Years ago I was talking to a nursery owner who said that all he used for potting medium was horse manure mixed with hardwood shavings, which he got from a friend's stable. He would spread it out onto the ground, apply 10-10-10 liberally and keep turning it with his tiller until it got so hot that it burned the weeds out.
He also was certified organic, so I was surprised that he could use chemical fertilizer that way.
He also was certified organic, so I was surprised that he could use chemical fertilizer that way.