Apparatus (1) for the distribution of a mixed fluid, in particular semi-liquid manure or liquid manure, on useful agricultural surfaces (100), with: - a distributor device (5) having at least one fluid inlet (3) connectable to a mixed fluid feed element and a plurality of fluid outlets (7), - a plurality of fluid lines (11) attached to the fluid outlets to distribute the mixed fluid in a predetermined working width, presenting the ducts of fluid (11) at its end located in favor of the current in each case a connection section (35b) for coupling to an applicator device (9), the particular applicator device (9) being designed to discharge the mixed fluid into direction of the useful surfaces (100), - defining respectively a fluid outlet (7) and the fluid conduit (11), connected to the fluid outlet, a flow path, characterized by a device (15) for the detection of blockage in individual flow paths, in several or in all the flow paths it presents - a plurality of probes (1) that are inserted in each case in one of the flow paths and are designed to emit a measurement signal dependent on the flow transported in the flow path, as well as - an electronic evaluation unit (17) that is designed to receive the measurement signals emitted by the probes (21), compare them with each other and identify the blockage in individual flow paths or in several flow paths based on signal deviations detected in this case, characterized in that the probes (21) are oriented in favor of the current on the side of their input in the flow path.Aparato (1) para la distribución de un fluido mezclado, en particular estiércol semilíquido o estiércol líquido, en superficies agrícolas útiles (100), con: - un dispositivo distribuidor (5) que tiene al menos una entrada de fluido (3) conectable a un elemento de alimentación de fluido mezclado y una pluralidad de salidas de fluido (7), - una pluralidad de conductos de fluido (11) unidos a las salidas de fluido para distribuir el fluido mezclado en una anc
