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How well-established is your pasture?

Dr. Rocky Lemus Published on 10 November 2010
Cattle in pasture

Pastures must be well-established to be highly productive. Before establishing new pastures or renovating existing pastures, producers must evaluate the farm’s forage needs.

It is important to consider whether the forage will be used for grazing or hay, what forage species are best suited for the area and what resources are available in terms of equipment, money and time.

The decision of whether or not to renovate a pasture should be based on existing percentages of the desirable species present in the pasture. The following criteria could be used in such a decision:

• If the pasture contains 75 percent or more desirable species, consider not renovating and instead concentrating on management.

• If the pasture contains 40 to 75 percent desirable species, consider overseeding and concentrating on management.

• If the pasture contains less than 40 percent desirable species, consider re-establishing.

Establishing a new pasture or renovating an existing pasture usually requires some management to get the forage growing quickly and vigorously. Consider the following points when planning your management strategy.

Soil fertility
Planning for a successful pasture establishment or renovation should begin well in advance, often six to 12 months before the actual pasture establishment or renovation. If possible, adjust soil fertility before seeding. With today’s high fertilizer prices, you cannot afford to guess how much fertilizer to apply.

Using soil test recommendations, incorporate necessary fertilizer during seedbed preparation. Avoid applying fertilizer to drought-stressed seedlings, as the application could cause burning injury to young seedlings already under stress.

For forages to be productive, grass pastures should be maintained at a pH of 5.8 to 6.2. Legume pastures should have a pH of 6.0 to 6.8. To maintain the ideal pH, lime application might be necessary in some areas. If lime is needed, it should be applied six to 12 months before seeding to allow for the pH to adjust in the root zone, which will maximize the use of nutrients.

Proper phosphorus application at seeding time is the key element in establishing grasses and legumes. Quick root development is especially important when establishing forages in the fall. Well-developed root growth will minimize winter injury and allow rapid growth in the spring.

Potassium is essential for plants to cope with heat and water stress. It also is essential for plant growth and reproduction.

Nitrogen is best applied in small, frequent applications when plants are actively growing. Nitrogen, along with proper defoliation management, stimulates tillering in grasses.

Seedbed preparation
Good seed-to-soil contact is essential to maintain adequate moisture near the seeds. This moisture is necessary for germination and for the small root systems of young grass seedlings. The best type of seedbed preparation depends on the type of equipment available and whether a new pasture is being established (conventional tillage) or an existing pasture is being renovated (no-till drill).

A properly prepared seedbed is a key step in pasture establishment.Conventional tillage should be used when a uniform seedbed is needed. Large soil clods and excess sod impact seed germination.

For conventional seeding, prepare a fine and firm seedbed. A firm seedbed will allow capillary action to draw water to the soil surface, where moisture helps to germinate seeds and sustain small seedlings during periods of dry weather. A firm seedbed may help ensure that seed is not planted too deeply, which usually results in poor seedling emergence and weak pasture establishment.

Forages usually establish more quickly and uniformly in conventional seedbed than in no-till established pastures. Conventional tillage seedbeds also warm more quickly, allowing for better seed germination at cool temperatures. However, conventional tillage may cause soil erosion, changes in soil structure and reduced moisture retention.

No-tillage involves using herbicides to kill existing vegetation and then seeding directly into the residue. Surface residue must be reduced in no-till seedbeds by hard grazing or hay removal; most no-till seedbeds are prepared in late summer and planted in fall. No-tillage seedbeds require fewer passes over the field, reduce the possibility of soil erosion and conserve moisture. On the other hand, seedlings in no-till seedbeds emerge more slowly and less uniformly.

Species selection
Selecting the right species or species mixture is extremely important. When establishing or renovating a pasture, it is important to match forage species to the site, soil type and type of operation (grazing or hay, animal species and class). Check soil survey maps to find out your soil types, soil composition, drainage and forage capability. This information can be used to predict the success or failure of a potential forage species.

Seasonal yield distribution is another factor to consider when making species selections. It is important to try to match the forage yield distribution with the animals’ daily requirements.

Cool-season perennial species, such as tall fescue, grow best between 60ºF and 80ºF; production usually peaks in the spring, drops in the summer and increases in the fall. Cool-season annuals, such as annual ryegrass and annual clovers, have some growth in the fall followed by a period of dormancy or minimal growth in the winter and highest production in the spring.

Warm-season annual species, such as sundangrass, millet and sorghum, and perennial species, such as bahaiagrass, dallisgrass and bermudagrass, grow best between 80°F and 95ºF. Most warm-season grasses start growing in April and continue to grow until the first hard freeze in fall. Warm-season grass production generally peaks during midsummer.

Legumes are also an important part of the establishment process because they can provide nitrogen to the grasses, increase production during the spring and increase pasture quality. Make sure the growth habit of the selected legume species is compatible with the grass species to help minimize competition.

Seeding methods
The ideal seeding method depends on the type of equipment available and whether you plant on a no-till or a conventional seedbed. To ensure good soil-to-seed contact, seed germination and timely emergence, different seeding methods are available. Some of these methods include drilling, cultipacking, and broadcasting.

Drilling cuts a thin furrow in the soil, deposits the seed then covers it and firms the soil with press wheels. A good rule is to plant the seed three to four times as deep as the diameter of the seed.

With a cultipack planter, the seed is dropped from a hopper onto the soil, where toothed rollers press the seed below the surface. When using a cultipacker, be careful not to bury the seed too deeply, decreasing germination.

Broadcast seeding with a fertilizer spreader can result in an uneven seed distribution if the overlap is too wide. Less seed is distributed on the outer third, so adjust your spacing to provide double coverage. Make sure the spreader is calibrated for the appropriate seeding rate. When broadcasting, increase recommended seeding rates by 20 percent. Roll with a cultipacker to establish a good soil-to-seed contact.

Seeding time
Seeding on the correct date is also very important. Warm-season grasses should be planted in late spring to early summer after the soil has reached a temperature of 65°F or above. Seeds planted in spring usually have plenty of moisture for germination, but they sustain increased weed pressure. Spring seeding should be made at least four weeks after the last killing frost.

Late summer seeding is recommended for wet areas because the soil is usually dry enough during the summer and has less weed pressure. Fall seeding should be made at least four to six weeks before the first killing frost in the fall; this timing allows seed adequate growth before winter. No-till drill planting in late summer might provide adequate moisture for seed germination because organic matter provides cooler soil temperatures and higher moisture levels.

Seeding rates
Proper seeding rates depend on forage species and seeding method. To obtain a good establishment, use seed that is pure, has a high germination rate and has not been stored for a long period of time.

High-quality, certified seed is recommended. Seed cost could be a major portion of the total establishment cost, but buying less-expensive seed does not always translate into savings. If the seed is of poor quality, it must be applied at higher rates to obtain a desirable stand, making the use of cheap seed with low quality neither agronomically nor economically sound.

If you seed legumes, make sure the seed is inoculated with the proper bacterial strain. Legume seed is often pre-inoculated. If the seed is not pre-inoculated, mix packaged inoculum with the seed just before seeding.

It is vital to have proper seeding depth and seed coverage. When drilling legumes, make sure to plant no deeper than a quarter of an inch to two inches, depending on the seed type and size. Planting depths greater than two inches will decrease seedling emergence as much as 50 percent in some forage species.

Weed control
A weed management plan will help ensure success in forage establishment. It is important to control weeds during establishment because newly emerged forage seedlings are extremely susceptible to weed competition. Weeds compete for water, nutrients and sunlight.

Broadleaf weed control is possible but may require multiple applications or applications at different times of the year. Applications at different times during the year will better control weeds that germinate during different seasons.

Do not allow animals to graze new stands too early or too frequently. Allow plants to become well-established before heavy grazing or set stocking. Mow or lightly graze pastures when plants are 8 to 12 inches tall. Most forage crops should not be grazed shorter than 3 to 4 inches. Maintaining proper grazing height will help trigger new plants to tiller or producer runners. Allow plants to grow to 8 to 12 inches before grazing or mowing again. A rotational grazing approach could be beneficial in ensuring successful establishment.

Proper forage establishment is a key step in having a thick, lush, profitable pasture. Many factors influence the success of a forage operation. No single program or system fits all situations, so evaluate how each factor impacts your forage system. Well-planned management will help ensure success for this potentially costly endeavor; failure or success often depends on adequate planning.  FG

References omitted due to space but are available upon request to .

—Excerpts from Mississippi State University Extension Service

When establishing or renovating a pasture, it is important to match forage species to the site, soil type and operation. Photo courtesy of Rocky Lemus.