Man’s trash is nature’s treasure: A novel way to tackle America’s food waste problem

RIVERSIDE, Calif. — Food waste is a critical issue: over a third of the food American consumers buy ends up in the landfill. And with COVID-19 restrictions shutting down restaurants and small businesses, even the landfills can’t keep up as farmers are forced to burn and bury unused crops. Not only is food not making it to hungry mouths, but precious resources like water and energy are needlessly misused.

But what if there were a way to turn food waste back into food? That’s exactly what researchers at the University of California Riverside have done. Except they’re not feeding man, but plants — by way of microbes.

“Beneficial microbes increased dramatically when we added fermented food waste to plant growing systems,” says lead researcher Deborah Pagliaccia in a media release. “When there are enough of these good bacteria, they produce antimicrobial compounds and metabolites that help plants grow better and faster.”

Bacteria is the critical link in the sustainable agriculture chain

On their quest to find a useful fate for food waste, the UC Riverside researchers gathered two significant sources of the problem in California: beer mash, and produce discarded by grocery stores. They worked with River Road Research, who fermented the waste. The UC Riverside researchers then added it to citrus plants in a greenhouse. Plants were watered with a closed irrigation system, which wastes less water. Within 24 hours, bacteria that produce useful compounds for plants had increased up to threefold.

The researchers also report that the bacteria were consuming carbon from the water. They think that this could help change the carbon-nitrogen ratio in favor of nitrogen, which is good for plants. There was also no sign of any problematic bacteria, such as Salmonella, in the soil or on the plants. This means that their eco-friendly fertilizer isn’t likely to make you sick.

“We must transition from our linear ‘take-make-consume-dispose’ economy to a circular one in which we use something and then find a new purpose for it. This process is critical to protecting our planet from constant depletion of natural resources and the threat of greenhouse gases,” said Pagliaccia. “That is the story of this project.”

These findings are published in the Frontiers in Sustainable Food Systems.