PURPOSE: To surely drive a seedling tank and seedling feed operation by coupling the seedling tank to a lead cam shaft moving laterally in engagement with a lead pawl in a lead metal cylinder and providing a seedling feed cam to a lead metal cylinder shaft.

CONSTITUTION: A seedling feed cam 9 for driving seedling feed operation is provided on a lead metal cylinder shaft 2 held on a shaft rotatably to a gear box 1. A lead cam shaft 4 having a lead groove 3 cut on the periphery is engaged with a lead pawl 5 and inserted into a lead metal cylinder shaft movably in the lateral direction. A seedling tank is coupled to a lead cam shaft by coupling levers 18 and 18 on both ends of the lead cam shaft.