Abstract: A liquid manure pump which, without the use of valves, can alternately be used for agitating and mixing liquid manure in a pit and for discharging liquid manure from the pit into a tank or vehicle for transport. The impeller of the pump is ordinarily driven by an electric motor attached to the frame of the pump apparatus, and knives which are fastened to the hub of the impeller and rotate with the impeller blades stick through the inlet port of the impeller housing to cut up solids and, by virtue of their shape, to force-feed the pump.