Type: Other Status: Published Year Published: 2016 Citation: Wszelaki, A. Season extension and potential for biodegradable mulches. Knoxville, TN. Growers' meeting presentation. (13 Feb, 2016; 25 growers)
  • Type: Other Status: Published Year Published: 2016 Citation: Wszelaki, A. Biodegradable mulches in vegetable production systems. Knoxville, TN. Extension agents' meeting presentation. (10 Agents)
  • Type: Other Status: Published Year Published: 2015 Citation: Cowan, J. Better farming through plastics: Season extension, mulch and more! Tilth Producers of Washington Annual Conference, Spokane, WA. (13 Nov, 2015; 30 growers)
  • Type: Other Status: Published Year Published: 2015 Citation: Wszelaki, A. Do biodegradable mulches have a place in your production system? Tennessee State University Third Tuesday Field Days and Educational Workshops. (20 Oct, 2015; 20 growers)
  • Type: Other Status: Published Year Published: 2016 Citation: Wszelaki, A. Biodegradable mulches in vegetable production systems. East TN Growers meeting. (27 Jan, 2016; 30 growers)
  • Type: Other Status: Published Year Published: 2016 Citation: Bandopadhyay, S. 2016, April. Microbial degradation of agricultural plastics. Presentation of proposal for PhD dissertation, University of Tennessee. 25 students and professors in attendance.
  • Type: Websites Status: Published Year Published: 2016 Citation: http://biodegradablemulch.org
  • Type: Journal Articles Status: Published Year Published: 2016 Citation: Cowan, J.S., A. Saxton, H. Liu, K. Leonas, D. Inglis, and C. Miles. 2016. Visual assessments of biodegradable mulch deterioration are not indicative of mulch degradation. HortSci 51(3):245-254.
  • Type: Journal Articles Status: Published Year Published: 2015 Citation: Jiang, J. T.L. Marsh, and P. Tozer. 2015. "Policy Induced Price Volatility Transmission: Linking the U.S. Crude Oil, Corn and Plastics Markets, Energy Economics, 52 Part A: 217-227.
  • Type: Journal Articles Status: Published Year Published: 2015 Citation: Dharmalingam, S., D.G. Hayes, L.C. Wadsworth, and R.N. Dunlap, J.M. DeBruyn, J. Lee, A.L Wszelaki. 2015. Soil degradation of polylactic acid / polyhydroxyalkanoate-based nonwoven mulches. J. Polym. Environ. 23(3): 302-315. doi: 10.1007/s10924-015-0716-9.
  • Type: Journal Articles Status: Published Year Published: 2015 Citation: Dharmalingam, S., D. Hayes, L. Wadsworth, R. Dunlap. 2015, Analysis of the time course of degradation for fully biobased nonwoven agricultural mulches in compost-enriched soil, Textile Research Journal,Nov 11. doi: 10.1177/0040517515612358
  • Type: Journal Articles Status: Submitted Year Published: 2016 Citation: Brodhagen,M., J. Goldberger, D.G. Hayes, D.A. Inglis, T.L. Marsh, and C. Miles. 2016. Policy considerations for limiting unintended plastic in agricultural soils. Science. (rejected; another publication outlet is being sought)
  • Type: Journal Articles Status: Published Year Published: 2016 Citation: Hayes, D.G., C. Miles, et al. 2016. Long-Term Impacts of Biodegradable Plastic Mulches for Sustainable Production of Fruits and Vegetables, 16th Annual Meeting of the American Ecological Engineering Society, Knoxville, TN, June 7-9.
  • Type: Journal Articles Status: Published Year Published: 2015 Citation: Sintim, H.Y., S. Bandopadhyay, S. Ghimire, M. Flury, A.I. Bary, S. Schaeffer, J.M. DeBruyn, C. Miles, D. Inglis. 2015 Soil quality, moisture, and temperature evaluation under different biodegradable mulches. American Society of Agronomy (ASA)-Crop Science Society of America (CSSA)-Soil Science Society of America (SSSA)-Annual Meeting, Minneapolis, MN, 15-18 Nov 2015.


Progress 09/01/14 to 08/31/15

Outputs
Target Audience:Target audiences reached during the first year of the project (Yr1) included specialty crop growers and intermediaries, including extension specialists and agents; agricultural plastic film and mulch manufacturers; agricultural plastics recyclers; scientists in several different disciplines; and undergraduate and graduate students. Three key efforts to reach target audiences in Yr1 of the project focused on developing extension publications and handouts, the project website, and the project's 21-member Advisory Committee (AC). The public website provides basic information resources, e.g., descriptions of how soil impacts are analyzed and a glossary of terms important to understand when considering use of biodegradable mulches, and will be a gateway to scientific outputs of the project. The project AC includes specialty crop growers and representatives of grower organizations; Extension specialists; experts in food safety, polymer science, mulch manufacturing, composting, materials standards, government policy, sociology, agricultural economics, soil microbiology, climate science, various horticultural specialties, and transdisciplinary research. Engaging the AC is paramount for our transdisciplinary project and was accomplished through team-wide meetings to review project research protocols and outreach plans, informal consultations with members via email and telephone, and participation of AC members in project Working Group (WG) meetings and conference calls. Members of the scientific community--particularly horticultural scientists and agricultural plastics researchers and industry representatives--were reached through two presentations at scientific conferences. Additional presentations have been accepted for scientific conferences occurring in fall 2015. Post-doctoral, graduate and undergraduate students were engaged in research, and students were targeted also through invited classroom lectures and other outreach and educational activities. Field-days and field tours engaged numerous specialty crop growers. Changes/Problems:There are no significant changes in the research schedule, goals, or research compliance protocols in Yr1. The only delay in expenditure resulted from delays in identifying one post-doctoral research associate and one PhD student at Washington State University and one Masters student at the University of Tennessee. These personnel have now been hired, and the delays will not have significant impact on rate of expenditure because the scheduled activities proceeded with the assistance of research associates and undergraduate students. In the first few months of the project, the team accepted a kind offer from Metabolix, Inc., to prepare a PLA+PHA film to serve as the "experimental BDM." (This is in lieu of the team preparing a Meltblown nonwoven material as proposed). Co-PI Larry Wadsworth coordinated the preparation of the BDM with assistance from Techmer, NatureWorks, and Metabolix in procuring the feedstocks and carbon black dye and in the preparation of the BDM film. The project is funded through August 2016 (two-years), with opportunity to reapply for funding for an additional three years (through August 2019). Data from the second field season will be produced through September 2016 and will require no-cost extension if the team does not secure year 3-5 funding. What opportunities for training and professional development has the project provided?Nine undergraduate students have assisted with research activities in Yr1, learning field and laboratory research methods and assisting with the annual meeting and field days. The project also has five PhD students and four Masters of Science students conducting research and developing outreach products to meet project objectives. Additionally, two Post-Doctoral assistants joined the project in August 2015. All project PIs and 12 AC members participated in the March 2015 meeting that involved two opportunities for professional development. As noted previously, this project's research and outreach objectives are being met through transdisciplinary activities. Inter-WG sessions occurred between all WGs at the meeting so that members could become familiar with all WG objectives, be introduced to each WG's research plans and methods, coordinated activities and outputs, and discern opportunities and needs for ongoing dialogue. Also, as the March 2015 meeting, all PIs and the participating AC members engaged in a training in Transdisciplinary Research. Details of this professional development are outlined in the Accomplishment, Goal G section, above. How have the results been disseminated to communities of interest?Dissemination of results is incorporated into two of our project objectives (Goal D and F). Efforts to disseminate results included two publications in conference proceedings (and the associated presentations) and two manuscripts submitted for publication in professional journals (one is awaiting publication and the other under review). Three Extension-type publications addressing various aspects of the project research also were produced and are available on the project and WSU Extension websites. Other efforts to disseminate results and engage our communities of interest included our public website http://biodegradablemulch.org , a field-day presentation in Washington State attended by 30 specialty crop growers, several trial plot tours, various presentations and classroom lectures about the project's research methods and objectives, and a number of university, Extension, and grower organization news articles explaining the project's aims. The field-day, presentations, and tours are captured in the table below. News articles are included as "other publications" in the "Publications" section of this report. What do you plan to do during the next reporting period to accomplish the goals?Analyses are underway of all the Yr1 environmental, horticultural, soil, and BDM performance data, and Yr1 horticultural results will be submitted for publication in Yr2. Laboratory analysis of soils and field-applied BDMs also are underway. Because long-term changes in productivity and soil are a project focus, multiple years of field trials are planned. The second field trial will begin in May 2016. In Yr2, the surveys to assess growers' perceptions of adoption barriers and consumers' awareness and interest will be conducted. The first set of farm case studies (with associated field demonstrations) will occur at locations in TN and WA. LCA will continue in Yr2, as will producer cost and benefits assessment. Several Extension publications are in progress or planned for Yr2, and a number of scientific presentations have been submitted to or are planned for conferences. Resources and information will be added to the project website.

Impacts
What was accomplished under these goals? Plastic mulch films that specialty crop growers use to reduce weeds and conserve water and soil, are stockpiled or burned subsequent to use because of poor biodegradability conventional plastic mulch materials and limited recycling options, releasing harmful residues into the environment. Concerns of growers, suppliers and county Extension agents about existing biodegradable mulches (BDMs) have limited their widespread use based on perceived barriers: lack of knowledge, high cost, and unpredictable breakdown. To overcome these hurdles, we are implementing a science- and application-based research design to improve crop production, reduce post-harvest and environmental costs, and increase economic vitality for growers and consumers by using BDMs. The project is on schedule to produce reliable data and information to better inform specialty crop growers, the policy/regulatory community, and consumers about biodegradable mulches. The first year of a multi-year field trial was begun. Researchers and Extension specialists collected data, produced mulch samples for laboratory analysis, built economic data that will help growers determine the feasibility of using biodegradable mulches on their farms, and disseminated information. Students collected and analyzed data and will be prepared to address future agricultural production issues using transdisciplinary research. Evaluate the impacts of long-term use of BDMs on 1) the soil ecosystem and 2) a specialty crop production system along with its associated growers and consumers. Significant coordination among the team members and advisors was essential in designing the experimental field trial, which is central to the entire project. The 5-year trial involves site locations in Knoxville, TN and Mount Vernon, WA and is guided by the protocol included in "Other Products." The plot design incorporated numerous experiments to assess effects of mulch treatments on: pumpkin yield and quality; pumpkin diseases, insects and weeds; mulch weathering; and soil chemical and physical quality parameters when mulches are tilled-into the soil or removed for composting after the growing season. The trial design accommodates environmental monitoring equipment, soil leachate collection, mulch sampling, a buried mulch study, and collection of economic data related to BDM use. The Yr 1 field trial was initiated May 2015. The WG members prepared plots, laid mulches, and planted and maintained pumpkin plants, and collected and recorded disease, insect, weed, and mulch performance data. In-field observations suggest that there will be many significant differences when the treatment and site comparisons are made (draft publication in fall 2015). The Soil Ecology WG team members developed research protocols (See "Other Products") and recorded environmental factors at field test sites using soil temperature and moisture sensors, lysimeters, and weather stations. For studies of soil quality, microbial community, carbon storage and leaching, and mulch particle leaching, the team conducted baseline soil sampling in May 2015. Data will be compared to post-harvest data to assess changes in soil health and soil quality. Progress included testing methods to identify microorganisms responsible for biodegradation. Preliminary tests of degradation-via-composting verified methods and showed that all mulches tested (in mesh bags, buried in compost) were completely degraded after 4 months. Consequently, the research protocol requires mulch pieces removed every two weeks. B. Identify BDM degradation mechanisms. The Plastics Analysis WG (PA WG) performed physicochemical testing on the test BDMs per the Plastics Analysis Protocol described in "Other Products." BDM samples were sent to Michigan State University's School of Packaging to perform simulated weathering in July, 2015. To determine the inherent biodegradability of BDMs measured by ASTM D5338 (composting) and 5988 (ambient soil conditions), the apparatus was assembled. PA and Soil Ecology WG members developed a white paper has been generated for collaborative experiments to deepen the understanding of the biodegradation process. C. Compare diverse scales of operation, climate regions, and methodology for evaluating the soil degradation of BDMs to improve performance regulations. See Objective A and B. D. Identify bridges and barriers to BDM adoption by growers and intermediaries; and educate growers, intermediaries, consumers, and the general public on BDMs. Research is scheduled (as per the proposal) to begin in Yr2 of the project. Preliminary discussions about the type of producers to engage in the survey research, the criteria for selecting farm case studies, and the goals of the focus groups occurred primarily during the spring 2015 project meeting and involved several AC members. Efforts to educate our various audiences in Yr1 are discussed in the "Dissemination." E. Assess the economic feasibility of agricultural products grown with BDM technologies through the entire supply chain to consumers. Literature reviews were completed to address the: (1) LCAs relevant to biodegradable mulch; (2) markets and prices for biodegradable plastics and materials; and (3) willingness to pay relevant to consumers' preference for environmentally favorable technologies and products. Supply Chain and LCA WG members (1) worked with the Field Activities WG members to identify the data needed to estimate BDM mulch use costs; (2) collected farm labor data relevant to BDMs at the TN test site and at production farms; (3) drafted consumer survey to assess the willingness to pay for agricultural products grown with BDMs; (4) developed a model of supply chain and markets involved in biodegradable plastic mulches; and (3) drafted an Excel spreadsheet version of a mulch calculator for use and disposal in agriculture. F. Interact with a community of stakeholders to increase interest in sustainable deployment of BDMs throughout the U.S. and worldwide. Significant interactions with our stakeholders occurred through their representatives on the AC (see "Target Audience."). Field tours and presentations are detailed in "Dissemination." At a BDM field demonstration, the "exit survey" showed the event changed participants' knowledge and awareness of BDMs positively and significantly, but the possibility that participants would adopt BDMs on their farms was not changed significantly. The Project Evaluation WG will compare these results to results from later field demonstrations that will involve project-based information about BDM performance. G. Educate and train project team on skills needed to work on transdisciplinary research problems. "Transdisciplinary" research integrates across disciplines and significantly involves stakeholders. Twelve AC members and 24 team members including 4 students participated in a transdisciplinary research training session that focused on overcoming transdisciplinary research barriers by building mutual understanding of disciplinary skill, theory, and language; expecting and accepting opportunities for collaboration; building institutional rewards for collaboration; and minimizing the transaction costs of collaborating. Other training occurred through: AC members participated in conference calls, reviewed draft publications, and visited trial plots WG members worked on activities outside their research area (e.g., social scientists and bioengineers participated in horticulture and soil science data collection). WG leaders collaborated on a publication that integrates various disciplinary perspectives and knowledge of BDM use and acceptance

Publications

  • Type: Journal Articles Status: Published Year Published: 2015 Citation: Miles, Carol. Biodegradable mulch film for organic production systems, American Society of Horticultural Science (ASHS) Annual Conference, New Orleans, LA. 5 Aug. 2015.
  • Type: Websites Status: Published Year Published: 2015 Citation: http://biodegradablemulch.org
  • Type: Journal Articles Status: Published Year Published: 2015 Citation: Miles, C. 2015. Performance and adoptability of biodegradable plastic mulch for sustainable specialty crop production, The Second Agricultural Plastics Recycling Conference (APRC 2015) Proceedings. San Diego, CA, 21 Aug 2015.
  • Type: Journal Articles Status: Accepted Year Published: 2015 Citation: Sintim, H.Y., Bandopadhyay, S., Ghimere, S., Flury, M., Bary, A.I., Schaeffer, S., DeBruyn, J.M., Miles, C., Inglis, D.: Soil quality, moisture, and temperature evaluation under different biodegradable mulches. American Society of Agronomy (ASA)-Crop Science Society of America (CSSA)-Soil Science Society of America (SSSA)-Annual Meeting, Minneapolis, MN, 15-18 Nov 2015.
  • Type: Journal Articles Status: Accepted Year Published: 2015 Citation: Schaeffer, S. et al.: Assessing soil quality as affected by different mulches. American Geophysical Union (AGU)-Annual Meeting, San Francisco, CA, 14-18 Dec 2015.
  • Type: Journal Articles Status: Under Review Year Published: 2015 Citation: Jiang, J. T.L. Marsh, and P. Tozer. 2015. "Policy Induced Price Volatility Transmission: Linking the U.S. Crude Oil, Corn and Plastics Markets, Energy Economics. Under revision.
  • Type: Journal Articles Status: Awaiting Publication Year Published: 2015 Citation: Dharmalingam, S., D. Hayes, L. Wadsworth, R. Dunlap. 2015, Analysis of the time course of degradation for fully biobased nonwoven agricultural mulches in compost-enriched soil, Textile Research Journal, in press. doi: 10.1177/0040517515612358
  • Type: Other Status: Published Year Published: 2015 Citation: Biodegradable Mulch Products. http://biodegradablemulch.org. University of Tennessee Institute of Agriculture (UTIA). July 2015. Online. https://ag.tennessee.edu/biodegradablemulch/Pages/factsheets.aspx
  • Type: Other Status: Published Year Published: 2015 Citation: Inglis, D., Miles, C., and Wszelaki, A. Why Grow Pumpkins in a Biodegradable Mulch Field Study? Performance and Adoptability of Biodegradable Mulch Report # FA-2015-01. June 2015. Online. https://ag.tennessee.edu/biodegradablemulch/Pages/factsheets.aspx
  • Type: Other Status: Published Year Published: 2015 Citation: Miles, C. and Scheenstra, E. Biodegradable Mulch Film for Organic Production Systems. Washington State University (WSU) Mount Vernon Northwestern Washington Research and Education Center (NWREC) Report 102. May 2015.
  • Type: Other Status: Published Year Published: 2015 Citation: Flury, M., Bary, A., DeBruyn, J., Schaefer, S., Sintim, H., and Bandopadyay, S. What Is Soil Quality and How Is It Measured? Performance and Adoptability of Biodegradable Mulch Report # SE-2015-01. August 2015. Online. https://ag.tennessee.edu/biodegradablemulch/Pages/factsheets.aspx
  • Type: Other Status: Published Year Published: 2015 Citation: Andrews, N., DeVetter, L., and Miles, C. Biodegradable mulch update  new NOP rule. Oregon Small Farm News X(3): 9 -12. Summer 2015. Online. http://smallfarms.oregonstate.edu/newsletter
  • Type: Other Status: Published Year Published: 2015 Citation: Biodegradable Mulch for Vegetable Production. WSU Extension. Online. June 2015. http://ext100.wsu.edu/impact/biodegradable-mulch-for-vegetable-production/
  • Type: Other Status: Published Year Published: 2015 Citation: McDaniels, P. UT Institute of Agriculture Leads Multi-State Bioplastics Mulch Investigation. UTIA News & Announcements. February 2015. Online. http://growingtennessee.com/features/2015/02/ut-institute-agriculture-leads-multi-state-bioplastic-mulch-investigation/
  • Type: Other Status: Other Year Published: 2015 Citation: Sanchez, Elsa. Project addresses barriers to using biodegradable plastic mulches. Penn State Extension Vegetable, Small Fruit, and Mushroom Production News. April 2015. Online. http://extension.psu.edu/plants/vegetable-fruit/news/2015/biodegradable-plastic-mulches