Overseeding winter annuals onto dormant summer perennial pastureland is a powerful tool used by producers who desire to extend the number of months spend grazing their livestock. To overseed winter annuals, producers simply broadcast or drill seed into the desired area once summer perennial growth has ended. Correct overseeding practices lead to the availability of winter annuals from late fall through the spring, depending on the forage species/combination of species planted. Common forages utilized in winter grazing systems from overseeding are small grains (oats, wheat, rye), ryegrass, and clovers. These species can be used in combination with each other to increase length of forage availability or to take advantage of the nitrogen fixing attributes of clovers. Overseeding is a fairly simple technique that leads to high benefits, however incorrect procedures for overseeding can lead to failure of winter annual establishment. Let’s review the benefits and practices recommended for successful overseeding:
Benefits of Overseeding:
Overseeding allows producers to lessen the amount of stored feeds necessary for production through the winter. The increased forage availability from winter annuals allow producers to more economically feed their livestock.
If winter annuals are broadcasted onto or drilled into sods (versus planted in prepared plots), pasture land is better able to uphold its integrity when animals graze after wet conditions or in areas that tend to hold water in the winter months.
Winter annuals are high quality forage and provide excellent nutrition to livestock throughout their growing season.
If a legume (such as clover) is used in the winter annual combination, nitrogen availability in the soil is increased. Legumes naturally fix nitrogen and thus increase nitrogen amounts available to companion plants growing with the clover and to plants growing after the clover’s growth ceases.
Techniques for Overseeding:
Overseed winter annuals onto pastureland in good condition for plant growth. Pastures should be well-drained and not subject to flooding on wet winter days. A soil test should be taken, and lime should be properly applied several months before overseeding. Potassium and Phosphorus should be applied while overseeding as directed by your soil test, and Nitrogen should be applied after winter annuals are up to minimize uptake and continued growth from summer forages. High quality seeds should be used, and legume seeds should be inoculated just before planting.
Pastures should be grazed down closely or clipped/forage removed prior to overseeding. Burning pastures is a less desirable option, due to inconsistency of burn, but is better than overseeding onto a sod with high levels of vegetation.
Disking of seeds into the sod is not a requirement for overseeding certain species in optimal pasture conditions. However, every pasture is different and should be evaluated prior to overseeding to determine if and how much disking is required. Factors that should be evaluated are desired date of planting (disking allows for earlier planting), soil type, species to be overseeded, and forage remaining on sod. If existing forage is not grazed or clipped down, tillage to disrupt current vegetation is necessary. One or two rounds of light disking can be beneficial to overseeding programs, and it is important to note that disking does not damage summer perennial return in subsequent years.
When to Plant:
Winter annuals should be overseeded later than if they were planted on prepared land. Since remaining summer perennials are still intact on many pastures used for overseeding, it is important to overseed after summer plants stop their growth. If overseeding is done too early, summer grasses that continue to grow will overwhelm and outcompete your winter annuals. In central Alabama, it is recommended to overseed winter annuals from October 15-October 30. If earlier planting on sod is desired, summer sod should be very thoroughly disked such that it is destroyed or weakened. In Bermudagrass fields, paraquat may be sprayed on summer pastures to provide an “early frost affect.” In both cases, overseeding can be done 2-3 weeks earlier than in standard conditions.
It is also important to overseed winter annuals by the October 30 cutoff date in central Alabama to allow for the young plants to germinate and be well established before the blunt of winter sets in. Increased survivability during winter frosts are noted in healthy, well established stands. In addition, if small grains are to be planted for utilization in late fall/early winter, adequate time is necessary post planting to allow for grazing availability.
Once winter annuals are ready for grazing, stock areas appropriately such that large, dense areas of winter annuals are not left on pastures. This could reduce summer forage emergence.
Click here to view a document with more facts on overseeding.
If you have questions regarding overseeding techniques or other fall planting guidelines, contact myself or other members of the ACES Animal Science and Forages Team.
Sarah Dickinson, M.S.
Regional Extension Agent I
Animal Science & Forages
Alabama Cooperative Extension System
Serving Chambers, Clay, Cleburne, Coosa, Lee, Randolph, Shelby, Talladega, and Tallapoosa Counties