Cant beat well rotted horse manure! ---chicken will do too--gotta watch how thick you spread it! I put this 6 to 8 inches deep, then subsoil 3 feet deep, then moldboard plow as deep as the plow will go,--usually 12 to 14 inches. In the spring hit it one time with tiller and plant.
"A machine you build yourself is a vote for a different way of life. There are things you have to earn with your hands."