Progress 09/15/23 to 09/14/24
Outputs
Target Audience:Our target audience includes growers/agricultural decision-makers, berry production companies (e.g., Driscoll's and Naturipe), scientific peers,state and federal environmental regulatory agencies, the members of the National Organic Standards Board,film plastic producers, recycling companies, graduate and undergraduate students, and the general public. Some farmers are fromgroups that are economically and socially disadvantaged. These audiences were reached through strategic efforts including development and distribution of scientific publications, factsheets, and videos have been posted on the project website (https://smallfruits.wsu.edu/plastic-mulches/publications/) and social media including a newly launched podcast called "Mulch Matters". Project results and communication with target audiences have also been disseminated through field days, workshops, advisory board meetings, conferencepresentations, classroom presentations, and one-on-one communications with regulators, berry production companies, and standard boards. Changes/Problems:We have added a new co-PI to our project team, Dr. Louie Nottingham. Dr. Nottingham will evaluate how mulch treatments applied in Washington State impact pest and beneficial insects. A portion of PD DeVetter's budget has been re-allocated to support this work. We have adjusted our Data Management plan by migratingto Microsoft Teams for cloud-based storage of project data instead of Google Drive. Measurements of aggregate stability, an variable used to assess soil quality, is delayed until the equipment arrives at the Washington State University lab in Mount Vernon, WA. What opportunities for training and professional development has the project provided? Annual and quarterly project team and advisory board meetings provide training and professional development opportunities for the entire team to learn about specific activities led by each Working Group as well as engage in interdisciplinary discussions related to project objectives. Assessments are done during quarterly meetings to gauge the effectiveness of provided trainings and quantify knowledge gain. Executing the research also provides undergraduate students, graduate students, and postdoctoral scholars with training and professional development opportunities. Within the reporting period, 11 undergraduate students have contributed 1,052 hours doing research in support of the project. An additional 45 undergraduate students in the Natural Resources Management and Environmental Science Senior Capstone class at CalPoly also worked in groups to assess current plastic mulch alternatives used by small growers. Five postdocs (2 of which are volunteers) and 10 graduate students (5 of which are volunteers) are also engaged in the project either as research assistants/scholars funded directly by the project or as volunteers that contribute as part of their thesis work or for professional development on extension communication. The project team has also established a charter that outlines expectations for the project (e.g., data management, quality control, authorship and credit agreements, processes for internal review, etc.) and charter is based on the NIH Collaboration and Working Group Science Field Guide. The team will continue to use this charter to guide collaborative team science. An updated system for data management using Microsoft Teams for cloud-based storage has also been refined. The project director sends out weekly project updates to the team, keeping the entire team and advisory board informed about current and planned activities, publications, and outputs from the team, publications relevant to the team, and dates of group meetings and professional meetings of interest. In addition, the team leading Objective 6 has established a schedule to develop needs-based outreach products and is involving graduate students so they can co-write and gain professional experience in science communication across stakeholder groups. These combined activities give involved students and junior scientists opportunities to expand their knowledge about the project as well as essential skills of communication with diverse audiences and project team management. How have the results been disseminated to communities of interest?Our team has been proactive at sharing project information across a diversity of platforms and communities of interest. In total, 6peer-review journal articles were published within the last reporting period and with additional manuscripts in review or nearing completion. We also levered stakeholder feedback and produced 2 new factsheets available on our website (https://smallfruits.wsu.edu/plastic-mulches/) titled, "PFAS is not present in BDM" and "Impact of mulching on specialty crop performance". Eight additional factsheets were revised and published. Additionally, 2 new slide decks with presenter notes were produced and 5 existing slide decks were updated to reflect new information. These slide decks and presenter notes are freely available on our website and distributed to extension educators via a "train the trainer" approach, enabling non-experts to share information about soil-biodegradable mulches, agricultural recycling, and the importance of agricultural plastic mulch in specialty crop production. Overall, the website is an important anchor to share information and resources with3591 views by 1469 userswithin the reporting period. Two members of our team led submission of public comments regarding the use of soil-biodegradable plastic mulches and non-biodegradable plastic mulches in certified organic agriculture to the National Organic Standards Board, which is an avenue that allows project information to inform national policy. Growers and crop consultants across the nation and world are also being educated on our project with field days (n=8), workshops (n=2), conference presentations (n=12), and one webinar accomplished within the reporting period. Of note, we have been invited to participate in a panel discussion and give a targeted presentation on our work at the Agriculture Plastics Recycling Conference with a workshop focused on soil-biodegradable mulches to be held before the conference with the aid of the conference organizers. Members of our team also review scientific literature with rigor to ensure that the science being produced is sound and we recently provided feedback on a manuscript submitted to Proceedings of the National Academy of Sciences of the United States of America. Our work was also featured in two popular press articles, ensuring project-level awareness and initial findings are reaching a more general audience. Our biennial newsletter (n=278suscribers) and podcast launched in Oct. 2023 called "Mulch Matters" also educates both the general public and agricultural audiences including growers and crop advisors. We have 7 podcasts episodes total, releasing one episode per month, and have ~400 downloads. LinkedIn (@MulchMatters, n=278 followers) and Instagram (@Mulch_Matters, n=93 followers) are other avenues we share project information. Lastly, we have been educating students about our work and the challenges of agricultural plastic waste through participation in undergraduate courses. What do you plan to do during the next reporting period to accomplish the goals?Plans for the next reporting period are as follows: Objective 1. Compare benefits of commercially available and emerging BDMs to conventional PE mulch in diverse strawberry systems: (1) Complete horticultural and environmental data collection for the soil-biodegradable mulch trials established in Washington, Nebraska, and Florida and continue collecting similar data in California. (2) Collect year 1 horticultural and environmental data for the separate trial evaluating emerging mulch technologies across trial locations in Washington, Nebraska, California, and Florida. (3) Continue collecting, analyzing, and interpreting soil health data for mulch trials established in Washington, Nebraska, California, and Florida. (4) Evaluate barrier properties of mulch films using fumigant cells and GC-MS against common fumigants, chloropicrin and 1,3-dichloropropene. (5) Test the influence of chloropicrin and the mixture of chloropicrin and 1,3-dichloropropene on BDMs via soil and liquid tests. Completing these tasks will permit comparisons to be made among different commercially available and newly emerging mulch technologies with regards to end-of-life outcomes and impacts on strawberry production. (6) Share findings with project team economists. (7) Begin drafting objective-specific scientific manuscripts and share information with the Extension Working Group for broader dissemination. (8) Attend the International Society for Horticultural Sciences Strawberry symposium and share project information with an international audience. Objective 2. Explore and optimize recycling technologies for improved end-of-life outcomes of conventional PE mulch for strawberry systems: (1) Continue to coordinate the collection and delivery of used polyethylene mulch film from the year 2 trial locations in California, Washington, Nebraska, and Florida. The film will be processed and analyzed similarly to what has been done before.(2) Densified pellets from used and characterized polyethylene mulch film obtained from the field trial locations and Advisory Board Member Gene Jones of SWIX will be prepared and sent to project team members at PDO and California State University Chico. Densified pellets will be incorporated into larger asphalt, pyrolysis, and composite material pilot runs. (3)Evaluations on the aspect ratios of the soil and organic contaminants present on the used polyethylene mulch films from the different regions will be assessed to understand their influence on material properties for recycling. (4) The performance tests of asphalt mixtures, including plant-mixed HMA, and laboratory-mixed HMA with and without used polyethylene mulch will be evaluated. Performance tests include fracture cracking, fatigue-load cracking, rutting resistance, moisture damage resistance, and draindown tests. Pyrolysis tests include CapEx/OpEx analysis of collection and densification, CapEx/OpEx analysis of conversion, contaminant load vs. product yield, and examination of logistical cost constraints. (5) Share project information with project team economists. (6) Begin drafting objective-specific scientific manuscripts and share information with the Extension Working Group for broader dissemination. Objective 3. Characterize and evaluate degradation, residence time of mulch fragments, and environmental fate of BDM degradation products in agricultural soils under various conditions within the strawberry cropping system: (1) Collect and finish processing soil samples for background and post-tillage microplastic analysis in California, Florida, Nebraska, and Washington. (2) Conduct preliminary analyses of BDM environmental fate and estimate residence time of mulch fragments in different soil and environmental conditions. (3) Continue to draft and publish manuscripts and engage with the Extension Working Group for broader information dissemination. Objective 4. Evaluate individual, sociocultural, and structural influences on decisions regarding plastic mulch end of life management: (1) Obtain feedback from the project team (including Advisory Board members) to finalize the survey instrument to be used for the mail/web survey of California strawberry growers. (2) Translate the survey instrument and all survey-related communications (e.g., cover letters, emails) into Spanish. (3) Widely publicize the survey with help from the project team (including Advisory Board members). (4) Conduct the survey of ~1,000 California strawberry growers in collaboration with WSU's Social and Economic Sciences Research Center. (5) Continue qualitative data collection (e.g., in-depth interviews). (6) Conduct preliminary analyses of survey and qualitative data. (7) Present preliminary results at academic conferences and other meetings. (8) Prepare a survey summary report. (9) Begin drafting academic manuscripts. (10) Attend the North American Strawberry Growers Association's annual meeting in February 2025. Objective 5.Identify direct and indirect economic and environmental impacts and optimal strategies for reducing plastic mulch pollution. (1) Continue contacting industry partners and other Working Group members leading project objectives to collect primary data for economic analyses and refinement of the overall LCA process.(2) Distribute a consumer survey via Qualtrics. (3) Preliminary analysis of baseline survey data addressing policy questions. (4) Draft and submit a review article led by PhD students working on LCAs. Objective 6.Deliver project information and outputs to stakeholders and evaluate success in technology transfer: (1) Continue writing targeted extension materials and draft articles for dissemination to industry stakeholders in coordination with project team members. (2) Target and translate a selection of new and current written materials into Spanish. (3) Record and release one podcast episode per month. (4) Revise and create new educational videos based on Advisory Board feedback. (5) Edit the project website (https://smallfruits.wsu.edu/plastic-mulches/) for enhanced user experience and update information as needed. A significant effort will be placed to adjust web content so we are compliant with new regulations for the Title II of the Americans with Disabilities Act. (6) Grow the social media presence of the project and the team. (7) Support execution of field days and provide Spanish translation so to better serve underserved populations. (8) Take advantage of opportunities to deliver workshops and presentations at industry and academic conferences. (9) Share science-based information stemming from the project that informs policy in partnership with the project team. In addition, Project Management (PD DeVetter, coPD Flury, and Project Manager Britton) will continue to ensure all Working Group members involved in the above objectives meet approximately monthly to aid project planning and coordination. The team will also continue to hold quarterly meetings open to the Advisory Board, submit quarterly progress reports, and organize a hybrid annual Advisory Board meeting in winter 2025. The project team will follow their Data Management plan as well as a project charter that guides codes of conduct for the project team and requirements for engagement with Advisory Board members. In addition, final analyses of baseline data for future impact reporting led by the Social & Economic Sciences Research Center at Washington State University will be completed and plans for the next evaluation will be formulated in partnership with Project Management with input from the Human Dimensions (i.e., Objective 4) and LCA/economics (i.e., Objective 5) teams.
Impacts
What was accomplished under these goals?
Objective 1. Compare benefits of commercially available and emerging soil-biodegradable plastic mulches (BDMs) to conventional PE mulch in diverse strawberry systems: (1) First year trials evaluating commercially available BDMs in strawberry systems in Washington, Florida, and Nebraska were completed and are ongoing in California. Second year trials were established in Washington and Nebraska in May 2024 and will be later established in Florida and California to coincide with their production cycles. (2) Baseline and post-tillage soil samples from the first-year trials were collected in all locations (except California, post-tillage samples will be collected fall 2024) and soil quality analyses are underway. (3) Soils sampled in year one for soilborne pathogen analysis are in storage. (4) Physical and mechanical property testing of new mulch treatments used in year one trials were completed. End-of-season physical and mechanical property testing from treatments used in year one are also in progress. (5) Emerging mulch technologies were identified, and a separate trial was established in Washington and Nebraska in May 2024. Treatments will also be trialed in Florida and California. (6) A laboratory procedure to evaluate the influence of soil fumigants on BDMs via soil and liquid immersion tests was developed, executed, and data analysis is underway. (7) Designed a fumigant cell for measuring the fumigant permeability of BDMs and permeability tests are underway. Objective 2. Explore and optimize recycling technologies for improved end-of-life outcomes of conventional PE mulch for strawberry systems. (1) Established an efficient sampling protocol for mulch films and densified pellets. (2) Characterization of PE mulch films and densified pellets from samples received from field site locations outlined in Objective 1 and from one of our Advisory Board members. Spectroscopy, chemical analysis, and rheology are used for characterization. (3) A field trip was made to the Objective 1 trial location in Washington in late September 2023 to observe mulch removal. Some of the PE mulch was sampled for in vitro tests of moisture content, ash content, and fertilizer analysis to understand contaminant load on removed PE mulch and how that may impact downstream recycling. (4) For asphalt evaluation, analysis of two binders modified by virgin PE mulch and recycled PE were completed. The preliminary performance results showed that the additions of mulch film as additives for asphalt binders improved the rutting resistance but slightly compromised the low-temperature thermal cracking resistance. Pelletized new PE mulch and recycled PE (rPE) mulch from WA and NE were received and analyzed. All tested mixtures had sufficient rutting resistance and optimization procedures were identified. (6) Pyrolysis work entailed combining two sources of densified film material and densifying via agglomeration.?The PE mulch had a high contaminant/tramp load but was cleaned and densified using either a California Pellet Mill or melt filtration.?When processed, the trial yielded about 78% product when normalized for the plastic content only. The tramp material lowers the overall yield by quite a bit. Pyrolysis of the film (which was low density PE) was quicker than a comparable load of high-density PE.? Little high molecular weight pyrolysis oil fraction with the LDPE was observed. A new graduate student will be hired soon to continue work on the pyrolysis. Objective 3. Characterize and evaluate degradation, residence time of mulch fragments, and environmental fate of BDM degradation products in agricultural soils under various conditions within the strawberry cropping system. (1) Leveraging the trial locations used for Objective 1, soils were sampled for background microplastic content pre-tillage in California, Florida, Nebraska, and Washington. Post-tillage soil samples were also collected after strawberry harvest in Washington, Nebraska, and Florda with California to follow once BDM treatments are tilled. Samples are only being collected for the black PE control (i.e., PE mulch is not tilled into the soil, but physically removed) and two black BDM treatments made with different compostable/soil-biodegradable feedstocks. Extraction and analysis of microplastics is underway. Pre-tillage mulch fragment samples were analyzed for mass, surface area, and number concentrations using ImageJ for all states. Post-tillage mulch sample analysis for mass, surface area, and number concentrations are still in progress. Differences in baseline microplastic contaminant levels were observed and are associated with history of plastic mulch usage. (2) Field-weathered mulch samples from the Washington trial location were collected in 2023 and then placed in mesh "decomposition" bags that were installed in Washington and will be retrieved over time. This procedure is being repeated for all states so degradation over time across the different locations will be characterized. Objective 4. Evaluate individual, sociocultural, and structural influences on decisions regarding plastic mulch end of life management. Much of the reporting period was spent assembling the team, conducting literature reviews, networking, and planning research activities. Key accomplishments include: (1) Obtaining exemption status from Washington State University's IRB for qualitative data collection. (2) Drafting a questionnaire to be distributed to California strawberry growers in late Fall 2024. (3) Compiling a mailing list of California strawberry growers for the survey to be conducted in late Fall 2024. Objective 5. Identify direct and indirect economic and environmental impacts and optimal strategies for reducing plastic mulch pollution. (1) A review paper was completed and under review. The review offers insights into the intricate interplay between the environmental impact and economic considerations associated with the production, use, and end-of-life of non-biodegradable PE mulch and BDMs. Additionally, it postulates impact mitigation strategies.(2) The LCA Product Systems structure was revised to cater for easier sensitivity simulations and analysis.(3) A problem with the OpenLCA processes was identified and solved by creating production processes to make missing providers available, without which impact assessment is inaccurate. (4)Finished a draft of the consumer survey and the survey is in its testing phase. (5) Development of the producer and policy surveys is ongoing. (6) Coordinated with other Working Groups on content and timing of survey instruments. (8) Prepared two new slide decks with presenter notes for the Extension team leading Objective 6 to use focused on life cycle assessment for BDMs. Objective 6. Deliver project information and outputs to stakeholders and evaluate success in technology transfer. (1) Sharing of project progress and solicitation of feedback was successful during the 2024 annual project Advisory Board meeting. (2) A total of 10 factsheets were published (2 new and 8 revised), promoted via social media, and are available for free on the project website (https://smallfruits.wsu.edu/plastic-mulches/). (4) Instructional videos are in progress. (6) A Train-the-Trainer session was held during the last quarterly team meeting to document transdisciplinary learning and professional development within the team. (7) Podcast guests are interviewed each month with monthly release of episodes. (8) Maintained and grew project social media presence. (9) Created two new slide decks. (10) Produced and released a biannual newsletter.(11) Regularly updated the project website to enhance user experience. In addition, Project Management in partnership with the Human Dimensions and LCA Working Groups supported development of a baseline survey for future impact reporting. Lastly, all members of the project team has produced manuscripts that are published (see "Products"), in review, or in progress.
Publications
- Type:
Journal Articles
Status:
Published
Year Published:
2023
Citation:
Li, S., F. Ding, M. Flury, and J. Wang. 2023. Dynamics of macroplastics and microplastics formed by biodegradable mulch film in an agricultural field. Science of the Total Environment. 894:164674. https://doi.org/10.1016/j.scitotenv.2023.164674
- Type:
Journal Articles
Status:
Published
Year Published:
2023
Citation:
Astner, A. F., A. B. Gillmore, Y. Yu, M. Flury, J. M. DeBruyn, S. M. Schaeffer, and D. G. Hayes. 2023. Formation, behavior, properties and impact of micro- and nanoplastics on agricul- tural soil ecosystems (a review). NanoImpact. 31: 100474. doi:10.1016/j.impact.2023.100474.
- Type:
Journal Articles
Status:
Published
Year Published:
2023
Citation:
Hofmann, T., S. Ghoshal, N. Tufenkji, J. F. Adamowski, S. Bayen, Q. Chen, P. Demokritou, M. Flury, T. Huffer, N. P. Ivleva, R. Ji, R. L. Leask, M. Maric, D. M. Mitrano, M. Sander, S. Pahl, M. C. Rillig, T. R. Walker, J. C. White, and K. J. Wilkinson. 2023. Plastics can be used more sustainably in agriculture. Comm. Earth Environ. 4: 332. doi.org/10.1038/s43247-023-00982-4. (doi.org/10.1038/s43247- 023-00982-4)
- Type:
Journal Articles
Status:
Published
Year Published:
2024
Citation:
Sarpong, K.A., F.A. Adesina, L.W. DeVetter, K. Zhang, K. DeWhitt, K.R. Englund, and C. Miles. 2024. Recycling agricultural plastic mulch: limitations and opportunities in the United States. Circular Agricultural Systems. 4: e005 doi: 10.48130/cas-0024-0003
- Type:
Journal Articles
Status:
Published
Year Published:
2023
Citation:
Shrestha, S., L.W. DeVetter, C. Miles, J. Mejia-Munoz, P. Krone, M. Bolda, and S. Ghimire. 2023. Building agricultural knowledge of soil-biodegradable plastic mulch. HortTechnology 33(5):455-463. https://doi.org/10.21273/HORTTECH05248-23
- Type:
Journal Articles
Status:
Under Review
Year Published:
2024
Citation:
Shcherbatyuk, N., S. Wortman, D. McFadden, B. Weiss, S. Weyers, W. Ahmad, D. Bajwa, S.P. Galinato, A. Formiga, G. Gramig, and L.W. DeVetter. 2024. Existing and emerging mulch technologies for organic and sustainable agriculture in the United States: A review. HortScience. In review.
- Type:
Journal Articles
Status:
Published
Year Published:
2024
Citation:
Yu, Y., and M. Flury. 2024. Unlocking the potentials of biodegradable plastics with proper management and evaluation at environmentally relevant concentrations. npj Materials Sustainability. 2:9 doi:10.1038/s44296-024-00012-0
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Progress 09/15/22 to 09/14/23
Outputs
Target Audience:Our target audience includes scientific peers, graduate students, state and federal environmental regulatory agencies, the members of the National Organic Standards Board, farmers, mulch film plastic producers, plastic recycling companies, berry production companies (e.g., Driscoll's and Naturipe), and the general public. Some farmers are from racial groups that are economically and educationally disadvantaged. These audiences were reached through strategic efforts including development and distribution of factsheets and videos have been posted on the project website (https://smallfruits.wsu.edu/plastic-mulches/publications/) and social media. A project logo, acknowledgement slide, QR code for DEI reporting, and slide templates have also been developed also for the whole project team to use for distributing project-related knowledge at outreach events. Project results have been disseminated through field days, conference presentations, and one-on-one communications with regulators, berry production companies, and standard boards. Changes/Problems:Our project manager had a stroke and will be on medical leave indefinitely. Washington also had a heat event, leading to some minor plant mortality in the field trial. What opportunities for training and professional development has the project provided?At this early stage of the project, meetings have been the primary professional development activity for members (including students) to learn about the project and project management and leadership. The project team has held one, hybrid, combined kickoff meeting and stakeholder advisory meeting in February 2023 at the Washington State University Research and Extension Center in Mount Vernon, WA, and has established a schedule of quarterly meetings and reports to facilitate communication across the team and streamline reporting to Project Management. All Working Group leads within the project are expected to attend and report on progress during these quarterly meetings and Working Group leads are also responsible for submitting quarterly reports. Working Groups are also encouraged to meet every 1-2 months to discuss progress within their designated Working Group, and PD DeVetter and co-PD Flury attend these meetings to keep abreast of achievements and planned activities within the working groups. The project team has also established a charter that outlines expectations for the project (e.g., data management, quality control, authorship and credit agreements, processes for internal review, etc.) and charter is based on the NIH Collaboration and Working Group Science Field Guide. The team will continue to use this charter to guide collaborative team science. A system for data management using Google Drive for cloud-based storage has also been developed which PD DeVetter backs up monthly on an external hard drive. DeVetter sends out weekly project updates to the team, keeping the entire team and advisory board informed about current and planned activities, publications, and outputs from the team, publications relevant to the team, and dates of group meetings and professional meetings of interest. In addition, the team leading Objective 6 has established a schedule to develop needs-based outreach products and is involving graduate students so they can co-write and gain professional experience in science communication across stakeholder groups. ? How have the results been disseminated to communities of interest?Three technical journal articles have been published and research-based information has been presented at four conferences. In addition, five factsheets on several topics of our research project have been published on our project website and we are in the process of developing four more factsheets. We further have led and participated in two field days on strawberry production.? What do you plan to do during the next reporting period to accomplish the goals?The first soil quality assessment, mulch, and soil plastic residue sampling will start in Washington and Nebraska at the end of September 2023, at the end of the strawberry growing season at these locations. The strawberry field trials in California will start in August 2023 and in Florida in October 2023. Starting in 2024, smaller field trials will be established in parallel to evaluate new and emerging mulch technologies identified with feedback from our Advisory Board and only a subset of variables (mulch deterioration and in-soil degradation) will be measured to enable initial, cost-effective assessments of new mulch technologies. All other activities will continue as planned in our proposal.
Impacts
What was accomplished under these goals?
Objective (1): Compare benefits of commercially available and emerging soil-biodegradable mulches (BDMs) to conventional non-biodegradable polyethylene (PE) mulch in diverse strawberry systems] and Objective (3): Characterize and evaluate degradation, residence time of mulch fragments, and environmental fate of BDM degradation products in agricultural soils under various conditions within the strawberry cropping system. Note Objectives 1 and 3 are presented together because activities are synergistic, complementary, and the Working Gropus coordinate regularly together. The team created a 51-page protocol document and experimental field trials evaluating different BDMs have been established in Washington and Nebraska in May 2023 in accordance with our timeline. Strawberry trials have been arranged in a randomized block design with 7 different mulch treatments and 4 replicates each in Washington. All other locations will have six treatments. Production, fruit quality, soil health, and mulch performace data will be collected for two years. In addition, a Nile Red staining method was tested for detecting PE and PBAT mulch fragments extracted from soil samples, but only white colored mulch could be successfully stained with Nile Red. The team is also working on preparation of sampling bags and labels for microplastic collection from previous SCRI sites in Tennessee and Washington. We also are testing mesh bag designs for our mesh bag studies which start in Fall 2023.? We have started to test air permeability of various plastic mulches to assess their performance when exposed to soil fumigants. Fumigants tested included 1,3-D, chloropicrin, metam sodium, and k-pam. Objective (2): Explore and optimize recycling technologies for improved end-of-life outcomes of conventional PE mulch. Used plastic mulches made from PE feedstock were obtained and analyzed to establish incoming feedstock protocols and preliminary trials were ran. A new graduate student working on the project is establishing consistent and accurate techniques to describe the mulch film for soil contamination, moisture, other contaminates and methods to turn the loose film into a usable pellet. Initial pelletizing of PE mulch generated approximately 80 lbs of pellets. These pellets were sent to our collaborators Kevin DeWhitt at PDO Technologies and Kun Zhang and Chico State University for pyrolysis and asphalt binder evaluation, respectively. As for asphalt testing, new PE (NPE) and recycled PE (rPE) mulch-modified asphalt binders were prepared and tested. The percentages of NPE added to blend with PG64 (i.e., a performance-grade asphalt) binders include 0.5%, 1%, 3%, 5%, 10%, and 15% by weight of asphalt binders. The preliminary performance results showed that the recommended dosage of using NPE to modify asphalt binders is 3% or 5%. Thus, the percentages of rPE used to modify asphalt binders were tried at 3% and 5%. Generally, as the dosages of added PE mulch increased, the production temperatures, high-performance grade (HPG), and rutting resistance of PE-modified asphalt binders increased, while the low-performance grade and thermal cracking resistance of PE-modified asphalt binders decreased. Compared between NPE- and rPE-modified binders, rPE has lower modification effectiveness than NPE, which is because of the effective PE contents and contaminations in rPE. For asphalt analysis, another performance-grade asphalt binder (PG58) will be modified with various NPE and rPE to verify the results for PG64 binders. Depending on the availability of other recycled PE mulch from the project, the asphalt binders modified by the recycled PE mulch will be iterated and tested. In addition, the mix design and performance tests of asphalt mixtures with NPE and rPE will start to be evaluated. Objective (3): see under Objective (1) above. Objective (4): Evaluate individual, sociocultural, and structural influences on decisions regarding plastic mulch end of life management. The team has recruited a postdoc and graduate student. Research planning is underway and data collection will start Fall 2023. A mixed method approach that integrates qualitative and quantitative data collection and analysis is planned. Data collection will occur in two phases where the first phase involves in-depth qualitative data collection (e.g., key informant interviews, participant observation, site visits, focus groups) of strawberry growers, Extension agents, agricultural input suppliers, crop consultants, recycling facility representatives, and other individuals and groups who make, use, recommend, supply, recycle, or otherwise interact with plastic mulches. The second phase will involve a survey about PE and BDM mulch use and other questions will be added based on the outcome of the first phase. Information from this objective will develop new knowledge about the factors that help or hinder specialty crop growers' adoption of more sustainable technologies (e.g., BDMs) and practices (e.g., PE mulch recycling) that can help address the growing problem of agricultural plastic pollution. Objective (5): Identify direct and indirect economic and environmental impacts and optimal strategies for reducing plastic mulch pollution. A graduate student has been recruited and is gathering inventory data from the literature and USDA databases specific to strawberry field operations, including field preparation, soil tillage, planting, fertilizer application, fumigation, and harvest. Data has also been provided by Advisory Board members. Preliminary simulations on OpenLCA have been initiated by inputting the inventory data into the created LCA process structure. The life cycle analysis (LCA) for BDM and PE mulch will occur in 2023 and 2024, while the LCA for PE mulch recycling technologies and alternative EOL processes will occur in 2024 through 2026. Consumer willingness to pay/risk and policy surveys are also under preparation. The willingness to pay survey will be distributed through 2024. The policy survey will be developed to address attitudes for traditional market-based instruments, pay-back mechanisms, and end-of-life strategies and will be completed in 2023, with dissemination and testing in 2024-2025. Lastly, a dynamic model of farm profitability that evaluates the tradeoffs between BDM degradation rate and the functionality of the mulch in improving agricultural productivity is in development. Information will be instrumental in addressing BDM adoption issues related to perceptions of cost. The Working Group leading this objective will develop a theoretical model in 2023 and 2024, collate data from experiments across the project and secondary sources in 2023 through 2025, develop empirical model and comparison scenarios in 2024 through 2025, and simulate optimal and comparative strategies in 2025-2026. Objective (6): Deliver project information and outputs to stakeholders and evaluate success of technology transfer. Factsheets, publications, videos, and social media accounts have been produced and distributed. The factsheets relate to BDMs in organic agriculture, storing soil-biodegradable plastic mulch on-farm, mechanically laying biodegradable plastic mulch, soil fumigation compatibility with soil-biodegradable plastic mulch and tarp recycling, testing degradation of soil biodegradable plastic mulches, description of bio-based content and its relevance for BDMs, advances in plastic mulch, impact of mulching on soil environment (in preparation), impact of mulching on crop yield and quality. ?
Publications
- Type:
Journal Articles
Status:
Awaiting Publication
Year Published:
2023
Citation:
Yu, Y., M. Velandia, D.G. Hayes, L.W. DeVetter, C.A. Miles, and M. Flury. 2023. Biodegradable plastics as alternatives for polyethylene mulch films. Advances in Agronomy. In press.
- Type:
Journal Articles
Status:
Published
Year Published:
2023
Citation:
Wang, X., C. Mattupalli, G. Chastagner, L. Tymon, Z. Wu, S. Jung, H. Liu, and L.W. DeVetter. 2023. Physical characteristics of soil-biodegradable and nonbiodegradable plastic mulches impact conidial splash dispersal of Botrytis cinerea. Plos one. e0285094.
- Type:
Book Chapters
Status:
Accepted
Year Published:
2022
Citation:
Flury, M., D.G. Hayes, and K. Mancl. 2022. Biodegradable Plastics-A Potential Solution for Agricultural Mulch? InsightOut, 8: 6269. https://www.wilsoncenter.org/publication/insightout-issue-8-closing-loop-plastic-waste-us-and-china?collection=46001
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