What’s yellow with black dots?
In orienteering it’s the map symbol #415 for cultivated land.
Orienteers must NOT cross land with growing crops. It’s best to assume that there are crops growing, even if you cannot see any! There are often paths round the outside of the field that you can use. Orienteers rely on the goodwill of landowners for permission to hold events.
(Pale yellow with a polka dot arrangement of black dots is symbol #211 for soft sandy ground.)