Biodegradable Mulch Team Uses Transdisciplinary Approach to Meet Objectives


Researchers say it’s a complicated issue for many fruit and vegetable producers--the adoption of biodegradable mulch. While the “environmentally friendly” alternative to plastic mulch may seem like the obvious choice, concerns remain about the impacts these mulches have on soil, productivity and farm economics. Through a Specialty Crop Research Initiative grant, scientists from several disciplines are now combining their expertise to find a solution to this issue.

“Using a transdisciplinary approach will allow researchers to learn from each other, solve problems by working in teams, and allow each discipline to bring a different perspective to the problem,” says Douglas Hayes, a professor in UT’s Biosystems Engineering and Soil Science department who is leading the Biodegradable Mulch Project Team. “Working on these kinds of grand challenges will be the norm in the future, but for many of our team members this is new ground.”

Transdisciplinary research is, essentially, team science. Using this approach, researchers contribute their expertise to the whole project, rather than one part. While the term transdisciplinary is sometimes used interchangeably with interdisciplinary or multidisciplinary, leaders of the Biodegradable Mulch Team distinguish differences.

“Transdisciplinary is a step up,” says Susan Schexnayder, senior research associate with UT’s Forestry, Wildlife and Fisheries department and project manager. “It involves integrating research across disciplines as well as engaging stakeholders in the design and implementation of the project so that the results are meaningful to the stakeholders.”

The transdisciplinary team includes faculty and staff from five UTIA departments: Biosystems Engineering and Soil Science; Plant Sciences; Forestry, Wildlife and Fisheries; Animal Science; and Agricultural and Resource Economics. UTIA is also partnering with Washington State University and Montana State University on the project. Additionally, there is involvement from an advisory committee that includes growers, biodegradable mulch representatives, suppliers, and Extension agents.

The team’s goal is to determine whether the profitability and sustainability of specialty crops can be increased through the adoption of biodegradable mulches. It’s standard practice for fruit and vegetable growers to use plastic mulch to suppress weeds, retain moisture, and prevent soil erosion. However, there are no good alternatives for plastic mulch disposal at the end of each growing season. These mulches are often stockpiled on farms or burned illegally, both of which are harmful to the environment.

Biodegradable mulches can be plowed into the soil during harvest season, reducing labor needs and disposal costs. However, the currently available biodegradable mulches are much more expensive than plastic mulches and long-term impacts of their use on soil-related ecosystems is uncertain.

“Evaluating the breakdown products of the biodegradable mulches and their fate in the soil over a multiyear period is extremely important as the standard practice of using plastic mulch for the production of many commercial vegetable crops poses a costly disposal issue,” says Annette Wszelaki, UT Extension Vegetable Specialist. Wszelaki and Jennifer DeBruyn, assistant professor, BESS, serve as project codirectors.

In-field research began this year at two sites: the East Tennessee AgResearch and Education Center’s Plant Sciences Unit and WSU’s Mount Vernon Research Center. Pie pumpkin is the test crop for the first two years of the study. (Currently most pumpkins in the U.S. are grown on conventional black mulch.) Researchers are evaluating six potentially biodegradable mulch products that will be plowed at the end of the season. They will measure soil quality as well as pumpkin size, color, and plant growth.

“This project is an opportunity to form a community of people who see this as a problem and want to work together to solve it,” says Hayes. “This project will benefit crop producers, mulch producers, composting facilities, and consumers.”

This multi-institution, multifunction project is a follow-up to a 2010 SCRI grant project that measured mulch biodegradability in the soil. If you would like to learn more about the project, visit the UTIA Biodegradable Mulch site.

Ginger Rowsey