• IMPORTANCE TO LIVESTOCK AND WILDLIFE
• PALATABILITY
• NUTRITIONAL VALUE
• COVER VALUE
• VALUE FOR REHABILITATION OF DISTURBED SITES
• OTHER USES AND VALUES
• MANAGEMENT CONSIDERATIONS

IMPORTANCE TO LIVESTOCK AND WILDLIFE:

Western wheatgrass is an important forage species on ranges in good condition in pinyon-juniper, chaparral, northern desert shrub, and shortgrass prairie [48]. It is one of the most valuable North American wheatgrasses [88]. Although leaves are stiff, they rarely become sufficiently coarse to discourage animal use [36,84,121].

Western wheatgrass is one of the primary grasses eaten by cattle in New Mexico and in central and eastern Montana [4,95]. It provides important domestic sheep forage in southeastern Montana, particularly during June, July, and August [2]. Fall regrowth cures well on the stem, so western wheatgrass is considered good winter forage for domestic livestock [68].

Bison feed on western wheatgrass in the Great Plains; it is preferred by bison to blue grama in northeastern Colorado [74,112,142]. Western wheatgrass makes up a higher percentage of bison diets on heavily grazed ranges than on lightly grazed sites [112]. In Wind Cave National Park, South Dakota, elk consume western wheatgrass during the fall, winter, spring, and summer [172]. It is eaten by white-tailed deer in eastern and central Montana, with heaviest use during the spring [4].

Western wheatgrass is used by various small mammals. It is heavily used by pocket gophers from May through September [35]. It is also heavily grazed by black-tailed prairie dogs in South Dakota [83].

PALATABILITY:

Western wheatgrass is described as "very palatable" [31]. New growth is particularly palatable to cattle and to domestic sheep. Plants often become coarse by early summer and palatability declines [68]. In some areas plants may become "stemmy and unpalatable" by late summer [130]. The degree of use shown by livestock and wildlife species is rated as follows:

                     CO    MT    ND    UT    WY
Cattle              Good  Good  Good  Good  Good
Domestic sheep      Fair  Fair  Fair  Fair  Good
Horses              Good  Good  Good  Good  Good
Pronghorn           ----  Poor  Poor  Fair  Fair
Elk                 ----  Good  ----  Fair  Good
Mule deer           ----  Poor  Poor  Fair  Fair
Small mammals       ----  Poor  Poor  Good  Fair
Small nongame birds ----  Poor  Poor  Fair  Fair
Upland game birds   ----  ----  Poor  Fair  Fair
Waterfowl           ----  ----  Good  Fair  Fair

NUTRITIONAL VALUE:

Western wheatgrass is described as "highly nutritious" [31]. It is rated as "good" in energy value and "fair" in protein value [45].

However, protein content varies by plant part and by seasonal development. Protein content peaks during the period of most rapid growth in the southern plains (usually in April) and is generally lowest at or just after the end of flowering [129]. Specific crude protein values are as follows [111]:

early May                     31.6%
regrowth in early July        13.0%
late 1st harvest early July    9.8%
1st harvest late July          7.9%

initial harvest early May     74.5%
initial harvest mid May       76%
late 1st harvest early July   59%
1st harvest late July         54%         

COVER VALUE:

Western wheatgrass can be used to produce good stands of nesting cover for various ducks in the Dakotas [91]. It provides good nesting sites for mallards, gadwalls, and blue-winged teal [99]. Grasses, including western wheatgrass, are frequently selected for nesting sites by green-winged teal, pintail, and northern shoveler [138]. The degree to which western wheatgrass provides cover for wildlife species is as follows [45]:

                         MT        ND        UT        WY
Pronghorn               Poor      Fair      Poor      Poor
Elk                     Poor      ----      Poor      Poor
Mule deer               Poor      Fair      Poor      Poor
White-tailed deer       Poor      Fair      ----      Poor
Small mammals           Fair      Good      Fair      Good
Small nongame birds     Fair      Good      Fair      Good
Upland game birds       Fair      Good      Poor      Fair
Waterfowl               Good      Good      Poor      Fair

VALUE FOR REHABILITATION OF DISTURBED SITES:

Western wheatgrass is a good soil binder and is well suited for reclamation of disturbed sites such as surface coal mines, erosion control, and soil stabilization [37,105,139]. It is commonly included in seed mixtures used for rangeland seeding, revegetation of saline-alkali areas such as saltwater blowout sites, and in critical areas for erosion control [27,69]. It can also be seeded onto wet areas or waterways [131].

Since rhizomes may persist in land broken for cultivation, western wheatgrass spreads rapidly on abandoned land [121,153]. In Wyoming and Montana, western wheatgrass is one of the most promising grasses for reclaiming saline seeps, as well as other problem sites [121]. In Nebraska and Saskatchewan, it shows potential value for controlling wind erosion in sand blowouts or on dunes [67,103,126]. Western wheatgrass is used for roadside revegetation at "higher elevations" in Arizona, and along roadsides in Iowa [24,47].

In Arizona, successful coal-mine reclamation included the use of fertilizers, a combination of natural rainfall and sprinkler irrigation for the first 2 years, and seeding perennial grasses including western wheatgrass, crested wheatgrass (Agropyron cristatum), and Indian ricegrass (Achnatherum hymenoides) [129]. The effects of 3 soil materials, 3 mulching treatments, and 2 soil moisture treatments on the growth and forage production of western wheatgrass when used in the reclamation of coal mine spoils were investigated during a 3-year experiment in Arizona. Average stems per pot and dry forage yield per pot for western wheatgrass were determined for all treatment combinations. The highest number of stems per plot, the tallest plants, and the highest forage yield were produced with Gila loam soil, barley straw mulch, and soil moisture treatment with maximum production. More vigorous plants and more forage were produced when soil mulch was used than when soils were not mulched [36].

Vesicular-arbuscular mycorrhizae are a common component of arid soils. They usually increase nutrient and water intake, as well as increasing the dry mass of plants. The disturbance of land often leads to the reduction or elimination of mycorrhizal fungi propagules. Workers investigating the development of vesicular-arbuscular mycorrhizae and proliferation of roots of western wheatgrass in a revegetated mine spoil in southeastern Wyoming found that western wheatgrass was not highly dependent on mycorrhizal infection for survival [100]. Researchers at the Kemmerer Coal Mine in southwestern Wyoming found that mycorrhizae benefited western wheatgrass [3].

Western wheatgrass can be successfully drilled or broadcast seeded [5,88]. It can be successfully seeded during the spring or fall [120]. Numerous cultivars, adapted to a wide range of environmental conditions, are available for commercial use [7,10,53,79,121,139]. 

OTHER USES AND VALUES:

Native and seeded stands of western wheatgrass are used for pasture and hay [152].

MANAGEMENT CONSIDERATIONS:

Western wheatgrass can tolerate moderate grazing but is damaged by close spring grazing [152]. Heavy grazing "may be tolerated, but production will be lowered considerably by this practice" [130]. Western wheatgrass is a decreaser on upland sites in the Great Plains with less than 20 inches (500 mm) average annual precipitation. In areas with over 20 inches, it is an increaser. When western wheatgrass is mixed with taller or more palatable species, it often increases. When it is mixed with shorter grasses and warm-season species, western wheatgrass decreases when grazed early in the spring [152]. However, Hafenrichter and others [68] report that continuous early spring grazing of mixed stands can result in nearly pure stands of western wheatgrass. Western wheatgrass increases in both density and frequency after grazing and chaining in pinyon-juniper communities [149].

Western wheatgrass is susceptible to grasshopper damage during moderate to heavy infestations. In prolonged wet periods, forage quality is decreased from ergot, as well as leaf and stem rusts [152].

In some instances large increases in western wheatgrass have been reported after herbicide application. In a Wyoming study, increases of 260% were reported within 2 years of herbicide applications, with increases of 490 to 720% live canopy cover reported during the 7th year after application [167]. Detailed information on response to various herbicides is available [114,167].

In North Dakota, western wheatgrass produces approximately 1/3rd of its annual yield prior to May 20th. The bulk of production occurs from May 20th to June 30th [165].

Related categories for SPECIES: Pascopyrum smithii | Western Wheatgrass