I used to have gardens every year........many of which were the envy of the neighborhood.....we are talking 3 foot cucumbers here.
My neighbor is a beef farmer and I got my "fertilizer" from him. He had one barnyard that got full sun all day so it was covered with a layer of sundried poop.....almost odorless, and dry and crusty.
This stuff was FANTASTIC.......Id put about 2-3 yards in my little plot and till it in; never had ANYTHING but great luck.
I DID, however, use plastic to prevent weed growth.