That's been an idea since at least the '50s. There are a lot of
problems with it; even if you could craft a soil-substitute out of
mixed waste and sand, sand's drainage is "too good" and it shifts too
much. Real soil is (a) complicated matter. And if you don't have the
right climate and hydrology to back it up, it doesn't develop turf
the way grasslands, savannahs or (somewhat misnamed) barrens do.
If you just dump the muck there, all you get is mucky sand until the
first few rainstorms--then you get the sand back and (maybe) some
muck many feet down. Now if you had a magic device that could
transform the sand into clay... Hmm, I think I hear the n-word
police coming... :)
MMB, at but not for OCC