Using Annuals to Supplement Perennial Forages

From April Wilson, Resource Conservationist, USDA-Natural Resources Conservation Service

The drought that started last fall and consumed hay supplies has livestock producers worried about fall and winter forages. Thin pastures have folks considering using winter annuals to supplement predominately cool-season grass fields. Thankfully the rains have started falling again and fall forage is looking more hopeful. In this article, we will look at some winter annuals and their application. 

The information in this article is adapted from the publication Extending Grazing and Reducing Stored Feed Needs, published by the Grazing Lands Conservation Initiative now called the National Grazing Lands Coalition. https://www.grazinglands.org/ 

For the most part, planting an annual into perennial grass is not a good practice. Thick stands of perennial grasses usually do not allow the seed of the annual plants to germinate due to lack of seed to soil contact or competition for sunlight. This year may be an exception if you have fields that are severely overgrazed, bare, or have had the stand partially or mostly killed due to drought stress. Check fields closely for plant survival. You may be surprised to see what is coming back.

Winter annual crops can be valuable when planted in areas where lower quality perennial forages dominate or to provide grazing at time when it would otherwise not be available. However, because winter annual forages are more costly to grow than most perennials, they may not be economical to use. 

Types of winter annuals.

Forages fall in to three categories: grasses, forbs (or broadleaf plants), and legumes (or nitrogen fixing plants). The most common winter annual grasses to plant are small grain cereal crops such as wheat, rye, oats, barley, or triticale. These can likely be planted by late September and will benefit from added fertility. Rye is more productive than wheat or triticale for both fall and spring production, however forage quality is better with triticale than with rye. Oats seeded in the fall can be excellent quality and are very productive but will be killed by cold weather during winter.  Depending on planting time and with adequate moisture, rye, triticale, and wheat should be available for grazing from October through much of December and then again in early spring. Wait to graze winter annual grasses until at least 8 inches of growth have accumulated. Remove livestock when 3 inches of growth remain to maintain sufficient leaf area for continued growth and recovery.

The most common winter annual forbs planted for forages are brassicas. Brassicas (including turnips, rape, kale, and swedes) are highly productive digestible forbs that contain relatively high levels of crude protein. Animals will readily consume the tops and will also grub the root bulbs out of the ground. These plants do not tolerate much competition. Brassicas should not comprise more than about two-thirds of cattle dies because of their low dry matter content. Therefore, it is important to provide adjacent pasture or a palatable, dry hay fed free choice to cattle when grazing these crops. It is also ideal to introduce animals to brassicas slowly by limiting grazing until their digestive systems are accustomed to them. These too should be planted by late September.  As with stockpiled forage brassicas should be strip grazed. If regrowth is desired, at least 2 inches of leaf should be left intact. Generally, animals will consume the leafy portion of the plant before progressing to the root portion. 

There are several winter annual legumes available to us; some being hairy vetch, crimson clover, and also some of our better-known clovers like white clover. These species may be grown with the other winter annual plants. Winter annual legumes make almost all of their growth in the late winter and spring, but the distribution of growth of various species within this time period varies. 

Over-seeding winter annuals on summer grass fields.

Winter annuals, including annual ryegrass, small grains, and various annual legumes such as clovers and vetches can be seeded as a single species or in various mixtures into to warm-season perennial grass sods such as bermudagrass to extend the grazing season by 30 to 60 or more days. Winter annuals should normally be over seeded about 2 or 3 weeks before the expected date of a killing frost. Unless some tillage is provided to ensure good seed-soil contact, the existing grass should be clipped to grazed to 1 to 2 inches tall. Producers wo have pastures of both tall fescue and summer perennial grasses may be able to graze the summer grass closely to facilitate over-seeding of winter annuals as the same time they are stockpiling tall fescue. Over-seeded pastures should be kept gazed closely in spring to prevent shading of summer species.

If you have questions about utilizing winter annuals in pastures about protecting or enhancing your farms resources, please give us a call at 417-683-4816 extension 3. The Natural Resources Conservation Service office is located in Ava, MO.

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