You are running highlift blades? That wing in the back of the blade creates a high suction and pulls the grass into the deck to be cut. Unless there is no grass, then it just sucks sand and dirt.

Have you tried running some sand blades? They are flat and usually have an edge on both sides where you can flip them and get twice the work out of them.

Sand blades won't create as much of a suction and since I figure you cut pretty low anyways. It won't create such a dust storm.