Why Is This Ump Kicking Dirt Onto The Plate?

Today’s bizarre video comes courtesy of a Texas Bi-District Playoffs game between Texas High School and Whitehouse High School. After a Texas High player mashes a homer, it sure looks like the umpire runs over to kick a bunch of dirt on home plate.

I’m really struggling to come up with a plausible explanation for what the ump does here. Anybody have any ideas?