PURPOSE:To enable covering of a seed with soil in high efficiency, by providing a gel-extrusion part having a nozzle with a valve and a cutting plunger at the bottom, placing a seed-feeding part above the gel-extrusion part and providing the feeding part with a suction drum placed in a seed storage tank. CONSTITUTION:The space in a drum 30 is maintained to negative pressure to suck a seed from a seed storage tank and the seed is dropped when the suction hole of the drum is closed with a closing member 50. A gel is transferred to a gel-extrusion part A by the action of one of the cylinders, a definite amount of the gel is extruded by opening a valve and a gel film is formed under a cutting plunger 5. The seed supplied from a seed-feeding part B is dropped on the gel film and a gel is extruded on the seed by the action of the other cylinder. The gel including the seed is dropped into a lower curing tank by its own weight according to the closure of the valve caused by the lowering of the cutting plunger 5.
