A plunger device for making soil blocks. The plunger device is used to form soil blocks in a grid to facilitate seedling growth. The plunger is made of a configuration and material by casting or molding to compress soil consistently and evenly into blocks for seeding. The plunger device includes a plurality of plungers joined together that align with the rows of cells within the grid. The benefit of cast or molded plungers of the present invention is their uniform shape that will not bend of deform as prior sheet metal plungers potentially can.

A seed unit for placing seeds into soil includes a seed meter for singulating seeds, a shaft to deliver the seeds into soil during operation, and an actuator coupled to the shaft. The actuator moves the shaft during operation and the shaft delivers seeds into the soil without a continuous seed trench.

A high-speed seeding system is provided. The system includes a crawler mechanism, a seed metering mechanism, and multiple hill-drop devices. The crawler mechanism includes a motor drive unit, transmission crawler belts, and a crawler support unit. The transmission crawler belts are provided with hill-drop mounting holes at intervals. The motor drive unit is configured to drive the transmission crawler belts through the crawler support unit. The hill-drop devices are respectively mounted in the hill-drop mounting holes according to seeding intervals. The seed metering mechanism is fixed on the crawler support unit and is configured to deliver seeds to the hill-drop devices and push the hill-drop devices downward for seeding when the hill-drop devices pass underneath the seed metering mechanism.