A field transplant system including a machine for sequentially forming groups of polymerized soil plugs having seed receiving recesses in one end thereof and supported on a carrier, and in certain cases interconnected by strips, the carrier being used to transport the soil plugs through a seeding station and then to a germination station and then to a growing station either in the flat or on a plant turning machine in a greenhouse to grow the germinated seeds to transplant size, and then using the carrier to transport the soil plugs with the transplants growing therein to the field for transplanting by an automatic transplanter; several forms of soil plugs are disclosed, and several methods for supplying seeds to the soil plugs are disclosed, as well as an improved method of mounting a mat of soil plugs on the cylinder of a plant turning machine.