I agree with Seedfork, if I can add emphasis to one phrase:
>> But that is all I do now, unless I am starting a new bed, just keep adding stuff on top and letting it decay, it forms a thin layer of very fertile looking very soft viable soil when the worms work it over a period of time. But when first starting out, I had no worms.
>> sure the clay was much more porous but it still looked like and acted like clay, after a couple of years I could actually see soil improvement, still a lot of my deeper clay still looks like clay.
That initial right-away improved porosity is what I was chasing with my deep turning and finely breaking up clay balls and mixing with compost and sand/grit/bark fibers. It improved the soil to the point where anything would grow. I should have stressed "and break up the clay and mix it finely". That IS a huge amount of work even for small beds.
It seems to me that the next big change that occurs over the first two years is that microbes and roots penetrate the soil. Once they have drainage and oxygen, they can improve and maintain soil structure and tilth.
>> still a lot of my deeper clay still looks like clay.
Maybe I'm over-ambitious in wanting root zones that go 18" deep. Or crazy!