$1.9M USDA Grant to Study Fruit and Vegetable Production Problem

bioplastic mulch pile, 2014

Growers throughout the nation have no effective strategy for  disposing of the plastic mulches they use to produce crops, so they often pile them on their property or illegally burn them. A new $1.9 million USDA grant involving the University of Tennessee Institute of Agriculture, Washington State University and Montana State University will research the problem and potential solutions beginning with the 2015 growing season. Image courtesy UTIA. Download image.

Meet the research team. Click here for image. From left to right, Jessica Goldberger, WSU; Mark Fly, UTIA; Doug Hayes, UTIA; Debra Inglis, WSU; Annette Wszelaki, UTIA; Carol Miles, WSU; and Tom Marsh, WSU.


KNOXVILLE, Tenn. — Growers throughout the nation are setting their sights on spring and the coming 2015 crop, but many of them — especially those who raise specialty fruit and vegetable crops like tomatoes, strawberries and pumpkins — struggle with the problem of disposing of the plastic mulches they use to produce their crops.

Mulching with plastic materials is standard practice for specialty crop growers throughout the U.S. and the world. The plastic forms a barrier in the field that reduces weeds, conserves water, and protects soil from erosion. Unfortunately, after their use in the field, which is typically a single growing season, no good alternatives exist for their disposal. What is more, retrieving conventional plastic mulches from the field is laborious and expensive. Once retrieved, they are often stockpiled on farms or burned, illegally. To add to the problem, any residual plastic left in the field persists in the environment and can negatively affect wildlife, soils and water quality.

The absence of an effective strategy for disposing of conventional plastic mulches threatens the profitability and sustainability of both large and small specialty crop farms.

To address the problem, a team of 22 experts with research and extension appointments at the University of Tennessee Institute of Agriculture (UTIA), Washington State University (WSU), and Montana State University (MSU) secured a $1.9 million grant from USDA to study the performance and adoptability of biodegradable plastic mulches (BDMs) for sustainable specialty crop production. Douglas Hayes, a polymer scientist with UTIA’s Department of Biosystems Engineering and Soil Science (BESS), will lead the two-year project, with the assistance of co-project directors Annette Wszelaki, a UT Extension vegetable production specialist with the Department of Plant Sciences, and Jennifer DeBruyn, a soil microbiologist, also with BESS.

The team also includes an advisory committee of experts in relevant scientific fields and government regulations, plastic mulch manufacturers, and specialty crop growers.  Near Knoxville, Techmer PM, a company in Clinton, Tenn. — which was a stop during President Obama and Vice-President Biden’s recent visit — is making an “in-kind” contribution to the project by compounding a blend of specialized biopolymers to produce an experimental BDM to be included in the research.

UTIA’s East Tennessee AgResearch and Education Center Plant Science Unit in Knoxville will serve as the site for field studies in Tennessee. WSU’s Mount Vernon Research Center will serve as a second site, offering different climate and soil conditions.

The initial effort is expected to take two years, but there is the possibility of $3 million of additional work that would extend the effort over five years for a total of nearly $5 million. As planting season approaches, the team, which also includes UTIA researchers in agricultural resources, rural economics and UTIA’s Human Dimensions Lab, is gearing up for action.

It’s a complicated problem that has to be solved with the help of scientists from several disciplines, says Hayes. He explains that while BDMs have been available as a substitute for conventional plastic mulches for more than 30 years, growers have been slow to incorporate them into their operations. “Specifically, the high cost of using BDMs, a lack of knowledge about how they might benefit long-term sustainability and their unpredictable breakdown have all contributed to their limited adoption,” he said.

Wszelaki explained that many BDMs
that were commercially marketed as “biodegradable” have not performed up to expectations. “Biodegradable mulches are supposed to provide the same benefits as conventional plastic mulches as well as the added benefit of being 100 percent biodegradable, either in the field or soil or in composting without formulating toxic residues,” she said. “Many have not been breaking down completely in the field, even over two years,” she said. “Examining the breakdown products of the BDMs and their fate in the soil over a five-year period is extremely important for organic and conventional production alike, as the standard practice of using plastic mulch for the production of many commercial vegetable crops poses a costly disposal issue.”

This project will examine the use and breakdown of five BDMs, and their effects on the soil ecology and crop production, as well as barriers to adoption of this technology and an assessment of the impact of these mulches on the environment throughout their life cycle.

Hayes says the long-term effort should identify the bridges and barriers to crop producers’ adoption of BDMs. It’s a stair-step effect, he said. “Understanding the barriers to adoption should help lead us to the development of best practices for BDM deployment and disposal. This, in turn, should lead to increased use of BDMs by stakeholders, which will then be followed by economic and environmental benefits for growers and consumers,” Hayes said.

Among the consumer benefits are a plentiful supply of healthy fruits and vegetables and rural landscapes devoid of degrading mounds of discarded plastic mulch.

The UT Institute of Agriculture provides instruction, research and outreach through the UT College of Agricultural Sciences and Natural Resources, the UT College of Veterinary Medicine, UT AgResearch, including its system of 10 research and education centers, and UT Extension offices in every county in the state.



Patricia McDaniels, UTIA Marketing and Communications, 615-835-4570, pmcdaniels@tennessee.edu


USDA List of Funded Projects:

Performance and Adoptability of Biodegradable Plastic Mulch for Sustainable Specialty Crop Production