A simple solution to goose poop in parks has been tried in Colorado, where I live: coyote cut-outs. The geese really do seem to think these cut-outs are the real thing and stay away. They’re not in all the parks in Colorado, but they work where I’ve seen them.

For your soccer fields, I’d suggest cut-outs on stakes so you could simply pull them up before a game and stick them back in the ground when the game is over. And how about adding a running event using these cut-outs, and maybe call it the Coyote 5-K or something like that? The 5-k entry fees could be used to pay for the cut-outs.

Norm Haberly