One way to reduce weeds in a pasture is to graze hard enough so cattle will eat them, since there is nothing else to eat, says Bruce Anderson, professor of agronomy at the University of Nebraska-Lincoln. But while many weeds can provide satisfactory protein and energy for cattle when eaten, controlling weeds with heavy grazing pressure might not be healthy for the pasture.
“Every pasture has millions of weed seeds in the soil and the potential to become weedy,” he says. “Since some pastures stay relatively clean while other pastures become weedy, other factors undoubtedly influence the weed population.” Simply grazing or controlling weeds by spraying or cutting does little to prevent weeds from coming back again unless these other factors are changed to better support desirable plants.
He says to control weeds, it is much more important to manage grazing to support healthy, desirable plants than to weaken or remove unwanted weeds. “Grazing that allows sufficient leaf area to remain following grazing to support rapid regrowth, allow good winterizing, and hold snow and rain moisture on the land rather than running off will benefit the desirable grasses and legumes.”
In addition, giving pasture plants adequate time to recover after grazing before grazing again is another way to improve or maintain pasture health and strengthen the competitive ability of desirable plants. Weeds in a pasture indicate that the pasture itself and the desired plants in it are not in a healthy condition. Therefore, changing management to strengthen desired grasses and legumes also is essential.