|Non-native earthworms rebound more quickly than native species after the soil is tilled.|
What stresses earthworms?
Tillage is a problem because it kills worms outright, it destroys nightcrawler burrows and by incorporating surface litter, it makes it more difficult for worms to find food. Worm species from western Eurasia are more adapted these stresses.
Earthworms are relatively resistant to herbicides. The problem with herbicides is that it reduces the amount of plant life which impacts the amount of surface litter later.
Mowing and grazing favor earthworms. A six inch tall grass-clover sward has a ton of edible matter for earthworms per acre but most of it is out of their reach. A six inch blade of grass is as accessible to them as an apple atop a 40' tree is to us. In particular, management intensive grazing produces and even distribution of manure around the sward. Manure is awesome worm food because the plant material is already broken down into small particles that can be easily ingested by all types and sizes of worms. Think of cow manure as the Chicken CmNuggets of the worm universe.
In some areas, like northern Minnesota, non-native worms are impacting the ecosystem. They quickly gobble up the mat of decaying leaves. That tilts the niche in favor of some species at the expense of others. For example, acorns and beechnuts that might have escaped being eaten by deer and turkeys because dead leaves drifted over them are now exposed.
Worms have been explored as a way to process solid, human waste.
There are two approaches. One is very low-tech and has been proposed as a better way to handle system over-loading along wilderness trails. In theory, passing pathogenic human wastes through worms is likely to break the transmission pathway that would infect other humans. Worms do not demand the same level of care and the high temperatures that other composting toilets require.
The high-tech approach is more energy intensive as it demands pressurized water.