29 September 2023

Earthworms play a critical role in global food production


According to a University of Colorado study, earthworms contribute about 6.5 percent of global grain production and 2.3 percent of legume production. Totaling more than 140 million tons per year

by Matteo Cavallito


Earthworms play an essential role in the global food production chain, contributing significantly to agricultural yields of grains and legumes. This is supported by a Colorado State University study published in the journal Nature Communications. The investigation thus highlighted the importance of these organisms whose role in soil ecosystem balances has long been the subject of study.

“This is the first effort that I’m aware of that’s trying to take one piece of soil biodiversity and say, ‘OK, this is the value of it; this is what it’s giving us on a global scale,” Steven Fonte, professor of agro-ecosystems ecology in the U.S. university’s Department of Soil and Crop Sciences and lead author of the research, said in a note released by the university.

Productivity increases by 25 percent

Earthworms, the authors point out, help create healthy soils by supporting plant growth in several ways. These include building good soil structure, supporting water capture and contributing to the transformation of organic matter that makes nutrients more available to plants. In addition, some research has shown how earthworms can facilitate the production of hormones that promote their growth by protecting them from common soil pathogens.

In this way, some estimates claim, these tiny living things can increase the overall productivity of plants by about 25 percent.

From this figure, the team of researchers-which includes Nathan Mueller, an associate professor in the Department of Ecosystem and Sustainability Sciences, and Marian Hsieh, a doctoral student in the same department-estimated the contribution of earthworms to global food production by overlaying and analyzing several variables, including the level of their presence, soil properties, fertilizer use and crop yield.

Earthworms are worth 140 million tons of food

The results collected at the end of the survey, the research says, “indicate that earthworms contribute to roughly 6.5% of global grain (maize, rice, wheat, barley) production and 2.3% of legume production, equivalent to over 140 million metric tons annually.” Their contribution, the study continues, “is especially notable in the global South, where earthworms contribute 10% of total grain production in Sub-Saharan Africa and 8% in Latin America and the Caribbean.”

The implications of this phenomenon are particularly significant and suggest the need to bet on agricultural strategies capable of protecting the ecosystem and its properties.

“Our findings suggest that earthworms are important drivers of global food production and that investment in agroecological policies and practices to support earthworm populations and overall soil biodiversity could contribute greatly to sustainable agricultural goals,” the researchers say.

Soil biodiversity provides support for crops

The authors therefore suggest managing soils in a more balanced way so as to make the most of their potential. Fonte, in particular, recalls how soils i contain about half of the world’s biodiversity. A  finding that has emerged from the most recent research that has revised upward previous estimates of around 25 percent. The study, he concludes, would therefore show how better management of soil biology where earthworms are already present can promote growth in agricultural yields by reducing dependence on agrochemicals in particular.