Dr. Milton Ganyard is an entomologist who enthusiastically espouses the benefits of an organic "no till" garden.
This makes sense. Nature does not till.
He describes the thousands of organisms that are working together in the community that is the soil, as individuals whose job it is to break down and recycle nutrients for the plants. This works fine in undisturbed soil. If you till, "you've destroyed their home and they can't work anymore." he exclaims in a delightful southern accent.
Other benefits include better water infiltration, better water holding capacity, better water drainage.
Another thing you will learn about here: Mulch, mulch, mulch!
All in all, this is a great ten minutes on how to improve the quality of your soil.