Oklahoma State University

Oklahoma State University

As more producers realize the reduction of inputs costs that may be associated with using cool-season perennial grasses for their winter stocker or cow-calf programs, many questions have arisen regarding establishment and management strategies. There is little specific information at present concerning the establishment of the various cool-season perennial grasses under evaluation at the present time. There is, however, basic information that producers should adhere to. This publication will attempt to address some of the issues regarding establishment and maintenance of cool-season perennial forage grasses currently under evaluation for Oklahoma. Information is also provided concerning annual ryegrass and matua prairiegrass.

The cool-season perennial grasses under current evaluation are primarily introduced forages that will warrant careful attention to grazing management and soil fertility. If the producer is not doing a good job of managing their current forage base, there is no reason to invest the time, effort, and money that will be required to establish cool-season perennial grasses. The money would be better spent improving current forage resources.

Species selection is an important aspect of stand establishment. If the species is not adapted to a particular region of the state, or if the species is not adapted to the type of soil where the cool-season perennial grass will be established, producers will experience less than satisfactory results ranging from thin stands and low yields to outright crop failure!

From producer-based accounts, it appears that most of the wheatgrass species (Luna, Manska, Oahe, Jose') may be established to a wide range of sites, but primarily west of Interstate 35 in Oklahoma. These species have been successfully established on clay-loam to sandy sites, although matua prairiegrass may be best suited for the sandier sites. Orchardgrass may require a somewhat deeper soil, and the bromegrass species are intermediate in their adaptation.

With regard to soil pH, it appears that the wheatgrasses may be successfully established on sites that are moderately acid (pH = 5.1-5.5) to near neutral (pH = 7.5). For sites with higher soil pH values, Jose' tall wheatgrass should be used. The literature suggests that Jose' tall wheatgrass will grow on sites with soil pH levels as high as 10.0.

The intermediate, pubescent, and tall wheatgrasses are reported in literature to be fairly long-lived and heat and drought tolerant. Paiute orchardgrass has been selected for drought tolerance. Although any of the grasses will survive some degree of flooding for a short period of time, Jose' tall wheatgrass (and tall fescue) is best adapted for periodic flooding and high water tables. Matua prairiegrass will have a slight advantage over ryegrass regarding drought tolerance; however, the reverse is true for soils that may stay excessively wet.

Producers should obtain a copy of the Standard Soil Survey for their county prepared by the Natural Resources Conservation Service (formerly Soil Conservation Service). This survey will indicate the type of soil on their property and will help dictate, in many instances, which of the cool-season perennial forage grass species to utilize. Using this approach, soil testing annually, applying fertilizer based on soil test recommendations, and practicing good grazing management will help ensure successful stand establishment and longevity of the stand.

With most forage species, there is usually a short period of time for successful stand establishment. For example, warm-season forages are typically established during the spring. Late freezes and early summer drought periods can play havoc with establishment and shorten or eliminate an otherwise wide-open window of opportunity.

The same is true for cool-season perennial grass establishment. If grasses are planted too early (late summer), then the possibility of plant mortality associated with drought is very real. If grasses are planted too late, there is a potential of mortality associated with an early freeze.

The best time for cool-season perennial grass establishment is late August or early September because of historical precipitation patterns. The chance for moisture is usually good during this time, and generally there is adequate time for plants to establish a root system in advance of cold temperatures. Improper timing of establishment may be the number one cause for crop failure.

Improper timing of establishment occurs in many instances because the producer was not prepared to act when the planting window of opportunity presented itself. Producers who anticipate establishing cool-season perennial grasses should plan ahead and be ready to take advantage of the first opportunity to plant. The seedbed should be prepared in advance. Lime, phosphorus, and potassium should be already be incorporated into the soil, and seed for the chosen species should be on hand. The equipment should be in good condition and ready to plant. If renting equipment, be sure to have the equipment located and ready to go when the planting opportunity presents itself.

To enhance the probability of stand establishment, a fine and firm seedbed should be prepared. Most of the cool-season perennial grasses have smaller seeds than wheat; thus, the need for a firm seedbed becomes more critical. The objective of the good seedbed is to maximize seed-soil contact. The better the seed-soil contact, the more likely the seed will come in contact with any available soil moisture.

Purchase the very best seed that you can find. The price of seed is a very small portion of the overall cost of establishment, but good seed can pay big dividends in germination and seedling vigor. Plant the seed at a rate based on published recommendations, or at a slightly higher rate if quicker coverage is desired. The seed should not be buried too deeply or the germinating seed may have a difficult time in sending the coleoptile to the soil surface. Plant the seed at a depth of approximately one-quarter to one-half inch.

Specialized equipment is not necessary to plant the cool-season grasses. Many producers have reported good results using their existing grain drills. Although some trial and error will be necessary to calibrate the drill for the species you choose to plant, if you presently own a grain drill, by all means use it! Other producers have chosen to mix seed with fertilizer and broadcast in the pasture. At present, some producers are electing to air-seed their pastures. Just remember, if you choose to broadcast or air-seed rather than drill, use a seeding rate approximately 25% higher than the rate used with a drill. Then follow the broadcast or air-seed application with a light drag to cover the seed with a minimum amount of soil. Bromegrasses are difficult to plant using a grain drill. Many conservation districts have a drill designed to plant grass seed that incorporate an agitator in the seed box.

In the case of annual ryegrass many producers broadcast ryegrass seed into clean-tilled fields or even short grass swards without any seedbed preparation and obtain good stands of grass. Ryegrass establishment into an existing grass sward, however, is most successful if a light disking is used prior to seeding followed by a drag to help move the seed down to the soil surface. Once established, ryegrass can successfully volunteer for many years if allowed to make seed each year.

The newly planted grass should have every opportunity for successful establishment and this begins with a soil analysis. Prior to planting, obtain a soil sample and have the soil analyzed for nutrient status. Some soil nutrients such as phosphorus and potassium, and lime are more effective if incorporated in to the soil. The best time to incorporate is while preparing the seedbed. Always apply fertilizer and lime according to the soil test recommendations. To do otherwise results either in applying too little or too much fertilizer.

Some producers will utilize anhydrous ammonia as their source of fertilizer nitrogen because of familiarity associated with wheat farming. Anhydrous ammonia should be applied prior to planting and will be available for grass seedlings. If you plan to utilize a form of dry nitrogen, the producer may wish to wait until they are sure of germination prior to applying the dry form of nitrogen fertilizer. Nitrogen application rates will vary depending on precipitation amounts and soil type; however, one-third of the nitrogen should typically be applied in September with the remainder applied during late February or early March to match the production curves of most cool-season perennial grasses. Typical application rates would be 25 to 40 pounds of actual nitrogen per acre in September and 50 to 80 pounds in March. A useful rule of thumb for nitrogen application might be 3 pounds of nitrogen per inch of annual precipitation down to 30 inches, and 2 and one-half pound of nitrogen per inch of annual precipitation below 30 inches to approximately 24 inches. In areas that receive less than 24 inches of precipitation, nitrogen applications rates will rarely exceed 40-50 pounds annually.

A producer can take all the precautions to plant at the right time with the right species on the right seedbed, but still suffer a crop failure due to poor early management. Proper early management strategies of newly established grasses can mean the difference between a vigorous or a weak stand. Early management strategies include delaying grazing until plants have a well-developed root system. If grazing is initiated too early, young seedlings can be uprooted and destroyed. Heavy pressure at too early a stage can also stress young seedlings beyond their ability to recover from grazing events. A good rule of thumb would be to allow the seedlings to reach 6 to 8 inches in height prior to turning livestock into newly established pastures.

Other early management strategies for newly established cool-season perennial grasses will probably include the use of herbicides to control unwanted weed competition and/or the use of insecticides to prevent insect damage to young seedlings. Lack of control of weeds during establishment can result in a complete loss of the stand. Different cool-season species may be susceptible to different pests; there is little information regarding pest problems associated with the cool-season perennial grasses in Oklahoma at this time. If you suspect a pest problem, or require further information, contact your local county Agricultural Agent concerning the most appropriate method of controlling pests. Remember to properly identify the target species and use the appropriate pesticide. Be sure to always follow label directions when utilizing herbicides, insecticides, or other chemical pesticides. This will help to ensure safe, effective, and economical treatment.

Most of the cool-season perennial grasses under consideration are described as long-lived. This is at best a vague description of the potential stand longevity. At present, there is no research data to indicate how long a stand of wheatgrass or orchardgrass may stay productive under Oklahoma growing conditions. Some producers, however, are into their fifth growing season with Luna pubescent wheatgrass and Paiute orchardgrass and report no evidence of stand decline at this time. Jose' tall wheatgrass is also known to persist for many years in Oklahoma under good management. Regardless of the species, a sound fertility program and good grazing management will ensure the stand life of the cool-season perennial grass species of choice is maximized.

Fertility: First, pastures should be analyzed for soil nutrient status every year, or at most every other year. Proper fertility is absolutely essential to maintain a healthy, vigorous stand of grass. Without adequate fertilizer nutrients, stand life will be decreased, the potential for forage production will not be realized, and the carrying capacity of the management unit will be reduced. The net result of an improper fertility program is decreased profitability of the enterprise.

Nitrogen is the number one limiting factor to forage production besides moisture. Do not scrimp on nitrogen. This is the one nutrient that will make money for you in your forage/livestock production enterprise. The producer should be fertilizer smart, however; if there is not a need for the forage, do not apply additional nitrogen. Think the process through and decide how much forage you require and apply nitrogen accordingly. See OSU Fact Sheet No. 2584, Forage-Budgeting Guidelines for help in determining your forage and fertilizer requirements. Phosphorus and potassium should be maintained at appropriate levels and producers should pay close attention to the soil pH. Acid soils can reduce the availability of certain nutrients such as phosphorus. Aluminum toxicity can also become a limiting factor as soil pH values decline below 5.0.

Grazing Management: Another critical aspect of maintaining a healthy stand of grass relates to stocking rate Maximum net return from livestock does not occur at maximum stocking rates because of reduced animal performance associated with intense competition for forage. Using a moderate stocking rate for the cool-season grass of choice will help ensure stand longevity, reduce the potential for weed infestation, maintain the carrying capacity of the management unit, and preserve the profitability of the enterprise. The amount of grazing pressure that each species will tolerate will vary; however, each of the cool-season perennial grass species of interest in Oklahoma at present are bunch grasses that will require that a minimum of 4 to 6 inches of residue be left for optimum plant performance. Rotational stocking of pastures may be beneficial in enhancing plant persistence and stand life. Further information on grazing systems and the relative advantages and disadvantages of continuous and rotational stocking can be found in OSU Fact Sheet F-2567, Grazing Systems for Pastures and F-2871, Stocking Rate: The Key to Successful Livestock Production.

Although matua prairiegrass is touted as a perennial, it is only a weak perennial at best in Oklahoma. This species should probably be managed as a reseeding annual such as annual ryegrass. In other words, both matua prairiegrass and annual ryegrass should be allowed to flower and set seed each year if the producer wants to take advantage of the reseeding capability. This will, however, require that the producer remove cattle during a part of the year that the grasses are actively growing and cattle are making good gains. In the case of ryegrass, it may be more economical to simply graze out the ryegrass and broadcast additional seed the following fall. Ryegrass seed is relatively inexpensive. When using matua prairiegrass, it may be more advantageous to manage for reseeding given the present cost of matua prairiegrass seed.

Cool-season perennial forages grasses are not unique in their requirements for establishment or maintenance. Every forage species demands the same careful attention to site adaptation, seedbed preparation, soil nutrient status, and grazing management. Some specific information is given in the following tables regarding dry matter production, nutritive value, seeding rate, life cycle, etc. Producers should be aware there is little information regarding the persistence or productivity of these grasses under Oklahoma growing conditions. Establishment should only be attempted on small tracts of land for initial evaluation purposes. Never plant more than you can afford to lose until further information is available. For additional help, contact your local county Agricultural Agent.