Abstract: A motor-transportable plant for delivering substances for treating roadways or the land, in which a tank is divided by a wall into two separate chambers, each accessible through a manhole, and which can be connected together by opening valves provided in the wall; one of said chambers comprises stirring means for a liquid and a solute contained in the chamber, and means for withdrawing the formed solution and feeding it to the outside of the tank, a motor being provided for said withdrawal and for feeding the solution; the second chamber comprises stirrer means and means for withdrawing a solid material contained in the chamber and for feeding it to distributors therefor; said stirrer and withdrawal means are extractable from the chamber through an aperture closable by means of a suitable cover; the tank is supported by a rigid quadrilateral frame provided with legs which can extend by hydraulic control and are each provided with orthogonal shafts which are inserted into the cross members of the frame to defi