Most of the matter in our bodies comes directly and indirectly from plants and those organisms lower on the food chain. Most of the actually molecules from those plants come from the atmosphere rather than the ground. If this weren't the case, trees would grow themselves into giant holes in the ground and we'd have to truck new dirt constantly to the heartland to fill in the holes produced by cornfields. Most of your molecules weren't dirt, they were air.
Ashes to Ashes, Air to Air.