A mixing apparatus for spraying-out of a liquid mixture of at least two liquids, each from a respective reservoir includes a number of liquid pumps corresponding to the number of liquids. The liquid pumps deliver into a common spraying-out conduit and are each driven by a respective hydraulic motor. The mixing apparatus includes a drive assembly directly operationally connected to a first hydraulic pump controlled in a pressure-regulating manner in dependence on the liquid flow at the outflow side of the apparatus. The first hydraulic pump is associated with a first motor operationally connected to both a first liquid pump and with a mechanical gear. The mechanical gear is directly operationally connected to at least one second hydraulic pump driving at least one second hydraulic motor for at least one second liquid pump having a variable working capacity and hence being controllable.