A Danish-French research team studied earthworms that had been living for generations in soil sprayed with a fungicide.
"They spend a lot of energy on detoxifying, and that comes with a cost,” said researchers Nicolas Givaudan and Claudia Wiegand, whose report was published in the journal Soil Biology and Biochemistry.
And that cost is that they are less successful at reproducing and are much smaller than worms living in organic farming fields.
That means there are often two to three times more earthworms in unsprayed soil than in soil treated with pesticide.
Earthworms are important to the environment because they help in the decomposition of decaying leaves, as well as eat parts of fungus and bacteria.
Their burrowing activity brings air into the soil.
Photo: Nicolas Givaudan