Broomsedge (Andropogon virginicis L.) is a native warm-season grass that can dominate poorly managed pastures and hayfields. While it has little value as a forage, it does provide good nesting habitat for birds such as turkey and quail. However, as a forage crop it definitely falls short. When it is found in pastures and hayfields it is often an indication that something is not quite right. In most cases it is related low soil fertility and poor grazing management. Read on to discover some approaches to reduce broomsedge and promote desirable forages.
Soil test and adjust fertility. Many people say that broomsedge infested pastures need lime. This may be true in some cases, but I have found over the years that they are more commonly low in phosphorus. Soil testing is the only way to tell what amendments you need to apply.
Manage grazing and clipping to favor desirable forage species. In many cases, there are desirable forage species in broomsedge infested pastures. By adjusting soil fertility and managing grazing to favor these species we can make them more competitive. Normally these species are cool-season grasses. So not grazing them closely and frequently during the summer months will get them ready to grow in late summer and fall when temperature and moisture conditions are ideal.
Clip pastures in late summer or early fall. Clipping broomsedge in late summer or early fall once just before it produces seed can reduce shading of desirable forage species, making them more competitive in the stand.
Apply nitrogen fertilizer in early fall. After we clip pastures in late summer, applying 60 lb N/A can stimulate desirable cool-season grasses helping to shift the botanical composition away from broomsedge.
Feed hay on broomsedge infested pastures. This is low input way of increasing soil fertility over time. Each ton of hay contains approximately 50 lb of nitrogen, 15 lbs of phosphorus, and 60 lbs of potassium. It is important to remember that although feeding hay does bring nutrients into a grazing system, it is a much slower way to build fertility than applying commercial fertilizer or broiler litter. Make sure to move feeding points around the pasture to get a more even nutrient distribution.
Burn broomsedge infested pastures. Not the best idea, because native warm-season grasses evolved under burning. This means that burning can actually enhance broomsedge stands.
Apply nitrogen in late spring or early summer and graze broomsedge. The idea is make the broomsedge more palatable and graze it during the summer months. The problem with this approach is that desirable forage species will tend to be overgrazed during the summer, putting them at a disadvantage. This approach may actually make your broomsedge problem worse over time.
Kill the existing the pasture with nonselective herbicide and reestablish it. Although this is viable approach to controlling broomsedge, without proper soil fertility and grazing management, the broomsedge will come back. In addition, this is by far the most time consuming and expensive approach.
Controlling broomsedge in pastures and hayfields will require a sustained effort of improving both soil fertility and grazing management. So make a plan, implement it, and over time you will see reduction broomsedge as your desirable forage species become more competitive.
To learn more about integrated weed control in pastures, contact your local extension office or visit the UK Weed Science Website .
~ Dr. Chris Teutsch, reprinted from Cow Country News