Abstract: The invention discloses a water feeding pump or a fertilizer applying pump for a pump station of a fertilization and irrigation system. The water feeding pump (2) or the fertilizer applying pump (3) is a centrifugal pump. The centrifugal pump includes a volute and an impeller. The impeller includes a front disc (12), a rear disc (13), and main blades (14), and a plurality of back blades (18) distributed along a circumferential direction are disposed on a back surface of the rear disc, where an auxiliary rotating disc (11) is disposed between the impeller and a rear side wall of the volute, the auxiliary rotating disc is a rotating member and is driven by the back blades of the impeller to rotate.