This is a question we get asked all the time and we usually tell people, “Not as much as you’d think.”
We mow and mow and mow about 9 months out of the year and all those grass clippings decompose and go back into the soil. Plus all the fertilizer and sometimes lime that we put on the fields help retain the soil.
Here’s an article from the Turgrass Producers International organization that goes into some detail about how much is lost or gained and some of the studies that have been done on soil depletion. It’s only three pages long and not too technical so check it out if you’ve ever wondered about this topic.