To solve the problems in a conventional one-wheel machinery for plant husbandry that support center of a pair of wheels is greatly eccentric from the center of machine body width, the center of gravity of a machine body is eccentric, thereby increasing a load on a worker gripping a steering wheel and running and operating the machine, running balance is reduced, and the worker loses his balance and falls when a load is marked, although the technique for utilizing the one-wheel machinery for plant husbandry as a two-wheel machinery for plant husbandry consisting of a pair of wheels by extending one of axles and fixing the wheel to the extended end is known because the one-wheel machinery for plant husbandry can move in a small circle even between narrow furrows in a vinyl house and on an inclined ground and improves the operation property, but it has no sufficient traction force for works such as tilling to a middle depth, traction, and soil formation.

A pair of wheels 8, 9 are supported in a lower part of a running transmission case 6, and an intermediate case 5 capable of arranging the support center 100 of a pair of wheels 8, 9 at substantially same position as the center 99 of the machine body width is provided between an upper part of the running transmission case 6 and an output part of a transmission case 3.