Product dosing system for agricultural machines, being of special utility in fertilizing machines such that the simple salts carrying nutrients, that is to say, nitrogen, potassium and phosphorus, can be arranged in granulated form in respective deposit hoppers 3, 3′ and 3″ aligned in the advance direction of the fertilizing machine to directly pour the simple fertilizer to the ground to be fertilized, as well as having an endless axle 8 for regulating the simple fertilizer for its conduction towards collection and pouring dosing means, thus, having an endless axle for regulating the doses of simple fertilizer in granulated form and dosing means for each of the hoppers, allowing the regulation and measurement speed to depend on the advance speed of the machine, the machine having to that end rolling means 4, through which the movement is transmitted to the regulating endless axles and to the axles of the collection and pouring dosing machines.
