Trench or sheet composting under cardboard?
Hi everyone. I'm converting part of my bermuda grass lawn to a vegetable garden this fall. For the beds, I was going to first dig up the bermuda (just to top few inches, so I don't really consider it to be tilling), put cardboard over it to smother out whatever survives the digging, and then pile a few inches of a mix of compost, manure, and top soil on top. Since the beds will sit all winter before planting, I think I'll try to mix in some greens and browns (probably kitchen scraps and paper unless I can get leaves from someone) too.
My question regards the soil underneath the cardboard. We have a sandy clay loam that tends to be very sandy on top with a clay layer a few inches down that is very difficult to dig or grow anything in. Organic matter is almost nonexistent. Will the pseudo-lasagna method of piling the organics, soil, and compost on top of the cardboard be enough to help amend that soil underneath by the time I want to plant in the spring, or can I help it along by digging in some greens before I lay down the cardboard? Will the trench composting make any difference or would my results be the same either way?