Shut off valve stuck

Does anyone know how this valve operates. It controls our lawn sprinkler system and I trying to turn it on for the first time, but I don’t want to force it too much for fear of breaking it. It won’t move when trying to turn it either clockwise or counter clockwise. It has just a little bit of play which you can move by hand.

Looks like my gas valve. Are you sure that is for a sprinkler?

It should turn 90deg. to the left, probably corroded, like the other post said make sure it's not a GAS valve in case you break it.

It's a 1/4 turn valve and they usually are a bit tight. Use a bigger wrench

With that "lock tab" it looks like a water meter valve, but in any case it opens by rotating counterclockwise.