Fermented food waste can boost bacteria that increase crop growth, making plants more resistant to pathogens and reducing carbon emissions from farming, a new study suggests.
According to the researchers, including Deborah Pagliaccia from the University of California, Riverside, in the US, food waste poses a serious threat to the planet.
“Beneficial microbes increased dramatically when we added fermented food waste to plant growing systems,” said Pagliaccia, who led the study.
“When there are enough of these good bacteria, they produce antimicrobial compounds and metabolites that help plants grow better and faster,” Pagliaccia added.
The waste represents not only an economic loss, but a significant waste of freshwater resources used to produce food, and a misuse of what could otherwise feed millions of low-income people who struggle with food security.
For the study, published in the journal Frontier in Sustainable Food Systems, the team looked for alternative uses for food waste.
They examined the byproducts from two kinds of waste that is readily available in Southern California: beer mash — a byproduct of beer production — and mixed food waste discarded by grocery stores.
Both types of waste were fermented and then added to the irrigation system watering citrus plants in a greenhouse.
Within 24 hours, the average population of beneficial bacteria were two to three orders of magnitude greater than in plants that did not receive the treatments, and this trend continued each time the researchers added treatments.
The researchers then studied nutrients such as carbon and nitrogen in the soil of the treated crops. And, it showed a spike in the amount of carbon after each waste product treatment, followed by a plateau, suggesting the beneficial bacteria used the available carbon to replicate.
Since the plants in this experiment were grown in a greenhouse, the benefits of the waste products were preserved within a closed watering system. The plant roots received a fresh dose of the treatment each time they were watered, the researchers said.