a tractor-mounted agricultural machine that digs cylindrical holes for planting seedlings of fruit or timber trees and for setting posts. The main working parts are removable augers, sharp screwlike implements that can move clockwise or counterclockwise. The holes measure 0.3–1.0 m in diameter and as much as 6 m in depth. The KlaU-100 hole digger used in the USSR digs 80–100 holes per hour.