To use a soil preparation rotor as a detection means for detecting the hardness of soil besides the essential soil preparation function of the soil preparation rotor although a conventionally known seedling transplanter has a constitution that the soil preparation rotor pivotally mounted on the front side of a float is forcedly rotated and driven to perform a soil preparation action, however, actions except the soil preparation action are not expected.
The seedling transplanter has a constitution that a seedling planting device equipped with a control means (4) is connected to the rear part of a traveling body and a lifting and lowering control action for retaining a planting depth at a set position based on the detected value of a ground sensor (5). An independently and vertically movable central soil preparation operation device (7) is provided in front of a center float (6) provided on the lower side of the seedling planting device and the control means (4) corrects the sensitivity of a lifting and lowering control based on the hardness of soil detected by the vertical movement of the central soil preparation operation device (7).
KONDA MITSUO
NAMOTO MANABU
