I guess I have strange notions, or maybe I'm just mentally stuck in the practices of a few generations ago. I don't worry as much as I should about manure (as long as its somewhat aged and buried / mixed under the soil).
Yet the idea of having a solid layer of sod under my garden "just seems wrong to me". I do know that many people have started beds that way, saved a huge amount of labor, and grew fine crops. And the grass did not emerge a few weeks later and reclaim the bed. The darkness does kill the grass, and it must rot down there if it gets enough oxygen.
Still, for no reason that I can defend logically, I always chop out the sod with a mattock and throw that into the compost heap. Then I assure drainage by sloping the floor of the bed and cutting trenches. Then I will somewhat amend the sub-soil (sub-clay), Then I replace the top layer with soil that I've made by amending my clay with compost, bark, and crushed rock. And I build it up above grade into a raised bed.
To me, that feels like "creating soil". I suppose it is necessary effort. Maybe I'm just masochistic.
Or, like Frank Sinatra, "I did it my way".
