Grubbers are sharp, U-shaped blades mounted on the front of crawler tractors, wheel loaders, excavators, or farm tractors to uproot individual trees. Smaller tractors (65 horsepower) often use hydraulically assisted blades that enhance the output by tearing roots loose as the blade is rotated. Width of the cutting blade is usually 3 or 4 feet. Tractor size and type depend on the size of trees to be grubbed and the type of terrain. Tractor horsepower varies from 65 to 170. Units are available commercially, but many are fabricated in welding shops. Some units clamp the tree and pull the tree from the soil.
Grubbing is an excellent method to selectively thin brush-infested land. This technique is called “sculpting” and it is very effective in protecting wildlife habitat while providing cleared areas for grazing. Wheel or track loaders or excavators give the operator excellent vision during plant uprooting. “Low-energy” grubbing is the use of small tractors on small trees, and it is cost efficient and effective. These units often use hydraulically assisted blades. Farm tractors with small, three-point-hitch grubbers are popular for use on limited acreages of previously cleared areas. Grubbing techniques can vary depending on sprouting characteristics of the targeted plant’s roots (see Appendix). Grubbing is not practical in rocky soil or when tree densities are more than 250 per acre over extensive acreages.
References / Additional Information
Wiedemann, H.T. 2007. Sculpting brush mechanically: Current state of the art. Rangelands. 29(5): 10-17.