The present invention addresses the problem of correcting defects such as twisting of transmission components caused by operating non uniform speed members in a rice transplanter having a rotary seedling transplanting device. This rice transplanter comprises a transmission case (11) that varies the power of an engine (10) mounted to a traveling machine body (1) a seedling transplanting device (2) that has a transplanting mechanism (8) with a planting claw (96) that describes a non circular motion trajectory a plant spacing speed changing device (26) that changes plant spacing by changing the working speed of the transplanting mechanism (8) with respect to the traveling speed of the traveling machine body (1) and a non uniform speed member (98 99) that transmits a non uniform speed rotational power to the transplanting mechanism (8). In addition the rice planter comprises a reverse phase torque generating member (130) that adds a reverse phase torque (Tan) the phase of which is opposite to a rotational torque (T) to the rotational torque (T) of the transplanting mechanism (8) based on the non uniform rotational power.
