Improve Your Pasture (Hay And) Land By Frost Seeding

DR. TERESA L. STECKLER

SIMPSON, ILL.
   Having traveled around southern Illinois extensively last fall, I noticed that many pastures are in dire need of attention. Lack of rain and overgrazing has taken a tremendous toll on pastures. The extent to which pastures are overgrazed or mismanaged will directly correlate to the vigor and production of stands this spring. Pastures, just like livestock, need good management to be productive. Neglecting fertility or management can have an appreciable financial impact – and not for the good! 
   Typically pastures are composed of grasses and legumes and these plants do very well when cared for properly. The goal of the forage mix is to allow complementary plants to flourish and provide a more productive pasture than is possible with a single type of plant.
The dominant plant species are often tall fescue, white clover and weeds.  In addition, the high cost of fertilizers and soil amendments in recent years generally have meant that pasture and hay ground has received little or improper amounts of inputs to maintain productive stands. Thus the result of this combination of conditions is usually low yields of low quality forages.
   The benefits of legumes in a pasture or hayfield are numerous. Grass-legume systems have a reduced need for nitrogen fertilizer, improved forage quality, better seasonal forage distribution, increased forage yields, and reduced risks to grazing animals when compared to grass monocultures. Legumes can be mixed in with grass seed when fields are first established or they can be broadcast or drilled into existing stands of grass in the spring or fall. The most common way that legumes are established is through a process known as frost seeding. 
   However, never let an opportunity go to waste! Overgrazed pastures represent an excellent opportunity to frost seed legumes or grasses. The principle of frost seeding is to broadcast forage seed in the early spring when the ground freezes at night and thaws during the day. The main advantage to frost seeding is the ability to establish desirable species into an undisturbed sod at a low per acre cost.   Other advantages include the ability to establish forages with minimum equipment investment, a shortened “non-grazing” period, and it is a method to maintain stands at productive levels with both grasses and legumes.
   There are several key points to keep in mind for successful frost seeding. First, seed to soil contact is critical. Seed to soil contact can be increased by closely grazing the pastures in the fall or winter to open stands and expose the soil or hoof action on stands with a thick layer of thatch covering the soil.  
   Second, competition of seedlings with established plants should be reduced. The seedlings must be given a chance to become established. Reducing competition can be accomplished via grazing the pastures down to 2 inches in the fall to slow spring regrowth, graze pastures regularly in the spring to allow light penetrations but avoid consumption of the seedlings prior to adequate root development.
   Third, select the correct species and apply at appropriate rates. Research has shown good results for frost seeding red clover and birdsfoot trefoil. Alfalfa, alsike clover, and white or ladino clover have also been frost-seeded with varying degrees of success. Do not frost seed alfalfa in situations where alfalfa plants already exist in the stand. Autotoxicity will prevent new seedlings from becoming established.
   Fourth, frost seed at the appropriate time and use the most appropriate method to broadcast the seeds. The fundamental principle behind frost seeding is that alternating freezing and thawing, along with spring rains, will help to incorporate the broadcast seed into the soil surface. Seeding on top of snow is acceptable if the depth is not too great. The risk of seeding on top of snow is that a rapid meltdown may result in runoff of both water and seed. Be certain to inoculate legume seeds prior to seeding. Bacterial inoculant is specific for each legume species. Several tools exist for making broadcast frost seedings. Seeders may be mounted on ATV’s or tractors.    Conventional roller and grain drill seeders can also be used but will require more trips across pastures. When using spinner-type seeders, be sure to determine the effective seeding width for each seed type or mixture. This will vary between species.
In summary it is already time to think about pasture health to reduce your yearly feed costs. The benefits of legumes in a pasture are numerous.  Frost seeding can be an effective, low-cost method to introduce new forage species into an existing sod or maintain the current forage composition of pastures. Control competition from grasses or other weeds the first few months of legume establishment and is accomplished primarily through mowing or grazing since most herbicides will kill legumes. Also it is important not to overgraze as this can kill young legume seedlings that are not yet established. With proper management your pasture will remain healthy, happy and productive for many years. Here’s to a successful 2018! ∆
   DR. TERESA L. STECKLER: Extension Specialist, Animal Systems/Beef, Dixon Springs Agricultural Center, University of Illinois