Weekly, Oklahoma State University Extension Beef Cattle Nutrition Specialist Paul Beck offers his expertise on the beef cattle industry. This is part of the weekly series known as the “Cow Calf Corner,” published electronically by Dr. Derrell Peel, Mark Johnson, and Beck. Today, he discusses managing interseeded winter annual grasses.
Interseeding cool-season annual grasses like wheat, rye and ryegrass into bermudgrass pastures is a common way to extend the grazing season and provide high-quality pasture when cattle need it most. By doing this producers are able to graze these pastures for 9 or 10 months instead of the 4 to 5 months of grazing we normally expect from pastures containing only warm-season grasses. Most of the benefit comes during the late winter and early spring when the cool-season annuals begin to rapidly grow through late February through early June. There are several issues with this production system that can cause big problems if they are not controlled.
Everybody that has ever grown a garden knows that bermudagrass and crabgrass are very hardy plants and difficult to kill. One of the surefire ways to kill bermudagrass is to shade or smother it out. We can easily do this in pastures or hay meadows with our cool-season annuals if we are not careful. If allowed to grow uncontrolled late into the spring when warm-season grasses are breaking dormancy, the cool-season grasses will outcompete the warm-season grasses for sunlight and nutrients. This will delay the growth of the warm-season grass or, in severe cases reduce stand vigor or thin out warm-season pastures.
One way to reduce this problem is to only plant the number of acres we can graze during the spring, but that would require limit grazing or limiting the use of the cool-season forages in some way until spring growth occurs.
If we plant enough winter annuals to stock with our cattle in the fall and winter, then we may be able to adjust fertilizer levels to drive forage production for the times when we need more (fall) and put out less when we have more forage than we can use. Fertilizer is a good investment if we need or can use the additional forage it will produce; it is not worth its cost if the forage will not be used.
The best alternative may be to harvest the additional forage for hay or silage. If we have the equipment and are ready to roll when the time comes, wheat, rye, and ryegrass all make good hay and can be a valuable resource for wintering cattle later in the year.
Cool-season grasses can be a detriment to our warm-season pastures and hay meadows, delaying our first warm-season hay cutting or delaying summer grazing. But, with proper management these effects can be lessened and total forage production will be greater than if we managed for warm-season grasses alone.
