A spraying boom is described for distributing organic liquid fertilizer such as slurry using a tractor-drawn or self-propelled tanker, preferably in the form of a drag hose boom. The spraying boom comprises a main frame and two side wings mounted thereon, which are divided into several sections.The sections are mutually swivelling for repositioning between a transport position, in which the side wings are arranged in planes that are broadly parallel to the tanker's direction of forward motion, and a working position in which at least some sections of the side wings are swivelled to a position broadly at right angles to the transport position. The spraying boom comprises hose holders, on which application hoses are mounted, and a hydraulic system with actuators for swivelling the spraying boom sections.Between each section and between the sections and the main frame, sensors are fitted for determining the mutual position between the sections and between the sections and the main frame. The sensors are connected to a computer which, on the basis of the input from the sensors, generates an output for controlling valves in the hydraulic system for activating the relevant actuators. As a result, the sections can be folded individually and automatically without manual intervention.
