To make a smooth and small turn by using a non-slip differential gear for front wheels during turning in a field.

This vehicular rice-planting machine 10 comprises a rear differential gear 42, a differential lock device 62 for forcibly stopping the function of the rear differential gear 42 and a front differential gear 66. The used front differential gear 66 is the non-slip differential gear for limiting the specified or more differential motion of right and left front wheels 12. Thus, when the front wheel 12 on the right side gets up on a ridge and the front wheel 12 on the left side floats during left turn in field run, torque is transmitted from the front wheel 12 on the left side floating and rotating faster to the front wheel 12 on the right side getting up on the ridge and rotating slower. Therefore, the specified or more differential motion of the right and left front wheels 12 is limited and the front wheel 12 on the right side getting on the ridge is driven at predetermined toque, making it possible to easily move the machine out of the ridge.