Management of Dryland Seeded Pastures

All range plantings will be protected from domestic grazing from the date of seeding for at least two consecutive growing seasons (April 15 to October 1), or longer if the seeding is not well established at the end of two years. If shrubs are included in the planting, their successful establishment should be used as the criteria for grazing deferment.

A planned grazing system that follows FOTG, Section IV, Practice Standards and Specifications, Prescribed Grazing (Code 528) will be applied immediately to the planted areas after the establishment deferment period is over.

During the two-year establishment period, excessive amounts of competitive weeds will be controlled by applying labeled herbicides or by clipping. Control weeds that compete with seedlings for sunlight and/or moisture during the growing season of the species planted and initiate clipping when weeds reach a height of six to eight inches. Clipping will be done before weed seed development, or prior to significant soil moisture competition. Heavy weed infestations should be clipped and removed from the site, while lighter stands can be spread uniformly across the planting site.

Herbicides must be applied very carefully to avoid injuring new seedlings. Apply herbicides according to label instructions. See FOTG, Section IV, Practice Standards and Specifications, Pest Management (Code 595), and Montana, Utah, Wyoming Weed Management Handbook for herbicide recommendations.

Practically all dryland pastures in Montana are seeded to cool-season species, and most management problems are related to the growth patterns of these species. In general, cool-season grasses make their initial growth in early spring and reach maturity in July, depending upon species and climate. To gain maximum forage use of these grasses it is desirable to pasture them during this period. Exceptions to this would be later-maturing warm-season grasses or those which remain palatable through midsummer or fall.

A. Management of the Single Species Pastures

The best time for utilization of single species pastures is during the period when palatability and growth are at their maximum. To maintain production, pasturing should begin in the spring when new foliage is four to six inches tall. Animal numbers should be adjusted so the grass will be allowed to grow and not be over-grazed. Some grasses such as crested wheatgrass and Russian wildrye can be more closely grazed than other species without loss of the stand, but too early and too severe use will decrease the vigor of any grass.

Introduced grasses usually reach their peak of production in about four to six years while natives will maintain vigor and productivity over a longer period. Therefore, introduced species should be grazed closer the first few years for maximum livestock production. Careful management based on an understanding of the growth habits of introduced grasses can extend the productive period of a stand. Proper grazing levels and occasional rest periods to allow recovery of vigor are required to sustain productive stands.

Single species stands are easier to manage than mixtures, especially in rotational grazing systems. Each species can be grazed during its period of maximum productivity and palatability.

B. Management of Mixtures

Mixtures of grasses and legumes usually yield more than a mixture of grasses or a single species grass planting. The nutritional values of grasses and legumes are higher than those of a single grass or mixture of grasses. A mixture of grasses having different growth habits gives more varied forage throughout the season. Differences in livestock preferences for the species in a mixture may cause uneven grazing. Species composition in a mixture may change because the preferred species become weak from overgrazing and are replaced by less palatable species. The management of mixed grasses should be keyed to the use made of the preferred species.

Alfalfa, sweet clover, or other legumes planted in mixtures with grasses provide nitrogen to sustain and increase yield and nutritive values of the entire mixture. However, it sometimes is difficult to keep legumes in the mixture because of their high palatability. Also, legumes may be removed by drought, winterkill, diseases, parasites, or inappropriate or over use of herbicide applications.

To reduce the hazard of bloat, alfalfa should be maintained at not more than one-third of the total composition. Any mixture containing a bloating legume should be pastured early, before the legume becomes a major part of the forage. Bloat usually is most likely during the first two or three years of a stand except in higher rainfall areas, where the danger period may be extended. As stands mature, the legume becomes less abundant in the composition and thus, less likely to produce bloat.

C. Pasture Renovation and Management of Old Stands

Pastures of introduced grasses without legumes generally show marked reductions in yield the third or fourth year after establishment. The reduction frequently is caused by a lack of available nitrogen. Yields often can be increased somewhat by tearing up the pasture sod, but the beneficial effects of this practice usually are short-lived. Seeding alfalfa into old stands of crested wheatgrass that are fairly open sometimes has been helpful. Applications of commercial fertilizers often boost yields sharply (except in dry years, where no yield advantages may be expected). To maintain any yield increased through fertilization applications will have to be made every year or two. Soil test results are recommended to base fertilizer application rates. Nitrogen fertilizer tends to favor grasses while phosphorus favors the legumes. A balanced fertility program will maintain a grass-legume composition.

One of the best ways to maintain continuous high production of improved pastures is through a crop-rotational system. When pasture production begins to fall off the pasture is broken and cropped for several years, then re-seeded to grass. Old, low-producing stands can be broken and fallowed for a year and then re-seeded. This method may not be practical on marginal lands or areas subject to accelerated erosion.

D. General Management of Seeded Pastures

The most efficient and economical method of utilizing seeded and native pastures is to manage them in combination. This will provide an extended grazing season and give maximum production on both areas. The use of seeded pastures in early spring allows the native range to develop to grazing readiness without the stress of grazing. Further benefits of this kind of management and a discussion of techniques and systems are found in the FOTG Section IV, Forage Integration.

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Last Modified: 07/05/2007