| 摘要 |
PROBLEM TO BE SOLVED: To improve draining, water management, well draining on a paddy field surface, activation of microbes breeding, and growth of a deep part of a root of paddy rice, which can be attained in a manner that, because water on a field surface reaches a culvert from an opening of a penetration mark groove and a vertical port passage via a digging groove, and thereby a distance from the field surface to the culvert is reduced.SOLUTION: The culvert forming device includes: a machine frame 4 arranged on an attachment frame 3 with a pivotal attachment mechanism 5 so as to be freely rotated horizontally; a penetration beam 6 vertically arranged on the machine frame so as to be oscillatingly operated in a travel direction; a bullet body 18 arranged on a lower part of the penetration beam and capable of forming a culvert H; an expansion member 19 arranged on the machine frame, capable of forming a vertical port passage T by expanding a side face of a penetration mark groove S formed by the penetration beam and extended in a vertical direction in a field soil W and opened on a ground surface M; an expansion mechanism 20 for forcibly expansion-operating the expansion member; and a plow member 28 arranged on the machine frame, for scooping the field soil to be discharged to a lateral side, and thereby forming a digging groove U at a vertical port passage formation position D.SELECTED DRAWING: Figure 16 |
