TEXAS AGRICULTURAL EXPERIMENT STATION {x
C. H. McDOWELL, Acting Director

College Station, Texas

BULLETIN NO. 669 MAY, 1945

THE CHEMICAL COMPOSITION OF GRASSES
OF NORTHWEST TEXAS AS RELATED TO SOILS AND
TO REQUIREMENTS FOR RANGE CATTLE

J. F. Fudge and G. S. Fraps

Division of Chemistry

* = I f} ‘L? '71 1m

unéd

 

AGRICULTURAL AND MECHANICAL COLLEGE OF TEXAS
GIBB GILCHRIST, President

 

E63-545-4M-L1 80

[Blank Page in Original Bulletin]

Young grasses from ranges in Northwest Texas usually contain suf-
ficient phosphoric acid for range cattle, but the more mature grasses
are frequently deficient in phosphoric acid and are sometimes deficient
in protein. Practically all of the grasses contain suflicient lime for
range cattle.

Chemical analyses were made of 1,916 samples of different species
of grasses at various stages of growth from more than 100 locations
in Northwest Texas. The chemical composition of the various grasses
according to species, stage of maturity, and location are presented.
Protein and phosphoric. acid decreased markedly with advancing
maturity; crude fiber and nitrogen-free extract usually increased
slightly; changes in limeiwere small and irregular. As the plants be-
came older, there was a marked increase in the proportion of samples
which were deficient in protein and phosphoric acid for range cattle.
Protein was sufliciently high for range cattle in over 99% of the young
grasses, but was deficient in 73% of the mature grasses. Phosphoric
acid was deficient in 34% of the samples of young grass and in 91%
of those of mature grasses. Lime was not deficient in any samples,
and was good in 63% and high in 29% of the samples. In general,
protein, phosphoric acid, and nitrogen-free extract were higher, and
lime and crude fiber were lower, in short grasses than in tall grasses.

There was no relation between total nitrogen in the soils of this
area and the percentage of protein in the grasses. Soils which con-
tained relatively high percentages of active phosphoric acid and lime
produced grasses which contained higher percentage of phosphoric
acid and lime than grasses produced on soils which contained lower
amounts of these constituents. This relation between composition of
the soils and the composition of the grasses was more pronounced in
the young grasses than in grasses at the intermediate or mature stages
of growth. Other factors besides the composition of the soil affected the
percentages of protein, phosphoric acid, and lime in the grasses.

CONTENTS

Page
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 5

Description of the region . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

Common and botanical names of the plants . . . . . . . . . . . . . . . . . . . . . . . . .. 9

Samples used . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

Protein, phosphoric acid, and lime in the grasses . . . . . . . . . . . . . . . . . . . . 11

Distribution of samples according to grades of constituents . . . . . . . . . . .. 20

Average feed constituents in the grasses . . . . . . . . . . . . . . . . . . . . . . . . . .. 29

The chemical composition of the soils . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35

Relation of the soil series to the composition of the grasses . . . . . . . . . . . . 37

Composition of grasses on different soil series at different times of year. . 42

Relation to quality of range land . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45
Relation of the chemical composition of the soils to the composition

of the grasses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 46
Acknowledgment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 54
Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54
Literature Cited . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 56

THE CHEMICAL COMPOSITION OF FORAGE GRASSES
FROM NORTHWEST TEXAS, AS RELATED TO SOILS
AND TO REQUIREMENTS FOR RANGE CATTLE

J. F. Fudge, Chemist, and G. S. Fraps, Chief, Division of Chemistry Q

This bulletin is the third in a series dealing With the chemical composi-
tion of forage grasses from ranges in Texas, particularly as related to the
chemical composition of the soils on which they were grown and to their
adequacy as feed for range cattle. Bulletins presenting the results of simi-
lar work in the East Texas Timber Country (7) and the Gulf Coast
Prairie (11) have already been published. This bulletin presents the re-
sults of the study in Northwest Texas.

A number of diseases and other evidences of malnutrition in animals
are attributed to a deficiency of various chemical constituents of the
forage grasses which the animals consume. The principal deficiency found
thus far in Texas grasses has been phosphoric acid; however, many mature
grasses are also deficient in protein. The symptons of a serious deficiency
of phosphoric acid include stiffness of the legs, swollen ‘joints, emaciation,
a poor unthrifty condition, abnormal development of the bones, and a
low concentration of phosphorus in the blood (2). The term usually used in
Texas to describe these- conditions in range cattle is “creeps”. Creepy cattle
have been reported from many sections of Texas, but particularly along
the Gulf Coast and in the East Texas Timber Country. Cattle suffering
from creeps develop a depraved appetite, evidenced by the chewing of
bones, wood, iron, and other substances. The chewing of bones may result
in infections leading to “1oin disease” (13). A deficiency of calcium may
also cause disturbances in the health of animals, but very few Texas
grasses have been found deficient in calcium for range animals. A 10W
protein content is often associated with a low phosphoric acid content of
forage plants (6, 10, 11), so that forage which is deficient in phosphoric
acid is often deficient in protein, especially during the fall and winter-
Disturbances in nutrition due to a deficiency of protein in the forage may
accompany and accentuate those due to a deficiency of phosphoric acid.
Deficiencies of cobalt, copper, and other elements have been found else-
where, but no evidence of such deficiences has yet been found in Texas (2).

Work done so far in Texas has shown that many forage grasses from
the humid section of the state are deficient in protein, a large number of
them are deficient in phosphoric acid, particularly at later stages of
growth, while very few of them are deficient in calcium (7, 11), that
many range soils are deficient in active phosphoric acid (6), and that
there is a relation between the percentage of phosp-horic acid in the
forage and the amount of phosphoric acid in the soils, whether naturally
(10, 11) or as the result of the application of superphosphate (2, 8, 9)-
This bulletin presents the results of similar studies in the northwestern
part of the state.

6 BULLETIN NO. 669, TEXAS AGRICULTURAL EXPERIMENT STATION

 
  
  
 

u. GronQProirie

2.‘ west Cross ‘fimbers
3, Reddish Prairies
4_"RO|llng Plains

5, High Plains

ARELA COVERED”

  

scAu-smfl
i=1‘
0 2o 40 Q

Figure 1. Area covered in this study

Section 1: Grand Prairie. Bluestem, grama, and buffalo grasses.

Section 2: West Cross Timbers. Oak trees, bluestem and other coarse grasses.

 
   

Section 3: Reddish Prairies. Buifalo, grama, and bluestem grasses.

Section 4: Rolling Plains. Buffalo and grama grasses on heavy soils; bluestemg and
other coarse grasses on sandy soils.

Section 5: High Plains. Bufialo and grama grasses on heavy soils; blustems and other
coarse grasses on sandy soils.

‘I

THE CHEMICAL COMPOSITION OF GRASSES FOR RANGE CATTLE 7

Description of the Region

The area of Texas included in the study reported in this bulletin is
roughly bounded by highways joining Waco, Fort Worth, Wichita Falls,
Amarillo, Lubbock, Abilene and Brownwood, and is shown in Figure 1.
This area includes all or most of four major geographical divisions of the
state: the Grand Prairie, the West Gross Timbers, the Rolling Plains,
and the High Plains. The characteristics of the several divisions cover a
wide range in climate, soils, and vegetative cover. These divisions have
been described by Carter (4), but certain general features are pertinent to
the work discussed in this bulletin.

The Grand Prairie, comprising about 7,000,000 acres in north central

Texas, occupies a high, rolling to hilly, deeply dissected limestone area.
Some fairly smooth to gently rolling lands occur, particularly north of

 the Brazos River. The principal soils are clay loams and clays of the

Denton and San Saba series. The black or very dark brown San Saba soils
occupy undulating to gently rolling areas. The brown Denton soils occur on
gently rolling to very rolling or hilly areas. In rough country, where most
of the normal surface soil has been eroded, soils of the Brackett series may
be gray or nearly white from limestone. Brown to reddish soils of the
Crawford series occur throughout the region. Most of the range land is
on shallow soils, and there are many areas of rough, stony land. All of
the soils are underlain by limestone, and most of the range soils are
calcareous. These soils are usually fair to good in total nitrogen, fair in
total phosphoric acid, deficient to very deficient in active phosphoric acid,
and high in active lime (6).

Most of the forage on the rolling to hilly sections of the Grand Prairie
is provided by various bluestem and grama grasses. Of particular impor-
tance are little bluestem (Andropogon scopcw-izis) and sideoats, Texas, and
hairy grama grasses (Bouteloua curfipendula, B. rigidiseta, and B.
hirsuta). Alkali sacaton (SIJOTObOZQIS (iiroides) and Johnson grass (Sor-
ghum halepeozsc) are of considerable importance on some ranges. Buffalo
grass (Buchloe dacfyloides) is often very important on level to gently
rolling upland soils and on terrace and bo-ttomland soils. White triodia
(Triodia- albescens) and vine mesquite (Panicmn obtusum) may provide
considerable forage along stream bottoms, where moisture conditions are
favorable to their growth.

The West Cross Timbers occupies about 7,000,000 acres in north central
Texas just west of the Grand Prairie. Range land is confined principally
to timbered or hilly areas; most of the prairie land is under cultivation.
The surface of the range lands varies from gently rolling to very rolling
or hilly, with many rough, stony areas. The dominant soils are fine sandy
loams of the brownish-gray Windthorst series and the gray Stephenville
and Nimrod series. Most of these soils are deficient to very deficient in
total nitrogen and total phosphoric acid, very deficient in active phos-
phoric acid, and fair to deficient in acid-soluble lime. The forage is com-
prised principally of coarse grasses, of which little bluestem is the most

 

8 BULLETIN NO. 669, TEXAS AGRICULTURAL EXPERIMENT STATION

important, although other Andmpogon species and love grasses (Eragrostis
spp.), panic grasses (Panicum spp.), and grama grasses may contribute
a considerable part of the total forage on many areas. Buffalo grass,
various crowfoot grasses (Chloris spp.), and, toward the southern end
of the region, curly mesquite grass (Hilaria Belangeri), are important on
the prairie areas.

The Rolling Plains covers about 24,500,000 acres West of the West Cross
Timbers, and is a rolling area greatly dissected by streams and severely
eroded in many places. Ranching is practically the only type of agriculture
in some sections, but is of relatively minor importance in other areas, par-
ticularly in the northern part. The soils differ greatly from place to place
in a number of important characterics, such as color, depth, and chemical
composition. The brown to dark-brown Abilene soils are by far the most
important of the dark-colored soils, although some small areas of the
very dark-brown Roscoe and the brown Foard soils occur. These soils are
good to fair in total nitrogen, fair in total phosphoric acid, deficient to
very deficient in active phosphoric acid, and good to high in acid-soluble
lime. Extensive areas of red and brownish-red soils are of the Vernon
and Miles series, most of which are fair in total nitrogen, fair to de-
ficient in total phosphoric acid, deficient to very deficient in active phos-
phoric acid, and fair to good in acid-soluble lime (6). Buffalo grass is
considerably more important than on sections to the east. Forage on many
ranges on the more level areas, particularly along the Red River, con-
sists almost entirely of buffalo grass. Curly mesquite becomes of increasing
importance farther south, and may form -the bulk of the forage on some
of these ranges. Forage on the more hilly parts of the region may be
made up very largely of grama grasses, particularly hairy and sideoats
gramas. Various Triod/ia and Aristida species often provide considerable
portions of the grasses, but many of these species are not usually
consumed by the cattle until most of the other species have been eaten.
On some of the sandier areas and in areas of “shinnery” oak, the forage
consists almost entirely of tall grasses, of which little bluestem is the
most important. Tobosa grass (Hilaria mutica) is practically the only
species of grass on some areas of rather fiat country, known locally as
“tobosa flats”. Sand dropseed (Sporobolus crytandrus) is of importance
on sandy soils, where overgrazing has killed out a large part of the more
desirable grasses; its relative importance is increasing rapidly.

The High Plains west of the Rolling Plain-s comprise about 21,000,000
acres; the surface is smooth but with a gradual slope to the southeast.
The noncalcareous, dark-brown Pullman, the black Richfield, and the cal-
careous, light-brown Potter soils are the principal dark-colored soils.
Randall clay occurs on many lake beds, locally termed “playas”, through-
out the region. The soils are fair in total nitrogen, fair to deficient in
total and active phosphoric acid, and good to high in acid-soluble lime.
The red Amarillo soils are fair to deficient in total nitrogen and total phos-
phoric acid, deficient to very deficient in active phosphoric acid, and fair
to good in acid-soluble lime. The forage on large areas of the Pullman

THE CHEMICAL COMPOSITION OF GRASSES FOR RANGE CATTLE 9

and Richfield soils consists almost entirely of a mixture of buffalo grass
and blue grama (Bouteloua gracilis), with small amounts of black grama
(Boztteloua criopoda) 0n some pastures. Buffalo grass is often the only
grass found on the Randall soils, although small amounts of western wheat
grass (Agropyrmz Smithii) and wild rye (Elymus canadevzsis) are occa~
sionally found. Hairy, blue, and sideoats grama grasses are the most im-
portant grasses on the Amarillo soils. Bufialo grass is of importance on
some of the heavier Amarillo soils, but does not occur on many of the
sandy soils, where moisture conditions preclude i-ts growth. Sand dropseed
is increasing rapidly in importance on these soils.

Small areas of alluvial or bottomland soils occur throughout the entire
section of the state covered by this bulletin. These soils contain higher
quantities of the various chemical constituents than the corresponding
upland soils. While these soils cover only a small part of the area, they
contribute an important amount of grazing as a valuable addition to the
thin grass cover of the rolling, eroded upland, especially since these alluvial
soils, where not heavily timbered, have dominantly the more valuable
short grasses.

Common and Botanical Names of the Plants

The common names of many of the species sampled, arranged in alpha-
betical order, together with the botanical names as given by Cory and
Parks (5), are shown in Table 1. Those classified as important tall (t)
or short (s) grasses are so designated in the tables. In nearly all cases
these are the same names given by Hitchcock (12). Considerable confusion
exists throughout the area with respect to the common names of several of
the species. Both feather sage grass and silver beardgrass are names
commonly used for Andropogon saccharoides. Panicum obtusum is com-
monly called grapevine mesquite, vine mesquite, or wire grass. Wire grass
is also used sometimes for Bermuda g-rass, Cynodon dactylon. Perhaps
the most widespread confusion exists with respect to buffalo grass, Batchiloe
dactyloides, and curly mesquite, Hilaria Belanger/i, two very important
and widespread grasses. Both names are used for the same grass and the
wrong name is sometimes used for either grass, although "the most com--
mon mistake is in calling buffalo grass curly mesquite, or simply mesquite
grass. Many other instances could be mentioned, but those given are suf-
ficient to show the desirability of a more widely disseminated knowledge
concerning the identity of the more important species of range grasses.

Samples Used

A total of 1,916 samples of forage grasses were collected in 1938, 1939,
and 1940 from over 100 locations in Bosque, Coleman, Dickens, Donley,
Eastland, Garza, Jones, Lubbock, McLennan, Montague, Palo Pinto, Potter,
Randall, Scurry, Somervell, Tarrant, Taylor, Wichita, and Wise counties.
Descriptions of locations from which forage samples were taken were
carefully recorded so that additional samples of forage and of soil could

 

10 BULLETIN NO. 669, TEXAS AGRICULTURAL EXPERIMENT STATION

Table 1.

Common and botanical names of species sampled

Common name

Botanical name

Arrowfeather grass . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Bear grass . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Beard grass . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Beard grass, Halls (t) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Beard grass, plains . . . . . . . . . .- . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Beard grass, silver (t) _ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Beard grass, silver . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Beard grass, silvery (t) . . . . . . . . . . . . _ . . . . . . . . . . . . . . . . . . . . . . . .

Beard grass, yellow/x’ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Bermuda grass (s) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Bluestem . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Bluestem, big (t) . . . . , . . . . . . . . . . . . . . . . . . . . . . . . r . . . . . . . . . . . . .

Bluestem, little (t) .l/. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

.Bl0waway grass . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Buffalo grass (s). fl . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Colorado grass . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Cottontop . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Crowfoot grass , . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Dropseed grass . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Dropseed grass, sand (s) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Finger grass _ _ , . . . . . . . . . . . . . . . . ; . . . . . . . . . . . . . . . . . . . . . . . . . .

Finger grass, black _ _ _ _ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Fin er grass, feather . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Gal eta grass . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Grama grass . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Grama grass, black . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Grama grass, blne (s) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Grama grass, hairy (s) , , . . . . . . . . . . . .' . . . . . . . . . . . . . . . . . . . . . . .

Grama grass, sideoats (s) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Grama grass, Texas (s) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Indian grass (t) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Johnson grass. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Love grass,,_.._ . . . . , . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..

Love grass, plains . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Love grass, weeping . . . . . . . . 4 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Mesquite grass, curly (s) ,  . . , . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Mesquite grass, grapevine (t) . . . . . . , . . . . . . . . . . . . . . . . . . . . . . . .

Mesquite grass, vine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Muhly grass . . . . . . . . . , . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Needle gras . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Needle grass, Texas _ _ _ . . . . . . _ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Needle and thgead grass . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Rescue grass . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Sacaton . . . . . ._ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Sacaton, alkali (s) _ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Switch grass . . . . . . . , . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Texas millet . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Three awn grass . . . . . . . . . . . . . . . . . . . . _ . . . . . . . . . . . . . . . . . . . . . .

Three awn grass, Fendler’s . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Three awn grass, purple . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Three awn grass, red . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Tqbosa grass (t) , , _ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Triodia grass . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Triodia grass, shortleaf . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Triodia grass, slim . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Triodia grass, Teicas . , . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Triodia grass, white . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Tumble grass _ _ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . = . . .

Turkeyfoot grass (t) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Aristida purpurascens
Andropogon barbinodis
Andropogon species
Andropogon Hallii
Andropogon barbinodis
Andropogon saccharoides
Andropogon barbinodis
Andropogon Iernarius
Andropogon ischaemum
Cynodon daciylon
Agropyron Smithii
Andropogon provincialis
Andropogon scoparius
Muhlenbergia pungens
Buchloe dactyloides
Panicum lexanum
Trichachne californica
Ioris species
Eragrostis Beyrichi i
Eragrostis cryplandrus
loris species
Chloris cucullala
Chloris virgata
ilaria Jamesii

Bouleloua species
Bouteloua eriopoda
Bouteloua gracilis
Bouieloua hirsuta
Boutelouu curti endula
Boutelouu rigi iseta
Sorghaslrum nutans
Sorghum halepense
Eragrostis species
Eragroslis intermedia
Eragrosiis curvula
Hilaria Belangeri
Panicum obtusum
Panicum obtusum
Muhlenbergia species
Aristida species,

Stipa leucotricha

Siipa conzata

Bromus catharticus
Sporobolus Wrightii
Sporobolus airoides
Panicum virgatum
Panicum lexanum
Arisiida species
Arisiida Fendleriana
Aristida purpurea
Aristida longiseta
Hilaria mutica

Triodia species
Triodia grandiflora
Triodia mutica

Triodia texana

Triodia albescens
Schedonnardus paniculalus
Andropogon Hallii

t or s-Important tall (t) or short (s) grasses discussed as groups in text.

be taken later from the same location. All of the important species of
forage on each location were sampled. Individual samples consisted of the
current year’s growth of a single species. So far as possible, samples
designated as young were those of early growth, regardless of the sea-
son of the year; as medium when the grass had passed the early stage and
before the appearance of seed stalks; as bloom when most of the plants

THE CHEMICAL COMPOSITION OF GRASSES FOR RANGE CATTLE 11

were flowering or were beginning to form seed; and as mature when and
after the seeds were well formed. The sample was placed loosely in a
cheesecloth bag, dried at 45° C., ground in a Wiley mill, and analyzed by
methods of the Association of Official Agricultural Chemists (1).

The number of samples of each species collected varied Widely. Some
species, such as buffalo grass, are of widespread occurrence throughout
the entire area, and many samples of these species were secured. Other
species, such as rescue grass and little barley, occur only at certain times
of the year, while others, such as tobosa grass, are found only on certain
areas, so that only a few samples of these species were taken. Only a few
species were found on some of the areas, particularly on the High Plains,
where buffalo and blue grama grasses make up practically all of the forage
on large areas. Many different species were sampled on most of the loca-
tions in the eastern part of . the area. The number and kind of species
found on a given location are determined by a number of factors, and
these factors may also afiect, to some extent, the chemical composition
of the forage.

Soil samples were collected from all areas from which forage samples
were secured several times. The samples were taken to a depth of about
six inches, dried, passed through a 20-mesh sieve, and analyzed for total
nitrogen and total phosphoric acid by methods similar to those of the
A.O.A.C\., and for active phosphoric acid by digestion with 0.2 N nitric
acid (6). Active lime is the lime dissolved by 0.2 N nitric acid, while basic-
ity is the 0.2 N nitric acid neutralized expressed as calcium carbonate.

Protein, Phosphoric Acid, and Lime in the Grasses

The average percentages of protein, phosphoric acid, and lime in different
species at different stages of maturity are shown in Table 2. The highest
and lowest analyses are also given in order to show the range. The number
of samples of some species is so small that the analyses given may not
show the true average composition. The number of samples of the most
important species was sufiicient to give averages reliably indicating what
can usually be expected in samples of that species and stage of growth
in this area. The analyses given in Table 2 and succeeding tables are
stated in terms of protein (nitrogen times 6.25), phosphoric acid (phos-
phorous pentoxide, P205), and lime (calcium oxide, CaO). The analyses
may be converted into terms of the element by multiplying protein by 0.16
for nitrogen (N), phosphoric acid by 0.4368 for phosphorus (P), and
lime by 0.7147 for calcium (Ca).

The average analyses given in Table 2 show some marked differences
among different kinds of grasses and among samples of the same kind
of grass at different stages of maturity. Young Johnson grass contained
twice as much protein, three times as much phosphoric acid, and much
more lime than young Texas grama grass. Protein and phosphoric acid in
the young grasses were usually two or three times as high as in mature
grasses. Maturity had little effect upon lime in the grasses. The effect of

Table 2. Protein, phosphoric acid and lime percentages in difierent species of grasses at various stages of growth
_ Stage of Number Protein Phosphoric acid Lime
Species growth of samples
Mean Low High Mean Low High Mean Low High
Agropyron Smithii Young 5 14.67 10.51 18.30 .47 .32 .57 .53 .47 .64
(Western wheat grass) Medium 3 7.07 6.20 7.89 .40 .33 .53 .52 .40 .58
Mature 3 .65 .99 5.44 .20 . 17 .25 .42 .32 .49
Andropogon barbinodis Bloom 2 6.65 6.32 6.97 .36 .32 .39 .64 .52 .75
(Plains beard grass) '
Andropogon Hallii (t) Young 6 11.28 8.28 17.50 .46 .28 .71 .58 .51 .73
(Turkeyfoot grass) Medium 3 7.44 6.77 8.38 .42 .31 . 56 .95 .84 1.14
Bloom 9 4.19 3.40 5.25 .24 .14 .44 .80 .41 1.10
Mature 12 4.02 2.77 5.52 .21 .11 .67 .71 .48 1.17
Andropogon ischaemum Young 1 17.53 . . . . . . . . . . . . . . . . .51 . . . . . . . . . . . . . . . . .81 . . . . . . . . . . . . . . . .
, (Yellow beard grass) Medium 2 8.39 7.98 8.80 .32 .28 .35 . 50 .42 .57
Andrcgzogon provincialis (t)*1' Young 3 11.16 9.48 12.61 .51 .43 .58 .75 .61 .83
( ig bluestem grass) Medium 5 6.93 5.01 9.30 .30 .21 .38 c .76 .40 1 .03
Bloom 1 5.75 . . . . . . . . . . . . . . . ». .24 . . . . . . . . . . . . . . . .. .96 . . . . . . . . . . . . . . ..
Mature 6 3.49 1.82 7.10 .18 .10 .27 .60 .30 .97
Andropogon saccharoidcs (t)*'|' Young 23 9.76 6.25 16.65 .46 .27 .77 .73 .36 1 .16
(Silver beard grass) . . . . . . . . . Medium 32 7.00 3.87 9.48 .35 .20 .56 .71 .34 1.71
Bloom 20 4.69 3.65 5.89 .28 .14 .48 .56 .34 1.01
Mature 2 3.46 2.41 5.48 .17 .08 .36 .61 .29 .97
Andropogon scoparius (t)*T Young 14 8.26 4.43 12.65 .36 . 11 .68 .78 .55 1.09
(Little bluestem grass) Medium 6 5.11 4.26 6.23 .20 . 14 .26 .64 .48 . 90
Bloom 3 2.96 2.60 3.45 .17 .14 .21 .51 .34 .76
Mature 16 3.44 2.37 4.76 .14 .08 .28 .48 .23 .87
Andropogon tcner*1' Young 1 9.41 . . . . . . . . . . . . . . . . .32 . . . . . . . . . . . . . . . . .50 . . . . . . . . . . . . . . . .
Medium 1 6.15 . . . . . . . . . . . . . . .. .21 . . . . . . . . . . . . . . .. .63 . . . . . . . . . . . . . . ..
Bloom 3 6.08 5.50 7.15 .28 22 .40 .65 .63 .67
Mature 3 3.48 2.33 4.37 .18 .11 .27 .82 59 .99
Andropogon lernarius (t)* Young 4 8.10 6.96 9.65 .32 .22 .48 .64 .49 .80
(Silvery beard grass) Medium 9 5.86 4.56 7.38 .21 .13 .42 .88 .36 1.31
Bloom 9 5.44 3.60 6.84 .28 .13 .51 .55 .32 1.03
Mature 8 3.30 2.28 6.08 .11 .06 .16 1.21 .68 2.68
Arislida Fcnrllerianrfil‘ Bloom 1 8.77 . . . . . . . . . . . . . . . . .25 . . . . . . . . . . . . . . . . .47 . . . . . . . . . . . . . . . .
(Fendlefs three-awn grass) Mature 4 5 . ()3 3 .82 5 68 .18 .12 22 .45 .27 .63
l

Z1

NOLLVLS LNEIWIHHJXEI TVHHLTHOIHDV SVXEIL ‘699 ‘ON NLLEITTIIEI

Aristida longiseta
(Red three-awn grass)

Aristida purp urascens
(Arrowfeather grass)

Arislida pllrpurea
(Purple three-awn grass)

Avena saliva
(Oat plants)

Bouteloua curtipendula (s) T
(Side-oats grama grass)

Bouleloua eriopoda
(Black grama grass)

Bouieloua gracilis (s)
(Blue grama grass)

Bouieloua hirsuta (s)
(Hairy grama grass)

Bouleloua rigidiseta (s)T
(Texas grama grass)

Bromus catharticusH"
(Rescue grass)

Bromus japonicus
(Japanese chess)

Bromus marginatus
(Brome grass)

Bromus mollis
(Soft chess)

Young
Medium
Bloom
Mature

Medium
Bloom
Mature

Young
Medium
Bloom
Mature

Young

Young
Medium
Bloom
Mature

Young
Bloom

Young
Medium
Bloom
Mature
Young
Medium
Bloom
Mature
Young
Medium
Bloom
Mature

Young
Young
Bloom

Young

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Table 2. Protein, phosphoric acid and lime percentages in different species of grasses at various stages of growth——Continued

_ Stage of Number Protein Phosphoric acid Lime
Species growth of samples
Mean Low High Mean Low High Mean Low High
Bromus texensis Young 3 9.99 7.96 11.13 .43 .34 .53 .77 .45 1.40
(Texas brome grass)
Buchloe dactyloides (s)'|' Young 97 9.45 5.20 17.65 .35 .14 .66 .80 .46 1.82
(Buffalo grass) Medium 68 6.95 3.93 11.81 .27 .13 .50 .88 .30 3.71
Bloom 40 6.45 4.65 9.60 .24 .13 .47 .80 .37 1.51
Mature 109 6.01 3.41 9.47 .22 .09 .36 .78 .34 2.99
Chloris cucullata Young 9 9.81 6.76 12.91 .49 .20 .69 .90 .53 1.62
Black finger grass) Medium 3 7.46 6.27 8.19 .39 .30 .50 .60 .52 .66
Bloom 2 5 . 57 5 .23 5. 90 .35 .26 .44 .64 .46 . 82
Mature 3 5.21 3.90 7.01 .33 .20 .44 .62 .45 82
Chloris veriicillata (s) Young 33 9.95 5.48 15.13 .43 .28 .76 .88 .58 1.73
(Windmill grass) Medi m 25 7.95 5.79 10.70 .42 .26 .60 .75 .52 1.56
Bloom 16 6.48 3.98 9.07 .34 .15 .54 1.04 .63 4.51
Mature 41 6.20 3.83 8.34 .30 .16 .69 .96 .27 2.30
Chloris virgata Young 4 11.37 9.55 14.50 .60 42 .81 .78 .66 1.00
(Feather linger grass) Bloom 1 6.00 . . . . . . . . . . . . . . . . .48 . . . . . . . . . . . . . . . . 55 . . . . . . . . . . . . . . . .
Cynodon dactylon (s)*1' Young 22 12.24 6.70 20.85 .50 .17 .81 .82 .43 1.92
(Bermuda grass) Medivn] 9 7.48 4.54 9.84 .42  .63 .95 .64 1.92
Bloom 11 6.10 4.48 8.25 .38 .22 .54 .79 .64 .94
Mature 11 5.13 3.06 8.25 .27 .14 .35 .88 52 1.54
Distichlis texana Young 2 9.87 7.76 11.98 53 .44 .62 .57 .49 .65
(Salt grass)
Elymus canadensis Young 1 18.54 . . . . . . . . . . . . . . . . .45 . . . . . . . . . . . . . . . . .98 . . . . . . . . . . . . . . . .
(Nodding wild rye) Medium 1 9.53 . . . . . . . . . . . . . . . . .59 . . . . . . . . . . . . . . . . .46 . . . . . . . . . . . . . . . .
Bloom 1 4.13 . . . . . . . . . . . . . . .. .27 . . . . . . . . . . . . . . .. .57 . . . . . . . . . . . . . . ..
Mature 2 3.02 2.40 3.64 .27 .07 .46 .91 .71 1.10
Elymuspillosus Young 1 19.31 . . . . . . . . . . . . . . . . .73 . . . . . . . . . . . . . . . . .67 - . - . . . . . . . . . . - . .
(Wald rye) Mature 1 7.77 . . . . . . . . . . . . . . . . .52 . . . . . . . . . . . . . . . . _56 . . . . . . . . . . . . . . . .
Emgrosiis Bcyrichii Young 2 11.72 10.39 13 .04 .64 .60 .68 .58 .57 .59
(Dropsccd grass) Medium 2 6.09 5.78 6.40 .43 .42 .43 .51 50 .52
Bloom 1 6.57 . . . . . . . . . . . . . . . . .36 . . . . . . . . . . . . . . . . .39 . . . . . . . . . . . . . . ..
Mature 1 6.61 . . . . . . . . . . . . . . .. .24 . . . . . . . . . . . . . . .. 2.65 . . . . . . . . . . . . . . ..
Eragroslis curvulla Young 3 13.24 9.20 16.75 .38 .34 .44 .72 1J8 .91

711

NOLLVLS JZNEINIHEIJXEI TVHIILTIIOIHOV SVXELL ‘699 ‘ON NILEYYIIIEI

Iiragroslis diflusa
Eragroslis intermedia*
(Plains love grass)

Eragroslis lugens *

Eragrostis sccundi/Iora*

Eragroslis sessilispica

IIilaria Belangeri (s)
(Curly mesquite grass)

Ililaria Jamesii
(Galleta grass)

Hilaria mutica (t)
(Tobosa grass)

Hordeum pusillum
(Little barley)

Muhlenbergia arenacea
(Muhly grass)

Muhlenbergia pungens
(Blowaway grass)

Munroa squarrosa
(False buffalo grass)

Panicuzn antidotale
(Stick grass)

Panicum arizonicum

Young
Mature

Young
Bloom

Young
Bloom

Young
Bloom
Mature

Young
Bloom
Mature

Young
Medi ‘m
Bloom
Mature

Young
Medium

Young
Medium
Bloom
Mature

Young

Young
Medium
Mature

Young
Medium
Bloom

Young

Young
Medium
Bloom

Young
Medium
Bloom

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Table 2.

Protein, phosphoric acid and lime percentages in ditferent species of grasses at various stages of growth——Continued

Stage of Number Protein Phosphoric acid Lime
Species growth of samples
Mean Low High Mean Low High Mean Low High
Panicum bulbosum Young 1 19.00 . . . . . . . . . . . . . . . . .64 . . . . . . . . . . . . . . . . .73 . . . . . . . . . . . . . . . .
(False Johnson grass) Bloom 2 5.60 4.00 7 .20 .37 .35 .39 .73 .60 .85
Panicum capillare* Young 1 15.46 . . . . . . . . . . . . . . . . .77 . . . . . . . . . . . . . . . . .54 . . . . . . . . . . . . . . . .
Witch grass) Medium 3 7.53 5.87 9.62 .36 .30 .47 1.09 .61 1.73
Bloom 2 5.79 4.09 7.49 .32 .28 .35 .56 .43 .69
Panicum capillarioides* Young 2 8.78 8.38 9.17 .47 .31 .63 .78 .43 1.12
Panicum geminatum Young 2 10.47 10.23 10.70 .48 .40 .56 .64 .60 .68
Medium 1 7.47 . . . . . . . . . . . . . . .. .23 . . . . . . . . . . . . . . .. 1.22 . . . . . . . . . . . . . . . .
Panicum Hallii Bloom 3 6.92 6.45 7.56 .25 .21 .29 .85 .60 1.19
(Hall’s panicum) _
Panicum ablusum (t) Young 18 11.30 7.25 21.35 .55 .31 1.20 .64 .44 1.35
(Vine mesquite grass) Medium 8 8.06 6.75 10.25 .40 .23 .65 .69 .44 .93
Bloom 5 8.26 6.05 9.35 .35 .24 .42 .74 .51 1.05
Mature 5 4.56 4.24 5.29 .18 .12 .27 .53 .40 .71
Panicum Reverchoni Young 1 12.90 . . . . . . . . . . . . . . . . 32 . . . . . . . . . . . . . . . . 55 . . . . . . . . . . . . . . . .
Panicum Scribnerianum Bloom 1 6.14 . . . . . . . . . . . . . . . . .40 . . . . . . . . . . . . . . . . .56 . . . . . . . . . . . . . . . .
Panicum sphaerocarpon Young 2 9.35 7.45 11.25 .37 .27 .47 .51 .45 .56
Bloom 1 4.79 . . . . . . . . . . . . . . .. .17 . . . . . . . . . . . . . . .. .54 . . . . . . . . . . . . . . ..
Panicum texanum Young 5 12.44 8.21 17.79 .44 .37 .50 .85 .62 1.11
(Colorado grass)
Panicum virgatumT Young 4 11.45 8.47 17.62 .44 .30 .62 .68 .49 .95
(Switch grass) Mature 2 4.83 4.50 5.15 .32 .25 .39 .57 .44 .70
PlISpGIIIIII ciliatif0liu1u* Bloom 1 6.65 . . . . . . . . . . . . . . . . .31 . . . . . . . . . . . . . . . . .81 . . . . . . . . . . . . . . . .
Paspalum dislichum*T Bloom 2 5.67 4.76 6.58 .48 .43 53 .73 .67 .78
(Knot grass)
Paspalum notalum*1' Mature 1 5.32 . . . . . . . . . . . . . . . . .24 . . . . . . . . . . . . . . . . .50 . . . . . . . . . . . . . . . .
(Bahia grass)
Paspalum setaceum*1' Bloom 1 4.76 . . . . . . . . . . . . . . . . .41 . . . . . . . . . . . . . . . . .93 . . . . . . . . . . . . . . . .
Mature 1 5.33 . . . . . . . . . . . . . . .. .33 . . . . . . . . . . . . . . .. .96 . . . . . . . . . . . . . . ..

NOLLVLS LNEIWIHEIJXEI TVHIILTIIOIHOV SHVXELL ‘699 'ONI NILEITIIIEI

91

Paspalum unispicalum* Young 4 9.64 5.22 14 .56 .39 .32 .47 .92 .57 1 .13
Phalaris carolinianai‘ Young 1 10.43 . . . . . . . . . . . . . . . . _71 . . . . . . . . . . . . . . . . .62 . . . . . . . . . . . . ..
(Southern canary grass)
Phalaris minorT Young 1 10.00 . . . . . . . . . . . . . . . . .87 . . . . . . . . . . . . . . . . .65 , . . . . . . . . . . . . . . .
(Little canary grass)
Schedonnardzzs paniculalus Young 6 8.48 6.01 12.60 .32 .20 .48 .87 .52 1.13
(Tumble grass) Bloom 3 6.34 5 .25 7.08 .34 .26 .47 .72 .68 .75
Setaria macroslachys Young 1 10.87 . . . . . . . . . . . . . . . . .39 . . . . . . . . . . . . . . . . .37 . . . . . . . . . . . . . . . .
(Plains bristle grass) Bloom 2 6 .49 5.00 7 .97 .45 .24 .66 .48 .43 .53
Setaria viridis Young 1 8.80 . . . . . . . . . . . . . . . . .45 . . . . . . . . . . . . . . . . .39 . . . . . . . . . . . . . . . .
(Green foxtail grass)
Sorghasirum nutans (t)*'l' Young l0 10.63 8.95 13.44 48 .33 .72 95 57 1.38
(Indian grass) IVIedium 8 6.63 4.59 9.79 30 19 .44 84 66 1.39
Bloom 3 4.59 4.07 5.57 29 13 .48 73 64 .83
Mature 5 4.36 2.87 5.90 17 08 .36 77 42 1.09
Sorghum halepense*1' Young 39 13.73 9 .06 26 . 15 65 .32 1 20 1 14 .51 2.30
(Johnson grass) Medium 14 7.56 4.35 10.93 .41 .22 70 1 O2 .58 1.77
Bloom 20 7 .00 3.90 11.22 .37 16 66 1 09 .76 1.50
Mature 4 6.58 3.07 9.42 .34 15 55 1 11 .94 1.42
Sporobolus airoides (s)T Young 14 9.48 7.39 11.19 39 25 .63 62 37 87
(Alkali sacaton grass) Medium 6 6.42 4.69 8.88 25 17 .34 84 57 1 22
Bloom 8 5 .88 3.82 8.83 27 15 .38 63 37 97
Mature 4 5 .20 4.44 6.18 35 26 . 44 67 3o 98
Sporobolus asper Bloom 4 6.08 4.00 1O 21 19 .12 26 43 25 62
Mature 1 4.35 . . . . . . . . . . . . . . .. 25 . . . . . . . . . . . . . . .. 59 . . . . . . . . . . . . . . ..
Sporobolus cryptandrus (s)* Young 37 11.36 6.29 20.88 39 26 .82 66 42 1 17
(Sand dropseed grass) Medium 3 8.63 7.76 9.65 47 31 .68 43 39 45
Bloom 4 6.59 4.91 7.98 26 21 .36 42 37 55
Mature 9 6.59 5.56 8.81 24 12 .32 54 36 81
Sporobolus Wrightii Medium 2 7.19 6.79 7.58 .42 41 .42 91 80 1 02
(Sacaton grass) Mature 1 4.17 . . . . . . . . . . . . . . . . 31 . . . . . . . . . . . . . . . . 33 . . . . . . . . . . . . . . . .
Stipa comala Young 13 10.23 6.89 13.07 33 23 .40 82 55 1 .26
(Needle and thread grass) Medium 3 8.10 7.40 8.54 24 .24 .24 88 75 1 . 12
Bloom 2 6 .07 5.16 6.98 24 23 .24 44 43 45
Mature 4 5.48 4.42 6.36 30 19 .39 64 43 91
Slipa leucotrichai‘ Young 5 10.25 7.63“ 12.86 39 24 .52 82 71 97
(Texas needle grass) Medium 4 6.85 6.38 7.77 28 25 .33 92 64 1 35
Bloom 2 7.85 7.42 8.28 29 28 .30 67 37 97
Mature 5 5.93 5.08 6.90 21 19 .24 99 61 1 64

LI EITLLVO EIONVH HOJ SGISSVHD JO NOLLISOrINOO 'IVOIWEIHO EIHL

Table 2. Protein, phosphoric acid and lime percentages in diflerent species of grasses at various stages of growth—Continued

Stage of Nvmber Protein Phosphoric acid Lime
Species growth of samples
Mean Low High Mean Low High Mean Low High
Trichachne califomica Young 5 8.22 6.94 9.51 .35 .19 .56 .58 .37 .95
(Cotton top grass)
Triodirz albescenst Young 23 10.86 8.73 16.57 .47 .30 .81 .70‘ .34 1.27
(White triodia grass) Medium 13 7.27 5.64 9.44 .37 .20 .72 .68 .46 1.02
Bloom 10 8.33 5.33 11.00  .19 .55 .63 .47 .91
Mature 1 5.98 . . . . . . . . . . . . . . .. .27 . . . . . . . . . . . . . . .. .76 . . . . . . . . . . . . . . ..
Triodia grandiflora Bloom 3 7.35 5 .78 8.23 .22 .18 .26 1.19 .72 2 .05
(Shortleaf triodiu grass)
Triodia mutica Bloom 1 5.85 . . . . . . . . . . . . . . .. .21 . . . . . . . . . . . . . . .. .84 . . . . . . . . . . . . . . ..
(Slim triodia grass) lWature 2 4.91 4.73 5 .08 .12 .11 .12 1.84 1.08 2.59
Triodia pulchella Bloom 1 8.27 . . . . . . . . . . . . . . . . .20 . . . . . . . . . . . . . . . . 1.81 . . . . . . . . . . . . . . . .
(Fluff grass) . . . . . . . . . . . .. Mature 1 5.92 . . . . . . . . . . . . . . . . .13 . . . . . . . . . . . . . . .. 1.29 . . . . . . . . . . . . . . ..
Triodia (exam: Young 5 10.24 6.53 12.21 .35 .23 .44 .57 45 75

(Texas triodia grass)

(t) or (s)—lmportant tall or short grasses (liscussed as groups in text. _
*Averages for these grasses in the East 'I‘exa_s 'l‘1n]b_er Country are given in Bulletin 582.
TAvcrages for these grasses in the Gmlf Coast Prairie are given in Bulletin 644.

NOLLVLS LNGIIAIIHIEIJIXEI TVHILUIDOIHDV SVXELL ‘699 ‘ON NLLEFFIIIH

 

THE CHEMICAL COMPOSITION OF GRASSES FOR RANGE CATTLE 19
advancing maturity upon the percentage of protein and phosphoric acid in
the grasses difiered in different species. The relative decrease in protein
with maturity was considerably greater with tall grasses than with
short grasses. Eight important species of tall grasses averaged
10.99% protein in the young grass and 3.98% in the
grass. Ten important species of short grasses averaged 9.44% pro-

mature .

Table 3. Principal species of grasses arranged in order of their average protein, phosphoric
acid and lime contents at young and mature stages of growth
Young Stage of Growth

Protein C7 Phosphoric acid m Lime (7

o /o o

Good Fair Hig
Little barley . . . . . . . . . . . . . 14.71 Johnson . . . . . . . . . . . . .65 Johnson . . . . . . . . . . . . 1.14

Western wheat . . . . . . . . . . . 14.67 Rescue . . . . . . . . . . . . . .63 Indian . . . . . . . . . . . . . .95

Johnson . . . . . . . . . . . . . . . . . 13.73 Vine mesquite . . . . . . .55 Windmill . . . . . . . . . . . .88

lgescued. . . . . . . . . . . . . . . . . .  Iéittle lciiarley . . . . . . . .  Good

ermu a . . . . . . . . . . . . . . .. 1 . ermu a . . . . . . . . . .. .0

Sand dropseed . . . . . . . . . . . 11.36 Indian . . . . . . . . . . . . . .48 lliermuda-dl ' ~ - ~ - - - ' ' 

Vine mesquite. . . .. . . . . . . . 11  Western _wh_eat . . . . . . .47 Nexffi need   ~ - '82

Turkeyfoot . . . . . . I . . . . . . . 112s White tfl0dlil . . . . . . . .47 Beg 1e an t Yea --- - 8O

\Vhite triodia . . . . . . . . . . . . 10.86 T_urke_vfoot . . . . . . . . . .46 T“ a 0 - ' - - - - ~ - ' - ~ - ~ '79

Indian . . . . . . . . . . . . . . . . . . 10.63 Silver beard . . . . . . . . .46 L373‘: gflllaérslfieh - ~ ' ' ' - '78

Fair gflffljgbgééd ' " " " " " ég Sideoats grama I I II I I I76

Texas needle . . . . . . . . . . . . . 10.25 Texas needlfl  '_      Silver beard. . . . . . . . .73

Tobosa . . . . . . . . . . . . . . . . . . 10.24 Alkali Sacaton _ _ _ _ _ _ _ _39 Rescue . . . . . . . . . . . . . .72

Needle and thread . . . . . . . . 10.23 Cuflv mesquitm _ _ _36 Tohosa. . .. . . . . . . . . . .72

Windmill . . . . . . . . . . . . . . . . 9.95 Littfe bluesterm _ __ y _ 36 White triodia . . . . . . . .70

Blue grama . . . . . . . . . . . . . . 9.76 Buffalo _ _ _ _ _ _ _ _ _ _ _ _ _ .35 Hairy grama . . . . . . . . .68

Silver beard . . . . . . . . . . . . . 9.76 Blue grama _ v _ _ _ _ _ _ _ _34 Little barley . . . . . . . . .67

Alkali sacaton . . . .. . . . . . . . 9.48 d h d 3 Sand dropseed . . . . . . .66
Needle an t rea . .. .3 . .
Buffalo. . .. . . . . . . . . . . . . . . 9.45 D f. . t Vine mesquite . . . . . . . .64

Curly mesquite. . . . . . . . . . 8. 86 e ‘Glen Curly mesquite . . . . . . .64

Sideoats grama . . . . . . . . . . . 9.79 Tobosa . . . . . . . . . . . . . .32 Blue grama . . . . . . . . . .62

Hairy grama . . . . . . . . . . . . . 8.33 Sideoats grama . . . . . . .32 Alkali sacaton . . . . . . . .62

Little bluestem . . . . . . . . . . . 8.26 Hairy grama . . . . . . . . .30 Turkeyfoot . . . . . . . . . .58

Texas grama . . . . . . . . . . . . . 7.19 Texas grama . . . . . . . . .24 Western wheat . . . . . . .53

Mature Stage of Growth
Protein Phosphoric acid Lime

r67“ F/Q H7211
< air air i

Sand dropseed . . . . . . . . . . . 6.59 Alkali sacaton . . . . . . . .35 Johnson . . . . . . . . . . . . 1.11

Johnson . . . . . . . . . . . . . . . . . 6.58 Johnson . . . . . . . . . . . . .34 Texas needle . . . . . . . . .99

Blue grama .. . . _ . . . . . . . . . . 6.40 Deficient Windmill . . . . . . . . . . . .96

Windmill . . . . . . . . . . . . . . . . 6.20 Needle and tin-amp __ _30 Bermuda . . . . . . . . . . . .88

Buffalo . . . . . . . . . . . . . . . . . . 6 .01 \Vindmi11 _ _ _ _ _ _ _ _ _ _ _ 30 Hairy grama. .. . . . . . .87

Deficient Ehite (tiriodia . . . . . . .  T Googo

White trioim _ ‘ ‘ _ _ _ ‘ _ _ K ‘ _ 5__ 3 ermu a . . . . . . . . . . . . 1 _exas grama . . . . . . . . .

Texas neeéle _ _ _ _ 4 _ _ v _ _ _ ‘ _ 593 gzind dropseed. . . . . .  ISBidfcfoats grama. . .. .. 

Needle and thread _ H _ _ ‘ __ {L48 B 11f? eraina . . . . . .  . .92 I 11d_8 O . . . . . . . . . . . . . 

Tobosa . . . . . . . . . . . . . . . . .. 5.23 u a“ - ' - ~ - ~ - - - - - ~- -~  lanlz": ~ ~ - ‘ ~ ' -' '

- r Texas needle... . . . . . .21 Vt hite triodia . . . . . . . .76
Alkali sacaton..... . . . . . .. 3.20 T k f t o] T kevfoot 71
Bermuda _ _ _ _ _ _ _ _ _ . _ _ 4 _ . _ 5_ 13 ‘xilr tey 00h. .  . . . . . . .§0 Curl _, . _.t.e . . . . . . .69
Texas gmma _ _ _ _ _ _ _ ' _ _ _ _ _ 512 es ern w ea . . . . . . ur y_ mesqui . . .

- Texas qrama . . . . . . . . .18 Alkali sacaton . . . . . . . .67
Curly mesquite. . . . . . 5.04 . e .
H - r 04 Vine mesquite. . . .. . . .18 Needle and thread... .64
airy grama . . . . . . . . . . . . . o. . .
'1 obosa . . . . . . . . . . . . . .17 Silver beard . . . . . . . . .61
\Vestern wheat . . . . . . . . . . . 4.65 . .-
- - (z Curly mesquite. . . . . .11 Blue grama . . . . . . . . . .56
Vinemesqiiite............ 4.5 Id. 17 q ddo ed 54
Sideoats grama . . . . . . . . . . . 4.47 I.‘ fan ~ - - - - - ~ ~ - - ‘ - - - *3“ r pee. - ~ - ' - ' '53

Indian ‘ _ _ _ I _ _ _ _ _ _ _ _ _ _ _ _ _ 436 Silver beard . . . . .. . . . .17 Vine mesquite . . . . . . . .48

Turkeyfoot . . . . . . . . . . . . . . 4.02 _ Very Deficient Ifltfile bluestem - ' - ' ' ' '46

Silver beard . . . . . . . . . . . . . . 3.46 Hairy grama . . . . . . . . .16 ° 0S3 - ~ - ‘ - - - - - - - - - '_

Little bluestem . . . . . . . . . . . 3 .44 Sideoats grama . . .. . . .16 - ‘ Fall‘

Little bluestem . . . . . . .14 “Festern wheat . . . . . . .42

k species, good in 15 species, and fair in western wheat grass. The dataff

   
    
    
  
 
 
 
  
 
  
  
  
    
   
   
    
  
   
 
 
 
  
 
   
   
    
  

20 BULLETIN NO. 669, TEXAS AGRICULTURAL EXPERIMENT STATION

tein in the young grass and 5.52% in the mature grass. The rela
decrease in percentage protein due to maturity amounted to 61% in I
tall grasses and only 41% in the short grasses. Phosphoric acid in I,
tall grasses averaged .4370 when the grasses were young and .17 % w
mature, while the short grasses averaged 36% and 23%, respectiv
The relative decreases in percentages of phosphoric acid were 61% and 36A
respectively, practically the same as for protein. Thus, while both 
tein and phosphoric acid averaged slightly higher in the tall grasses i,’
in the short grasses when the grasses were young, they averaged cont‘
erably lower when mature, and the relative decreases in the tall gras
were about one and one-half times those in Ithe short grasses. 

Table 3 compares the relative order of important species in con i
of protein, phosphoric acid, and lime in samples of young and i»:
grasses. In the young grasses, protein ranged from 14.71% in little bar
to 7.19% in Texas grama grass, or only one-half as much. Phosphoric :{
ranged from .65% in Johnson grass to 24% in Texas grama grass, "
only one-third as much. Lime ranged from 1.14% in Johnson grass}
53% in Western wheat grass, or less than one-half as much. The pro 
was classed as good in 10 of the 22 species and as fair in 12 speci’
Phosphoric acid was classed as deficient in tobosa grass and in h'_l
sideoats, and Texas grama grasses, and fair in 18 species. Lime '_
classed as high in Johnson, Indian, and windmill grasses and as good
19 species. In the 21 mature grasses, protein was classed as fair in 5 s’
cies and as deficient in 16 species. Phosphoric acid was fair in alkali 
ton and Johnson grasses, deficient in 16 species, and very deficient in 1i
blue-stem and sideoats and hairy grama grasses. Lime was high ind?‘

Table 3 show the comparatively wide differences in chemical composif
of different important grasses, the marked decrease in percentages "
protein and phosphoric acid with maturity, and the effect of maturity u

the relative chemical composition of the difierent grasses. 

Distribution of Samples According to Grades of Constituents

In order to facilitate comparison of the composition of the samples : '1
to provide an estimate as to their adequacy as feed for range cattle, _
samples were grouped into the five grades or classes shown in Table 4, {I
was done in work reported in previous publications. The limits of the 1 n;
were chosen after careful consideration of a large amount of experimen
work reported in the literature, so that the grades carried as much meani
as possible (7, 11). <1

The distribution of the samples according to the different grades of p
tein, phosphoric acid, and lime is shown in Table 5. Protein was classed i
very deficient (Grade 5) in only 28 of the 1,916 samples, but as deficit
(Grade 4) in 695 samples, 36% of the total. Protein was high in 62 out I
640 samples of young grass; 26 of the 28 samples in which protein ' l
very deficient were mature grasses. Practically all of the samples in whi

 

THE CHEMICAL COMPOSITION OF GRASSES FOR RANGE CATTLE 21

Table 4. Grades for protein, phosphorus and calcium in forage for range animals
Grade _
Crude protein Protein
1 High . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15.00 +

2 Good . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 50 to 14.99

3 Fair . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 6.00 to 10.49

4 Deficient . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 3.00 to 5.99

5 Very deficient . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0 to 2.99
Phosphorus P P205
1 High . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. .45 + 1.01 +

2 Good . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. .30 to .44 .67 to 1.00

3 Fair . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 15 to .29 33 to .66

4 Deficient . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .08 to .14 .17 to .32

5 Very deficient . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0 to 07 O to . 16
Calcium Ca CaO
1 High . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61 + .83 +

2 Good . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31 to .60 .43 to .82

3 Fair . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. .16 to .30 .22 to .42

4 Deficient . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. .08 t0 .15 .11 t0 .21

5 Very deficient . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0 to .07 0 to . 1O

protein was classed as good (Grade 2) were of young grasses (197 out of
206 samples). Protein was fair (Grade 3) in 56% of the samples of young
grass, 72% of the grasses at the medium stage, 43% of the grasses in bloom,
and 27% of the mature grasses. Protein was deficient in 3% of the young
grasses, 27% of the grasses at the medium stage, 55% of the grasses in
bloom, and 739% of the mature grasses. The proportion of samples in which
protein was deficient also differed with different species. Protein was defi-
cient in 14% of the samples of Johnson grass, 29% of the samples of buffalo
grass, 57% of those of curly mesquite grass, and 70% of those of hairy
grama grass. Considerable range in the proportion of deficient samples was
shown among different species of the same genus. Protein was deficient in
31% of the samples of blue grama, 45% of those of Texas grama, 60% of
sideoats grama, and 70% of hairy grama. Protein was deficient in 43% of
the samples of silver beard grass and 72% of those of little bluestem. The
proportion of samples in which protein was deficient averaged 53% in 7 im-
portant species of tall grasses and 36% in 10 species of short grasses. There
were also considerable differences when both species and stage of" maturity
were considered. Protein was deficient in all samples of silver beard and lit-
tle bluestem grasses at bloom and mature stages of growth, whereas it was
deficient in only one-third of the samples of buffalo and blue grama grasses
at the bloom stage of growth and in about one-half of the samples of ma-

‘ ture grasses.

PivwrwgTw/v I

A much higher proportion of the samples was deficient or very de-
ficient in phosphoric acid than in protein. Phosphoric acid was very
deficient (Grade 5) in 324 samples (17% of the total) and deficient (Grade
4) in 920 samples (48% of the total). In other words, the percentage of
phosphoric acid in two-thirds of the samples collected was too low for
satisfactory performance of range cattle. Phosphoric acid was very de-
ficient in 2% of the samples of young grass, 8% of those at the medium
stage of growth, 19% of the grasses in bloom, and 38% of mature grasses.
Phosphoric acid was deficient in 32%, 59%, 57%, and 53% of the samples

Table 5. Number of samples of diflerent species of grasses at various stages of growth within each grade of constituents

Protein grade

Phosphoric acid grade

Lime grade

Stage of No. of Very Defi- Very Defi-
Species growth samples defi- cient Fair Good High defi- cient Fair Good Fair Good High
cient 3.00 6 .00 10.50 Over cient .17 .33 .67 .23 .43 Over
Below to to to 14.99 Below to to to to to .82
3.00 5 .99 10.49 14.99 .17 .32 .66 1.00 .42 .82
Agropyron Smilhii Young 5 . . . . . . . . . . . . . . . . . . 3 2 . . . . . . 1 4 . . . . . . . . . _ . . 5 . . . . . .
(Western wheat grass) Medium 3 . . . . . . . . . . . . 3 . . . . . . . . . . . . . . . . . . . . . . . . 3 . . . . . . 1 2 . . . . . .
Mature 3 . . . . . . 3 . . . . . . . . . . . . . . . . . . . . . . . . 3 . . . . . . . . . . . . 1 2 . . . . . .
Andra ogon barbinodis Bloom 2 . . . . . . . . . . . . 2 . . . . . . . . . . . . . . . . . . 1 1 . . . . . . . . . . . . 2 . . . . . .
( lains beard grass)
Andra ogon provincialis Young 3 . . . . . . . . . . . . 1 2 . . . . . . . . . . . . . . . . . . 3 . . . . . . . . . . . . 2 1

( ig bluestem grass) Medium 5 . . . . . . 2 3 . . . . . . . . . . . . . . . . . . 3 2 . . . . . . 1 2 2

Bloom 1 . . . . . . 1 . . . . . . . . . . . . . . . . . . . . . . . . 1 . . . . . . . . . . . . . . . . . . . . . . . . 1

Mature 6 4 1 1 . . . . . . . . . . . . 3 3 . . . . . . . . . . . . l 4 l

Andropogon Hallii Young 6 . . . . . . . . . . . . 3 2 1 . . . . . . 1 4 1 . . . . . . 6 . . . . . .

(Turkeyfoot grass) Medium 3 . . . . . . . . . . . . 3 . . . . . . . . . . . . . . . . . . 1 2 . . . . . . . . . . . . . . . . . . 3

Bloom 9 . . . . . . 9 . . . . . . . . . . . . . . . . . . 3 4 2 . . . . . . 1 4 4

Mature 12 2 10 . . . . . . . . . . . . . . . . . . 5 6 . . . . . . 1 . . . . . . 9 3

Andropogon ischaemum Young 1 . . . . . . . . . . . . . . . . . . . . . . . . 1 . . . . . . . . . . . . 1 . . . . . . . . . . . . 1 . . . . . .

(Yellow beard gragg) Medium 2 . . . . . . . . . . . . 2 . . . . . . . . . . . . . . . . . . 1 1 . . . . . . 1 1 . . . . . .

Andropogon saccharoides Young 23 . . . . . . . . . . . . 17 4 2 . . . . . . 3 19 1 2 15 6

(Silver beard grass) Mediirm 32 . . . . . . 7 25 . . . . . . . . . . . . . . . . . . 15 17 . . . . . . 3 23 6

Bloom 20 . . . . . . 20 . . . . . . . . . . . . . . . . . . 2 12 6 . . . . . . 2 17 1

Mature 20 7 13 . . . . . . . . . . . . . . . . .. 11 8 1 . . . . .. 5 11 4

Andropogon scoparius Young 14 . . . . . . 4 7 3 . . . . . . 2 5 6 1 . . . . . . 7 7

(Little bluestem grass) Medi-im 6 . . . . . . 5 1 . . . . . . . . . . . . 1 5 . . . . . . . . . . . . . . . . . . 5 1

Bloom 3 2 1 . . . . . . . . . . . . . . . . . . 2 1 . . . . . . . . . . . . 2 1 . . . . . .

Mature 16 3 13 . . . . . . . . . . . _ . . . . . . 13 3 . . . . . . . . . . . . 8 6 2

Andropogon lener Young 1 . . . . . . . . . . . . 1 . . . . . . . . . . . . . . . . . . 1 . . . . . . . . . . . . . . . . . . 1 . . . . . .

Medium 1 . . . . . . . . . . . . 1 . . . . . . . . . . . . . . . . . . 1 . . . . . . . . . . . . . . . . . . 1 . . . . . .

Bloom 3 . . . . . . 2 1 . . . . . . . . . . . . . . . . . . 2 1 . . . . . . . . . . . . 3 . . . . . .

Mature 3 1 2 . . . . . . . . . . . . . . . . . . 1 2 . . . . . . . . . . . . . . . . . . 1 2

Andrnnogon fernarius Young 4 . . . . . . . . . . . . 4 . . . . . . . . . . . . . . . . . . 3 1 . . . . . . . . . . . . 4 . . . . . .

(Silver beard grass) Medi m 9 . . . . . . 5 4 . . . . . . . . . . . . 4 4 1 . . . . . . 1 3 ‘ 5

Bloom 9 . . . . . . 7 2 . . . . . . . . . . . . 1 6 2 . . . . . . 3 5 1

Mature 8 5 2 1 . . . . . . . . . . . . 8 . . . . . . . . . . . . . . . . . . . . . . . . 1 7

ZZ

uomvms LNEINIHEIJXH TVHIIUIQOIHSV svxam. ‘e99 ‘on NILEFFIIIH

Aristida Fendleriana
(Fendler’s three-awn grass)

Aristida Iongisela
(Red three-awn grass)

Aristida purpurascens
(Arrowfealher grass)

Arislida purpurea
(Purple three-awn grass)

Avena saliva
(Oat plants)

Boutelqua curtipcndula
(Sldeoats grama grass)

Bouleloua eriopoda
(Black grama grass)

Bouteloua gracilis
(Blue grama grass)

Boulelouq hirsula
(Halry grama grass)

Bouieloua rigidiscta
(Texas grama grass)

Bromus calharticus
(Rescue grass)

Bromus japonicus
(Japanese chess)

Bromus marginalus
(Brome grass)

Bloom
Mature

Young
Medium
Bloom
Mature

Medium
Bloom
Mature

Young
Medium
Bloom
Mature

Young

Young
Medium
Bloom
Mature

Young
Bloom

Young
Medium
Bloom
Mature

Young
Medi m
Bloom
Nlature
Young
Medi m
Bloom
Mattire

Young
YO“Ilg

Bloom

p-A

I-H-l
C? r-lkr-l®\l 006300 $030205 QP‘

 

 

 

v-u-a n-A
N) LWOOIJQ NGIQH‘ CfllCH-"d '-‘

2a ramuvo aimvu 110.21 sassvao a0 NOILISOdWOO qvolwano EIHJ.

1f

Table 5. Number of samples of diiferent species of grasses at various stages of growth within each grade of constituents——Continued
Protein grade Phosphoric acid grade Lime grade
_ Stage of No. of Very Defi- _ Very Defi- _
Species growth samples defi- cient Fair Good H1gh defi- cient Fair Good Fair Good High
cient 3.00 6 . 00 10.50 Over cient .17 .33 .67 .23 .43 Over
Below to to to 14.99 Below to to to to to .82
3.00 5 .99 10.49 14.99 .17 .32 .66 1.00 .42 .82
Bromus mollis Young 3 . . . . . . . . . . . . . . . . . . 3 . . . . . . . . . . . . . . . . . . 3 . . . . . . . . . . . . 2 1
(Soft chess)
Bromus texensis Young 3 . . . . . . . . . . . . 1 2 . . . . . . . . . . . . . . . . . . 3 . . . . . . . . . . . . 2 1
(Texas brome grass)
Buchloe daclyloides Young 97 . . . . . . 2 71 21 3 3 43 51 . . . . . . . . . . . . 62 35

(Buffalo grass) Medium 68 . . . . . . 18 49 1 . . . . . . 3 53 12 . . . . . . 6 42 20

Bloom 40 . . . . . . 13 27 . . . . . . . . . . . . 7 28 5 . . . . . . 3 22 15

Mature 109 . . . . . . 59 50 . . . . . . . . . . . . 24 77 8 . . . . . . 5 77 27

Chloris cucullata Young 9 . . . . . . . . . . . . 6 3 . . . . . . . . . . . . 1 7 1 . . . . . . 5 4

(Black finger grass) Medium 3 . . . . . . . . . . . . 3 . l . . . . . . . . . . . . . . . 4 1 2 . . . . . . . . . . . . 3 . . . . . .

Bloom 2 . . . . . . 2 . . . . . . . . . . . . . . . . . . . . . . . . 1 1 . . . . . . . . . . . . 2 . . . . . .

Mature 3 . . . . . . 2 1 . . . . . . . . . . . . . . . . . . 1 2 . l . . . . . . . . . . 3 . . . . . .

Chloris verticillata Young 33 . . . . . . 1 19 12 1 . . . . . . 5 26 2 . . . . . . 17 16

(Windmill grass) Medium 25 . . . . . . 1 23 1 . . . . . . . . . . . . 4 21 . . . . . . . . . . . . 18 7

Bloom l6 . . . . . . 6 10 . . . . . . . . . . . . 1 7 8 . . . . . . . . . . . . 10 6

Mature 41 . . . . .. 19 22 . . . . . . . . . . .. 3 26 11 1 1 21 19

Chloris virgaia Young 4 . . . . . . . . . . . . 2 2 . . . . . . . . . . . . . . . . . . 3 1 . . . . . . 3 1

(Feather finger grass) Bloom 1 . . . . . . . . . . . . 1 . . . . . . . . . . . . . . . . . . . . . . . . 1 . . . . . . . . . . . . 1 . . . . . .

Cynodon daclylon Young 22 . . . . . . . . . . . . 9 9 4 . . . . . . 3 17 2 . . . . . . 16 6

(Bermuda grass) Medium 9 . . . . . . 1 8 . . . . . . . . . . . . . . . . . . 3 6 . . . . . . . . . . . . 5 4

Bloom 11 . . . . . . 6 5 . . . . . . . . . . . . . . . . . . 3 8 . . . . . . . . . . . . 7 4

Mature 11 . . . . . . 1O 1 . . . . . . . . . . . . 2 6 3 . . . . . . . . . . . . 6 5

Distichlis texana Young 2 . . . . . . . . . . . . 1 1 . . . . . . . . . . . . . . . . . . 2 . . . . . . . . . . . . 2 . . . . . .
(Salt grass)
Elymus canadensis Young 1 . . . . . . . . . . . . . . . . . . . . . . . . 1 . . . . . . . . . . . . 1 . . . . . . . . . . . . 1 _ , . . . .

(Nodding wild rye) Medium 1 . . . . . . . . . . . . 1 . . . . . . . . . . . . . . . . . . . . . . . . 1 . . . . . . . . . . . . . . . . . . 1

Bloom 1 . . . . . . 1 . . . . . . . . . . . . . . . . . . . . . . . . 1 . . . . . . . . . . . . . . . . . . 1 . . . . . .

Mature 2 1 1 . . . . . . . . . . . . . . . . . . 1 . . . . . . 1 . . . . . . . . . . . . 1 1

Elymus villasus Young 1 . . . . . . . . . . . . . . . . . . . . . . 4 . 1 . . . . . . . . . . . . . . . l . . 1 . . . . . . 1 . . . . . .

(Wild rye) Mature 1 . . . . . . . . . . . . 1 . . . . . . . . . . . . . . . . . . . . . . . . 1 . . . . . . . . . . . . 1 . . . . . .

VZ

NOLLVLS LNIEIWIHHJXEI “IVHHLTIIOIHDV SVXELL ‘699 'ON NLLEPTIHEI

Eragrostis Beyrichii
(Dropseed grass)

Eragroslis curvulla

Eragrostis difiusa

Eragrosiis intermedia
(Plains love grass)

Eragroslis lugens

Eragrostis secundiflora

Eragroslis sessilispica

Hilaria Belangeri _
(Curly mesquite grass)

Hilaria Jamesii
(Galleta grass)

Hilaria mutica
(Tobosa grass)

Hordeum pusillum
(Little barley)

Muhlenbergia arenacea
(Muhly grass)

Muhlenbergia pungens
(Blowaway grass)

M unroa squarrosa
(False buffalo grass)

Young
Medium
Bloom
Mature

Young

Young
Mature

Young
Bloom

Young
Bloom

Young
Bloom
Mature

Young
Bloom
Mature

Young
Medium
Bloom
Mature

Young
Medium

Young
Medium
Bloom
Mature

Young
Young
Medium
Mature
Young
Medium
Bloom

Young

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Table 5. Number of samples of dilferent species of grasses at various stages of growth within each grade of constituentk-Continued
Protein grade Phosphoric acid grade Lime grade
_ Stage of No. of Very Defi- Very Defi- _

Species growth samples defi- cient Fair Good High defi- cient Fair Good Fair Good High
cient 3.00 6 .00 10.50 Over cient . 17 . 33 .67 .23 .43 Over
Below to to to 14.99 Below to to to to to .82

3.00 5.99 10.49 14.99 .17 .32 .66 1.00 .42 .82
Panicum antidotale Young 3 . . . . . . . . . . . . . . . . . . 1 2 . . . . . . . . . . . . 2 1 . . . . . . 2 1

Medium 1 . . . . . . . . . . . . 1 . . . . . . . . . . . . . . . . . . . . . . . . l . . . . . . . . . . . . l . . . . . .

Bloom 1 . . . . . . 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 . . . . . . . . . . . . 1 . . . . . .

Panicum arizonicum Young 1 . . . . . . . . . . . . 1 . . . . . . . . . . . . . . . . . . . . . . . . 1 . . . . . . . . . . . . 1 . . . . . .

Medium 4 . . . . . . . . . . . . 4 . . . . . . . . . . . . l 3 . . . . . . . . . . . . . . . . . . 3 1

Bloom 3 . . . . . . . . . . . . 3 . . . . . . . . . . . . . . . . . . 3 . . . . . . . . . . . . . . . . . . 2 1

Panicum bulbosum Young 1 . . . . . . . . . . . . . . . . . . . . . . . . 1 . . . . . . . . . . . . 1 . . . . . . . . . . . . 1 . . . . . .

(False Johnson grass) Bloom 2 . . . . . . 1 1 . . . . . . . . . . . . . . . . . . . . . . . . 2 . . . . . . . . . . . . 1 1

Panicum capillare Young 1 . . . . . . . . . . . . . . . . . . . . . . . . 1 . . . . . . . . . . . . . . . . . . 1 . . . . . . 1 . . . . . .

(Old witch grass) Medium 3 . . . . . . 1 2 . . . . . . . . . . . . . . . . . . 2 1. . . . . . . . . . . . . 1 2

Bloom 2 . . . . . . 1 1 . . . . . . . . . . . . . . . . . . 1 1. . . . . . . . . . . . . . 2 . . . . . .

Panicum capillarioides Young 2 . . . . . . . . . . . . 2 . . . . . . . . . . . . . . . . . . 1 1 . . . . . . . . . . . . 1 1

Panicum geminaium Young 2 . . . . . . . . . . . . l l . . . . . . . . . . . . . . . . . . 2 . . . . . . . . . . . . 2 . . . . . .

Medium 1 . . . . . . . . . . . . 1 . . . . . . . . . . . . . . . . . . 1 . . . . . . . . . . . . . . . . . . . . . . . . 1

Panicum lIallii Bloom 3 . . . . . . . . . . . . 3 . . . . . . . . . . . . . . . . . . 3 . . . . . . . . . . . . . . . . . . 2 1
(IIall’s panicum)
Panicum oblusum Young 18 . . . . . . . . . . . . 7 8 3 . . . . . . 3 11 4 . . . . . . 16 2

(Vine mesquite grass) Medium 8 . . . . . . . . . . . . 8 . . . . . . . . . . . . . . . . . . 4 4 . . . . . . . . . . . . 6 2

loom 5 . . . . . . . . . . . . 5 . . . . . . . . . . . . . . . . . . 2 3 . . . . . . . . . . . . 4 1

Mature 5 . . . . .. 5 . . . . . . . . . . . . . . . . .. 2 3 . . . . . . . . . . .. l 4 

Panicum Reverchoni Young 1 . . . . . . . . . . . . . . . . . . 1 . . . . . . . . . . . . 1 . . . . . . . . . . . . . . . . . . 1 . . . . . .

Panicum Scribnerianum Bloom 1 . . . . . . . . . . . . 1 . . . . . . . . . . . . . . . . . . . . . . . . 1 . . . . . . . . . . . . 1 . . . . . .

Panicum sphaerocarpon Young 2 . . . . . . . . . . . . 1 l . . . . . . . . . . . . 1 1 . . . . . . . . . . . . 2 . . . . . .

Bloom 1 . . . . . . 1 . . . . . . . . . . . . . . . . . . . . . . . . 1 . . . . . . . . . . . . . . . . . . 1 -

Panicum texanuln Young 5 . . . . . . . . . . . . l 3 1 . . . . . . . . . . . . 5 . . . . . . . . . . . . 1 4
(Colorado grass) g

Panicum virgatum Young 4 . . . . . . . . . . . . 3 . . . . . . 1 . . . . . . 1 3 . . . . . . . . . . . . 3 1
(Switch grass) Mature 2 . . . . . . 2 . . . . . . . . . . . . . . . . . . . . . . . . 1 1 . . . . . . . . . . . 2 . . . . . .

98

NOIILV-LS JJNEINIHEIJXEI TVHILIIIHOIHDV SVXELL ‘699 ‘ON NLLEYITIIH

Paspalum ciliatifolium

Paspalum dislichum
(Joint grass)

Paspalum_ notalum
(Bahia grass)

Paspalum setaceum

Paspalum unispicatum

Phalaris caroliniana
(Southern canary grass)

Phalaris minor
(Little canary grass)

Schedonnardus paniculatus
(Tumble grass)

Selaria macrostachys
(Plains bristle grass)

Selaria viridis
(Green foxtail grass)

Sorghaslrym nutans
(Indian grass)

Sorghum halepense
(Johnson grass)

Sporobolus airoide;
(Alkali sacaton grass)

Sporobolus asper

Sporobolus cryplandrus
(Sand dropseed grass)

Bloom

Bloom
Mature

Bloom
Matu re

Young
Young

Young

Young
Bloom

Young
Bloom

Young

Young
Medium
Bloom
Mature

Young
Medium
Bloom
Mature

Young
Medium
Bloom
Mature

Bloom
Mature

Young
Medium
Bloom
Mature

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(Dfiwfl Huh >500

. . - . . .

1 . . . . ..

. . . . .. 2

1 . . . . ..

. . . . .. 1

. . . . .. 1
1 3
3 3
2 1
. . . . .. 1
1 1
. . . . .. 1
. . . . .. 9
5 3
1 1
. . . . .. 1
1 26
4 8
9 1O
. . . . .. 3
7 7
5 1
5 2
1 3
2 . . . . ..
1 . . . . ..
9 27
1 1
3 1
8 . . . . ..

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Table 5. Number of samples of difierent species of grasses at various stages of growth within each grade of constituents—Continued

Protein grade

Phosphoric acid grade

Lime grade

_ Stage of No. of Very Defi- Very Defi-

Species growth samples defi- cient Fair Good High defi- cient Fair Good Fair Good High
ient 3.00 6.00 10.50 Over cient . 17 . 33 . 67 .23 .43 ver
elow to to to 14.99 Below to to to to to .82
3.00 5.99 10.49 14.99 .17 ' .32 .66 1 .00 .42 .82

Sporobolus Wrightii Medium 2 . . . . . . . . . . . . 2 . . . . . . . . . . . . . . . . . . . . . . . . 2 . . . . . . . . . . . . 1 1

(Sacaton grass) Mature 1 . . . . . . 1 . . . . . . . . . . . . . . . . . . . . . . . . 1 . . . . . . . . . . . . 1 . . . . . . . . . . . .

Stipa comata Young 13 . . . . . . . . . . . . 6 7 . . . . . . . . . . . . 6 7 . . . . . . . . . . . . 8 5

(Needle and thread grass) Medium 3 . . . . . . . . . . . . 3 . . . . . . . . . . . . . . . . . . 3 . . . . . . . . . . . . . . . . . . 2 1

Bloom 2 . . . . . . 1 1 . . . . . . . . . . . . . . . . . . 2 . . . . . . . . . . . . . . . . . . 2 . . . . . .

Mature 4 . . . . . . 3 1 . . . . . . . . . . . . . . . . . . 3 1 . . . . . . . . . . . . 3 1

Stipa leucotricha Young 5 . . . . . . . . . . . . 3 2 . . . . . . . . . . . . 2 3 . . . . . . . . . . . . 3 2

(Texas needle grass) Medium 4 . . . . . . . . . . . . 4 . . . . . . . . . . . . . . . . . . 3 1 . . . . . . . . . . . . 2 2

Bloom 2 . . . . . . . . . . . . 2 . . . . . . . . . . . . . . . . . . 2 . . . . . . . . . . . . 1 . . . . . . 1

Mature 5 . . . . . . 3 2 . . . . . . . . . . . . . . . . . . 5 . . . . . . . . . . . . . . . . . . 2 3

Trichachne califomica Young 5 . . . . . . . . . . . . 5 . . . . . . . . . . . . . . . . . . 3 2 . . . . . . 2 2 1

Triodia albescens Young 23 . . . . . . . . . . . . 15 7 1 . . . . . . 1 21 1 11 6

White triodia grass) Medium 13 . . . . . . 2 11 . . . . . . . . . . . . . . . . . . 7 5 1 . . . . . . 1'1 2

Bloom 10 . . . . . . 2 7 1 . . . . . . . . . . . . 5 5 . . . . . . . . . . . . 8 2

Mature 1 . . . . . . 1 . . . . . . . . . . . . . . . . . . . . . . . . 1 . . . . . . . . . . . . . . . . . . 1 . . . . . .

Triodia grandiflora ‘Bloom 3 . . . . . . 1 2 . . . . . . . . . . . . . . . . . . 3 . . . . . . . . . . . . . . . . . . 2 1
(Short leaf triodia)
Triodia mutica Bloom 1 . . . . . . 1 . . . . . . . . . . . . . . . . . . . . . . . . 1 . . . . . . . . . . . . . . . . . . . . . . . . 1

(Slender triodia) Mature 2 . . . . . . 2 . . . . . . . . . . . . . . . . . . 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

Triodia pulchella Bloom 1 . . . . . . . . . . . . 1 . . . . . . . . . . . . . . . . . . 1 . . . . . . . . . . . . . . . . . . . . . . . . 1

(Fluff grass) Mature 1 . . . . . . 1 . . . . . . . . . . . . . . . . . . 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

Triodia texana _ Young 5 . . . . . . . . . . . . 2 3 . . . . . . . . . . . . 2 3 . . . . . . . . . . . . 5 . . . . . .

(Texas triodia grass)

All samples Young 640 . . . . . . 18 363 197 62 13 207 375 45 25 419 196
Medium 362 . . . . . . 97 260 5 . . . . . . 3O 215 113 4 28 220 114
Bloom 354 2 195 154 3 . . . . . . 66 201 87 . . . . . . 33 215 106
Mature 560 26 385 148 1 . . . . . . 215 297 46 74 344 142
Total. . . . 1916 28 695 925 206 62 324 920 621 51 160 1198 558

83

NOI-LVLS LNIHWIHEIJXEI TVHHJIIIIOIHDV SVXEICL ‘699 'ONI NILEITIHH

THE CHEMICAL COMPOSITION OF GRASSES FOR RANGE CATTLE 29

at the several stages of growth, and fair in 59%, 31%, 24%, and 8%. Thus,
phosphoric acid was deficient or very deficient in about one-third of the
young grasses, two-thirds of the grasses at the medium stage of growth,
three-fourths of the grasses in bloom, and nine-tenths of the mature grasses.
None of the grasses was high in phosphoric acid, and only 51 of the 1,916
samples were classed as good, of which 45 were of young grasses. Phos-
phoric acid was deficient in 21% of the samples of Johnson grass, 66% of
those of buffalo grass, 88% of those of curly mesquite, and 95% of those
of Texas grama grass. When the grasses were young, phosphoric acid
was deficient in 72% of the samples of sideoats grama, 47% of those of
silver beard grass, and 16% of those of windmill grass; when the grasses
were in bloom, the percentages of deficient samples were 87%, 70%, and 50%
respectively. The proportion of samples which were deficient in phosphoric
acid averaged 70% in 7 important species of tall grasses and 59% in 10
species of short grasses. Very high proportions of the samples of Texas
grama (95%), hairy grama (91%), and sideoats grama (88%) were de-
ficient in phosphoric acid. When these three grama grasses are omitted
from the short grasses, the average proportion of deficient samples for the
remaining 7 species of short grasses was 46%, as compared with 70% for
the 7 tall grasses.

Lime was not deficient in any samples, and was high in about one-fourth
of them.

The data presented in Table 5 show that protein was deficient in many of
the grasses during later stages of growth, phosphoric acid was deficient in
many grasses during early growth and in most of them during later growth,
and lime was probably not deficient in any of the samples, that advancing
maturity greatly increased the proportion of samples which were deficient in
protein and phosphoric acid, and that different species differed in the pro-
portion of samples which were deficient in protein or phosphoric acid.

Johnson, Bermuda, Indian, big and little bluestems, and silver beard
grass are found both in the humid section of the state and in the eastern
part of the region covered by the present study. Protein in these grasses,
when young, averaged 7.33% for the East Texas Timber Country, 10.08%
for the Gulf Coast Prairie, and 10.96% for Northwest Texas. Phosphoric
acid averages were .35%, .40% and .49%, respectively. Average analyses
for the East Texas Timber Country were lower than those of the Gulf Coast
Prairie partly because the “young” group included some samples of late
vegetative growth excluded from the “young” groups of the other two
regions. Protein and phosphoric acid averaged considerably higher in these
grasses in northwest Texas than in either of the two regions in the humid
section.

Average Feed Constituents in the Grasses
The averages of feed analyses on 441 samples of the grasses are given in
Table 6. Averages for protein in Table 6 are slightly different from those

given in Table 2 because the averages given in Table 6 do not include all
of the samples whose averages are given in Table 2.

s

Table 6. Average composition of diflerent grasses at various stages of growth (percentages of air-dry matter)

Stage Number Nitrogen-
of of Protein Ether Crude ree Water Ash
growth samples extract fiber extract
Agropyron Smilhii Young 3 13.95 3.66 24.39 37. 75 8.04 12 .21
(Western wheat grass) Medium 3 7 .07 2 .30 31 .81 44. 17 8 .00 6.65
Andropogon barbinodis Bloom 2 6.65 1.91 30.39 45.42 7.84 7.79
(Plains. beard grass)
Andropogon Hallii Young 2 9.98 2.39 24.94 43.89 7.37 11.43
Medium 2 7.78 2.08 29.97 43.13 8.02 9.02
Bloom 3 4.82 2.52 31.80 44.86 8.16 7.84
Mature 2 3.10 2.28 32.03 45.14 9.17 8.28
Andropogon ischaemum Young _ 1 17. 53 2 .08 22 .01 36.98 7.94 13 .46
Medium 1 8.80 1.58 27.58 43.21 7.15 11.68
Andropogon saccharoides Young 6 10.93 1 .92 27.92 39.91 7.77 11 .55
(Silver beard grass) Medium 4 6.34 1.78 31.74 42.53 7.73 9.88
Bloom 3 5.17 1.78 31.88 44.29 8.23 8.65
Mature 4 2. 96 1.44 34.99 43. 62 8.22 8.77
Andropogon scoparius Young 1 8.02 3.21 29 04 45 40 7.09 7.24
(Little bluestem)
Andropogon lernarius Young 3 8.48 2.35 31 .03 41 .72 8.28 8.14
(Silvery beard grass) Medium 3 6.07 2.84 29.78 44. 91 7.76 8.64
Bloom 4 5.80 1.83 32.82 43.73 7.73 8.09
Mature 4 2.70 1.88 33.09 46.35 8.11 7.87
Aristida longisela Young 3 7.67 1.58 32. 57 41.64 7.32 9 .22
(Red three-awn) Medium 2 5.27 1.27 32.58 43.10 7.64 10.14
V Bloom 1 5.67 1.33 35.22 42.67 7.91 7.20
Mature 7 4.51 1.21 31.99 42.66 7.79 11.84
Arislida purpurascens Medium 2 5.89 1 .34 33.99 42 .24 7.56 8.98
(Arrow feather) Bloom 1 5 .23 1.02 35.13 41.39 7. 78 9 .45
Mature 3 3.96 0.95 32.14 43.30 7.31 12.34
Arisiida purpurea Young 3 9.39 1.58 30. 70 42 .06 7.14 9.13
(Purple three-awn) Medium 3 5.55 0.95 29.35 42.23 6.68 15.24
Bloom 3 5.78 1.18 33.58 41.74 7.32 10.40
Mature 2 4.59 1.31 31.91 40.81 7.71 13.67

08

NOLLVLS LNEIWIHEIcIXIEI TVHHIIIIIOIHDV SVXELL ‘699 "ON NLLHTIIIH

7' urrwev-uwnqqmpq-vv: v '1 r

Boutcloua curtipendula
(Sideoats grama)

Bouleloua eriopoda
(Black grama)

Bouteloua gracilis
(Blue grama)

Boulelouq hirsuta
(Hairy grama)

Bouteloua rigidiseta
(Texas grama)

Bromus cathariicus
(Rescue grass)

Bromus japonicus
(Japanese chess)

Bromus mollis (Soft chess)
Bromus lexensis (Texas brome)

Buchloe dactyloides
(Buffalo)

Chloris cucullata
(Finger grass)

Chloris verlicullaia
(Windmill grass)

Cynodon daclylon
(Bermuda grass)

Elymus canadensjs
(Nodding wild rye)

Young
Medi m
Bloom
Mature

Young
Bloom

Young
Bloom
Mature

Young
Bloom
Mature

Young
Medium
Bloom
Mature

Young
Young

Young
Young

Young
Medium _
Bloom
Mature

Young
Bloom
Matu re

Young
Medium
Bloom
Mature

Young
Bloom
Mature

Young
Bloom
Mature

n-A
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Table 6. Average composition of difierent grasses at various stages of growth (percentages of air-dry matter)-r—Continued

Stage Number Nitrogen-
of of Protein Ether Crude ree Water Ash
growth samples extract fiber extract
Elymus villosus (Wild rye) Young 1 19.31 2.73 19.49 34 .25 10.14 14 .08
Eragrosiis Beyrichii Mature 1 6. 61 1.52 30.21 43.23 7.67 l0. 76
(Dropseed)
Eragrostis curvulla Young 2 11.49 2.48 26.99 44.23‘ 7.31 7.50
Eragrostis diflusa Young 2 10.81 3.40 28.25 41.58 8.26 7.70
Eragrostis inlermedia Young 3 11.62 1.81 29. 96 38.47 7.71 10.43
(Plains love grass) Bloom 2 5.53 1.87 30.89 43.51 7.14 11 .06
Eragroslis Iugens Young 1 12.16 1 .91 27.22 41.02 7.65 10.04
Eragroslis secundiflora Young 1 10.17 2.06 32.30 37. 69 7.94 9.84
Bloom 2 5.75 1.91 31.99 40.76 7.60 11.99
Mature 1 3.48 2.13 36.73 43.69 8.04 5.93
Eragrostis sessilispica Young 2 8.43 2.01 30.31 42.66 7.02 9.57
Bloom 2 4.68 1.55 38.08 38.61 7.66 9.42
Mature 2 3.29 1.51 36.01 42.25 7.93 9.01
Hilaria Belangeri Young 3 8.91 1.90 25.31 43.96 7.38 12.54
(Curly mesquite) Bloom 4 6.04 1.78 28 18 39.85 7. 70 16.45
Mature 5 4.41 1.81 25.60 41.91 7.72 18.55
Hilaria Jamesii (Galleta) Medium 2 9.17 1.79 29.88 41.42 7 .23 10.51
Hilaria mulica Young 4 10.24 1.66 27.70 38.94 7.58 13.88
(Tobosa) Medium 4 7.18 1.60 29 .03 42.03 7. 56 12. 60
Bloom 1 5.25 1.16 30.52 42.74 8.06 12.27
Mature 3 5.47 1.13 31.84 43.05 7.28 11.23
Hordeum pusillum Young 9 12. 74 2. 71 2O 40 46.71 7.06 10.38
(Little barley)
Muhlenbergia arenacea Young 2 12.17 1.78 27. 98 36.63 8 .27 13.17
(Muh y grass) Medium 2 6.74 1.18 31.29 39.58 6.94 14.27
Muhlenbergia pungens Young 3 16.89 1.57 24.89 38.88 7.49 10.28

(Blowaway grass)

Z8

NOLLVLS LNEIWIEIHJXE TVHIIJIIIIOIHDV SVXELL ‘699 'OI\I NILLEYYIHH

Munroa squarrosa
(False buffalo)

Panicum antidotalc

Panicum arizonicum

Panicum bulbosum
(False Johnson grass).

Panicum capillare
(Old witch grass)

Panicum capillarioides
Panicum geminatum

Panicum obtusum
(V1ne mesquite)

Panicum texanum

(Colorado grass)
Panicum virgatum (Switch grass)
Paspalum ciliatifolium

Paspalum distichum
(Joint grass)

Paspalum setaceum
Paspalum unispicatum

Phalaris carolinicus
(Southern canary)

Phalaris minor (Little canary)

Schedonnardus paniculatus
(Tumble grass)

Setaria macrostachys
(Plains bristle grass)

Selaria viridis
(Green foxtail)

Young

Young
Young
Medium
Bloom
Young
Young
Medium
Young

Young
Medium

Young
Bloom
Mature

Young

Young
Bloom

Bloom

Bloom
Young
Young

Young

Young
Bloom

Young
Bloom

Young

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.93
.67

99

.31

16.

19..
27.

35.
22.‘

24.
30.
22.

31.
24.
27.

25.

28.
30.

32.
32.

28.

.98
.42

.42

.03
.54

f’ i’

. 1J1)
I 17
.06

42.
38.
47.

41.
38.
41.

39.

43.

33.
35.

42.

C73

\l

<0

O0

Q

\l \"|OO\l \l\l 0O \‘lO‘-> \l\lO0 OO

.67

.48

48
ob
0.3

.49

14
23

.63

49
58
46

66

.92
.14
.79

.99

7.74

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OOOOQNIOOQ

.71

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.13

99

49
36

.10

12..

12.
.29
11.
12.
11.

14.
14.
.82

14.

.87
.38

13.
13.

.90

17

12
99

.27
.77

.69

.26
.24
.58
.67
.30

.20

.91
13.
12.

60

06

69

99

80
57

EITLLVO EIDNVH H031 SESSVHS .210 NOLLISOdTAlOO "IVOIWEIHO EHL

88

Table _6. Average composition of dilferent grasses at various stages of growth (percentages of air-dry matter)——Continued

Stage Number Nitrogen-
of of Protein Ether Crude free Water Ash
growth samples extract fiber extract

Sorghastrum nulans Young 6 11.23 2.71 28.10 40.64 7.19 10.13

(Indian grass) Mature 1 5.70 2.55 28.84 46.26 7.67 8.98

Sorghum halepense Young 8 13.82 2.58 26.55 38.80 8.20 10.05

(Johnson grass) Bloom 5 7.87 2.06 29.89 42.51 8.31 9.36

Sporobolus airoides Young 6 9.66 1.80 31.33 40.65 7.89 8.67

(Sand dropseed) Medium 1 6.26 1.49 32.40 42.79 7.21 9.85

Bloom 3 5.77 1.59 33.77 43.07 7.60 8.20

Mature 2 4.58 1.92 33.83 45.44 7.70 6.53

-Sporob0lus cryptandrus Young 7 11 .01 1 .59 28. 95 40 .40 7.70 10.35

(Sand dropseed) Mature 2 5.61 1.53 32.18 46.36 7.71 6.61

Sporobolus Wrightii Medium 1 6.79 1.72 29.85 42.52 8.92 10.20

(Sacaton) Mature 1 4.17 1.63 28.75 31.75 8.29 5.41

Slipa comata Young 6 11.06 2.45 26.89 40.88 7.30 11.42

(Needle grass) Medi ;m 1 7.40 4.81 26.50 38.71 7.89 14.69

Bloom 2 6.07 2.39 32.25 41.46 8.14 9.69

Mature 3 5.18 3.36 30.04 41.24 8.26 11.92

Slipa leucotricha Young 4 9.60 2.58 28.45 41.55 8.05 9.77

(Texas needle grass) Medium 3 6.54 3.24 28.01 40.66 7.34 14.21

Bloom 1 8.28 2.50 30.24 39.52 7.55 11.91

Mature 2 6.29 2.65 29.25 41.97 8.43 11.41

Trichachne californica Young 5 8.22 1.75 33 39 38.56 7.49 10.59

Triodia albescens Young 6 11.08 1.85 30.16 38.93 8.19 9. 79

(White triodia) Medium 4 7.03 1.91 32.36 41.16 7.96 9.58

Bloom 1 5.33 1.30 33.56 44.08 6.64 9.09

Triodia grandiflora Bloom 3 7.35 1.40 27 76 37 46 7.02 19.01
(Flully triodia)

Triodia mutica _ Bloom 1 5.85 .88 20.72 24.29 5.35 42.91

(Slender triodia) Mature 1 5.08 1.21 20.54 33.41 5.48 34.28

Triodia pulchclla (FlulT) Bloom 1 8.27 1.41 30.66 37.98 7.16 14.52

Mature 1 5.92 1.08 23.43 35.24 6.62 27.71

Triodia lexana Young 3 11.16 1.83 30.70 38.49 8.01 9.81

NOLLVLS LNEINIHEIJXEI TVHIILTIIOIHDV SVXHL '699 ‘ON NLLEVYIIIH

78

THE CHEMICAL COMPOSITION OF GRASSES FOR RANGE CATTLE 35

Ether extract was 10w in all samples and it is doubtful if the differences
among species at the same stage of growth are of practical importance.
Crude fiber in the short grasses averaged about 25% as compared with 30%
or more in many of the tall grasses, and was considerably lower in the
young grasses than in the older grasses. Nitrogen-free extract ranged from
38% to 42% in most young grasses and from 42% to 46% in mature
grasses; differences among species are small and of doubtful significance.
Water averaged about 8% in the dried samples; this figure is sufiiciently
close to convert the analyses given in the various tables to the moisture-
free basis if desired. Ash usually ranged from 10% to 12%, although it was
considerably higher in some species; ash includes not only the minerals
taken up by the plants, but also soil which has collected upon them.

The Chemical Composition of the Soils

Samples of soils from locations on which grass samples were collected
several times were taken in order to study the relation between the chemical
composition of the soils and that of the grasses grown on the soils. A
knowledge of this relation is of value in estimating the probable relative
chemical composition of grasses from soil types already mapped and
whose general chemical composition is known (6). Averages for the princi-
pal chemical constituents of the 95 soils, arranged in seven groups, and the
distribution of the soils in different grades, are given in Table 7. Reasons
for the adoption of these grades have been published (6).

Total nitrogen was classed as deficient in only 3 of the 95 soils analyzed;
these were a Vernon clay loam from a badly eroded area, a Nimrod fine
sand, and a Windthorst fine sandy loam. Nitrogen was classed as high in 22
soils, of which 11 were soils of the Denton-San Saba group from the
Grand Prairie. The latter group of soils was considerably higher in total
nitrogen than any other group. Total phosphoric acid was deficient in 23
soils, of which 10 were in the Windthorst-Nimrod group and 7 in the Miles-
Vernon group. None of the soils were high in total phosphoric acid; only
18 soils were good in this constituent. Active phosphoric acid was deficient
in 32 of the 95 soils, and 12 were very deficient. All of the Windthorst-
Nimrod soils were deficient or very deficient in active phosphoric acid; only
1 of the Potter-Pullman-Richfield soils (a Potter gravelly loam) was
deficient. Soils of the Denton-San Saba group and the Windthorst-Nimrod
group averaged in Grade 4 (30 to 100 p.p.m.); the soils of the Denton-
San Saba group (66 p.p.m.) contained over twice as much as the Wind-
thorst-Nimrod group (31 p.p.m.). Terrace and bottom-land soils (260
p.p.m.) and the dark-colored Potter-Pullman-Richfield soils of the High
Plains (299 p.p.m.) averaged well above the lower limit of Grade 2 (200
p.p.m.) and are good in this respect. The soils in this section of the
state averaged much higherin active phosphoric acid than those previ-
ously reported for the East Texas Timber Country (7) and the Gulf
Coast Prairie (11).

Basicity averaged deficient (Grade 4) in the Windthorst-Nimrod group
(32%) and fair (Grade 3) in the Amarillo group (1.50%). Basicity was

Table 7. Average analyses and number of soils of groups according to percentages of certain constituents

Terrace
Denton- Wind- Miles- Abilene and Potter-
San Saba thorst- Vernon Valera Bottom- Amarillo Pullman- Total
Nimrod land Richfield
Total number of soils . . . . . . . . . . . . . . . . . . . . . . .. 19 10 26 9 12 7 12 95

Nitrogen, average, % . . . . . . . . . . . . . . . . . . .  . .. .185 .075 .120 .170 .155 .114 .141

Grade 4, Deficient, .031 to .060% . . . . . . . . . O 2 1 0 O 0 0 3

Grade 3, Fair, .061 to .120% . . . . . . . .. 2 8 14 2 3 3 4 36

Grade 2, Good, .121 to .180% . . . . . . . .. 6 0 8 4 5 4 7 34

Grade 1, High, Over 180% . . . . . . . . . . . 11 0 3 3 4 0 1 22

Total phosphoric acid, average, % . . . . . . . . . . . . . .084 .036 .065 .079 .089 .063 .101

Grade 4, Deficient, .026 to .050% . . . . . . . . . 1 1O 7 2 1 1 1 23

Grade 3, Fair, .051 to .100% . . . . . . . . . 14 0 17 5 8 6 4 54

Grade 2, Good, .101 to .150% . . . . . . . .. 4 0 2 2 3 0 7 18
Active phosphoric acid, average, p. p. m... .. . . . . 66 31 158 149 260 127 299
Grade 5, Very deficient, 0 to 3O p. p. mu . .. 7 5 0 0 0 0 0 12
Grade 4, Deficient, 31 to 100 p. p. In . . . . .. 7 5 11 5 1 2 1 32
Grade 3, Fair, 101 to 200 p. p. In . . . . . . 5 0 9 1 2 5 3 25
Grade 2, Good, 201 to 400 p. p. m... . . . 0 O 5 3 7 0 5 20
Grade 1, High, Over 400 p. p. m . . . . . .. 0 O 1 0 2 0 3 6

Basiciiy, average, % . . . . . . . . . . . . . . . . . . . . . . . . . 14.80 .32 4.85 9.91 3.24 1.50 5.72

Grade 5, Ver deficient, 0 to 30% . . . . . . . . . 0 4 2 0 O 0 0 6

Grade 4, De rcient, .31 to .60% . . . . . . . . . .. 1 5 2 0 2 0 0 10

Grade 3, Fair, .61 to 2.00% . . . . . . . . . . . . .. 3 1 9 2 5 5 5 30

Grade 2, Good, 2.01 to 5.00% . . . . . . . . . . .. 5 0 7 2 1 2 4 21

Grade 1, High, Over 5.00% . . . . . . . . . . . . . .. 10 0 6 5 4 0 3 28

98

NOLLVLS LNHWIHEIcIXEI "IVHILUIIIOIHDV SVXELL ‘699 ‘ON NLLEYYIIIEI

THE CHEMICAL COMPOSITION OF GRASSES FOR RANGE CATTLE 37

deficient or very deficient in 16 soils, of which 9 were in the Windthorst-
Nimrod group and 4 in the Miles-Vernon group. The individual soils in
the latter group differed widely in basicity. Grades for active lime and
acidity (pH) are not shown in Table '7 because very few of the soils were
deficient in active lime or were acid. Active lime was deficient (be-
low 1600 p.p.m.) in only 5 soils, of which 4 were in the Windthorst-
Nimrod group. Only 4 of the soils were on the acid side of neutrality;
the most acid soil sampled had a pH of 6.02, which indicates that it is
only slight acid and probably does not need lime to correct the acidity.
Many of the soils had a pH above 8.0 and thus were alkaline.

The Windthorst-Nimrod group was relatively quite low in all im-
portant cons-titutents except nitrogen, in which it was fair. The Denton-
San Saba group was deficient in active phosphoric acid but high in nitro-
gen and basicity. The other groups of soils were fair to high in most
of the important constitutents, although considerable range occurred in
the analyses of the individual samples (Table 7), particularly in the
Miles-Vernon group. With the exception of one Potter gravelly loam, which
could perhaps more properly be called rough, stony land, none of the
soils in the Potter-Pullman-Richfield group were deficient in any of the
principal chemical constituents.

Relation of the Soils Series to the Composition of the Grasses

The grass samples were grouped according to stage of growth and then
according to the principal soil series groups upon which the grasses were
grown. The data with respect to protein in the grass samples within each
group are given in Table 8, to phosphoric acid, in Table 9, _and to lime,
in Table 10. Protein in the young grasses exceeded 10.5% in samples from
the Miles-Vernon and the terrace and bottomland soils of the Rolling
Plains and the Potter-Pullman-Richfield soil-s of the High Plains, and
was lowest (9.56%) in the samples from the Abilene-Valera soils of
the Rolling Plains. Nearly half (45%) of the samples of young grass
from the Miles-Vernon and terrace and bottomland soils contained more
than 10.5% protein, compared with about one-third of the samples
from the other soil groups. At the medium stage of growth, the relative
order of the different groups of soils was approximately the same, but
the percentage of protein in the grass samples was about 40% lower than
at the young stage of growth. None of the groups averaged less than
6% protein, but the proportion of samples which contained less than 6%
protein ranged from 10% of the samples from the Amarillo soils to 30%
of the samples from the Abilene-Valera soils. At the bloom stage of
growth, only the samples from the Amarillo, Miles-Vernon, and terrace
and bottomland soils averaged over 6% protein, with the samples from
the Windthorst-Nimrod soils down to 5.15% protein. Only 28% of the
samples from the Amarillo soils contained less than 6% protein, compared
with 80% of the samples from the Windthorst-Nimrod soils. At the mature
stage of growth, protein ranged from 6.39% in samples from the Amarillo

Table 8. Average protein in grass samples from soil groups according to series and percentage of samples in groups according to protein in grasses
Wind- Terrace Potter-
Denton- thorst- Miles- Abilen.e- an Amarillo Pullman-
San Saba Nimrod Vernon Valera Bottom- Richfield
land
Average nitrogen in soils, % . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .185 .075 .120 .170 155 .114 .141
Young grasses

Average protein in all grass samples, % . . . . . . . . . . . . . . . 9 .89 9.74 10.93 9.56 10. 78 10.25 10.89
Number of samples . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 120 84 170 44 120 38 64

Percentage of samples with protein
Below 6 . 00% . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 6 3 5 1 0 2
6.01% to 8.25% . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 30 30 19 27 16 18 30
8.26% to 10.49% . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 29 28 33 38 38 45 27
Over 10.49% . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37 36 45 30 45 37 41

Grasses at medirm stage

Average protein in all grass samples, % . . . . . . . . . . . . . . . 6.60 6.36 7.02 6.79 7.41 7.44 6.79
Number of samples . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83 35 93 39 73 21 19

Percentage of samples with protein
Below 4.50% . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 3 5 3 2 0 5
4.50% to 5.99% . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 27 29 24 33 16 10 32
6.00% to 8.25% . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 65 65 49 46 55 62 58
Over 8.25% . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 7 3 22 18 27 28 5

Grasses in bloom

Average protein in all grass samples . . . . . . . . . . . . . . . . . .. 5.91 5.15 6.27 5.60 6.20 6.71 5.56
Number of samples . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66 49 14-6 16 37 15 22

Percentage of samples with protein
Below 4.50%. _ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 20 32 13 35 16 17 31
4.50% to 5.99% . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 35 48 40 29 32 11 31
6.00% to 8.25‘% . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 38 20 35 24 41 55 38
Over8.25% . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 7 0 12 12 11 17 0

Matvre grasses

Average protein in all grass samples. % . . . . . . . . . . . . . .. 4 .80 4.64 5.33 5.07 5.11 6.39 5.64
Number of samples . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 105 54 169 60 54 41 77

Percentage of samples with protein
Below 3% . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 2 7 5 0 5 2
3.00% to 4.49% , . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 34 44 28 30 30 5 29
4.50% to 6.00% . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 43 50 35 40 46 39 29
Over 6 .00% . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 4 30 25 24 51 40

88

NOLLVLS mnawnmaxa "IVHILIIIIIOIHSV SVXELL ‘699 "ON NLLEPYIIIH

Table 9. Average phosphoric acid in grass samples from soil groups according to series and percentage of samples in groups according to

phosphoric acid in grasses

Wind- Terrace Potter-
Denton- thorst- Miles- Abilene- and Amarillo Pullman-
San Saba Nimrod Vernon Valera Bottodm- Riehfield
an
Active phosphoric acid in soils, p. p. m . . . . . . . . . . . . . . . . . . . . 66 31 158 149 260 127 299
Young grasses

Average phosphoric acid in all grass samples, % . . . . . . . . .39 .38 .40 .35 .52 .36 .44
Number of samples . . . . . . . . . . _ . . . . . . . . . . . . . . . . . . . . . . 120 84 170 44 120 38 64

Percentage of samples with phosphoric acid
elow .16% . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 3 1 2 9 0 O 0
.17% to .327 , . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 37 33 35 35 2O 51 31
.33% to .4917’; . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4O 52 37 40 34 38 37
Over .49% . . . . . . . . . , . . . . . . . . . . . . . . . . . . . . . . . . .. 20 13 26 16 46 11 32

Grasses at medirvm stage

verage phosphoric acid in all grass samples, % . . . . . . . . .27 .30 .28 .23 .37 .35 .33
Number 0f samples . . . . . . _ . . . . . . . . . . . . . . . . . . . . . . . . . . 83 35 93 3 73 21 19

Percentage of samples with phosphoric acid
Below .16 0 . _ . . . . . . . . _ . . . . . . . . . . . . . . . . . . . . . . .. 7 6 12 21 O O 11
.17% to .24% _ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . 35 35 38 46 12 5 11
25% to .32% , . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 40 26 21 21 28 4O 37
Over .32% . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 18 32 29 13 60 55 42

Grasses in bloom

Average phosphoric acid in all grass samples, % . . . . . . . . .24 .24 .25 .22 .36 .34 .29
Number of samples . . . . . . . . . . , . . . . . . . . . . . . . . . . . . . . . . 66 49 146 16 3'7 15 22

Percentage of samples with phosphoric acid
Below .16% . _ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 21 22 21 31 3 0 0
.17% to .24% . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 39 39 38 25 3 20 36
.25% to .32% . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2O 29 24 31 32 2O 32
Over .32% . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2O 10 18 13 62 6O 32

Mature grasses

Average phosphoric acid in all grass samples, % .18 .20 .20 .15 .20 .27 .27
Number of samples . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 105 54 169 6O 54 41 77

Percentage of samples with phosphoric acid
Below .10% . . . . . . . . . . . . . . . . . . . . _ . . . . . . . . . . . . . . 7 O 9 17 5 0 O
.l1% to .16% _ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 39 41 36 53 27 5 12
.17% to .24% , . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 38 39 36 25 50 3» 31
Over .24% . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 16 20 19 5 18 61 57

68 EITLLVO EIDNVH ‘HOS: SEISSVHD JO NOLLISOJNOO ‘IVOIWHHO {KHJL

Table 10. Average lime in grass samples from soil groups according to series and percentage of samples in groups according to lime in grasses
Wind- _ Terrace Potter-
Denton- thorst- Mlles- Abilene- an Amarillo Pullman-
San Saba Nimrod Vernon Valera Bottom- Richfield
_ land
Basicity in soils, % . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 14.80 0.32 4.85 9.91 3.24 1.50 5.72
Young grasses

Average lime in all grass samples, % . . . . . . . . . . . . . . . . . . .99 .62 .70 .84 .67 .75 .74
Number of samples . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 120 84 170 44 120 38 64

Percentage of samples with lime
Below .43 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0 11 6 2 7 3 0
43% to 62% . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 1O 59 33 11 4O 16 22
63% to .82% . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 27 19 33 41 33 58 50
ver .82% . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63 11 28 46 20 24 28

Grasses at medium stage

Average lime in all grass samples, % . . . . . . . . . . . . . . . . . . 1 .23 .64 .74 .86 .63 .70 .63
Number of samples . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83 35 93 39 73 21 19

Percentage of samples with lime
Below .43% . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 0 14 8 0 14 O 16
.43% to 152% . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 7 37 32 23 41 38 42
.63% to .82% . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 29 43 25 4-1 31 47 26
Over .82% . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 64 6 35 36 14 l5 16

Grasses in bloom

Average lime in all grass samples, % . . . . . . . . . . . . . . . . . . .91 .59 .72 .65 .72 .58 .70
Number of samples . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66 49 146 16 37 15 22

Percentage of samples with lime
Below 43% . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. O 15 16 0 13 0 0
.43% to .62% . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 15 39 27 31 35 67 27
.62% to .82% . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 27 36 28 38 22 33 41
Over .82% . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 58 1O 29 31 30 O 32

Mature grasses

Average lime in all grass samples . . . . . . . . . . . . . . . . . . . . . 1 .11 .55 .7 .84 .67 .58 .66
Number of samples . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 105 54 169 6O 54 41 77

Percentage of samples with lime
Below .43 0 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 2 28 15 7 9 15 17
.4370 t0.62% . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 2O 48 34 25 45 39 4O
133% to .82% . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3O 18 3O 3O 28 34 26
Over .82% . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48 6 21 38 18 12 17

0T’

NOLLVLS LNEIWIHEIJXH TVHIILTIIOIHSV SVXELL ‘699 ‘ON NLLEFYIIIH

THE CHEMICAL COMPOSITION OF GRASSES FOR RANGE CATTLE 41

soils to 4.64% in those from the Windthorst-Nimrod soils, with the pro-
portion of samples containing less than 6% protein ranging from 49%
to 96% of the samples from those soil groups.

Phosphoric acid (Table 9) in the young grasses ranged from .52% in the
samples from terrace and bottomland soils to 35% in those from the Abi-
lene-Valera soils. Phosphoric acid was over .32% in 80% of the samples
from the terrace and bottomland soils and in only 56% of those from the
Abilene-Valera soils. At the medium stage of growth, phosphoric acid
averaged 33% or higher in samples from terrace and bottomland soils of
the Rolling Plains and the Amarillo and Potter-Pullman-Richfield soils
of the High Plains, and below that percentage in all other groups, with
over two-thirds of the samples containing less than .83% phosphoric acid.
The data with respect to the samples at the bloom stage of growth are
very similar to those at the medium stage of growth, except that a higher
percentage of the samples from some of the soils contained less than
33% phosphoric acid. At the mature stage of growth, "samples from the
Amarillo and Potter-Pullman-Richfield soils of the High Plains averaged
.27% phosphoric acid, and were the only samples which averaged over
.20%. The proportion of samples which contained less than .17% phos-
phoric acid ranged from 5% of the samples from the Amarillo soils to
70% of the samples from the Abilene-Valera soils. The relatively poor
showing for the Abilene-Valera soils with respect to both protein and
phosphoric acid was due largely to the comparatively low percentages of
protein and phosphoric acid in the samples from the Valera soils (see
Tables 11 and 12). The Abilene soils contained more nitrogen and active
phosphoric acid than the Valera soils and produced grasses containing
higher percentages of protein and phosphoric acid.

Lime (Table 10) was higher in grass samples at all stages of growth
from soils of the Denton-San Saba and Abilene-Valera soils and lower in
samples from the Windthorst-Nimrod soils than in vthose from the other
soils. About two-thirds of the samples from the Denton-San Saba soils
and less than one-third of the samples from the Windthorst-Nimrod soils
were high in lime. As previously noted, very few of the samples from any
group of soils were low in lime.

The Amarillo soils produced grasses which averaged over 6% protein
at all stages of growth and over 33% phosphoric acid at all stages except
the mature stage. Grasses produced on the Potter-Pullman-Richfield soils
and on the terrace and bottomland soils were almost as high in protein
and phosphoric acid as those produced on the Amarillo soils. Grasses
produced on the Denton-San Saba and Windthorst-Nimrod soils in the
eastern part of the region were lower in protein and phosphoric acid than
grasses produced on soils farther west. A large part of this difference
is probably due to the fact that the grasses produced on the eastern
soils were sometimes composed largely of tall species, in which protein and
phosphoric acid are usually lower than in the short species produced
farther Wes-t, particularly at later stages of growth (see Table 2).

 

 

42 BULLETIN NO. 669, TEXAS AGRICULTURAL EXPERIMENT STATION

Composition of Grasses on Different Soil Series at Different Times of Year

The grass samples were here grouped according to date of collection
rather than to stage of growth. Samples were collected four times during
the year over nearly a three-year period. Samples collected the last of
April or the first of May were nearly all young, although some mature
samples were collected from a few hilly locations on the Rolling Plains
and from several locations on the High Plains. Samples collected the lat-
ter part of June were mostly at the medium stage of growth. Those collected
the middle of September were mostly of grasses in bloom, although some
mature samples were secured where fall rains had not yet begun. Samples
collected the first part of November were nearly all of mature growth. A
subgrouping of the samples was made, based upon the principal soil
series from which they were collected. The average percentages of pro-
tein and the proportions of the samples in which protein was deficient
(below 6.00%) are shown in Table 11. Similar data for phosphoric acid
are given in Table 12.

The average percentage of protein in the samples collected in April 

varied from 11.91% in samples from bottomland pastures of the Rolling

Plains to 6.65% in samples from the stony or hilly Valera and Crawford a

soils. The proportion of samples classed as deficient ranged from 0% on
the San Saba soils to 32% of the samples from the stony soils (Valera
and Crawford). Many of the latter were mature samples. Protein in
the June samples ranged from 8.64% in the samples from the Pullman-

Richfield soils to 5.44% in those from the Nimrod soils, with from 4% to A
91% of the samples deficient in protein. Protein in the September samples l

averaged slightly above 6% in the samples from all soils except the
Denton, Windthorst, Nimrod, and stony soils, and averaged down to 4.22%
on the Nimrod soils. The proportion of deficient samples ranged from
27% of those collected from the Pullman-Richfield soils to 100% of those
from the Nimrod soils. Protein averaged below 6% in samples collected
in November from all groups of soils, and below 4.50% in those from
Denton, Windthorst, and Nimrod soils. Over 80% of the samples collected
in November from soils of the Grand Prairie, YVest Cross Timbers, and
the Miles, stony, and terrace soil-s of the Rolling Plains were deficient in
protein.

Phosphoric acid in the April samples ranged from .57% in the samples l
from the bottomland soils to .22% in those from the stony soils of thei

Rolling Plains, of which 90% were deficient (below .33%) in phosphoric
acid. Most of the latter samples were mature. Phosphoric acid also averaged
below 33% in the samples from the Vernon soils (.30%), of which many
were from hilly locations and some were mature grasses. Phosphoric acid
in the June samples ranged from .56% in the samples from the Pullman-
Richfield soils to .24% in those from Denton soils, with from 16% to 86%
of the samples deficient. Phosphoric acid in samples from the stony soils
of the Rolling Plains and from the Amarillo and Pullman-Richfield soils
of the High Plains averaged considerably higher in the June samples

Table 11.

Average protein in grass samples at difierent seasons and from diflerent soil series

_ Total Samples deficient in protein as
Nitrogen number of Average protein in grasses, % percentage of total
Soil group in SOIlS samples of
% grasses April June Sept. Nov. April June Sept. Nov.
Grand Prairie
Denton . . . . . . . . . . . . . . . . . . . . . . . . . . .. .196 147 10.03 6.51 5.65 4.47 4 26 55 9O
San Saba . . . . . . . . . . . . . . . . . . . . . . . . .. .192 128 10.71 7.09 6.25 4.76 0 22 50 81
West Cross Timbers
Windthorst . . . . . . . . . . . . . . . . . . . . . . . . . .080 206 9.81 7.57 5.24 4 .49 7 20 87 89
Nimrod . . . . . . . . . . . . . . . . . . . . . . . . . . .. .055 44 7.04 5.44 4.22 4.04 31 91 100 100
Rolling Plains
Miles . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. .149 258 11.00 8.51 6.83 4.68 15 15 42 82
Vernon . . . . . . . . . . . . . . . . . . . . . . . . . . . . .100 236 8.78 8.00 6.35 5.42 25 16 49 68
Abilene . . . . . . . . . . . . . . . . . . . . . . . . . . .. .151 165 8.85 8.43 6.12 5.86 11 23 50 59
Stony soils (Valera—Crawford). . . . . . .. .176 153 6.65 6.68 4.71 5.01 32 21 88 85
Terrace soils (Wichita-Calumet) . . . . - . .141 204 8.34 7.87 6.08 4.76 28 28 57 80
Bottomland soils (Miller-Spur). . . . . . . 165 175 11.91 8.50 7.06 5.87 22 9 46 59
High Plains
Amarillo. . . .- . . . . . . . . . . . . . . . . . . . . . .. .107 130 9.92 7.28 6.64 5.99 8 14 27 48
Pullman-Richfield . . . . . . . . . . . . . . . . . . . .151 116 11.29 8.64 6 .28 5.45 12 4 50 63

8f’ {TLLLVO EIDNVH ‘HOJ SEISSVHD :10 NOLLISOJWOO “IVOIWHHO HHL

*7.

Table 12. Average phophoric acid in grass samples at dilferent seasons and from diflerent soil series
- Active Total Average phosphoric acid in Samples deficient in phosphoric
phosphoric number of grasses, 0 acid as percentage of total
aci samples of
in soils grasses _ _
p. p. m. Apr1l June Sept. Nov. Apr1l June Sept. Nov.
Grand Prairie
Denton . . . . . . . . . . . . . . . . . . . . . . . . . . . . 86 147 .36 .24 1 .11 38 86 94 100
San Saba . . . . . . . . . . . . . . . . . . . . . . . . . . 52 128 .44 .32 . >8 .21 26 61 a 75 94
West Cross Timbers
indthorst . . . . . . . . . . . . . . . . . . . . . . . . . 34- 206 .41 .31 .25 .17 43 61 74 100
Nimrod . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 44 .33 .26 .23 .14 54 66 93 100
Rolling Plains
Miles . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 226 258 .35  .28 .19 44 54 69 88
Vernon . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1411 236 .30 .25 .26 .18 75 77 90 100
Abilene . . . . . . . . . . . . . . . . . . . . . . . . . . . . 216 165 .35 .34 .25 .17 42 52 82 100
Stony soils (Valera-Crawford). . . . . . . . 58 153 22 .31 .13 . 17 90 60 97 100
Terrace soils (Wichita-Calumet) . . . . . . 174 204 38 .35 .26 .22 56 45 75 77
Bottomland soils (Miller-Spur). . . . . . . 276 175 .57 .41 .36 .26 25 3O 52 70
High Plains
Amarillo . . . . . . . . . . . . . . . . . . . . . . . . . . . 123 130 .25 .40 .32 .30 41 57 58 62
Pullman-Richfield . . . . . . . . . . . . . . . . . . . 340 116 . 42 .56 .37 .29 42 16 37 79

W’

NOLLVLS LNEIWIHEIdXEI "IVHHLTHOIHDV SVXELL ‘699 ‘ON NILLEITIHH

THE CHEMICAL COMPOSITION OF GRASSES FOR RANGE CATTLE 45

than in the April samples; a number of mature samples were collected
from these soils in April, because of lack of sufficient early spring rain-
fall to start growth on several locations. With the exception of samples
collected from bottomland and Pullman-Richfield soils, phosphoric acid in
the samples collected in September averaged below .33% and as 10W as
18% in the samples from the stony soils of the Rolling Plains. Phosphoric
acid in the September samples was deficient in only 37% of the samples
from Pullman-Richfield soils and in over 90% of those from Denton, Nim-
rod, and stony soils. Phosphoric acid in the November samples averaged
below .3370 in all groups, and decreased to .14% in the samples from the
Denton and Nimrod soils. All of the samples from six of the soil groups
were deficient in phosphoric acid.

Important dilferences among the soils as grouped in Tables 8 and 9
are shown by the closer grouping given in Tables 11 and 12. Throughout
the year, both protein and phosphoric acid were considerably higher in
grasses produced on the Windthorst soils than on the Nimrod soils, and
the data in the second column of Tables 11 and 12 show ‘that the Wind-
thorst soils contained considerably more nitrogen and active phosphoric
acid than did the Nimrod soils. This same relation between the chemical
composition of the grasses and that of the soils is found for the Miles
soils as compared with the Vernon soils, the Abilene soils as compared
with the Valera-Crawford soils, and for the Pullman-Richfield soils as
compared with the Amarillo soils. One important exception is the Denton-
San Saba group (Table 8), of which the San Saba soils produced grasses
considerably higher in both protein and phosphoric acid throughout the
year than those produced on the Denton soils, although the Denton soils con-
tained as much nitrogen and considerably more active phosphoric acid than
were found in the San Saba soils. The San Saba soils are level to gently
rolling and fairly deep, while the Denton soils are rolling to hilly and
in many places, very shallow. Consequently, water is held better by the
San Saba soils, and the plants are kept in a young stage of growth for a
longer period. All of the superior soils in the previous comparisons were
also better in their water content than the corresponding poorer soils.

Relation to Quality of Range Land

Samples of grasses were secured at four different times of the year
from four areas on the Winston ranch at Snyder on the Rolling Plains,
which were rated by the owner as good, high medium, low medium, and
poor quality of range land. The good area was a bottomland pasture on
Spur clay, the medium areas were on fairly level areas‘ of Abilene clay
loam and Miles clay loam, and the poor area was a hilltop of very shallow
Potter gravelly loam. A total of 70 samples was secured from the four
locations; nearly all of these samples were at intermediate or mature
stages of growth. The analyses of the 4 soils and the average analyses
of the grass samples from each of the areas is shown in Table- 13. As
the rating of the range land decreased, the average protein in the grasses
decreased slightly, from 6.61% on the good land to 5.08% on the p001‘

46 l BULLETIN NO. 669, TEXAS AGRICULTURAL EXPERIMENT STATION

Table 13. Average composition of grasses from 4 soils, as related to the rating of the
quality of the range land

Potter
Spur clay Abilene Miles gravelly
clay loam clay loam loam
High Low
Good medium medium Poor
rating rating rating rating
Analysis of soils
Total nitrogen, % . . . . . . . . . . . . . . . . . . . . . .245 .190 .188 .090
Total phosphoric acid, % . . . . . . . . . . . . . . . .093 .094 .067 .044
Active phosphoric acid, p. p. m . . . . . . . . . 292 348 162 57
Basicity, % . . . . . . . . . . . . . . . . . . . . . . . . .. 1.6 4.7 3.5 21.4
Analysis of plants
Number of samples . . . . . . . . . . . . . . . . . . . . 20 18 17 15
Protein, % . . . . . . . . . . . . . . . . . . . . . . . . . .. 6.61 6.63 6.05 5.08
Phosphoric acid, % . . . . . . . . . . . . . . . . . .. .29 .23 .21 .13

land, and the average phosphoric acid decreased considerably from .29%
to 13%. The total nitrogen, total phosphoric acid, and active phosphoric
acid in the soils also decreased in a similar way. The results of this ex-
periment show a close relation between the chemical composition of the
grasses, the chemical composition of the soil, and the rating of the range
land as estimated by a practical ranchman, although the number of
samples is very small.

Relation of the Chemical Composition of the Soils to the Composition
of the Grasses

The relation between the total nitrogen in the soils and the protein
in the grasses at different stages of growth is shown in Table 14. Similar
data for phosphoric acid are given in Table 15, and for lime, in Table
16. Active lime was determined in soils of low lime content. Basicity was
determined in soils of high lime content; basici-ty is the capacity of the
"soils to neutralize acid, expressed as per cent calcium carbonate.

The protein in the grasses had very little relation to total nitrogen in
the soils in this area. Only 3- of the 95 soils contained less than .061%
nitrogen; the other soils are distributed fairly evenly in three other
groups. Protein in 54 samples from soils which contained less than .061%
nitrogen was as high as in those produced on soils which contained more
than .180% nitrogen. There are no consisten-t differences in average
percentage of protein or in the distribution of the samples at different
quantities of protein in the grasses produced on the four different groups
of soils.

The average phosphoric acid in the grasses increased, and the per-
centage of samples which contained relatively low percentages of phos-
phoric acid decreased, when the quantity of active phosphoric acid in the
soils increased. At the young stage of growth, phosphoric acid in grass
samples from soils which contained less than 31 p.p.m. active phosphoric

I 

THE CHEMICAL COMPOSITION OF GRASSES FOR RANGE CATTLE 47

Table 14. Average protein in grass samples from soil groups according- to nitrogen in
soils and percentage of samples in groups according to protein in grasses.

Below .061 % to .121 % to Over
.061% .‘120% ._180% ._180%
nitrogen nitrogen nitrogen nitrogen
in soil in soil in soil in soil
Number of soils . . . . . . . . . . . . . . . . . . . . . . . . .. 3 36 34 22
' i?»
Young grasses
Average protein in all grass samples, %. . 10.67 10.22 10.51 9.85
Number of samples . . . . . . . . . . . . . . . . . . . . 21 225 243 122
Percentage of samples with protein
Below 6.00% . . . . . . . . . . . . . . . . . . . . . 5 3 2 7
6.01% to 8.25% . . . . . . . . . . . . . . . . .. 28 24 23 26
8.26% to 10.49% . . . . . . . . . . . . . . . .. 24 33 37 27
Over 10.49% . . . . . . . . . . . . . . . . . . . . . 43 40 38 4O
Grasses at medium stage
Average protein in all grass samples, % . . 7.42 6.84 7.15 6.71
Number of samples . . . . . . . . . . . . . . . . . . . . 11 118 118 101
Percentage of samples with protein
Below 4. 50% . . . . . . . . . . . . . . . . . . . . . 9 3 2 2
4.50% to 5.99% . . . . . . . . . . . . . . . . .. 9 26 17 32
6.00% to 8.25% . . . . . . . . . . . . . . . . .. 55 53 62 54
Over 8.25% . . . . . . . . . . . . . . . . . . . . .. 27 18 18 12
Grasses in bloom
Average protein in all grass samples, %. . 5.55 .94 6.20 5.85
Number of samples . . . . . . . . . . . . . . . . . . . . 17 156 93 80
Percentage of samples with protein
Below 4.50% . . . . . . . . . . . . . . . . . . . . . 41 9 17 20
4.50% to 5.99% . . . . . . . . . . . . . . . . .. 12 51 30 40
6.00% to 8.25% . . . . . . . . . . . . . . . . .. 25 30 43 31
Over 8.25% . . . . . . . . . . . . . . . . . . . . .. 12 10 10 9
Mature grasses
Average protein in all grass samples, % . . 4.94 .28 .32 4 89
Number of samples . . . . . . . . . . . . . . . . . . . . 5 199 184 136
Percentage of samples with protein
Below 3.00% . . . . . . . . . . . . . . . . . . . . . 0 6 3 6
3.00% to 4.49% . . . . . . . . . . . . . . . . .. 40 31 29 32
4.50% to 6.00% . . . . . . . . . . . . . . . . .. 60 34 36 47
Over 6% . . . . . . . . . . . . . . . . . . . . . . . . . - 0 29 32 15

acid averaged 35%, compared with an average of .48% in samples from
soils which contained from 201 to 400 p.p.m. The proportion of samples
which contained less than .33% phosphoric acid, and are thus to be
considered deficient in this constituent (Table 4), amounted to 52% and
20%, respectively, in those two groups of soils. At later stages of growth,
the relation between phosphoric acid in the grasses and active phosphoric
acid in the soils was still significant, although not so marked. At medium
and bloom stages of growth, the grass samples from soils which con-
tained from 201 to 400 p.p.m. active phosphoric acid were the only
samples in which phosphoric acid averaged 33% or more. Over half of
these samples contained more than 32% phosphoric acid, compared with
only about one-fifth of the samples from the two groups of soils which
contained less than 100 p.p.m. active phosphoric acid. Nearly all of the
mature grasses contained less than 33% phosphoric acid, regardless of the
quantity of active phosphoric acid in the soils, but the percentages of
phosphoric acid in the grasses were higher in samples from soils con-
taining the larger amounts of active phosphoric acid than from those

Table 15.

groups according to phosphoric acid in grasses

Average phosphoric acid in grass samples from soil groups according to active phosphoric acid in soils and percentage of samples in

Below
31 p. p. m.
active phos-
phoric acid

31 to
100 p. p. m.
active phos-
phoric acid

101 to
200 p. p. m.
active phos-
phoric acid

201 to
400 p. p. m.
active phos-
phoric acid

Over
400 p. p. m.
active phos-
phoric acid

in soils in soils in soils in soils in soils
Number of soils . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 32 25 2O 6
Young grasses

Average phosphoric acid in all grass samples, % . . . . . . . . . . . . . . . . . . . .35 .38 .41 .48 .46
Number of samples . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77 177 172 160 26

Percentage of samples with phosphoric acid
Below .17% . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 5 0 O 0
17% to .32% . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 51 37 31 20 29
33% to .49% . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32 38 46 39 50
Over .49% . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 16 2O 23 41 23

Grasses at medium stage

Average phosphoric acid in all grass samples, % . . . . . . . . . . . . . . . . . . . .26 .28 .30 .34 .31
Number 0f samples . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53 109 111 62 8

Percentage of samples with phosphoric acid
Below . 17 O . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 9 7 11 0
.17% to .24% . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 3O 40 22 16 25
.25% to .32% . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 40 27 37 18 50
Over .32% . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 24 34 55 25

Grasses in bloom

Average phosphoric acid in all grass samples, % . . . . . . . . . . . . . . . . . . . .23 .25 .26 .33 .29
Number of samples . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41 160 80 48 13

Percentage of samples with phosphoric acid
Below .17 0 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 24 22 13 15 0
.17% to .24% . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 42 36 35 2 23
.25% to .32% . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 17 26 26 25 46
Over .32% . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 17 16 26 58 31

Mature grasses

Average phosphoric acid in all grass samples, % . . . . . . . . . . . . . . . . . . . .17 .18 .23 .22 .21
Number of samples . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 73 199 124 91 36

Percentage of samples with phosphoric acid
Below .11 0 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 11 2 4 O
.1l% to .16% . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 44 42 23 24 21
.17% to .24% . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33 29 37 38 47
Over .24% . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 14 18 38 34 32

8V

NOLLVLS LNEIWIHEIdXEI TVHHJIIHOIHDV SVXEIL ‘699 'ON NLLEITIIIH

Table 16.

according to lime in grasses

Average lime in grass samples from soil groups according to active lime or basicity in soils and percentage of samples in groups

Number of soils . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Young grasses

Average lime in all grass samples, % . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Number of samples . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..

Percentage of samples with lime
Below 43% . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
.43% t0 .62% . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..
63% t0 82% . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Over 82% . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Grasses at medium stage
Average lime in all grass samples, % . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Number 0f samples . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Percentage 0f samples with lime
Below .43%

Over .82% . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Grasses in bloom

Average lime in all grass samples, % . .

Number of samples . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Percentage of samples with lime
Below 43% . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
43% to 62% . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
63% to 82% . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..
Over 82% . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Nlature grasses
Average lime in all grass samples, "0 . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Number of samples . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Percentage of samples with lime

Over .82 % . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Below
1600
p. p. m.
active llmC
in soils

.61
38

1O

58
10
.56
21

14
53

. 60
2O

1O
35
5

1600 to 3201 to Below
3200 6400 5€@
p. p. m. p. p. m. basicity
acfivelhne acfivelhne in yum

in sofls in sofls

10 30 21
.59 .70 .85
92 213 108

5 7 3
71 29 17
15 41 40

9 23 40
.60 .70 .84
38 110 60
16 9 5
45 37 23
29 33 30
10 21 42
.50 .71 .76
61 100 58
35 6 5
39 35 29
21 31 31

5 28 35
.52 .68 .77
62 182 99
34 11 14
45 48 28
16 28 31

5 18 27

Over

5%
basicity
in soils

28

6V EFLLLVO EIDNVH 30.1 SEISSVHD JO NOLLISOcTWOO TVOIWCIHO EIHJ.

phoric acid in the soils in 19 of the 44 comparisons. The relation "

  
 
  
  
 
 
 
  
 
  
   
  
  
 
 
  
   
 
  
   
 
  
   
  
 
  
  
  
   
  

50 BULLETIN NO. 669, TEXAS AGRICULTURAL EXPERIMENT STATION

lower in this constituent. About one-quarter of the samples of ma vf‘
grasses from soils containing over 100 p.p.m. active phosphoric I“
contained less than .17% phosphoric acid, compared with over one-
of the samples from soils containing less than that amount. l

 

Lime (Table 16) in the grasses at all stages of growth was rela
to the active lime or basicity in the soils, except for the two groups i,
soils which contained less than 3,200 p.p.m. of active lime. The differen
in those groups were small, irregular, and of doubtful significance. W
active lime in the soil exceeded 3,200 p.p.m., the lime in the g
increased with an increase in the active lime or basicity in the soils.

Coeflicients of correlation between phosphoric acid in the grasses
active phosphoric acid and total phosphoric acid in the soils and betw
protein in the grasses and total nitrogen in the soils were calcul
in several groups of grasses. The samples of buffalo, grama, and bl
stem grasses were divided into two groups, according to whether t
were produced east or West of the line of 25-inch rainfall. The coefficients
correlation are given in Table 17, together with averages for the sev l
constituents concerned. In estimating whether or not a given coefficient ‘y7‘
significant the usual method was followed. The number of samples in 
group is important. For example, the coefficient for a group of 
samples must be higher than .443 to be significant, while only .197 f
required for a group of 100 samples (14). Significant coefficients a‘
indicated by one asterisk in Table 17, and highly significant coeffici
by two. A

Phosphoric acid in the grasses was significantly related to acti
phosphoric acid in the soils in 30 of the 44 comparisons shown in Ta
17. The relation was much closer in grasses and soils from east of i
line of 25-inch rainfall than in those from west of that line. Of the 5
groups of grasses from the eastern section of the area, receiving mo:
than 25 inches of rainfall annually, the coefficients were significant in 
cases except mature bluestem grasses. Of the 12 groups from the west ‘
section, receiving‘ less than 25 inches of rainfall, the coefficients w‘
significant only for buffalo grass at bloom and mature stages of grohi
and in mature bluestem grasses. When the two divisions were combin l
the coefiicients were significant in all groups except grama grasses
young and medium stages of growth. Active phosphoric acid in the we
soils was two or three times as high as in the eastern soils. Phospho l
acid in the grasses was usually higher in those produced in the weste
section, but differences in the grasses were not nearly as great as in t
soils.

Phosphoric acid in the grasses was significantly related to total ph

much closer in buffalo and Johnson grasses than in the other grasses.
coefficients were significant in 8 of the 12 eastern groups and in only 0 _
of the 12 western groups. Total phosphoric acid averaged essentially th;

»

Table 17.

grasses and total nitrogen in soils

Coefficients of correlation between phosphoric acid in grasses and active and total phosphoric acid in soils and between protein in

Number Phosphoric Active phosphoric acid
of acid in —~———~—*4A»‘—*- —*
grass grasses In sofls Corr
sanqflcs 95 p.p.rn. coef
Iluffalo grass (l9uchl0e daclyloides)
Samples east of 25" rainfall
'Young . . . . . . . . . . . . . . . . . .. 33 .333 85 632**
h4edi4n1 . . . . . . . . . . . . . . . . .. 32 .270 98 409*
Blooni . . . . . . . . . . . . . . . . . . .. 24 .209 69 .386*
A4ature . . . . . . . . . . . . . . . . . .. 41 .194 80 5l7**
Samples west of 25" rainfall
Young . . . . . . . . . . . . . . . . . .. 59 .367 192 .041
l\4edi1n1 . . . . . . . . . . . . . . . . .. 33 .285 179 .166
loom . . . . _ . . . . . . . . . . . . . . 16 .275 183 .607*
h4atnre _ . _ . . . . . . . . . . . . . . .. 59 .235 202 .292*
All samples
"Young . . . . . . . . . . . . . . . . . .. 92 .344 153 216*‘
Medium . . . . . . . . . . . . . . . . . . 65 .276 129 313*
Blooni . . . . . . . . . . . . . . . . . . .. 40 .237 117 655**
h4ature . . . . . . . . . . . . . . . . . .. 100 .218 152 426**
Grama grasses (Boutclolza spp.)
Sannfles east of 25” rainfafl
'Yonng . . . . . . . . . . . . . . . . . .. 50 .317 74 596**
h4ediun . . . . . . . . . . . . . . . . .. 49 .243 84 378**
Bl0OH1 . . . . . . . . . . . . . . . . . . .. 42 .195 77 .718**
h4ature . . . . . . . . . . . . . . . . . .. 77 .149 56 .163
Samples west of 25" rainfall
01mg . . . . . . . . . . . . . . _ . . .. 5O .310 195 .126
h4ediun1 . . . . . . . . . . . . . _ . . .. 18 .243 203 .288
Blooni . . . . . . . . . . . . . . . . . . .. 48 .222 141 .007
h4ature . . . . . . . . . . . . . . . . . .. 106 .214 206 .095
All samples
Young . . . . . . . . . . . . . . . . . . . 100 .314 134 .095
h4edhun . . . . . . . . . . . . . . . . .. 67 .243 117 .220
Blooni . . . . . . . . . . . . . . . . . . .. 90 .209 110 297**
h4ature . . . . . . . . . . . . . . . . . .. 183 .187 143 339**

Total phosphoric acid

l f iln soils

Protein

_ Total nitrogen
~ in grasses ~   ~ - ~ ~-
U

Corr A In sofls Corr

0 coef. 9% cocf
.068 .425* 9.34 .148 .435*
.087 419* 6.82 .160 367*
.060 .328 6.53 .144 685**
072 319* 5.35 .169 .055
.076 .074 9.70 .128 .172
.073 .146 7.46 .142 .147
.073 .508* 6.11 .139 030
.078 .120 6.25 .131 .206
.073 .221* 9.57 .135 .207*
.081 360** 7.26 .153 .026
.065 .464** 6.27 .143 .480**
.076 .197* 5.92 .145 .191
.062 316* 8.36 .136 .417**
.073 .326* 6.36 .153 .347*
.063 .373* 5.38 .139 .015
.064 .162 4.59 .154 .013
.076 .247 9.42 .124 .274
.076 .193 6.76 .152 .039
.065 .043 6.36 .113 .319*
.078 .133 5.92 .129 .243*
.069 .141 8.89 .130 .088
.074 .280 6.47 .152 .235*
.064 .119 5.86 .126 .276**
.072 235** 5.28 .140 .206**

I9 EYIQLLVO {EIDNVH HOEI SHSSVHE) JO NOLLISOcIWOO "IVOIWHHO Ell-LL

1Q

Table 17. Coefficients of correlation between phosphoric acid in grasses and active and total phosphoric acid in soils and between protein in

grasses and total nitrogen in soils——Continued

Number Phosphoric Active phosphoric acid Total phosphoric acid Protein in Total nitrogen
of _ acid _ grasses _
grass in grasses In soils Corr. In soils Corr. % In soils Corr.
samples % p. p. m. coef. 0 coef. 0 coef.
Bluestcm grasses (Andropogon spp.)
Samples east of 25" rainfal
Young . . . . . . . . . . . . . . . . . .. 24 .414 85 .575** .063 .093 V8.29 .127 554**
Medium . . . . . . . . . . . . . . . . .. 42 .311 113 .602** .079 .304* 6.46 .151 .665**
Bloom . . . . . . . . . . . . . . . . . . .. 27 .246 111 .808** .061 775** 4. 78 .124 .203
Mature . . . . . . . . . . . . . . . . . .. 48 .135 66 .147 .071 .194 3.71 .162 .042
Samples west of 25" rainfall
Young . . . . . . . . . . . . . . . . . . . 21 .477 244 .053 .088 .095 11.02 .129 .397
Medium . . . . . . . . . . . . . . . . . . 11 .363 195 .240 .075 .463 7.50 .130 .067
Bloom . . . . . . . . . . . . . . . . . .. 17 .301 144 .111 .064 .244 5.19 .104 .000
Mature . . . . . . . . . . . . . . . . . .. 23 . 199 188 .432* .077 .348 4.01 .127 .014
All samples
Young . . . . . . . . . . . . . . . . . .. 45 .443 159 381*’? .074 166 10.03 .128 .114
Nleditim . . . . . . . . . . . . . . . . . . 53 .322 130 .494** .078 197 6.89 .143 .375**
Bloom . . . . . . . . . . . . . . . . . .. 44 .267 124 .465** .074 411** 5.06 .117 3309*
lVIHtUTC . . . . . . . . . . . . . . . . . .. 71 156 106 .556** .073 .281 3.81 .150 014
Crowfoot grass (Chloris spp.)
All samples
 40 .463 156 .568** .070 385* 9. 3 .116 140
Nlediim . . . . . . . . . . . . . . . . .. 26 .421 121 .270 .064 .059 7.58 .124 .214
loom . . . . . . . . . . . . . . . . . .. 16 .335 112 .533* .057 .378 6.63 .102 .075
lvlature . . . . . . . . . . . . . . . . . . . 33 .309 116 .597** .070 .276 6.03 .142 055
Johnson grass (Sorghum Izalepense)
All samples
Young . . . . . . . . . . . . . . . . . .. 31 .636 134 .673*"‘ .084 .415* 12.59 .146 .073
Medium and bloom . . . . . .. 27 .387 113 .709** .072 .423* 7.05 .125 .229
SpO/‘(I/JOIUS spp.
All samples
Young . . . . . . . . . . . . . . . . . .. 47 .379 160 .538** .073 .313* 10.31 .132 .134
lflcdiwm and bloom. . .. . .. 22 .257 78 .454* .072 .. 130 6.54 .138 .264

*C0rrclation significant  is less than 5%)
**Correlation highly significant (P is 1% or less)

Z9

NOLLVLS LNHNIHEIdXEI "IVHIILTIIOIHSV SVXELL ‘699 ‘ONI NILEITIDEI

 

 

THE CHEMICAL COMPOSITION OF GRASSES FOR RANGE CATTLE 53
same in the soils from the two sections. The relation for these grasses was
not as close as for young grasses from the East Texas Timber Country
m. _,

Protein in the grasses was significantly related to total nitrogen in
the soils in 15 of the 44 comparisons. Significant coefficients were secured
in 7 of the 12 eastern groups and in 2 of the 12 western groups. Protein

averaged significantly higher in all western groups than in the eastern‘

groups, although total nitrogen in the soils from the two sections averaged

about the same.

The correlation between the chemical composition of the grasses and that
of the soils on which they were produced was higher for active phos-
phoric acid than for total phosphoric acid or total nitrogen in the soils,
for grasses produced east of the line of 25-inch rainfall than for those
produced west of that line, and for grasses at early stages of growth
than for those at later stages of growth.

A comparison of the average protein, phosphoric acid, and lime in young
grasses produced on soils containing similar quantities of nitrogen, ac-
tive phosphoric acid, and lime, from the East Texas Timber Country (7),
from the Gulf Coast Prairie (11), and from Northwest Texas, is given
in Table 18. The averages given for the East Texas Timber Country are
averages of averages for Bermuda, Dallis, carpet, and big and little bluestem
grasses only (Table 12, Bulletin 582). On soils of similar nitrogen content,
protein was highest in grasses produced in Northwest Texas, next higher
in grasses from the Gulf Coast Prairie and lowest in the grasses from
the East Texas Timber Country. Protein in the grasses was related to
nitrogen in the soils of the East Texas Timber Country and of the Gulf

Table l8. Comparison of the chemical composition of young grasses produced on soils con-
taining similar quantities 01' constituents but from difierent sections of Texas

 

East Texas Gulf Coast Northwest
Constituents in soils Timber Prairie Texas
Country I
Protein in grasses, per cent
l
0 to .060% nitrogen . . . . . . . . . . . . . . . . . . ..‘ . . . . . .. 7.42 . . . . . . . . . . .. 10.67
.61 to 120% nitrogen . . . . . . . . . . . . . . . . . . . . . . . .. 7.65 9.02 10.22
.121 to 180% nitrogen . . . . . . . . . . . . . . . . . . . . . . .. 8.22 9.33 10.51
Over 180% nitrogen . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10.59 9.85
Phosphoric acid in grasses, per cent
0 t0 30 p. p. m. active phosphoric acid . . . . . . . . . . . .27 .30 .3
31 to 100 p. p. m. active phosphoric acid . . . . . . . .. .33 .41 .38
101 to 200 p. p. m. active phosphoric acid . . . . . . . . .41 .55 .41
201 to 400 p. p. m. active phosphoric acid . . . . . . . . .40 . . . . . . . . . . . . .48
Lime in grasses, per cent

0_ to 1600 n. p. m. active lime . . . . . . . . . . . . . . . . . .. .49 .52 .61
1601 to 3200 p. p. m. active lime . . . . . . . . . . . . . . . . .55 .62 .59
3201 to 6400 p. p. m. active lime . . . . . . . . . . . . . . . . .49 .67 .70

  
 
   
   
  
  
   
   
   
  
   
  
   
  
    
  
   
   

54 BULLETIN NO. 669, TEXAS AGRICULTURAL EXPERIMENT STATIONV]

Coast Prairie, but not in most of those of Northwest Texas. On p;
taining similar quantities of active phosphoric acid, phosphoric 
grasses produced in Northwest Texas was considerably higher Q
those produced on soils of the East Texas Timber Country, but wast
than in grasses from the Gulf Coast Prairie, except on the r3.‘
taining less than 31 p.p.m. active phosphoric acid. The percen 
phosphoric acid in the grasses Was related to active phosphoric 
the soils of all three sections. With similar percentages of lime, 
centage of lime was higher in grasses from Northwest Texas A
grasses from the Gulf Coast Prairie, which in turn was higher w‘;
grasses from the East Texas Timber Country. Lime in the 
Was related to active lime in the soils of Northwest Texas i,
Gulf Coast Prairie, but not in the soils of the East Texas Timber 
While the composition of the soil affects the protein, phosphoric a1
lime content of the grasses, other factors also affect their comp
and are sometimes more potent than the composition of the soil. 

ACKNOWLEDGMENT . ‘ l
Credit is due T. L. Ogier, s. E. Asbury, Waldo Walker, and
members of the staff for analyses and other work necessary in wt

‘the data here presented. >-
3 SUMMARY

Protein, phosphoric acid, and lime were determined in 1,916 == 
of various species of grasses at four stages of growth collected at 
times during 1938, 1939, and 1940 from over a hundred locatio 
tributed throughout northwest Texas. Crude fiber, ether extractlil‘.
nitrogen-free extract were determined in 441 of these samples. x

The average protein content of 23 important species of grasses,
young, ranged from 14.71% in little barley to 7.19% in Texas 1‘
grass, and when mature, from 6.59% in sand dropseed to 344'
little bluestem grass. Protein was classed as deficient for range HQ
in i?) of the young samples and 73% of the mature samples. Protein‘
deficient in 70% of the samples of hairy grama grass and in only,-
of the samples of Johnson grass. Protein averaged lowest in forage = Q
from the Windthorst-Nimrod soils of the West Cross Timbers and hig ii
the bottomland Miller and Spur soils of the Rolling Plains and thef
Amarillo soils of the High Plains. Protein was classed as deficient int‘;
than one-fourth of the samples collected in April and June, in about;
half of the samples collected in September, and in most of the ~51
collected in November. Protein in the forage samples was not cl,’
related to total nitrogen in the soils. 

The average phosphoric acid content of 23 important species of g1? 
when young, ranged from .65% in Johnson grass to 24% in Texas i 
grass, and when mature, from .35% in alkali sacaton to» .14% in'\
bluestem. Phosphoric acid was sufiicient for range animals in ~»

THE CHEMICAL COMPOSITION OF GRASSES FOR RANGE CATTLE 55

 grasses except in tobosa grass and sideoats, hairy, and Texas grama
 grasses but was deficient in all mature grasses except alkali sacaton and
 Johnson grass. Phosphoric acid was sufiicient for range cattle in 66% of
ithe samples of young grass but deficient in 91% of the samples of
fimature grass. Phosphoric acid averaged considerably higher in samples
‘from San Saba than from Denton soils, from Windthorst than from
‘Nimrod soils, from Miles than from Vernon soils, and from Pullman-
=‘Richfield than from Amarillo soils. Phosphoric acid was deficient for
lcattle in one-half to two-thirds of the samples collected from various
;S0ll groups in April and June, in three-fourths to nearly all of the
samples collected in September, and in all of the samples collected from
l- most of the soil groups in November. Phosphoric acid in the forage at
-all stages of growth was related to the quantity of active phosphoric acid
in the soils.

Lime was not deficient in any samples of forage and was high in over
one-fourth of them. Lime in the forage increased significantly with in-
creases in the quantity of lime or basicity in the soils.

Nitrogen-free extract usually ranged between 38% and 42% in young
rgrasses and between 42% and 46% in mature grasses; differences among
§species at the same stage of growth were usually small and of doubtful
significance. Crude fiber usually averaged about 25% in short grasses,
’while tall grasses often contained more ahan 30%; advancing maturity
increased the crude fiber in most species and the difference due to ma-
turity was usually greater with tall grasses than with short grasses.

The percentages of protein, phosphoric acid and lime in the grasses are
related to the total nitrogen, active phosphoric acid and active lime or
basicity of the soils, but there are other factors which affect the compo-
sition of the grasses, and the effect of these other factors at times may
be greater than the effect of the composition of the soil.

56 BULLETIN NO. 669, TEXAS AGRICULTURAL EXPERIMENT STATION

LITERATURE CITED

1. Association of Official Agricultural Chemists. 1940. Official and tentative me -
analysis, Fifth Edition. Washington, D. C.

   
   
   
   
  
   
  

2. Black, W. H., Tash, L. H., Jones, J. M., and Kleberg, R. J., Jr. 1943. Efl

phosphorus supplements on cattle grazing on range deficient in this mineral. U.S.
Tech. Bul. 856.

3. Brittingham, W. H. and Fudge, J . F.-1944. Yield, chemical analysis, and fe
response of eleven forage grasses. Texas Agr. Exp. Sta. Progress Rpt. 875.

4. Carter, W. T. 1931. The soils of Texas. Texas Agr. Exp. Sta. Bul. 431.

5. Cory, V. L., and Parks, H. B. 1937. Catalogue of the flora of Texas. Texas
Exp. Sta. Bul. 550.

6. Fraps, G. S., and Fudge, J. F. 1937. Chemical composition of soils of Texas.
Agr. Exp. Sta. B I. 549. g
'7. Fraps, G. S., and Fudge, J . F. 1940. The chemical composition of forage grasses of A‘
East Texas Timber Country. Texas Agr. Exp. Sta. Bul. 582. "

8. Fraps, G. S., Fudge, J. F. and Reynolds, E. B. 1937. Effect of fertilization on'

composition of a Lufkin fine sandy loam and of oats grown on it. Jour. Amer. Soc.
29:990-996.

9. Fraps, G. S., Fudge, J. F., and Reynolds, E. B. 1943. Effect of fertilization o ,
Crowley clay loam on the chemical composition of forage and carpet grass, Aa: n"
Afinis. Jour. Amer. Soc. Agron. 34:560-566. ~ i

10. Fudge, J. F., and Fraps, G. S. 1938. The relation of nitrogen, phosphoric acid, >
lime in the soils of East Texas to those constituents in Bermuda and little bluestem g :: '
Proc. Amer. Soc. Soil Sci. 3:189-194. ,-

11. Fudge, J. F., and Fraps, G. S. 1944. The chemical composition of forage : 1w
from the Gulf‘Coast Prairie as related to soils and to requirements for range c8- L
Texas Agr. Exp. Sta. Bul.-644. -'

P 1b2. ZHitchcock, A. S. 1935. Manual of the grasses of the United States. U. S. D. A. ~ 
u . 00. ‘"

13. Schmidt, H. 1924. Field and laboratory notes on a fatal disease of cattle appea
on the coastal plains of Texas (Loin Disease). Texas Agr. Exp. Sta. Bul. 319.

14. Snedecor, G. W. 1938. Statistical methods. Collegiate Press, Inc., Ame-s, Iowa.

‘SDJKVD
‘ED317013 l’! if V
' lib? I8 I ‘I: