Why plant winter annual forages? One major reason is that species such as ryegrass, wheat and oats grow and provide grazing during the period when bermudagrass and bahiagrass are dormant and unproductive. Nutritive quality is high and this reduces the need for feeding of protein and energy supplements. If legumes are included, they provide a bonus of free nitrogen. Even though fertilizer and fuel prices are high, planting a winter pasture may be the most economical way of wintering your cattle.
Productive winter pastures actually begin prior to planting. Field selection, soil testing, site preparation and selection of the crops and varieties best suited for your soils and your needs, well in advance of planting time, can help avoid many of the errors of last minute decision making.
Some producers may desire to have their winter pasture available for grazing prior to Jan. 1. For these producers, planting into a prepared seedbed in late September or early October provides the best opportunity for early grazing. With this type of pasture, small grains (wheat, rye or oats) plus ryegrass is a popular mixture. This type of pasture is expensive due to the seedbed preparation in addition to seed, fertilizer, etc.
Also, early seedlings can be devastated or destroyed by fall armyworms. Oats can be planted in early September, but rye, ryegrass and wheat should not be planted until after Sept. 20.
Overseeding winter annuals on summer grass sod is generally one of the least expensive types of pasture to produce, but does not provide much fall or early winter grazing. Ryegrass is commonly planted and is very productive if properly fertilized. Small grains are sometimes included, but much of their potential early growth is missed because the overseeding must be delayed until the summer grass becomes dormant, usually in mid to-late October.
Overseeding has several advantages, especially for wintering beef cows. First, since little seedbed preparation is carried out, it is less expensive than systems that include more cultivation. With overseeding there is also a reduction in potential erosion because the soil is always covered with some vegetation.
The summer pasture sod is usually firm and provides good footing to cattle during the winter grazing season. In contrast, winter pastures that are planted in thoroughly cultivated seedbeds are often soft and boggy much of the winter. Finally, if grazing is managed properly during the winter and spring, the summer grass sod can be encouraged to resume growth in the spring and provide grazing as the cool season plants fade out.
Prior to overseeding, producers need to make sure the summer sod is short. Graze the sod to a height of one to two inches or clip it as short as possible before planting time and keep it grazed short until seedlings start to emerge. Don't plant too early or too late. The best planting time depends on the weather and the time that the summer grass goes dormant. In most years, seeding should not occur before mid October in northern Louisiana or late October in southern Louisiana.
Winter pastures can be planted in row crop fields after harvesting the row crops, provided no harmful chemical residues are present. This type of pasture is usually planted late so that much of the potential value of including small grains may have been lost. Ryegrass is commonly planted in this situation. The amount of seedbed preparation varies with the soil and the amount of crop stubble left.
Due to the high cost of commercial nitrogen fertilizer, there has been a great deal of interest among producers in using clovers as a component of their winter forage program. One of the first considerations to make if clovers are to be planted is to match the plants to the soil. There is wide variation in soil capabilities on almost every farm.
Clovers differ in their tolerance to and ability to persist in various soils. It is important to match the clover species or mixture of species to the different soils so that greatest returns can be realized as well as proper soil and water conservation. For example, berseem clover is better adapted to poorly drained sites than crimson clover.
Producers also need to match plants to the intended use. They should plan for maximum quality and versatility in their forage program. Select clovers that produce high quality feed and plant to use each field for hay and/or pasture as weather and feed needs dictate. For example, tallergrowing clovers such as red clover are more adapted for use as a hay crop than a clover such as white clover, which is used primarily for grazing.
A common misnomer about using clovers is that nitrogen in a clover plant is released into the soil through the clover roots while the plant is actively growing. Research has shown there is only a very small amount of nitrogen transfer from clover roots to the soil and/or to other plants. The primary pathways for nitrogen transfer are through grazing livestock and the decomposition of dead clover plant material. The root system and unused leaves and stems of clovers die at plant maturity and are decomposed by soil microbes over time.
Nitrogen contained in this plant material is released over time to the soil and is available to other plants. In an overseeding situation, this results in the warm season perennial grasses in the pasture such as bermudagrass and bahiagrass receiving the most benefit from the clover. Estimates are this amount can be between 50 to 100 lbs. of nitrogen per acre.
After you have decided which type of winter pasture program would best fit your operation, you will need to select one or more fields for planting. Areas with poor drainage should be avoided since the winter and spring months are frequently wet. The fields you select should have a medium or higher level of fertility and a satisfactory pH. Most grasses tolerate a pH as low as 5.5, but most clovers generally do better if the pH is between 6.0 and 7.0. Any needed lime should be applied well in advance of planting for maximum benefits.
Ryegrass and clovers can be planted using a drill or a broadcast seeding method. For these species, the optimum planting depth is between 1/4 and 1/2 inch in the soil. If small grains are included in the mixture, they will need to be planted at a depth of one to two inches.
Probably the best way to plant a winter grazing mixture is to plant the small grain with a grain drill and plant the ryegrass and clover seed with a broadcast seeder and then cultipack or roll the seedbed after seeding. This will ensure that the seeds are in firm contact with the soil so they can easily germinate and become established, and will aid in reducing soil movement and erosion from rains that occur prior to establishment of a good sod.
Producers need to provide adequate fertility for maximum production of the winter pasture. Phosphorus and potassium fertilizer should be applied at or near planting time as recommended by soil test. For nitrogen fertilizer, a good rule of thumb is to figure on using about 1 lb. of nitrogen for each day of grazing. Grazing for 180 days would require 180 lbs. of nitrogen per acre, while 90 days of grazing would require only 90 pounds of nitrogen per acre. The nitrogen fertilizer requirement can be split into two or three applications made during the growing season.
It is important to avoid grazing winter pastures too early. When the plants are small, the cattle may pull up entire plants when grazing, and in addition, trampling damage may be severe. It is best to keep the animals out of the pasture until the pasture height is at least six inches. Grazing can then begin, but it is important to not graze below a stubble height of about two to three inches.
Limit grazing is a system that many livestock producers follow to make efficient use of winter pastures. In this system, cattle have access to pasture with high quality grazing for a short period of time each day or on alternate days. Grazing for two to six hours each day allows the animals to obtain much of their needed nutrients, especially protein, without excessive trampling damage. It also means that the remaining nutritional needs can usually be met by feeding a lower quality feed such as hay. In this way, a limited supply of high quality pasture can be used by more animals or by a set number over a longer period of days.
During the late spring period, there are many acres of winter pasture throughout the Gulf South region that are wasted. This is a time period of rapid growth for ryegrass and clovers, and many producers don't have enough livestock to keep up with this excess growth. One option available is to use electric fencing to fence off areas of excess winter pasture and cut that area for hay.
Ryegrass and clovers offer some of the best quality hay available if they can be properly harvested and stored. The growth stage for harvesting these crops that offers good yields of high quality forage is the boot to early heading stage for ryegrass and a flowering stage for clovers. Once hay is baled, it should be stored in a protected place as quickly as is convenient.
Ed Tividwell is an extension forage specialist with the Louisiana State University AgCenter.