Volume 21, Number 3 (May 1969)

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Wheatgrass Establishment

with Tillage and Herbicides in a

Mesic Medusahead Community1

JAMES A. YOUNG, RAYMOND A. EVANS, AND RICHARD E. ECKERT, JR. Range Scientists, Crops Research Division., Agricultural

Research Service, U.S.D.A., Reno, Nevada.

Highlight

Intermediate wheatgrass seedlings were successfully es- tablished in a medusahead community in 1965, 1966, and 1967 with mechanical or chemical-fallow treatments. Sum- mer fallowing by disk harrowing was the most successful treatment. The most productive wheatgrass stands sup- pressed but did not eliminate medusahead.

Medusahead

(Taeniatherum

asperum

(Sim.)

Nevski) poses a difficult problem for ranchers and

resource managers in California,

Idaho, Nevada,

Oregon and Washington.

When this winter annual

grass becomes

established

on depleted

ranges,

forage productivity

is drastically

reduced (Tore11

et al., 1961; Turner et al., 1963). Grazing capacity

on some ranches has been decreased as much as

757,

(Major et al., 1960).

The ultimate

control of medusahead

over the

millions of acres of rangeland that it now occupies

is basically a matter of suppression by well-managed

perennial grasses (Torell,

1967). By the time medu-

sahead becomes established and occupies extensive

areas in a rangeland

community,

the perennial

grass component of the community

is too depleted

to respond to management.

In these situations the

need for range seeding is imperative.

The extreme competition

offered by dense me-

dusahead stands makes weed control essential for

establishment

of perennial

grass seedlings.

Kay

and McKell

(1963)

used several

preemergence

herbicides

to aid in establishment

of rose clover

(Trifolium

hirtum

All.) and hardinggrass

(Phalaris

tuberosa

L. var.

stenoptera

(Hack.) in medusahead

stands. The most widely tested herbicide

for me-

dusahead

control

is 2,4-dichloropropionic

acid

(dalapon).

This

herbicide

has successfully

con-

trolled

medusahead

in California,

Idaho,

and

l Received July 12, 1968; accepted for publication September 6, 1968. Cooperative investigation of the Crops Research Division, Agricultural Research Service, U.S. Department of Agriculture and the Agricultural Experiment Station, University of Nevada, Reno. Journal Series No. 93. The authors gratefully acknowledge the cooperation given by Phillip Martinelli, Nevada Department of Agriculture. Our appreciation is extended to Harry Drackert for fur- nishing land for the experimental plots and to L. N. Langen of the Soil Conservation Service, U.S. Depart- ment of Agriculture for his technical advice and assistance in soil description interpretation.

Oregon (Kay, 1963; Turner

et al., 1963; Torell,

1967). On the California

annual range, control of

medusahead

with low rates of l, l’-dimethyl-4,4’-

bipyridinium

salts (paraquat)

has been extremely

effective in the establishment

of hardinggrass

and

annual clovers (Kay, 1966).

Our objectives in this study were: (1) to evaluate

tillage and herbicide

treatments for control of me-

dusahead;

(2) to determine

the most effective

method for establishment

of perennial

grasses in

conjunction

with medusahead control; and (3) to

ascertain the best adapted perennial

grass species

for seeding on the medusahead site being investi-

gated.

Methods

We conducted

this investigation

at Verdi, Ne-

vada (11 miles west of Reno at the base of the Sierra

Nevada Mountains).

The medusahead

infestation

is found on a formerly

cultivated,

unimproved

pasture.

The experimental

plots were established

on a long 5% slope facing east-to-southeast.

Soil

moisture increases along a gradient beginning with

dry rangeland at the upper end and ending in a wet

meadow at the lower. The upper portion of the

slope is occupied almost entirely by medusahead.

Small areas disturbed by rodents or grazing animals

supported sparse stands of downy brome

(Bromus

tectorum

L.) and hairy chess

(B. commutatus

Schrad.). Growing intermixed with, but suppressed

by the medusahead

population,

were scattered

plants of field bindweed

(Convolvulus

arvensis

L.)

and poverty weed

(Iva axillaris

Pursh.).

The only

remaining

perennial

grasses on the upper portion

of the site were scattered bunches of squirreltail

(Sitanion hystrix

(Nutt.) J. G. Smith) and isolated

rhizomatous

clumps

of streambank

wheatgrass

(Agropyron riparium

Scribn. and Smith). The more

mesic lower slope supported a thick stand of me-

dusahead

around

dense clumps of Baltic

rush

(Juncus balticus

Willd.).

A thin remnant stand of

pine bluegrass

(Poa scabrella

(Thurb.)

Benth.) and

meadow barley

(Hordeum

brachyantherum

Nevski)

was interspersed in the medusahead.

Precipitation

amounts and distribution

were ex-

tremely variable during the investigation.

In 1963-

64 (July-June)

13.4 inches of precipitation

were

received.

The

1964-65

precipitation

was 12.8

inches.

In 1965-66 virtually no precipitation

fell

after January

and the total was

7.3 inches.

The

winter and spring of 1966-67 were extremely wet

with 33 inches of precipitation

recorded.

Reno,

Nevada has a long-time average annual precipita-

tion of 7.73 inches, while at Truckee,

California,

25 miles west of Verdi and higher in the moun-

tains, the annual precipitation

averages over 30

inches ([J.S.D.A.,

1941).

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152 YOUNG

ET AL.

laquolls. They have developed in gravelly alluvium

from andesite, tuffs, and tuff breccias.

Design of all field trials involving

logarithmic

spraying of herbicides

was a four-replicated

split

plot with systematic arrangement

of subplots (rates)

(Cochran & Cox, 1950).

We visually evaluated weed control through the

growing season on all plots. Oven-dry yields of the

mature weeds were used to evaluate season-long

control.

We evaluated stand establishment

of perennial

grasses by lst-year seedling counts and height mea-

surements

made in late July after annual plants

had died. In 1964, perennial grass seedlings were

counted several times during the growing season,

to study time of stress and mortality of seedlings.

To further evaluate stand establishment,

vigor,

and productivity,

we clipped perennial

grasses for

yield in successive years after establishment.

1964

Experiments.-We

applied paraquat and 2-

chloro-4-ethylamino-6-isopropylamino-s-triazine

(at-

razine) logarithmically

at rates ranging from 2.0

to 0.25 lb/acre and dalapon ranging from 6.0 to

0.75 lb/acre on plots 8

x 100

ft on April 24, 1964.

Herbicides

were applied in water at 58 gpa and

30 psi. The surfactant

X-772 at 0.1% v/v was

used with all spray solutions.

Other treatments

were disk-harrowing,

furrow-

ing, and control.

The disk-harrowing

was done

with an offset-disk harrow. Furrows, 4 to 6 inches

deep and 4 inches across at the bottom and 10 to 12

inches at the top, were made with shovels attached

to a toolbar.

We seeded two rows of intermediate

wheatgrass

(Agropyron

intermedium

(Host) Beauv.) and one

row each of standard

crested wheatgrass

(Agro-

pyron desertorum

(Fisch.)

Schult.)

and Russian

wildrye

(EZymus junceus

Fisch.) immediately

after

treatment except for the plots treated with dalapon

and atrazine.

Plots treated with dalapon

were

seeded two weeks later using the same species; plots

treated with atrazine

were left unseeded.

The

perennial

grass seedlings failed to become estab-

lished in any of the treatments.

On November 24,

1964, all treatments

that had been seeded in the

spring of 1964 were reseeded with two rows of

Amur intermediate

wheatgrass and one row each of

standard

crested wheatgrass

and fairway crested

wheatgrass

(Agropyron

cristatum

(L.) Gaertn.).

A

dense stand of field bindweed developed in 1965 on

all plots where medusahead was controlled.

To re-

duce the field bindweed competition,

we applied 1

lb /acre acid equivalent

of propylene glycol butyl

ether

esters

of 2,4-dichlorophenoxyacetic

acid

(2,4-D) on May 21 and July 3, 1965.

1965

Experiments.-We

disk-harrowed

a 50

X 100

ft block on May 5, 1965. The disk-harrowing

2 X-77 is a trade-mark surfactant containing alkylarylpoly-

oxyethylene glycols, free fatty acids, and isopropanol.

provided

a summer-fallow

free of medusahead

plants although we had to spray the area on May

24 and June 16 with 2 lb/acre of 2,4-D to reduce

the bindweed population.

We seeded the fallow on

October

1, 1965, with Amur intermediate

wheat-

grass.

1966

Experiments.-We

repeated the most suc-

cessful

1964 treatments-disk-harrowing,

furrow-

ing, and dalapon-in

1966. The very low precipita-

tion during the winter of 1965-66 permitted earlier

application

of treatments

in 1966 than in 1964.

Using the same experimental

design as the one em-

ployed in 1964, we seeded disk-harrowed

and fur-

rowed plots to Amur intermediate

wheatgrass on

March 15, 1966. Because of incomplete emergence

of the medusahead population,

the 3 lb/acre dala-

pon treatment

was delayed until April 19. Plots

treated with dalapon were seeded on May 3, 1966

to intermediate

wheatgrass.

The disk-harrow and

furrow treatments were repeated on April 19, a date

comparable

to the 1964 treatments.

Field bind-

weed was again a serious problem.

We sprayed all

treatments with 1.5 lb/acre of 2,4-D on May 4 and

June 15, 1966. Perennial

grass stands on both the

March and April plots were unsatisfactory;

we

therefore reseeded all plots with Amur intermedi-

ate wheatgrass on October 11, 1966.

Red

ts

1964 Experiments.-

Paraquat

caused consider-

able discoloration

of medusahead leaves soon after

application.

After a few weeks the medusahead

plants completely

recovered and no weed control

was obtained.

Atrazine at rates ranging from 1 to

2 lb/acre controlled

medusahead

on the drier,

upper slope portion of the plots. The treatments

located on the moist lower slope required

2 lb,

acre of atrazine to control medusahead.

Dalapon

at rates ranging from 2 to 6 lb/acre resulted in

excellent

control.

The

disk-harrowed

and fur-

rowed plots were essentially

free of medusahead.

All treatments

that reduced

medusahead

were

followed by a heavy infestation

of field bindweed.

No seedlings of any perennial

grass species sur-

vived after August 1. More seedlings of intermedi-

ate wheatgrass emerged and lived longer than the

other three grass species tested. Also, more seed-

lings emerged and lived longer in the disked and

furrowed treatments

than m the dalapon-treated

areas (Fig. 1). The dalapon treatment

had the

disadvantage of a 2-week delay of seeding. Residual

herbicidal

activity of dalapon in the soil made this

delay necessary (Holstun and Loomis, 1956).

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WHEATGRASS

FURROWS

O l S K HIRROW - - - OALlPON 6185 ,bCRE - - - -

2 7

FIG. 1. Intermediate wheatgrass seedling survival in relation to weed control treatments. All treatments were applied and seeded in the spring of 1964.

with atrazine had unsatisfactory

wheatgrass stands,

except at the 2 lb/acre rate which had a fair stand.

Two lb/acre of atrazine and disk-harrowing

mark-

edly reduced medusahead

yield below the control

population.

The 0.5 lb/acre atrazine treatment in-

creased medusahead production.

An important

factor in the successful establish-

ment of the wheatgrass

seedlings

was the sup-

pression of field bindweed

with application

of

2,4-D.

Plots that were disk-harrowed or which had been

sprayed with higher rates of dalapon in 1964 pro-

duced more intermediate

wheatgrass and less me-

dusahead in 1966 than the other 1964 treatments

(Table

2). In 1967, the plots sprayed with 6 lb/

acre of dalapon or disk-harrowed

in 1964 produced

significantly

more intermediate

wheatgrass

than

the other treatments.

The plots treated with atra-

zine in 1964 supported vigorous wheatgrass plants,

but stands were too sparse for satisfactory yields.

In the very wet season of 1967, medusahead growth

Table 1. Medusahead yield and wheatgrass seedlings per ft of row 1964 fall seeded treatments.a

Wheatgrass seedlings/ft of row

Inter- Standard Fairway Medusahead mediate Crested Crested Treatment Yield lb/Ah Whtg Whtg Whtg

Dalapon (lb/A)

6 280b 6.2 0.4 0.1

3 200bc 6.0 0.1 0.2

1.5 15oc 6.0 0.0 0.0

0.75 270b 5.5 0.1 0.1

Atrazine (lb/A)

2 120dc 1.2 0.1 0

1 230b 0.9 0.1 0.1

0.5 440a 0.2 0.0 0

Disk harrow 14oc 6.2 0.7 0.1

Furrows 200bc 5.4 0.3 0.6

Control 280b 0.4 0.0 0.0

“Medusahead yield was taken the fallow year (1964) and seedling counts were made the seedling year (1965).

b Means followed by the same letter are not significantly different at 0.5 probability level as determined by Duncan’s Range Test.

ESTABLISHMENT

153

Table 2. Yield in lb/acre dry matter of medusahead and intermediate wheatgrass for two and three years after establishment of perennial grass seedlings.*

1966 1967

Inter- Inter-

Rate mediate Medusa- mediate Medusa- Treatment (lb/A) Whtg head Whtg head

Dalapon 6 940a 39oc 1600a 770b

3 860b 590b 1llOb 750bc

1.5 920ab 510bc 1 IOOb 71oc

0.75 380d 460~ 560~ 830b

Atrazine 2 54oc 740a 640~ 760b

1 360d 640a 460~ 740bc

Disk-harrow 1lOOa 280d 1540a 770b

Furrows 600~ 45oc 980b 820b

Control Oe 650a Od 13OOa

“Weed control treatments applied in spring, 1964; intermediate wheatgrass seeded in fall, 1964.

bMeans followed by the same letter are not significantly different at the 0.5 probability level as determined by Duncan’s Range Test. All comparisons are made vertically.

was significantly

suppressed by all treatments;

but

yield of medusahead in successful wheatgrass stands

exceeded that of control plots in 1966. The most

productive

wheatgrass stands suppressed, but did

not eliminate medusahead.

A few scattered plants of standard and fairway

crested wheatgrass were established in the dalapon,

disk-harrowed and furrowed treatments, but stands

were too sparse for yield measurements.

The con-

trol plots were devoid of all wheatgrass plants by

the 1966 sampling.

1965 Experiments.-The

50

x

100 ft block that

was summer fallowed by disk-harrowing

in 1965,

and seeded in October, 1965, produced an excellent

stand of intermediate

wheatgrass in 1966.

More

than five perennial

grass seedlings/ft

of row be-

came established

in spite of the extremely

dry

spring and summer of 1966. Because the block was

used for other experiments,

2nd year wheatgrass

yields were not taken.

1966

Experiments.-

Plots furrowed

and ones

disk-harrowed

in March, 1966 produced marginal

stands of intermediate

wheatgrass seedlings in 1966

(Table 3). Treatments

applied in April 1966 were

complete failures.

When intermediate

wheatgrass

Table 3. Intermediate wheatgrass seedlings per ft of row 1966 treatments (All seedings made in 1966).

Seeded Reseeded Seeded Reseeded Treatment March October April October

Furrowed 1.8 9.0 0 4.3

Disk-harrow 1.1 7.0 0 6.2

Dalapon, 3 lb/A Ob 2.0 Ob 1.9

Control 0 0.4 0 0

“Seedling counts made in late July 1966 and 1967.

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154 YOUNG

ET AL.

was reseeded in October,

1966, plots treated in

March produced more seedlings than those treated

in late April.

Discussion

Intermediate

wheatgrass seedlings were success-

fully established

in a medusahead

community

in

1965, 1966, and 1967 with mechanical

or chemical-

fallow treatments.

With the exception of the 1965

summer fallow by disk-harrowing,

treatments were

not exclusively

designed to create a fallow. How-

ever, the summer fallow option was always much

more successful than spring seeding and summer

fallowing by disk-harrowing

was the most successful

treatment.

The advantages of summer fallowing

for seeding perennial wheatgrass on downy brome-

infested

rangelands

have been demonstrated

by

Eckert and Evans (1967).

During years of average

or above average precipitation,

the Verdi site is too

wet and muddy to permit weed control and seeding

treatments

until late in the spring. This severely

limits the chances of success with spring seeding.

During the very dry spring of 1966, it was possible

to apply treatments and seed in March, but result-

ing wheatgrass stands were marginal.

Using similar

weed control techniques

on sites in Nevada where

early spring treatment

is possible,

Evans et al.

(1967) have been successful in establishing

wheat-

grass in downy brome communities

with spring

seedings.

Any reduction

in medusahead

density at Verdi

resulted in an increase in field bindweed.

The sup-

pression of the field bindweed by spraying 2,4-D

during the summer fallow and the seedling years

aided establishment

of wheatgrass seedlings. Tore11

(1967) reported similar problems with other broad-

leaf species in Idaho.

Downy brome did not significantly

increase on

plots treated with dalapon at Verdi.

This species

has significantly

increased

on other medusahead

sites and caused severe competition

to wheatgrass

seedlings

following

dalapon

fallow

treatments

(Torell, 1967).

The disk-harrowing,

furrowing, and higher rates

of dalapon treatments virtually eliminated

the me-

dusahead population

for one year. Even though

wheatgrass seedlings

completely

stocked plots so

treated, medusahead reinvaded the plots during the

seedling year. Wheatgrass

stands, after the seed-

ling year, suppressed growth of medusahead,

but

certainly did not eliminate it. Turner, et al. (1963)

advocated weed control treatments

to remove me-

dusahead from established

stands of wheatgrass.

On the Verdi medusahead

site, Amur interme-

diate wheatgrass was superior to standard or fair-

way crested wheatgrass in seedling stand establish-

ment.

The site at Verdi is representative

of the margins

of wet meadows in degraded condition

found in

the Great Basin.

Medusahead

is evidently

well-

adapted to these environmental

conditions.

The

discontinuous

distribution

of meadows in the Great

Basin should hinder the spread of medusahead.

However, no matter how remote and disjunct these

meadow sites may be, competitive

species such as

baltic rush are omnipresent.

Given time, medusa-

head may become widely distributed

on these re-

stricted sites.

The generally steep and rocky terrain of much

medusahead-infested

rangeland imposes limitations

on the feasibility

of applying the tillage methods

developed at Verdi to all medusahead infestations.

The acreage of rangelands

infested with medusa-

head where these tillage methods may be applied

is small in comparison to the total acreage infested

by the species, but the tillable sites are usually the

most productive

and offer the greatest return of

investment.

If weed control necessary to establish

wheatgrass seedlings could be accomplished

by a

chemical fallow, thousands of acres ordinarily tilled

only with difficulty, could be seeded with a heavy

rangeland

drill.

Conclusions

Intermediate

wheatgrass seedlings were success-

fully established

in a medusahead

community

in

1965, 1966, and 1967 with mechanical

or chemical-

fallow treatments.

Summer fallowing with a disk

harrow was the most successful treatment.

How-

ever, chemical-fallowing

with dalapon offers the

possibility of extending the technique

to areas not

suitable for tillage.

The fallow treatments were much more success-

ful for wheatgrass establishment

than spring seed-

ing following tillage or herbicide

treatments.

Any reduction

in medusahead

density resulted

in an increase in field bindweed.

The suppression

of field bindweed

by spraying 2,4-D during the

summer fallow and seedling years aided establish-

ment of wheatgrass seedlings.

Intermediate

wheatgrass produced the best stands

among all grasses seeded regardless of weed con-

trol method.

Established

stands of intermediate

wheatgrass greatly suppressed but did not eliminate

medusahead.

LITERATURE CITED

COCHRAN, W. G., AND G. M. Cox. 1950.

Experimental

designs. John Wiley & Sons, Inc., New York. 454 p. ECKERT, R. E., AND R. A. EVANS. 1967. A chemical-fallow

technique for control of downy brome and establishment of perennial grasses on rangeland. J. Range Manage. 29:35-41.

EVANS, R. A., R. E. ECKERT, JR., AND B. L. KAY. 1967. Wheatgrass establishment with paraquat and tillage on downy brome ranges. Weeds 15:50-55.

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TOBOSA

GRASS

155

KAY, B. L. 1963. Effects of dalapon on a

medusahead

TORELL, P. J. 1967. Dowpon-an aid to reseeding me- community. Weeds 3:207-209. dusahead-infested rangeland. Down to Earth 23:6-S. KAY, B. L. 1966. Paraquat for range seeding without cul- TORELL, P. J., L. C. ERICKSEN, AND R. H. HAAS. 1961.

tivation. California Agr. 20:2-4. The medusahead problem in Idaho. Weeds 9: 124-131. KAY, B. L., AND C. M. MCKELL. 1963.

Preemergence

TURNER, R. B., C. E. POULTON, AND W. L. GOULD. 1963.

herbicides as an aid in seeding annual rangelands. Weeds Medusahead-A threat to Oregon rangeland. Special Rep. 11: 260-264. 149, State Univ. Corvallis, Oregon. 37 p.

MAJOR, J., C. M. MCKELL, AND L. J. BERRY. 1960. Im- U. S. DEPARTMENT AGRICULTURE. 1941. Climate and Man. provement of medusahead-infested rangeland. Calif. Expt. Yearbook of Agriculture, U. S. Government Printing Sta. Ser. Leaf. 123. 3 p. Office, Washington, D. C. 1248 p.

Chemical Composition of Tobosa

Grass Collected by Hand-Plucking

and Esophageal-Fistulated Steers’

H. E. KIESLING, A. B. NELSON,

AND C. H. HEBBEL2

Graduate Student and Professor, Department of Animal, Range and Wildlife Sciences, New Mexico State University,

Las Cruces; and Range Scientist, Jornada Experimental Range, Crops Research Div., Agricultural Research

Service, U.S.D.A., Las Cruces.

Highlight

Organic matter recovery of seven feeds collected through esophageal fistulae of three steers averaged 90.4%. Six of the seven fistula samples contained significantly more ash than the feeds offered. Fistula samples of grazed tobosa (Hiluriu muticu (Buckl.) Benth.) contained less A.O.A.C. fiber but more silica, ash, protein, ether extract, detergent fiber and detergent lignin than hand-plucked grass. Except for ash, the differences in chemical composition between hand-plucked and esophageal-fistula samples were appar- ently due to selectivity by the grazing steers. We assume that samples collected by means of an esophageal fistula are more nearly representative of the forage consumed by graz- ing steers than samples hand-plucked by a technician.

Esophageal-fistulated

animals have been proposed

as a means of determining

the nutrient

content

of the diet of grazing animals.

Several researchers

(Bath et al., 1956; Lesperance et al., 1960; Lombard

and Van Schalkwyk,

1963; Marshall

et al., 1967;

Campbell et al., 1968) have compared the chemical

composition

of feeds offered with samples of these

l Published as Journal Series No. 306, Agricultural Experi- ment Station, New Mexico State University, Las Cruces, New Mexico. Cooperative investigations of the Depart- ment of Animal, Range and Wildlife Sciences, New Mexico Agricultural Experiment Station and the Crops Research Division, Agricultural Research Service, U.S.D.A. Par- tially supported by Western Regional Research Project W-94. Received May 17, 1968; accepted for publication November 15, 1968.

^The assistance of Dr. Jack Ruttle in the preparation of the fistulated steers and of Mr. Monte Mauldin in conduct- ing part of the chemical analysis is gratefully acknowledged.

feeds collected through an esophageal fistula. Some

(Edlefsen et al., 1960; Campbell et al., 1968) have

compared

the chemical

composition

of fistula

samples with hand-plucked

grass while others have

compared fistula samples with clipped forage (Bath

et al., 1956; Weir and Torell,

1959; Bredon et al.,

1967).

The purpose of this study was to compare the

chemical composition

of esophageal-fistula

samples

with both feed and hand-plucked

grass samples.

Methods

Experiment

l.-

Each of seven feeds was divided

into four portions.

One portion

was used for

chemical analysis and the others were fed to each

of three esophageal-fistulated

Hereford steers which

had been kept off feed overnight.

Two hundred

and fifty grams of tobosa hay and 451 to 454 g each

of alfalfa hay, ground milo, cottonseed meal, pel-

leted mixture, alfalfa hay mixture and cottonseed

hull mixture were fed to and consumed by each

steer (see Table

1 for ingredient

content of mix-

tures). There were no feed refusals.

Esophageal-

fistula samples were collected in a plastic bag within

a canvas bag positioned below the fistula. All saliva

collected remained as part of the sample. All sam-

ples were weighed and dried at 70 C in a forced-air

oven, ground through a 60-mesh screen in a Wiley

mill and analyzed for dry matter, ash, crude pro-

tein, ether extract, and fiber (A.O.A.C.,

1960).

(10)

TOBOSA

GRASS

155

KAY, B. L. 1963. Effects of dalapon on a

medusahead

TORELL, P. J. 1967. Dowpon-an aid to reseeding me- community. Weeds 3:207-209. dusahead-infested rangeland. Down to Earth 23:6-S. KAY, B. L. 1966. Paraquat for range seeding without cul- TORELL, P. J., L. C. ERICKSEN, AND R. H. HAAS. 1961.

tivation. California Agr. 20:2-4. The medusahead problem in Idaho. Weeds 9: 124-131. KAY, B. L., AND C. M. MCKELL. 1963.

Preemergence

TURNER, R. B., C. E. POULTON, AND W. L. GOULD. 1963.

herbicides as an aid in seeding annual rangelands. Weeds Medusahead-A threat to Oregon rangeland. Special Rep. 11: 260-264. 149, State Univ. Corvallis, Oregon. 37 p.

MAJOR, J., C. M. MCKELL, AND L. J. BERRY. 1960. Im- U. S. DEPARTMENT AGRICULTURE. 1941. Climate and Man. provement of medusahead-infested rangeland. Calif. Expt. Yearbook of Agriculture, U. S. Government Printing Sta. Ser. Leaf. 123. 3 p. Office, Washington, D. C. 1248 p.

Chemical Composition of Tobosa

Grass Collected by Hand-Plucking

and Esophageal-Fistulated Steers’

H. E. KIESLING, A. B. NELSON,

AND C. H. HEBBEL2

Graduate Student and Professor, Department of Animal, Range and Wildlife Sciences, New Mexico State University,

Las Cruces; and Range Scientist, Jornada Experimental Range, Crops Research Div., Agricultural Research

Service, U.S.D.A., Las Cruces.

Highlight

Organic matter recovery of seven feeds collected through esophageal fistulae of three steers averaged 90.4%. Six of the seven fistula samples contained significantly more ash than the feeds offered. Fistula samples of grazed tobosa (Hiluriu muticu (Buckl.) Benth.) contained less A.O.A.C. fiber but more silica, ash, protein, ether extract, detergent fiber and detergent lignin than hand-plucked grass. Except for ash, the differences in chemical composition between hand-plucked and esophageal-fistula samples were appar- ently due to selectivity by the grazing steers. We assume that samples collected by means of an esophageal fistula are more nearly representative of the forage consumed by graz- ing steers than samples hand-plucked by a technician.

Esophageal-fistulated

animals have been proposed

as a means of determining

the nutrient

content

of the diet of grazing animals.

Several researchers

(Bath et al., 1956; Lesperance et al., 1960; Lombard

and Van Schalkwyk,

1963; Marshall

et al., 1967;

Campbell et al., 1968) have compared the chemical

composition

of feeds offered with samples of these

l Published as Journal Series No. 306, Agricultural Experi- ment Station, New Mexico State University, Las Cruces, New Mexico. Cooperative investigations of the Depart- ment of Animal, Range and Wildlife Sciences, New Mexico Agricultural Experiment Station and the Crops Research Division, Agricultural Research Service, U.S.D.A. Par- tially supported by Western Regional Research Project W-94. Received May 17, 1968; accepted for publication November 15, 1968.

^The assistance of Dr. Jack Ruttle in the preparation of the fistulated steers and of Mr. Monte Mauldin in conduct- ing part of the chemical analysis is gratefully acknowledged.

feeds collected through an esophageal fistula. Some

(Edlefsen et al., 1960; Campbell et al., 1968) have

compared

the chemical

composition

of fistula

samples with hand-plucked

grass while others have

compared fistula samples with clipped forage (Bath

et al., 1956; Weir and Torell,

1959; Bredon et al.,

1967).

The purpose of this study was to compare the

chemical composition

of esophageal-fistula

samples

with both feed and hand-plucked

grass samples.

Methods

Experiment

l.-

Each of seven feeds was divided

into four portions.

One portion

was used for

chemical analysis and the others were fed to each

of three esophageal-fistulated

Hereford steers which

had been kept off feed overnight.

Two hundred

and fifty grams of tobosa hay and 451 to 454 g each

of alfalfa hay, ground milo, cottonseed meal, pel-

leted mixture, alfalfa hay mixture and cottonseed

hull mixture were fed to and consumed by each

steer (see Table

1 for ingredient

content of mix-

tures). There were no feed refusals.

Esophageal-

fistula samples were collected in a plastic bag within

a canvas bag positioned below the fistula. All saliva

collected remained as part of the sample. All sam-

ples were weighed and dried at 70 C in a forced-air

oven, ground through a 60-mesh screen in a Wiley

mill and analyzed for dry matter, ash, crude pro-

tein, ether extract, and fiber (A.O.A.C.,

1960).

(11)

156 KIESLING

ET AL.

Table 1. Time required for feed consumption and organic Table 2. Chemical composition of feeds and esophageal matter recovery through the esophageal fistula.1 fistula samples.

Organic Matter Consumption

Total min G/min

Alfalfa hay 12 32 Tobosa hay 12 17 Pellets” 8 47 Alfalfa hay

mixture4 7 56 Cottonseed hull

mixture5 6 65 Ground milo 7 57 Cottonseed

meal 9 45 Average

IAverage of three steers. 2Standard error.

Grams Recovery consumed % S.E.”

381.3 88.0 1.22 205.6 92.0 0.72 378.9 95.2 0.61

388.2 87.5 1.91

387.9 91.7 1.04 397.0 90.4 2.95

403.9 88.2 4.58 90.4

Percent composition Fistula Nutrient and feed Feed Mean1 SE.

Ash, % of dry matter Alfalfa hay Tobosa hay Alfalfa-milo pellets 20% alfalfa hay mixture 20% cottonseed hull mixture Ground milo

Cottonseed meal

11.1”” 14.2 0.17

12.7”” 15.6 0.16

10.9”” 12.6 0.10

5.0” 6.1 0.22

5.2* 6.2 0.14

1.5” 2.6 0.19

7.1 8.3 0.30

3Alfalfa hay, 70%; milo, 25%; molasses, 5%.

4Steam rolled milo, 74.5%; ground alfalfa hay, 20.0%; molasses, 5.0%; salt, 0.5%.

6Steam rolled mile, 66.9%; cottonseed hulls, 20.0%; cottonseed meal, 7.0%; molasses, 5.0%; ground limestone, 0.6%; salt, 0.5%.

Protein, % of organic matter Alfalfa hay

Tobosa hay Alfalfa-milo pellets 20% alfalfa hay mixture 20% cottonseed hull mixture Ground milo

Cottonseed meal

22.5 23.6 0.48

12.2 12.5 0.15

17.1 17.4 0.10

12.4 12.2 0.01

12.5 12.4 0.24

7.9” 8.2 0.05

48.1 47.4 0.20 ter

ings of three consecutive days. Three pastures were

sampled on the first day, two pastures on the second

day and two pastures on the third day. The pas-

tures were nearly pure stands of tobosa and the

steers were restricted

to areas where tobosa was

the only forage. The hand-plucked

samples were

obtained by a technician breaking off, or plucking,

parts of plants similar

to those observed

being

consumed by a steer grazing for about 15 minutes.

The

hand-plucked

samples were ground and

analyzed for dry matter, ash, silica, crude protein,

ether extract, and fiber according to the A.O.A.C.

(1960) methods and for acid-detergent

fiber and

lignin by the Van Soest (1963) method. The fistula

samples were frozen and a representative

sample

was taken from each collection by sawing out cross

sections.

Part of each sample was dried at 70 C in

a forced-air

oven, ground and analyzed for dry

matter, ash, silica, crude protein, ether extract, and

A.O.A.C. fiber. Wet fistula samples were used for

the acid-detergent

fiber and lignin determinations.

The Student’s

t

was used as a test of significance

for the chemical

composition

between

feed and

fistula samples. Analysis of variance and Duncan’s

multiple range tests were used for the hand-plucked

and fistula comparisons (Steel and Torrie, 1960).

Ether extract, “/o of organic mat Alfalfa hay

Cottonseed meal

1.2 1.0 0.06

1.2 1.0 0.00

1.5”” 1.0 0.02

2.8”* 2.4 0.02

2.8”” 2.3 0.04

3.0** 2.1 0.03

4.0 3.8 0.12 Fiber, “/o of organic matter

Alfalfa hay Tobosa hay Alfalfa-milo pellets 20% alfalfa hay mixture 20% cottonseed hull mixture Ground milo

Cottonseed meal

30.5” 32.4 0.21

36.4” 35.2 0.26

24.3 25.5 0.55

6.1 6.4 0.16

10.3 10.5 0.42

2.8 3.2 0.26

10.4 11.7 0.19 Nitrogen-free extract,

% of organic matter Alfalfa hay

Cottonseed meal

45.8 43.0 0.75 50.2 51.2 0.42 57.2 56.1 0.51 78.7 79.0 0.28 74.3 74.8 0.30 86.3 86.5 0.24 37.5 37.1 0.46

l Average of three steers.

+ P < .05 for feed vs. fistula samples. +* P < .Ol for feed vs. fistula samples.

Results and Discussion

Experiment 1

The feeds offered were eaten in a relatively short

period (Table l), and no difficulty was encountered

in collecting

the samples through the fistula. The

pellets, concentrates

and high-concentrate

mixtures

were consumed at a much faster rate than the hays.

Tobosa

was consumed

at the slowest rate with

alfalfa hay intermediate

between tobosa hay and

the other feeds.

The organic matter recoveries

varied from 87.5 to 95.2y0 and were similar to those

reported by Campbell et al. (1968) for concentrate-

type feeds but considerably

higher than those for

clipped grasses.

(12)

TOBOSA

GRASS

157 content was significantly

higher in the fistula sam-

ples for all feeds except cottonseed

meal.

This

increased

ash was apparently

due to saliva con-

tamination,

and is in agreement

with the results

reported by other researchers

including

Campbell

et al. (1968), Hoehne et al. (1967) and Lesperance

et al. (1960).

Because of increased ash, McManus

(1961) and Grimes

et al. (1965) suggested that

chemical composition

be expressed on an ash-free

or organic matter basis.

Only in the case of ground milo was the protein

content significantly

higher in the fistula samples

than in the feed samples.

Since saliva dry matter

contains about 4.51 y0 protein (Bailey and Balch,

196 I), large amounts of saliva collected

with a

sample could increase the protein content.

HOW-

ever, Bath et al. (1956),

Edlefsen

et al. (1960),

Lesperance et al. (1960) and Campbell et al. (1968)

have reported no increase of protein in esophageal

fistula samples.

Hoehne et al. (1967) found that

fistula samples of prairie sandreed and blue grama,

which were squeezed to remove excess saliva, were

lower in protein than feed samples, and that non-

squeezed fistula samples of prairie sandreed were

significantly

higher than squeezed samples.

The ether extract content of the three mixed

feeds and ground milo was significantly

higher in

the feed than in the fistula samples.

Bath et al.

(1956), Campbell

et al. (1968), Lesperance

et al.

(1960) and Lombard

and Van Schalkwyk

(1963)

have reported

no significant

difference

in ether

extract for similar feeds.

Fiber content

of the fistula samples was sig-

nificantly

higher

for alfalfa hay and lower for

tobosa hay than the feed offered. Lesperance

et al.

(1960)

reported

an increase

of fiber in fistula

samples while Bath et al. (1956), Lombard and Van

Schalkwyk

(1963) and Campbell

et al. (1968) re-

ported no significant change in fiber.

None of the differences

in nitrogen-free

extract

was significant.

This agrees with the findings of

Bath et al. (1956) for alfalfa hay, and with Camp-

bell et al. (1968) f or concentrate-type

feeds. With

their clipped grass, however, the fistula samples

were lower in nitrogen-free

extract.

Lombard and

Van Schalkwyk (1963) also reported a decrease in

nitrogen-free

extract

of fistula samples for hays

and green feeds.

Experiment 2

Chemical composition of hand-plucked

grass and

esophageal-fistula

samples is given in Table

3. The fistula samples contained

significantly

more

ash and protein, but less A.O.A.C. fiber, than hand-

plucked grasses. This agrees with the results of

most researchers

and apparently

reflects the ash

added by saliva and selection of a higher quality

diet by grazing steers. Weir and Tore11 (1959) re-

ported

that sheep consistently

selected

forage

higher in protein and lower in fiber than hand

clipped grasses. Bredon et al. (1967) stated that

fistula samples of tropical forage contained

more

protein and less fiber than clipped forage.

Fistula samples also contained more silica, ether

extract,

detergent

fiber,

and detergent

lignin.

Edlefsen et al. (1960), however, found that fistula

samples were significantly

lower in lignin;

and

Campbell et al. (1968) reported that fistula samples

of bermudagrass

were lower in ether extract than

hand-plucked grass.

Acid-detergent

fiber

was significantly

higher

than 14.0.A.C.

fiber for both hand-plucked

and

fistula samples in all pastures. Pasture differences

were also significant

for both methods.

Since de-

tergent fiber was determined on wet fistula samples

which were not ground and, therefore,

contained

many large particles of forage, incomplete digestion

during refluxing

could have resulted

in higher

values for the detergent fiber.

However, this was

not true for hand-plucked

samples, since the prep-

aration of the samples was the same for both fiber

determinations.

Pasture differences

were signifi-

cant for all constituents

except ash. The forage

sprayed with molasses plus urea was highest in pro-

tein and lowest in nitrogen-free

extract, but that

sprayed with molasses only contained the least pro-

tein and most nitrogen-free

extract. These pasture

samples also contained

significantly

less A.O.A.C.

fiber and detergent

fiber.

Samples of grass from

pasture 3 (fed tobosa hay) contained

more lignin

than samples from the other pastures.

The pasture x method interaction

was significant

for ash, protein, and detergent fiber. These inter-

actions were probably

due to the pasture treat-

ments.

Pasture differences

within methods were

considerable

and are shown in Table 3. For ash

there was a significant difference between methods

in all pastures. The fistula samples from the pas-

ture in which cottonseed meal pellets were fed and

the control pasture contained more protein, while

fistula

samples from the pasture sprayed with

molasses plus urea contained

less protein

than

hand-plucked

grass.

Conclusions

Organic matter recovery of seven feeds collected

through esophageal fistulae of three steers averaged

90.4%.

The

fistula

samples

were significantly

higher in ash for all feeds except cottonseed meal,

in protein for ground milo, and in A.O.A.C. fiber

for alfalfa hay; but they were lower in ether extract

for a pelleted mixture, alfalfa hay mixture, cotton-

seed hulls mixture,

and ground

milo and in

A.O.A.C. fiber for tobosa hay. Chemical composi-

tion of feed samples collected through an esopha-

geal fistula should be expressed on an organic

matter basis.

(13)

158 KIESLING

ET AL.

Table 3. Chemical composition (%) of hand-plucked grass aI-4 esophageal-fistula samples.1

Composition of organic matter

Pasture Method Silica Ash Protein extract Ether A.O.A.C. fiber extract N-free Detergent fiber Detergent lignin

1 Fertilized 2 Cottonseed meal pellets 3 Tobosa hay

4 Burned 5 Molasses 6 Molasses

and urea

7

Control

Mean

Plucked 7.23

Fistula 7.66

Difference 0.43

Mean 7.44bc

Plucked Fistula Difference Mean

6.06 2.15j

8.53 6.25~~

2.47 4.10”

7.3Obc 4.20 Plucked Fistula Difference Mean 1 9.74

IO.08

0.34 9.91a Plucked Fistula Difference Mean

8.83 2.14j

9.75 5.87~

0.92 3.73”

9.20ab 4.00 Plucked

Fistula Difference Mean

7.48 3.62’

9.72 6.34~~

2.24 2.72”

8.60~“~ 4.98 Plucked

5.83 3.62’

8.43 6.08~~

2.60 2.46”

7.13bc 4.85 Plucked

6.33 2.8Oij

7.01 6.78~

0.68 3.98”

6.67~ 4.79 Plucked

Fistula Difference

7.36 2.79 4.70

8.71 6.13 5.68

1.35”” 3.34”” 0.98”” 2.46j 5.51y 3.05” 4.08 2.77j 5.9oy 3.13” 4.22 5.06j 6.26~~ 1.20 5.66” 3.64jkl 5.58~ 1.94” 4.61cd 4.76jk 6.36~~’ 1.60” 5.56bc 3.33k’ 4.87~2 1.54” 4.10d 2.29kl 3.792 1.50 3.04e 10.06’ 7.51x 2.55” 8.78a 3.76jkl 5.43y 1.69” 4.58d

1.06 40.42 1.01 38.21

0.05 2.21

1.04d 39.31n

53.46 58.26j 8.59

54.52 59.98s 5.98

1.06 1.72 0.39

53.99b 59.1 led 8.79”

0.99 40.62 1.27 39.04

0.28 1.58

1.13bcd 39.838

54.76 57.08j 8.80

54.12 64.92x 9.38

0.64 7.84” 0.58

54.44b 6 1 .OO”c 9.09b 0.94 41.38

1.20 37.98

0.26 3.40

1.07” 39.68a

52.92 62.76’ 10.60

54.45 67.77~ 10.42

1.53 5.01* 0.18

53.68b 65.27a 10.51a 1.13 40.80

1.71 37.65

0.58 3.15

1.42a 39.23a

54.74 60.22ij 8.62

55.77 67.70~ 9.64

1.03 7.48” 1.02

55.26” 63.96a” 9.13b 0.98 35.28

1.55 34.06

0.57 1.22

1.27abc 34.67b

61.45 53.13k 7.54

60.60 58.28~ 9.21

0.85 5.15* 1.67

61.02a 55.70e 8.38b

0.90 36.29 1.31 36.85

0.41 0.56

l.lOcd 36.57”

52.75 53.12k 7.86

54.33 60.92s 9.72

1.58 7.80” 1.86

53.54b 57.02de 8.79” 1.16 41.88

1.44 38.17

0.28 3.71

1.30ab 40.02a

53.22 58.9Oj 8.04

55.30 59.91s 9.88

2.08 1.01 1.84

54.26b 59.40cd 8.96”

1.02 39.52 54.76

1.36 37.42 55.58

0.34”” 2.10”” 0.82

57.64 8.58

62.78 9.60

5.14** 1.02””

1 Average of three samples for each method.

abcde Pasture means within the same column with different letter superscripts are significantly different (P < .05).

IJkl Pasture means within hand plucked samples in the same column with different letter superscripts are significantly different (P < .05).

XV Pasture means within fistula samples in the same column with different letter superscripts are significantly different (P < .05). * P < .05 for method differences.

#+ P < .Ol for method differences.

nificantly

more silica, ash, protein, ether extract,

LITERATURE

CITED

detergent

fiber,

and detergent

lignin,

but less

A.O.A.C. fiber than hand-plucked samples obtained

A.O.A.C. 1960. Official Methods of Analysis

from seven pastures of tobosa. Pasture differences

_.

_{.^_}

_{__}

₁

Association of Official Agricultural Chemists. _{ton, D.C.}

(9th ed.). Washing-

were significant

ior all constituents

except ash and

the pasture x method interaction

was significant for

ash and protein.

Except for ash, the differences

in chemical com-

position

between

hand-plucked

and esophageal-

fistula samples were apparently due to selectivity by

the grazing steers. We assume, therefore, that sam-

ples collected

by means of an esophageal

fistula

are more nearly representative

of the forage con-

sumed by grazing steers than samples hand-plucked

by a technician.

BAILEY, C. B., AND C. C. BALCH. 1961. Salivary secretion and its relation to feeding in cattle. Part I: The composi-

tion and rate

of secretion to parotid saliva in a small

steer.

Brit. J. Nutr. 15:371-382.

BATH, D. L., W. C. WEIR, AND D. T. TORELL. 1956.

The use of the esophageal fistula for the determination of composition and digestibility of pasture forage by sheep. J. Anim. Sci. 15:1166-1171.

BREDON, R. M., D. T. TORELL, AND B. MARSHALL. 1967.

(14)

CHAPARRAL

MANIPULATION

159

CA~IPBELL, C. M., K. S. ENG, JR., A. B. NELSON, AND L. S. MARSHALL, B., D. T. TORELL, AND R. M. BREDON. 1967.

POPE. 1968. Use of the esophageal fistula in diet sam-

pling with beef cattle. J. Anim. Sci. 27:231-233. Comparison of tropical forages of known composition with EDLEFSEN, J. L., C. W. COOK, AND J. T. BLAKE. 1960. Nu- samples of these forages collected by esophageal fistulated

trient content of diet as determined by hand plucked animals. J. Range Manage. 2O:3 10-313.

and esophageal fistula samples. J. Anim. Sci. 19:560- MCMANUS, W. R. 1961. Properties of roughage feed-

567. stuffs collected from oesophageal fistulas. Aust. J. Exp.

GRIMES, R. C., B. R. WATKINS, AND P. F. MAY. 1965. The Agr. Anim. Husb. 1: 159-163.

botanical and chemical analysis of herbage samples ob- STEEL, R. G- D-9 AND

J- He TORRIE. 1960.

Principles and tained from sheep fitted with oesophageal fistulae. J. Procedures of Statistics. McGraw-Hill Book Company,

Brit. Grassl. Sot. 20: 168-173. Inc., New York.

HOEHNE, 0. E., D. C. CLANTON, AND C. L. STREETER. 1967. TORELL, D. T.

Chemical changes in esophageal fistula samples caused 1954. An esophageal fistula for animal by salivary contamination and sample preparation. J. nutrition studies. J. Anim. Sci. 13:878-884.

Anim. Sci. 26: 628-63 1. VAN SOEST, P. J. 1963. Use of detergents in the analysis

LESPERANCE, A. L., V. R. BOHMAN, AND D. M. MARBLE. of fibrous feeds. II. A rapid method for the determination 1960. Development of techniques for evaluating grazed of fiber and lignin. J. Ass. Offici. Agr. Chem. 46:829-835. forage. J. Dairy Sci. 43:682-689. WEIR, W. C., AND D. T. TORELL. 1959. Selective grazing LOMBARD, P. E., AND A. VAN SCHALK~YK. 1963. Verande- by sheep as shown by a comparison of the chemical com-

ringe in samestelling van voere tydens monsterneming position of range and pasture forage obtained by hand met behulp van’n slukdermfistel. S. Afr. J. Agr. Sci. 6:

205-211. J. Anim. Sci. 18:641-649. clipping and that collected by esophageal-fistulated sheep.

9 Chaparral Manipulation Affects

Soil Moisture Depletion Patterns

and Seedling Establishment

1

CYRUS M. MCKELL, J. R. GOODIN, AND CAMERON DUNCAN2

Professor of Agronomy, Assistant Professor, and Laboratory Technician I, Agronomy Department,

University of California, Riverside.

Highlight

Soil moisture depletion in the first 3 ft of soil under chaparral reaches high levels of stress each dry season. Hand clearing the chaparral or spraying with a brush- killer herbicide decreases soil moisture stress and increases the chance for successful perennial grass establishment.

Approximately

ten million

acres of California

land supports

a vegetation

cover of chaparral.

These lands are increasingly

important

as water-

sheds, grazing lands, recreation

areas, homesites,

and for their esthetic

value.

To increase

land

values for these uses and yet to reduce fire and

erosion hazards of areas not subject to soil slippage,

conversion of certain chaparral areas from brush to

perennial

grass has been recommended.

The re-

1 Research supp orted by funds from Grant W121, Water Re- sources Center, University of California. Received *June 24, 1968; accepted for publication October 28, 1968.

2Grateful acknowledgment is given to Mr. and Mrs. Bud Pepper in San Diego County and to Oak Glen Investments, Inc., in Long Beach for the use of their property as sites for these studies.