Hi Russell,
I think soil building/improving crops can be a great idea. If you are really looking long term, maybe you could plant something like buckwheat which grows aggressively, smothers out competition, but if cut back just before going to seed dies on its own. The result is a clean seedbed.
Another option is to bring in
cardboard, newspaper, or similar, lay down a barrier and pile new garden bedding on top. The barrier smothers out old growth but decays in short order.
I am somewhat obsessive about piling on
wood chips and breaking them down with
mushrooms to get really rich and fertile garden bedding. This would make that garden area into a raised bed, something many gardeners like to have.
Nice that you already have the space for a garden!
Eric