Gaining control of woody encroachment on pasturelands
By Brett Gaube, AAg, Range Management Extension Specialist, Weyburn Saskatchewan Agriculture
Ranchers have observed an increase in woody species, such as western snowberry (or buckbrush) and wolf willow in their pasturelands. An increase in woody species or ‘brush’ density results in reduced acres for livestock grazing. The loss of grazing acres can have a large economic cost. With the increased density of woody species, the grassland is also negatively impacted through a shift in the desired plant community. Major barriers to addressing woody encroachment include the time and the cost involved in managing it. When determining the best method to reduce brush, consider the cost of management versus the economic improvements that may occur from elimination of woody species. Some approaches that are being used today to control woody species on pasturelands include cultural, chemical and mechanical methods.
Cultural Methods:
Grazing is a well-known and effective way of helping to control brush growth while promoting the development of desired plants. Consider matching the herd size with the area being managed. If the area is too large for the herd, it will result in ineffective control.
Some livestock species prefer to graze bushes and shrubs. The introduction of small ruminant species, such as sheep or goats that favour eating woody species, may help control the spread.
Prescribed burning is a planned, ignited and controlled fire that is set to burn unwanted growth and restore desired vegetation. Proper planning, permissions, consultations and safety measure should be adhered to. Prior to using prescribed burning as a technique, speak with local officials to ensure compliance of regulations, permissions and procedures are met.
Chemical Methods:
The use of herbicides may be beneficial for eliminating woody species; however, this should be carefully thought out. Non-selective herbicides will affect all vegetation, including desirable species. Consider your options for herbicides carefully and select herbicides that will target only the species of concern. Herbicides work best when applied at recommended times and rates. Before using herbicides, read the herbicide labels, directions, recommendations and consult an agronomist.
Mechanical Methods:
Mechanical methods for weed control involve the use of equipment to manage brush. It can include using mowers, bulldozers, rollers, choppers or drags. The type of mechanical treatments used will depend on the time of year, weather, terrain, area and species. Using mechanical methods to control woody species generally involves repeated, long-term efforts.
In summary, woody encroachment on pastureland has negative economic and environmental impacts. Early identification and implementation of multiple control methods appears to be most effective in addressing encroachment on pasturelands. Regularly monitor the control methods to determine the most cost-effective method.
For more information on encroachment on pasturelands, contact your local range management extension specialist or call the Agriculture Knowledge Centre at 1-866-457-2377.