I am with @Skydiver about using the leaf litter from the woods. Just read the ingredients on some of the largest suppliers “Aged Forest Products”. It will be packed with the microbes that break it down and supplier package and sell.
As for the corn field soil try this. Put some in a small pot, water it thoroughly, and let it dry out. You will more than likely find that it turns into a brick. Our vegetable gardens were once alfalfa / corn fields. I lost track of how many yards of topsoil and compost (by the truck load), bags of peat, sand etc etc I have added to them over the years.
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