Thats how "Mother Nature" does her gardening as well....
The animals migrate over the forest floor, the mushrooms grow & die, and then the leaves fall, only to start all over again. Its all layered. They've even proven that layered soil is more effective in growing plants (in GENERAL), but our modern cultivated crops have had their wild ways hybridized out of them (they are sensitive).
In fact when a plant sends a root out for an element it sends them out horizontally to find more of the same. Thus turning the soil actually hinders the growth (but you need all the nutrients to start with).