Question
I have a section of my yard filled with mushrooms.  I've been adding these  rascals to my compost pile...and than I think: is this a good idea?  Will I create a lawn/garden w/ more mushrooms next spring when I spread the compost?

Answer
Mushrooms are the fruiting bodies of Fungi.  If that worries you, consider this: Only specialized Fungi are able to make the high intensity enzymes needed to break down Lignin in Wood.  In other words, you NEED Mushrooms for full cycling of Compost.

The Mushrooms/Fungi that break down Wood make plenty of spores that you would, as you wonder, be spreading all over the Garden when you apply your Compost.  But they won't grow without the right substrate and moisture.  The part of your yard that is growing Mushrooms now must contain some very specific triggers.  This could be the Tree in the corner (friendly Fungi trade nutrients with favored Tree species).  It could be Wood Mulch (other Fungi specialize in certain Woods).  Or a buried stump that was cut down decades ago but is still decomposing.

These are very different from a disease-causing Fungus, like Botrytis, Pythium or Fusarium.  Do you think those Truffles-growers in France would think of exterminating their grounds of their deluxe-prized underground Mushrooms?  And remember, those Truffles don't grow anywhere but under a certain Tree, underground, where they want to.  These Fungi are specialized.  Very, very, picky.

Bottom line: Yes, I think it's a good idea.  Whatever needs decomposing in your Soil is going to rot thanks, and only thanks, to those Mushrooms.  Once it's gone, the spores will stay dormant, and they'll stay that way for years, if not forever.

THE LONG ISLAND GARDENER