The most common method of ditching is done by use of a ditching machine.

使用挖土机是最常用的挖沟方法。

Thus, Calculating the critical rotational speed of the helix ditching machine.

由此，推导出立轴柱形变螺距螺旋开沟机的临界转速。

It also includes removal of tree stumps and roots in the ditch line that would interfere with operation of ditching machine.

还包括清除在挖管沟范围内影响挖沟机工作的树桩和树根。

The peanut hill-drop planter comprises a push hand, a machine frame, a ditching knife, a ground wheel, a sowing box and a hill-drop wheel;

该穴播机包括推手、 车架、开沟刀、地滚轮、播种箱和穴播轮；