Study: Food waste compost less effective than potting mix alone

COMPOST STUDY: Watermelon seedlings are seen in trays with pure food waste substrate, pure commercial peat moss-based potting mix, and blends of the two with varying ratios in a study to compare seedling germination, growth and nutrient uptake. | U of A System Division of Agriculture photo

By MADDIE JOHNSON | University of Arkansas System Division of Agriculture

With an estimated 30-40% of the United States’ food supply ending up as waste, according to the U.S. Food and Drug Administration, food science and horticulture experts teamed up to study if it could lay the foundation for growing the next bunch of crops. 

“It’s capturing food waste that would otherwise go to landfill and produce greenhouse gases and cause harm to the environment in some capacity,” said Matt Bertucci, assistant professor of sustainable fruit and vegetable production with the University of Arkansas System Division of Agriculture. 

“Instead, we are utilizing it to generate an organic substrate, an organic amendment compost that can then be utilized for propagating seedlings,” he said.

Bertucci is part of the department of horticulture within the Division of Agriculture’s research and outreach arms — the Arkansas Agricultural Experiment Station and the Cooperative Extension Service — and the Dale Bumpers College of Agricultural, Food and Life Sciences at the University of Arkansas.

The study, “Assessing Food Waste Compost as a Substrate Amendment for Tomato and Watermelon Seedlings,” was published in HortTechnology last year. 

Researchers grew tomato and watermelon seedlings in pure food waste substrate, pure commercial peat moss-based potting mix, and blends of the two with varying ratios to compare seedling germination, growth and nutrient uptake. The pure food waste substrate was made up of food scraps from a commercial partner and wood chips from a tree service company.

The study found that while food waste compost might not be viable as a standalone alternative to commercial potting mix, it could be suitable as part of a substrate mix.

Results showed that mixtures with less than 50% food waste compost produced better seedling emergence and growth and had better biomass accumulation than pure food waste, a key indicator of a plant’s health and potential yield.

Still, Bertucci underscored the value of composting food waste, which he said prevents waste from going to landfill and offers a usable byproduct.

“Compost is the sweet spot for sustainability,” he said.

Co-authors included former graduate student Allyson Hamilton and professor Kristen Gibson of the department of food science, and department head Mary Savin, program associate D.E. Kirkpatrick and graduate student R.C. Woody-Pumford of the department of horticulture. Gibson is a professor of food safety and microbiology, the Donald “Buddy” Wray Endowed Chair in Food Safety and director of the experiment station’s Arkansas Center for Food Safety. Savin is a professor and head of the department of horticulture. 

This project was funded by an Arkansas Specialty Crop Block Research Grant (award no. AM180100XXXXG157), with additional support from the United States Department of Agriculture National Institute of Food and Agriculture Hatch project no. 102445.

To learn more about the Division of Agriculture research, visit the Arkansas Agricultural Experiment Station website. Follow us on X at @ArkAgResearch, subscribe to the Food, Farms and Forests podcast and sign up for our monthly newsletter, the Arkansas Agricultural Research Report. To learn more about the Division of Agriculture, visit uada.edu. Follow us on X at @AgInArk. To learn about extension programs in Arkansas, contact your local Cooperative Extension Service agent or visit uaex.uada.edu.