Abstract: Liquid manure contained in a trailer-mounted tank is supplied to a downwardly extending injector pipe whose lower end carries a disc adapted to rotate about the axis of the pipe. During forward travel of the trailer, the rotatable disc slices through the ground to permit the pipe to inject a stream of liquid manure into the ground below the surface thereof, the disc causing the manure to be spread thinly and relatively uniformly in the ground to stimulate crop growth rather than depressing it because of over application to a confined area.