The invention relates to an agricultural machine for spraying a phytosanitary liquid over cultivated land, said machine comprising means for moving the machine, a spray boom having at least one arm, a mechanism for inclining the boom and/or at least one of the arms in relation to a frame of the machine and vertically when the machine is on a flat and horizontal surface, and a mechanism for raising/lowering the boom along an axis fixed in relation to the frame of the machine. At least one of the arms is provided with at least one sensor, each sensor measuring a distance between the surface of the land and said sensor or, if necessary, between the crop and the sensor. The control unit is connected to each sensor, provided with a memory for storing information provided by each sensor, and able to control the raising/lowering mechanism according to information stored in the memory.
