Crested wheatgrass

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CRESTED WHEATGRASS

By H. L. Westover, senior agronomist, Division of Forage Crops and Diseases,
Bureau of Plant Industry* ;

INTRODUCTION INTO THE UNITED STATES

Crested wheatgrass (Agropyron cristatum Gaertn.) is a hardy,
drought-resistant perennial bunch grass, native to the cold, dry
plains of Russia and Siberia. The first recorded introduction into
the United States was made through the efforts of the United States
Department of Agriculture in 1898, but the possibilities of the grass
did not attract much attention until after 1915, when it was sown
in the northern Great Plains, where it proved especially adapted.

DESCRIPTION AND CHARACTERISTICS

Crested wheatgrass is closely related botanically to slender wheat-
grass (A. tenerum Vasey) and western wheatgrass (A. smithii
Rydb.), both native to the northern Great Plains. It is a typical
bunch grass, differing in this respect from western wheatgrass and
bromegrass (Bromus inermis Leyss.), both of which spread by under-
ground rootstocks and tend to develop a uniform turf.

A wide range of types is found in commercial seedings, but typical
plants have a dense, dark-green foliage during the early part of the
season. Aiter heading, the plants appear less leafy, but the stems
are fine, and when harvested early the grass makes hay of excellent
quality.

The seeds of some plants have pronounced awns, while those of
others are awnless or practically so. Seeds with long awns are
objectionable, as they have a tendency to hang together and do not
feed readily through the drill.

Crested wheatgrass has a longer productive period than slender
wheatgrass or bromegrass and under favorable moisture conditions
has yielded well for 10 to 15 years or more. In comparable tests
bromegrass and slender wheatgrass have frequently yielded more
the first 2 or 3 years, after which the slender wheatgrass tends to
die out and the bromegrass becomes sod-bound, while crested wheat-
grass continues to produce satisfactorily, provided moisture condi-
tions are favorable. At the Northern Great Plains Field Station,
Mandan, N.Dak., a seeding made in rows in 1915 produced more in
1933, its eighteenth year, than bromegrass, slender wheatgrass, or
later seedings of crested wheatgrass.

Crested wheatgrass is able to grow at low temperatures, and as a
result makes earher and more rapid growth than other grasses with
which it has been compared. This characteristic is probably due to
its extensive root system, which permits storage of abundant food
reserves and ready utilization of water. The grass has a tendency
to become dormant during hot, dry periods, but seems to suffer no
permanent injury, growth being resumed upon arrival of the cool
days of autumn, and with a favorable moisture supply continuing
until late in the season. Its ability to grow at low temperatures

1The writer is indebted to J. T. Sarvis, Mandan, N.Dak., Leroy Moomaw, Dickinson,
N.Dak., and M. A. Bell, Havre, Mont., for suggestions in the preparation of this leaflet.

d8747—34

CRESTED WHEATGRASS 3

enables it to utilize the soil moisture to such an extent as to check
the growth of other grasses and weeds where the moisture supply
is limited.

In thin seedings, individual plants tend to enlarge, sometimes be-
coming rough and bunchy, especially where there is much soil-
blowing. The grass is more easily killed by plowing than brome-

grass, and, therefore, is better suited for growing in rotations.

ADAPTATION

Crested wheatgrass is especially well adapted to the northern
Great Plains, where the temperatures are severe and the moisture
supply is limited. It is one of the most promising dry-land grasses
for eastern Oregon and Washington and northeastern Calfornia.
In Colorado crested wheatgrass is reported to give good results as
a pasture crop at altitudes of 5,000 feet or more, but it has not
appeared promising at lower altitudes. At the United States Dry
Land Field Station, Akron, Colo., it has proved to be the best of
available pasture grasses, although far from satisfactory for pasture.
The grass has some possibilities as a seed crop in that locality when
grown in cultivated rows.

The results from limited tests with crested wheatgrass as a dry-
land crop for Kansas have not been sufficiently conclusive to permit
specific recommendations. In tests at Hays, Kans., it has not ap-
peared promising, but has given good yields under irrigation near
Garden City, Kans. In the eastern part of the State, where moisture
conditions are more favorable, other adapted grasses are doubtless
superior. Until further information is available regarding the value
of the grass in Kansas it is suggested that prospective growers test
it experimentally before sowing any considerable acreage. Crested
wheatgrass is being tested in pasture mixtures in some of the humid
northern States, where it gives some promise. As a result of seed-
ings made by farmers in many other parts of the United States, more
definite information regarding its limits of usefulness should soon
be available.

There are no records of an established stand of crested wheatgrass
having been killed by cold or drought where the grass is adapted.
Although it has survived the most severe drought of the northern
Great Plains the grass is not productive during extreme heat or
drought. It remains dormant during such periods, growth being
renewed when rains occur. Available results seem to indicate that
with 18 or more inches of rainfall properly distributed, bromegrass
may yield as much as, and alfalfa may yield more than, crested
wheatgrass.

Crested wheatgrass does not appear promising for the southern
half of the United States except possibly at high altitudes. Under
the more favorable moisture conditions of the Eastern States it is
not equal to timothy and other adapted grasses.

The grass does well on productive soils of almost any texture
ranging from light sandy loam to heavy clay.

SEEDING

Crested wheatgrass, being tender in the seedling stage, requires
favorable conditions for germination and early growth. A firm seed

4. LEAFLET 104, U.S. DEPARTMENT OF AGRICULTURE

bed well supphed with moisture and comparatively free from weeds is
essential to a satisfactory stand. It is generally easy to secure these
conditions following a crop of corn or after summer fallow. Where
the moisture supply is more favorable a good seed bed may be pre-
pared on fall- or spring-plowed grain stubble. The land should be
worked down well, smoothed with a spike-tooth harrow, and packed,
if necessary, just before seeding.

The most favorable time to sow crested wheatgrass varies with

the locality and the season. The usual practice is to sow in the
spring at about the time spring wheat is sown, as moisture conditions
are likely to be most favorable at that time. Where weeds are
abundant better stands result from seedings made late enough to
permit 2 or 3 cultivations with a disk harrow, a spring-tooth aaa
or a duck-foot cultivator before seeding; in this way many of th
weeds are killed. In most of the region to which the grass Sate
even delayed seedings ordinarily should be made not later than
June 1. While spring seedings are much to be preferred, fall seed-
ings often give good results where moisture conditions are favorable,
though sometimes such plantings are subject to injury from cold or
drought or grasshoppers. In parts of eastern Washington fall seed-
ings have generally proved more satisfactory than spring seedings.
In this region it 1s generally advisable to drill the seed in grain
stubble, which tends to check soil- blowing during the winter. In the
northern Great Plains fall seedings should be made not later than
the early part of September.

Crested wheatgrass may be sown in close drills or in rows wide
enough apart to be cultivated. Where the crop is to be utilized for
hay or pasture, close drills are preferable, except where the moisture
supply is very limited. The seed should be sown with a grain drill
and covered ‘about one half inch (fig. 1). The double disk drill
is preferable to the single disk drill, as it does not cover so deeply.
While the seed runs through the drill more freely than seed of most
other grasses, it 1s advisable to watch closely to see that none of the
cups or spouts become clogged.

If grown mainly for seed production, the grass should be sown
in rows and kept cleanly cultivated, since with a limited moisture
supply more seed of better quality can be produced in rows than in
close drills (fig. 2). The seeding may be made in single rows or in
double rows. In single rows the seed is dr opped from one spout of
the grain drill, and in double rows from two adjacent spouts which
are ‘usually 6 or 7 inches apart. The latter method is preferable
since skips are less likely to occur. The most satisfactory distance
between rows is 36 to 42 inches for either single or double rows. The
orass may be grown in rows for hay in areas where the rainfall is
very limited, ‘put under most conditions close-drill seedings are
preferable for hay or pasture. Hay preduced in rows is likely to
contain consider: able dust and dirt, and the increase in yield, if any,
usually is not sufficient to offset the poorer quality of ‘hay ‘and the
extra labor involved in keeping the rows cleanly cultivated.

The usual rate of seeding in close drills is 10 to 12 pounds per
acre. ‘To seed crested wheatgrass at this rate, the grain drill should
be set at about one half the rate usual for seeding “wheat, as a trial,
and then adjusted to seed more or less according to needs. Where the

wre hy

CRESTED WHEATGRASS 5

moisture supply is limited, heavier seedings result in decreased yields.
In cultivated rows 2 or 3 pounds of seed per acre is ample for single
rows and 4 to 5 pounds for double rows 42 inches apart.

FIGURE 1.—Seeding crested wheatgrass, Dickinson, N.Dak.

Under dry-land conditions it is generally safer to sow crested
wheaterass without a nurse crop. ‘Where the moisture supply is

FIGURE 2.—Crested wheatgrass in rows for seed production, Dickinson, N.Dak.

favorable good results are usually obtained when seedings are made
me a nurse crop of wheat or oats sown at about one half the usual
rate

Where it is desired to seed a considerable area of abandoned farm
land as cheaply as possible, seeding in strips and permitting the

6 LEAFLET 104, U.S. DEPARTMENT OF AGRICULTURE

plants to mature and the seed to shatter, so that the entire area is
eventually covered with volunteer plants, has some possibilities.
The strips should be about 100 feet apart and at right angles to the
prevailing winds. The seed may be sown with a hand seeder from
a moving car or horseback. Another and probably better method
is to seed the strips with a grain drill in single or double rows about
36 inches apart.

TREATMENT

Ordinarily a close-drilled field of crested wheatgrass does not re-
quire any attention during the year that it is sown. In a favorable
season a light hay crop may be obtained; but usually there is not
enough growth to pay for the labor of harvesting. If weeds, become
very troublesome the field may be clipped, but ordinarily it is better
not to mow during the year of seeding. After the first year weeds
- give little trouble in close-drilled fields. Row seedings require 2 or 3
cultivations during the season.

UTILIZATION

In the areas to which it is adapted, crested wheatgrass fills a unique
place as a pasture grass, and it is probable that its greatest usefulness
will be for this purpose (fig. 3). In palatability the hay compares
most favorably with the high quality of western-wheatgrass hay.
Analyses of plants cut at different stages of growth show that crested
wheatgrass has a higher nutritive value at most stages than slender
wheatgrass or bromegrass.

The average analyses of crested wheatgrass, slender wheatgrass,
and bromegrass cut at various stages of growth are given in table 1.
The samples were taken at about 2-week intervals from April 10 to
August 25.

TABLE 1.—Average composition of crested wheatgrass, bromegrass, and slender

wheatgrass
< Ether | Crude |
Kind of grass Ash extract. | protein Crude fiber
Percent Percent Percent Percent
Crested swiheaterdss sss. ies «Seer ai eae a epee 7. 02 2. 33 14. 25 24. 86
Slender wheaterasseo-ce oso - | jG i Seager ee 8. 00 RPT 11. 67 27. 48
BT OMIGEEASS SSG ese he Ss Ee tn 2 ee 8. 65 2. 24 13. 23 FASS

The hay is eaten readily by all classes of livestock, horses being
particularly fond of it and often preferring it to bromegrass hay.
If the best quality of hay is to be obtained, the grass should be
cut shortly after it comes into bloom. The hay cures readily, and
with favorable weather can be stacked or stored soon after being
mowed. Where the grass is adapted, yields have ranged from three
fourths of a ton to 1 ton of cured hay per acre over a period of years,
with considerably higher yields in the more favorable seasons.

Crested wheatgrass is a very valuable pasture grass in the north-
ern Great Plains when used in mixtures or in combination with
other grasses or legumes that provide more feed during the heat
of summer when crested wheatgrass is dormant. The use of mix-

CRESTED WHEATGRASS ci:

tures results in prolonging the grazing season, as the crested wheat-
grass starts growth several days earlier in the spring than other
grasses, and when moisture is available continues to grow later in
the fall.

In grazing tests conducted in cooperation with the Bureau of
Dairy Industry at the United States Dry Land Field Station,
Ardmore, S.Dak., crested wheatgrass for dairy cows proved _supe-
rior to bromegrass, sweetclover, and native pasture. At the Judith
Basin Branch Station, Moccasin, Mont., crested wheatgrass, brome-
grass, and sweetclover have given practically equal returns from
pasturing, and all three were superior to native grass.

Figure 3.—Cattle grazing on mature crested wheatgrass in the Judith Basin, Mont.

Crested wheatgrass has an important place in the crop-replace-
ment program in the areas in which it is adapted. It has been
used with good results in reseeding depleted ranges and abandoned
plowed areas. The grass also has a place on dry-land lawns, golf
courses, and airports, where the finer turf grasses cannot be main-
tained, and for seeding right of ways along highways where a
permanent growth is needed to control coarse weeds. :

SEED PRODUCTION

Crested wheatgrass has good seed habits as it yields well, ripens
early, and can be harvested with machinery available on grain
farms. As the seed ripens while the plants are still green, the
straw is of considerable value for feeding. Because crested wheat-
grass seed shatters readily, harvest should begin when the earliest
heads begin to shatter. Much of the seed may be lost in windy
weather if the grass is allowed to become too mature. The crop
may be cut with a grain binder, and should be shocked immedi-

8 LEAFLET 104, U.S. DEPARTMENT OF AGRICULTURE

ately (fig. 4). Under normal weather conditions, 10 days in the
shock is sufficient for drying before threshing. The seed is easily
threshed with an ordinary grain separator (fig. 5). To avoid loss

FIGURE 4.—Harvesting a seed crop of crested wheatgrass, Dickinson, N.Dak.

of seed in threshing, the speed of the fan should be reduced or the
air intake to the fan closed. With some separators it is desirable
to lower the rear of the machine from 6 to 12 inches so that the
seed may pass back to the delivery and the straw be handled more |
satisfactorily. |

FIGURE 5.—Threshing crested wheatgrass, Dickinson, N.Dak.

Crested-wheatgrass seed can be cleaned with an ordinary farm
fanning mill equipped with the proper sieves. A fair standard
for crested wheatgrass seed is a bushel weight of 22 pounds, a purity
of 88 to 90 percent, and a germination of 90 percent.

U.S. GOVERNMENT PRINTING OFFICE: 1934

For sale by the Superintendent of Documents, Washington, D.C. - - - - - - Price 5 cents