What is a grass on which sports like baseball are played?

Clay or Grass

Just a guess, but softball fields are usually owned or maintained by municipalities with small budgets. Clay requires less maintenance than the manicuring necessary for infield grass. Clay is just plain cheaper than grass.

No, It's because in Baseball the ball comes off the bat faster, so they have grass so they can slow it down. In, softball the ball doesn't come off the bat as fast so they don't need the grass to slow the ball down.