Standard Crested Wheatgrass

Standard Crested Wheatgrass (Agropyron desertorum)

Plant Species
From Montana Interagency Plant Materials Handbook *
By S. Smoliak, R.L. Ditterline, J.D. Scheetz, L.K. Holzworth, J.R. Sims, L.E. Wiesner, D.E. Baldridge, and G.L. Tibke

Standard crested wheatgrass is one of the most important cultivated grasses introduced into the United States. It is native to the cold, dry prairies of eastern Russia, western Siberia and central Asia. It has been used widely for forage and conservation plantings. In Montana it has been the chief grass used to regrass abandoned croplands and depleted ranges in the Northern Great Plains. It is best adapted at low and moderate elevations.

It has been suggested that at least five or six species make up the standard crested wheatgrass complex. This complex also may involve mechanical mixtures from seed or hybrids between closely related species.

Standard crested wheatgrass typically grows in "open" stands, i.e., plant populations are low with much bare ground between plants. In areas of higher rainfall it maintains a higher plant population.

Description

Standard crested wheatgrass is an extremely long-lived, bunch-type grass. It is very winterhardy, and has an extensive, deep, fibrous root system that gives it excellent drought resistance. The roots may extend 8 to 10 feet down and spread as much as 4 feet. Growth form is quite variable. It may be quite leafy with both basal and stem leaves or it may be quite stemmy. Its leaf growth is rapid and steady from mid-April to late June and ends by mid-July when seeds start to ripen. Stems are upright and may reach a height of 36 inches. Seeds shatter soon after maturity and seedlings volunteer readily.

Adaptation

Standard crested wheatgrass does well on most good soils, including heavy clay, but it is also noted for its ability to establish itself on sandy soils. Productive stands more than 25 years old are not uncommon. Some stands have died on very heavy soils. The grass is particularly adapted to dry conditions. It grows best in areas receiving 12 to 18 inches of precipitation. It withstands close grazing and trampling, and competes successfully with plants of other species. It is fairly tolerant of high alkalinity, has a moderate salt tolerance and requires a well-drained site.

Germination of standard crested wheatgrass is normally high. Seedlings are vigorous and develop rapidly with good growing conditions. Seeds can remain alive in dry soil for long periods until moisture is adequate for germination.

Standard crested wheatgrass stands are responsive to fertilizer. Applications of nitrogen will revitalize unproductive or old stands.

Limitations

This forage is generally not well-adapted to the moister parts of Montana where cool, short seasons with ample moisture prevail. This is probably due to its lack of resistance to root rots. Standard crested wheatgrass tolerates only a short period of spring flooding and is intolerant of high water tables. It has only a fair tolerance to alkali salts and acidity. Standard crested wheatgrass has limited value for winter grazing.

Use for Hay

Standard crested wheatgrass compares well with other grasses in hay yield and quality, but deteriorates rapidly after heading. It dries rapidly after cutting. Although this forage is vigorous and competitive, the strong bunch habit of growth allows space for legumes to grow. In the drier areas it is often preferred for mixtures with legumes. Regrowth after hay cutting is very poor.

Use for Pasture

This grass is best suited to pasture production as established stands can be considered more or less permanent. It yields well and is very palatable early in spring. It greens up two to three weeks before most native and introduced grasses. Early grazing use should be alternated between two or more pastures so that very early use is not practiced each year on the same pasture. The early growth is high in protein and is palatable to all classes of stock. It supplies nutritious forage at this critical season. Palatability drops off markedly in summer as the plant matures and becomes dormant. With good summer rainfall the plant may maintain palatable growth most of the season. For this reason, standard crested wheatgrass provides a longer grazing season in parts of the foothills and mountain areas of Montana than on the eastern plains. Fall growth starts quickly with the advent of fall rains.

Standard crested wheatgrass acreage should be limited to an amount that can be utilized in the average year by the time it begins to mature seeds. Management problems, due to differences in palatability, can best be avoided by seeding in pure stands (or with a legume) fenced away from other grasses and range. Failure to observe this rule in the past has resulted in thousands of acres of standard crested wheatgrass in Montana which are only lightly used by livestock.

Standard crested wheatgrass can be used for winter grazing by feeding supplements to supply protein, vitamins and energy. Cattle eat it better when there is snow, probably because it increases moisture content of the forage.

Stocking rates up to 1 acre/a.u.m. and 70 percent use can be safely employed on good sites if grazing is terminated while soil moisture is still available for regrowth. Compared to native prairie range it yields about twice as much, and since it is more tolerant to grazing, it can be stocked three times as heavily early in the season. However, it does not tolerate over-grazing. About 2 inches growth should be left ungrazed at the end of the season. Under semi-arid conditions it is best not to graze during the first season of establishment until after a killing frost. Grazing after freezing will remove growth that would interfere with grazing the following spring.

Seed Production

Seed production is relatively easy with standard crested wheatgrass, and you can expect about 100 to 200 pounds per acre on dryland and about 500+ pounds per acre on irrigated fields.

* The Montana Interagency Plant Materials Handbook (EB69) is no longer in print, but is available for viewing in
Montana County Extension Service and National Resource Conservation Service Offices.