LIBRARY»
§A & M COLLEGE.
camrus.

A34-140-9M-L1 80

TEXAS AGRICULTURAL EXPERIMENT STATION

A. B. CONNER, DIRECTOR
COLLEGE STATION, mmzos COUNTY, TEXAS

BULLETIN NO. 582 MARCH 1940

DIVISION OF CHEMISTRY

The Chemical Compositionjof Forage
Grasses of the East Texas Timber
Country

 

AGRICULTURAL AND MECHANICAL COLLEGE OF TEXAS
T. O. WALTON, President

NEE

 

Chemical analyses were made 0f 1,432 samples of various species
of forage at various stages 0f growth from 100 locations in East
Texas. Protein and phosphoric acid decreased markedly with
advancing maturity of the plants, crude fiber and nitrogen-free
extract in general increased slightly, while changes in lime con-
tent were irregular. When graded in 5 classes, protein and phos-
phoric acid in practically all of the samples ranged from fair to
very deficient, and as maturity approached, there was a marked
increase in the proportion of the samples which were deficient
or very deficient in these constituents. Very few of the samples
were deficient in lime. Johnson, Dallis, and Bermuda grasses
were in general higher in protein, phosphoric acid, and lime
than were the principal native species collected.

There is a relation between the total nitrogen, the active phos-
phoric acid and active lime in the soil and the protein, phosphoric
acid, and lime in the forage. The relation between the chemical
composition of the soil and that of the forage was much closer
for carpet grass, bluestems, broomsedge and Eragrostis lugens
species than for Bermuda, Dallis grass and Georgia grass.

Forage grasses of East Texas appear to supply sufficient lime
(or calcium) to grazing animals, but in general they do not
supply enough phosphorus (phosphoric acid) and at times do
not supply enough protein for best results.

TABLE OF CONTENTS

 
 
 
 
 
 
 
 
   
 
  
  
 
  

Introduction . . . . . . . . . . . . . . . . . . . . ._ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . f

Description of the region . . . . . . . . . . . . . . . . . . . . . .l . . . . . . . . . . . . . . . . . 

Collection of samples . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 

Common and botanical names of species . . . . . . . . . . . . . . . . . . . . . . . . . .. 

Average analyses of species of forage . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 

Comparison of different species with Bermuda . . . . . . .  . . . . . . . . . . . .. 

Average feed constituents in species of forage . . . . . . . . . . . . . . . . . . . . .. A

Grades of constituents of forage . . . . . . . . . ._ . . . . . . . . . . . . . . . . . . . . . . .. 

Distribution of samples aacording to grades of constituents. . . . . . . .. j

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

Relation of the chemical composition of the soils to the botanical __

composition of the forage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Average analyses of forage grasses from soils of different series.  1
Relation of chemical composition of soils to that of forage . . . . . . . .. 
Acknowledgment . . . . . . . . . . . . . . . . . . . . . . . . . . .  . . . . . . . . . . . . . . . . . .. if A
Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Literature cited . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . _y

BULLETIN NO. 582 MARCH 1940

THE CHEMICAL COMPOSITION OF FORAGE GRASSES OF
IPHE ‘EAST TEXAS TIMBER COUNTRY

By

o. s. FrapsmChief, andhkF. Fudge, Chemist,
Division of Chemistry

The importance of an adequate supply of minerals in the rations
fed to animals for their growth and maintenance has long been recognized.
It is only within comparatively regent years, however, that extensive
’ and intensive studies byfa large number of investigators throughout the
world have shown that a number o'f'ld1seases of range animals are definitely
y associated with deficiencies of minerals in the available forage. Most of
these deficiency diseases are due to a lack of sufficient phosphorus in the
ration. The symptoms of most of the diseases due to a deficiency of
phosphoric acid in the ration are pica (depraved appetite), stiffness of the
legs, swollen joints, brittle bones, emaciation, and generally poor con-
' dition. Pica, or depraved appetite, may result in the chewing of bones,
wood and other substances. Schmidt (20) showed that loin disease in
cattle on the Gulf Coast Prairie in Texas was due to infection from
1 chewing bones of diseased cattle. Similar results "have been secured by
i Theiler (23, 24, 25) in South Africa, by Eckles, Becker, and Palmer (6)
‘in Minnesota, by Becker, Neal, and Shealy (3) in Florida, and by various
workers in other areas. To a much smaller degree, a deficiency of cal-
tcium may also cause disturbances in the health of the animals. A defi-
ciency of cobalt has also caused trouble. Deficiency of phosphorus or
calcium may result in decreased growth, or small animals even when
there are no symptoms of disease. Various workers (10, 11, and others)
have also shown that a close relation exists between’ the phosphorus
content and protein content of plants, so that usually forage which is
deficient in phosphorus is also deficient in protein. Disturbances or smaller
growth due to protein deficiency in the forage may accompany those due
to phosphorus deficiency.

The percentage of the constituent in the forage, rather than the total
quantity of forage available, is the determining factor in the develop-
ment of the nutritional disturbance. It is possible for animals with
abundance of forage to show marked evidence of phosphoric acid defi-
ciencies. Mitchell and McClure (18) state that “the basic fault in a chain
of disasters that has harassed the cattle industry in so many areas is a
deficiency of the soil in available phosphorus, giving rise to forage
crops limited in quantity by lack of essential plant food, but still more
limited in quality by a phosphorus content below minimal physiological
requirements,” and that “all soils that respond with increased fertility
to phosphorus fertilizers may produce deficient pasturage or hay crops.”
lHart, Guilbert, and Goss (12) in California, Stanley (22) in Arizona,

6 BULLETIN NO. 582, TEXAS AGRICULTURAL EXPERIMENT STATION

Watkins (26) in New Mexico, and others have presented work whi
substantiates this conclusion. Fraps and Fudge (9) have shown that t
soils over large areas in Texas are deficient in total and active ph
phoric acid and in nitrogen; this is particularly true of the soils of t
East Texas Timber Country.

In order to determine what deficiencies occur in Texas forages and
study the relation of the chemical composition of the forage to the che
ical composition of the soils, an extensive study is being made of r
composition of samples of forage from Texas ranges and of the so’
on which the forage was grown. This bulletin presents the results
this study in the East Texas Timber Country.

Description of the Region

The East Texas Timber Country covers an area of about 26,000,0l
acres located in eastern and northeastern part of Texas (4). The so‘
of the region form the western part of the great coastal belt of ti
bered sandy land extending from New Jersey southward along f
Atlantic and Gulf seaboards. They are mainly light in texture and 
color and low in organic matter and fertility, particularly with respe
to total and active (N/5 nitric acid-soluble) phosphoric acid and
nitrogen (9). Much of the region is covered with either post-oak o
short-leaf pine timber. Free range from large areas of cut-over lan,
provides the major part of the grazing for large numbers of low grad
cattle and hogs in a number of areas in the region. i

The forage consists of many different species, some of which are no
common in the Eastern States. The principal native grasses are littl
bluestem (Andropogon scoparius) and big bluestem (Andropogon provin-

cialis). Eragrostis species, particularly Eragrostis lugens, Uniola sessili-

flora, flatstemmed panic grass (Panicum anceps), and Paspalums of thj
setacea group, particularly Paspalum pubescens, form an important pa §
of the woodland forage. Needle or three-awn grasses (Aristida species,"
particularly Aristida oligantha), together with Poor Joe weed (Diodia
teres) provide most of the forage on land which at one time has bee
under cultivation. The principal “improved” grasses are Bermuda (Cyno-
don dactylon) and Dallis (Paspalum dilatatum); Vasey grass (Paspalumif
urvillei) provides a great deal of forage in the lower areas. Carpet grass§

(Axonopus compressus) is of minor importance in the northern section,

of the region, but increases in importance in the southern section until»
it becomes one of the principal forage grasses in the eastern section of.
the Gulf Coast Prairie just south of the East Texas Timber Country;
The latter grasses, although not indigenous to the region, are now grow-l

ing throughout the area on favorable soils. Common lespedeza (Lespedeza.
striata) occurs on open land, and in the early spring considerable forage

is provided by a number of the clovers, of which the principal species‘
is white clover (Trifolium repens). i

  
   
  
 
 
 
 
 
 
 
 
 
 
    
  
  
   
   
  
    
     
   
  
 
   
 
  
   

Collection of samples

_ Forage samples were collected at various times between April and
November in 1936 and 1937 from several counties well distributed through-
out the area. Counties from which samples were secured were Angelina,
Bowie, Brazos, Camp, Freestone, Harrison, Houston, Lamar, Leon, Nacog-
pdoches, Polk, Red River, Robertson, Trinity, and Van Zandt. Notes were
taken describing in detail the location from which samples were taken
so that the place was definitely known at subsequent samplings. The
stage of maturity (whether young, in bloom, or mature) of each species
was noted and the soil type identified. All of the important species on
the location were sampled. Individual samples consisted entirely of the
current year’s growth of a single species. The samples, after cutting,
were packed loosely in a cheesecloth sack, dried in an oven heated to
about 45°C, ground in a Wiley mill, and analyzed by methods similar to
those of the Association of Ofiicial Agricultural Chemists.

The number of samples of a given species which were collected varied
widely with different species. Samples of all of the species growing on
the location selected, which contributed significantly to the forage of the
area, were collected. Some species are of general and widespread occur-
rence throughout the East Texas Timber Country, and samples of these
species were secured from many locations at all samplings. Other species
pre of importance only at certain times of the year or on certain soils.
or example, annual bluegrass (Poa annua) and rescue grass (Bromus
itharticus) are early spring grasses and disappear during the summer
Yd fall. Bermuda, Dallis, and carpet grasses usually occur in fairly
“pen locations on soils which are in general of somewhat higher fertility
i d under better moisture conditions than are common in the area. Other
fecies, such as Eragrostis lugens and Uniola sessiliflora, usually occur
1m timberland and on poorer soils. Prairie three-awn or needle grass
“Aristida oligantha) occurs usually in open land which has at one time
 under cultivation or overgrazed, and most of the soils on which

.5 .

p s species occurs are very low in fertility. A number of factors are
us in operation in determining the species of forage which may be
iowing on a given location, and these same factors undoubtedly influ-
)1 to some extent the chemical composition of the forage.

i The differentiation of samples of the same species on the basis of
ge of growth, that is, whether young, in bloom, or mature, is some-
j: es difficult. In some species, particularly the Paspalums, all three
i ges of growth can be found on the same plant at the same time. Some
cies, such as Bermuda and carpet grasses, may come into bloom and
lture seed at any time during the growing season when weather con-
g 'ons become unfavorable for vigorous vegetative growth. Other species,
ch as the Andropogons, come into bloom only once during the latter part
' the growing season. Even with these species, considerable variation
possible, since the plant will be designated as young at any time between

CHEMICAL COMPOSITION OF FORAGE GRASSES 7

8 BULLETIN NO. 582, TEXAS AGRICULTURAL EXPERIMENT STATION

   
   
   
    
  
   
 
    
   
  
   
   
  
  
  
    
   
  
   

the first vigorous growth in the spring and the very slow growth in t,
latter part of the summer when moisture conditions over much of t’
region are so unfavorable that growth has practically stopped. Differen
ation as to whether a plant should be considered in the bloom stage ~
the mature stage is also difficult, because there is a gradual gradati“
between the two, and mature seeds may occur on one part of the pla
while other stalks of the same plant are just coming into bloom. Grazin
burning, or mowing on a location may be such that very young pla'
material is secured throughout the growing season, regardless of t
natural growth habit of the species. These facts explain in part w
the number of samples of young grass of the different species was mu
higher than the number of samples in the bloom or mature stages I
growth, and also the principal objection to the use of the dates of r
lection as the basis for difierentiation. In spite of these consideratio
however, the authors believe that some differentiation between vario,
samples of a species is. necessary because of great differences in che i
ical composition and feeding value, and that the grouping of the sampl
into young, bloom, and mature stages of growth is open to less serio‘
objections than any other practicable system of differentiation.

Soil samples were collected from all areas from which forage sampl
were secured throughout the period. The samples were taken usually i
a depth of about six inches. The samples were dried, passed through
20-mesh sieve, and analyzed for total nitrogen and total phosphoric aci
by the methods of the Association of Official Agricultural Chemists an
for various constituents soluble in N/ 5 nitric acid, referred to in th
later discussion as active constituents. ‘

Common and botanical names of species

An alphabetical list of the common names of the different species o
forage collected, together with the botanical name of the species as give
by Hitchcock (14) and Cory and Parks (5), is given in Table 1.
many cases, the same species is known in different localities by differe
common names. In a number of cases, the same species has been give‘
different botanical names by different botanists. Hitchcock is the authori
for most of the botanical names used in this bulletin. Cory and Par:
have made an intensive study of the grasses of Texas, and in cases I
differences, the names given by them are used in this publication. N I
attempt was made to separate a single species into different varieties i:
that species. In the case of a number of species which contribute signi
cantly to the forage of the area, only the botanical name of the speci
is used since no common name is in general use for the species. i

Average analyses of various species of forage

The analyses of 1,432 samples are summarized in Table 2. The avera A
analyses for protein, phosphoric acid, and lime in different species i
various stages of maturity are shown in Table 2. Phosphorus is present

   
   
  
  
 
 
  
   
 
  
   
  
   
  
  
  
 
  
    
  
   
     
   
   
  
     
    
   
   
  

in terms of phosphoric acid (P205); this can be converted to terms of
phosphorus (P) by multiplying by 0.4368. Lime is presented in terms of
calcium oxide (CaO); this can be converted to terms of calcium (Ca) by
multiplying by 0.7147. Protein is presented in terms of crude protein
. (nitrogen times 6.25). Consideration of Table 2 shows that on an average
the.protein, phosphoric acid, and lime are highest in the young samples,
and lowest with the mature samples, in almost all cases. There is thus
a decrease in quality with the age of the plants. This change is not as
pronounced with grasses as with other kinds of plants. Many other
investigators have shown such changes to take place with growing
plants.

Table l Common and botanical names of grasses sampled

Common name Botanical name
Bahia grass . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Paspalum notatum

Beardgrass, East Texas . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Andropogon tener

Beardgrass, prairie . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..Andropogon scoparius

‘Beardgrass, silver . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Andropogon saccharoides

Beardgrass, silvery . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Andropogon ternarius

Bent grass, water . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Agrost1s verticillata

Bermuda . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Cynodon dactylon

Bluegrass, annual . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .- . . . . . . . . . . . . .Poa annua

Bluestem. big . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .And|opogon provincialis

Bluestem. silver-top . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Andropogon saccharoides

Bluestem, little .\ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Andropogon scoparius

Bluestem. Texas . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Andropogon tener

Broomsedge. . . .' . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Andropogon virginicus and
" Andropogon scoparius
-arpet grass . . . . . . . . . . . . . . . . . . . . _ . . . . . . . . . . . . . . . . . . . . . . . . . ..A>_<o_nopus compressus

rab grass . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Digitaria sanguinalis

p rab grass, flat . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Axonopus furcatus

lover, bur . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Medicago arabica

, lover, California bur . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Medicago hispida

1 lover, white . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Trifolium repens

allis grass . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  . . . .Paspalum dilatatum

ropseed, sand . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Spor0bolus cryptandrus

oxtail, green . . . . . . ; . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . fletaria viridis

1 oxtail. yellow . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Setaria lutescens

3, amagrass, eastern . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Tripsacum dactyloides _

’ orgia grass . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Pas aalu licgtulurp i,

i» air grass . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1VluElen ergia capillaris

dian grass . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Sorghastrum nutans

ohnson grass . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Sorghum halepense

int grass . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Paspalum distichum

' not grass . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..Paspalum distichum

' pedeza . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Lespe:lc7a striata

‘_ve_ grass, strong-scented . . . . . . . . . . . . . . . . . . . . . . . .' . . . . . . . . . . . . Eragrostis cilianensis

ve grass, plains . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Flragrostis intermeclia

ve grass, purple . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Eragrostis spectabilis

ve grass, Pursh’s . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Eragrostis pectinacea

, eedle grasses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Aristida species

d witch grass . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..Panicum capillare

.anic grass, beaked . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Panicum anceps

nic grass, flatstemmed . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Panicum anceps

{nic grass, Lindheimer’s . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..Panicum lindhcimeri _

_eue grass. . . . . _._ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Bromus catharticus '

ge grass. . T." . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ., . . . . . . . . . . . .Andro'p0gon scoparius

' e grass, bluejointed . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Anclropogon provincialis

e grass, East Texas . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Andropogon tener

ge grass, feather . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Andropogon saccharoides

~ .; grass, feathery . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Andropogon ternarius

 ur . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . _ . . . _ . . . . . . . . . . .Ccnchrus pauciflora

‘rut grass . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Spor0bolus poiretii

kgrass . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Eragrostis cilianensis

‘=1 ee-awn grasses . . . . . . . . . . . . . . c . . . . . . . . . . . . . . . . . . . . . . . . . . . .Aristida species

.- ee-awn, Fendlefs . . . . . ._ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Aristida fendleriana

ree-awn, prairie: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Aristida oligantha

rkeyfoot, bluejoint . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Andropogon provincialis

L ~- grass . . . . . . . . . I . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Paspalum urvil i

llC grass . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Panicum capillare

CHEMICAL COMPOSITION OF FORAGE GRASSES 9

OI

Table 2. Protein, phosphoric acid, and lime content of difierent species of grasses at various stages of maturity

   

U!
Stafge Number Protein Phosphoric acid Lime a
0 o
growth samples Mean Low High Mean Low High Mean Low High E
% % % O % 0 o 0 0 g
Z
Agrostis verticillata . . . . . . . . . . . . . . . . Young 1 10.23 . . . . . . . . . . . . . . . . .37 . . . . . . . . . . . . . . . . 64 . . . . . . . . . . . . . . . . Z
(Water bentgrass) Mature 3 5.53 4.60 6.55 .23 17 .28 60 35 62 ,0
Andropogon provincialis . . . . . . . . . . .. Young 79 6.69 4.07 13.72 .26 14 .46 50 17 1 16 m
(Big bluestem) Bloom 21 4.03 2.40 5.50 .17 12 .28 47 18 73 on
Mature 14 3.95 2.37 5.95 .14 07 .29 50 30 75 5°
Andropogon saccharoides . . . . . . . . . . . . Young 21 6.63 4.19 13 .50 .32 17 .62 52 36 95 ,4
(Silver beardgrass) Bloom 8 5.14 3.55 7.65 .25 16 .40 41 31 57 :11
Mature 8 4.36 2.18 5.96 .22 08 .28 41 34 56 >4
Andropogon scoparius . . . . . . . . . . . . . . Young 112 6.18 3.34 13.73 .27 11 .61 45 23 78 I>
R _/ (Little bluestem) Bloom 47 4.79 2.25 11 .30 .22 10 .43 48 16 83 m
‘ Mature 22 3 .82 2 .65 6 . 04 .16 07 .35 52 30 79 ;>
Andropogon tener . . . . . . . . . . . . . . . . . . Young 15 5.78 3.57 7.85 .27 16 .40 53 33 73 Q
(Texas bluestem) Bloom 6 4.07 2.68 5.65 .21 1O .38 48 34 64 a
Mature 3 4.77 3.81 5.58 .17 14 .22 56 48 65 Q
Andropogon ternarius . . . . . . . . . . . . . . . Young 14 6.54 3.92 8.16 .25 15 .35 49 25 79 c‘,
* (Silvery beardgrass) Bloom 3 . 45 2.68 4.65 .18 15 .25 32 26 43 Ir‘
’ Andropogon virginicus . . . . . . . . . . . . . . Young 30 6.59 3.88 8.66 .33 18 .63 39 14 75 "3
’ (Broomsedge) Bloom 1O 5 .00 3 .45 7 .53 .25 13 .36 31 23 37 g
I Aristida fendleriana . . . . . . . . . . . . . . . . . Young 1 5.87 . . . . . . . . . . . . . . . . .27 . . . . . . . . . . . . . . . . 34 . . . . . . . . . . . . . . . . a,
p (Fendlers three-awn) Bloom 1 5.47 . . . . . . . . . . . . . . . . .22 . . . . . . . . . . . . . . . . 36 . . . . . . . . . . . . . . . . L-q
Aristida longespica . . . . . . . . . . . . . . . . . Young 5 6.49 4.31 8 18 .20 .11 .33 5O 44 .64
(Needle grass) Bloom 2 5.00 4.80 5 20 16 .15 .16 42 32 .51 m
Mature 4 5.73 4.64 6.80 21 .13 .28 34 29 .37 a
Aristida oligantha . . . . . . . . . . . . . . . . . . Young 32 5.98 4.16 7.85 20 .12 .35 54 37 .73 m
(Prairie needle grass) Bloom 2 5.75 5.72 5 78 .23 .30 31 28 .34 g1
g Mature 63 5.19 3.45 11.42 2O .11 .39 42 25 .71 "‘
Axonopus compressus . . . . . . . . . . . . . . . Young 63 \ 7.3 4.78 13 58 31 .17 .67 5O 32 .78 E
(Carpet grass) Bloom 2O "717 4.69 12 O5 34' .17 .51 48 28 1.21 z
Mature 16 \5.5 3.61 6 95 22 .12 .35 44 33 .53 ,5
Axonopus furcatus . . . . . . . . . . . . . . . . . Bloom 2 6.31’ 5.83 6.80 26 .23 .28 43 4? .43
Bromus catharticus (Rescue) . . . . Young 3 ,/ 18.00~- 16 .50 19 .32 62 .45 .77 69 53 .81 g
Cenchrus pauciflora (Sandbur) . . . . . . . Young 3 I7 .41 6.14 74 .74 .51 .87 58 52 .68 a,
Cynodon dactylon . . . . . . . . . . . . . . . . .. Young 143 ' 9.14 4.20 16 7O .40 .16 .77 63 39 1.15 h]
(Bermuda grass) f Bloom 46 /8.1? 3.73 1 O2 38 .18 .68 64 35 1.08 6
Mature 19 , 7.2 4.96 10 56 41 .21 .58 60 45 1.00 z
Digitaria sanguinalis (Crab) . . . . . . . . . Bloom 4 9. 5.17 13 55 '47 .27 .62 56 43 .71
Eragrostis cilianensis . . . . . . . . . . . . . . . Young 6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
(Stinkgrass) Bloom 5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . \ . . . . . . . . . . . . . . . . . .

lragnrosltis Kintermedia . . . . . . . . . . . . . . 

Eragrostis lugens . . . . . . . . . . . . . . . . . . .
Eragrostis pcctinacea . . . . . . . . . . . . . . .
Eragrostis secundiflora . . . . . . . . . . . . . .

Eragrostis spectabilis . . . . . . . . . . . . . . .
(Purple lovegrass)

Lespedeza striata . . . . . . . . . . . . . . . . . .
(Lespedeza)

Medica o arabica (Bur clover) . . . . . . .

Muhlen ergia capillaris . . . . . . . . . . . ..
(Longawned hairgrass)

Panicum anceps . . . . . . . . . . . . . . . . . . . .
(Flat-stemmed panic grass)

Panicum capillare . . . . . . . . . . . . . . . . . .
(Old W1tch grass)

Panicum capillarioides . . . . . . . . . . . . . .

Panicum helleri. . . ._ . . . . . . . . . . . . . . . .
Panicum lin_d_heimer1 . . . . . . . . . . . . . . . .
Paspalum c1l1atifol1um . . . . . . . . . . . . . .

Paspalum dilatatum . . . . . . . . . . . . . . . .
(Dallis grass)

Paspalum distichum . . . . . . . . . . . . . . . .
(Joint grass)
Paspalum ilorxclanum . . . . . . . . . . . . . . .

Paspalum minus . . . . . . . . . . . . . . . . . . .
Paspalum monostachyum . . . . . . . . . . .

Paspalum notatum . . . . . . . . . . . . . . . . .
Paspalum plicatulum . . . . . . . . . . . . . . .
(Georg1a grass)

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Young
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Mature
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Mature
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Bloom
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Bloom
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Bloom
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Young
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9.17 .31 .17 .57 .52
13 4.00 .11 .09 .13 .55
53 7.35 .24 .17 .30 .45
73 9.02 .33 .23 .39 .45
45 9.07 .32 .15 .52 .51
05 9.73 .32 .20 .41 .44
35 3.50 .23 .15 .37 .73
03 15.23 .24 .14 .40 .51
53 5.70 .30 .21 .41 .55
. . . . . . .. .19 ................ .32
77 3.34 .25 .15 .39 .54
12 3.93 .34 .13 .51 .47
30 5.51 .15 .12 .13 .51
23 7.55 .29 .17 .45 .49
75 5.57 .15 .09 .20 .47
03 17.23 .35 .23 .44 1 29
13 13.32 .23 .20 .44 1.03
95 13.43 .43 .33 .43 1.07
25 23.59 .70 .57 .33 1.13
02 5.54 .25 .23 .30 .44
43 4.51 .13 .10 .15 .35
55 10.15 .34 .22 .34 .53
37 3.30 .27 .19 .35 .55
03 5.05 .21 .13 .23 .52
25 7.10 .23 .20 .33 .45
93 5.47 .29 .25 .32 .41
42 5.73 .23 .22 .24 .49
55 9.24 .43 .19 1.00 .55
30 7.33 .25 .13 .34 .51
43 7.33 .27 .21 .37 .59
22 12.55 .31 .15 .53 .45
33 11.15 .31 .24 .33 .54
79 5.20 .23 .21 .24 .40
40 5.11 .23. .22 .24 }%3
20 14.13 .44’ .23 .70 . 41
94 9.55 .34 .22 .53 .45)
04 4.55 .17 .15 .13 .51/
. . . . . . .. .32 ........ ........ :52
. . . . . . .. .23 ................ .94
95 10.05 .31 .17 .50 .51
05 12.15 .25 .13 .50 .55
55 3.30 .12 .10 .15 .51
. . . . . . .. .51 ................ .43
51 7.31 .35 .24 .43 .73
31 9.02 .23 .15 .40 .52
44 5.25 .35 .25 .45 .33
49 3.23 .25 .17 .35 -.55
15 5.53 .25 .17 .33 .59
10 5.33 .19 .13 .21 .77

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II SEISSV 9 EIDVHQI JO NOLLISOJWOO "IVOIWEIHO

Table 2 (continued). Protein, phosphoric acid, and lime content of ditferent species of grasses at various stages of maturity

Z1

Stafge NUIIfIbGI‘ Protein Phosphoric acid Lime
o o
growth samples Mean Low High Mean Low High Mean Low High
% % % % % % % % %
Paspalum pubescens . . . . . . . . . . . . . . .. Young 18 6.77 4.77 10.89 .30 18 .46 .83 43 1 25
Bloom 6 5.88 4.70 6.69 .24 13 .36 .71 59 86
Mature 2 3.73 3.73 3.73 .15 13 .17 .53 44 62
Paspalum setaceum . . . . . . . . . . . . . . .. Young 8 7.05 5.76 9.44 .32 21 .48 1.00 68 1 32
Bloom 2 5.94 5.55 6.33 .27 21 .32 .74 64 83
Paspalum stramineum . . . . . . . . . . . . . . Young 6 7.11 5.65 7.82 .32 22 .56 6O 31 79
Bloom 7 7.19 5.27 11.29 .33 18 .54 50 36 71
Paspalum unispicatum . . . . . . . . . . . . . . Young 3 8.83 6.75 10.89 .35 27 .40 74 43 91
" Bloom 3 5.98 5.33 6.99 .22 17 .32 81 70 87
Paspalum urvillei . . . . . . . . . . . . . . . . . . Young 8 7.91 5.82 9.68 .39 26 .56 56 37 74
(Vasey grass) Bloom 11 5.99 4.70 6.73 .37 20 .53 50 30 1 04
Mature 1 5.44 . . . . . . . . . . . . . . . . .45 . . . . . . . . . . . . . . . . 46 . . . . . . . . . . . . . . . .
Poa annua . . . . . . . . . . . . . . . . . . . . . . .. Young 2 15.51 12 80 28 22 .64 46 81 70 50 90
(_Annual bluegrass)
Setarla lutescens . . . . . . . . . . . . . . . . . .. Young 4 6.35 5 90 7 48 .42 28 54 .55 50 61

(Yellow foxtail) Bloom 1 11.26 . . . . . . . . . . . . . . . . .42 . . . . . . . . . . . . . . . . .48 . . . . . . . . . . . . . . . .

_ Mature 1 5.45 . . . . . . . . . . . . . . .. .54 . . . . . . . . . . . . . . . . .54 . . . . . . . . . . . . . . . .

Setarla viridis . . . . . . . . . . . . . . . . . . . . . Young 1 17.30 . . . . . . . . . . . . . . . . .75 . . . . . . . . . . . . . . . . .46 . . . . . . . . . . . . . . . .

Sorghastrum nutans . . . . . . . . . . . . . . . . Young 3 6.13 4.78 6.82 33 21 .46 .50 46 .56

Sorghum halepense . . . . . . . . . . . . . . . .. Young 19 9.21 4.65 14.53 51 31 1.01 .88 51 1.40
(Johnson grass) Bloom 14 7.10 3.81 9.18 47 19 .64 .81 58 1.20
Mature 2 5.36 4.76 5.95 38 29 .47 .64 63 .64

Sporobolus cryptandrus . . . . . . . . . . . . . Young 7 12.79 10.61 16.35 47 38 .59 .42 36 50
Sporobolus poiretii . . . . . . . . . . . . . . . .. Young 16 7.99 5.67 10.15 33 24 .44 .55 36 1 13
(Smut grass) Bloom 7 6.14 4.72 9.09 34 25 .43 .38 27 50

_ _ IVIature 8 5.06 3.40 7.08 27 12 .36 .51 37 89
Trifohum repens (white clover) . . . . . . . Young 5 19.58 14.31 27.05 o3 31 .62 2.03 1 53 2 79
Tripsacum dactyloides . . . . . . . . . . . . . . Young 3 8.78 7.40 9.38 48 29 .57 .33 32 35
_ (Eastern gamagrass) Bloom 2 6.83 5.75 7.90 48 42 .53 31 25 37
Uniola sessiliflora . . . . . . . . . . . . . . . . . . Young 14 6.85 5.88 8.94 35 17 .74 43 27 57
. Bloom 6 5.40 5.01 5.75 31 22 .37 42 31 50
Mature 8 5 .03 3 .04 6 .20 22 19 .44 55 32 78

Total . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1432

NOLLVLS ILNEIWIHEIdXEI TVHILITIIIDIHDV SVXEIL ‘Z89 'ONI NLLEPTIIIH

   
 
    
  
   
  
   
  
  
  
   
   
   
   
  
   
   
  
   
  

CHEMICAL COMPOSITION OF FORAGE GRASSES 13

g he lowest and highest quantity of each constituent found in any of
e samples analyzed is also given in Table 2, thus affording an estimate
the range of analyses Within the same species at the same stage of
iwth. The differences in the protein, phosphoric acid, and lime
ltents of different samples of the same species were wide in all of
c species, even when comparison was confined to samples of the same
ige of growth. The minimum analyses are much lower and the max-
um analyses much higher in some species than in others. Comparisons
» be more easily made and are more reliable in the species of which
considerable number of samples were collected. In young little blue-
m, protein varied between 3.34% and 13.73%; phosphoric acid between
1% and .61%; and lime between .23% and .78%. In young Bermuda,
e variation in proteinlwas between 4.20% and 16.70%; in phosphoric
id, between .16% and .77%; and in lime, between .39% and 1.15%. In
ung Johnson grass, the range in protein was between 4.65% and 14.53%;
i phosphoric acid, between .31% and 1.01%; and in lime, between
3% and 1.40%. Very high analyses were secured in a few cases. One
iple of annual bluegrass contained 28.22% protein, and 3 samples of
 ng rescue grass averaged 18.00% protein. Low analyses were secured
other cases; this is particularly true in the case of phosphoric acid in
1e various species in the bluestem (Andropogon) group. White clover
ntained a great deal more protein and lime than did any of the prin-
w: grasses; this is also true of lespedeza and bur clover, but to a
i ~ marked degree. Other comparisons may be made by reference to
Able 2. It is well known that legumes contain more protein and lime
“n grasses.

¢

 Table 3, the principal species of grasses are averaged in order of
jreasing content of protein, of phosphoric acid and of lime at the
A, ng stage of growth (in which the plant contains the highest per-
tage of protein, lime, and phosphoric acid). Protein in Johnson, Ber-
 and Dallis grasses is much higher than in any of the other grasses,
leraging over 9%. None of the other species averaged as high as
e protein, 5 of the species averaged between 7% and 8%, all of the

le 3. Principal species of grasses arranged in order of their proteinfphosphoric acid, and
lime contents at the young stage of growth

k Protein Phosphoric acid Lgne
. 0 ' 0 O
Jason . . . . . . . . . . . . . . 9.21 Johnson . . . . . . . . . . . . .51 Johnson . . . . . . . . . . . . .88

uda . . . . . . . . . . . . . . 9.14 Dallis . . . . . . . . . . . . . . .44 Georgia . . . . . . . . . . . . .65

's . . . . . . . . . . . . . . . . 9.07 P. capillarioides. . . . . .43 Bermuda . . . . . . . . . . . .63

ut . . . . . . . . . . . . . . . . . 7.99 Bermuda . . . . . . . . . . . .40 P. floridanum . . . . . . . .61

ceps . . . . . . . . . . . . . 7 .73 P. anceps . . . . . . . . . . . .34 P. anceps . . . . . . . . . . . .58

_ et . . . . . . . . . . . . . . . 7.32 Smut . . . . . . . . . . . . . . .33 P. capillarioides. . . . . .56

apillarioides . . . . . . . . 7 .05 ‘Broomsedge . . . . . . . . .33 Smut . . . . . . . . . . . . . . .55

oridanum . . . . . . . . . 7 .02 Silver beardgrass. . . . .32 Dallis . . . . . . . . . . . . . . .54

6.69 Carpet . . . . . . . . . . . . . .31 Prairie three-awn . .. . .54

6.63 P. floridanum . . . . . . . .31 Silver beard . . . . . . . . .52

6.60 Old Witch . . . . . . . . .. .28 Big bluestem. . . .. . .. .50

6.59 Little bluestem . . . . . . .27 Carpet . . . . . . . . . . . . . .50

6.54 Georgia . . . . . . . . . . . . .26 Old Witch . . . . . . . . . . .45

6.18 Big bluestem . . . . . . . . .26 Little bluestem . . . . . . .45

5.98 Prairie three-awn. .. . .20 Broomsedge . . . . . . . . .39

  

14 BULLETIN NO. 582, TEXAS AGRICULTURAL EXPERIMENT STATION

Andropogons averaged between 6% and 7%, and prairie three-awn aver
aged only 5.98% protein. i’

Phosphoric acid is .40% or above in Johnson, Dallis, and Bermu
grasses, and Panicum capillarioides. Six of the species contained betwee
.30% and .39%, while the remaining five species contained from .20%
.28%, with prairie three-awn lowest with .20% phosphoric acid.

Lime in Johnson, Georgia, Bermuda grasses and in Paspalum fioridan g
averaged over .61%, Johnson grass much higher than any of the othe
(.88%). Eight of the remaining species contained between .50% t.
.58%, two contained .45%, and broomsedge was lowest, with .39% lime. "a

The principal improved grasses of the region are Johnson, Bermu
Dallis, and carpet grasses. As noted above, Johnson, Bermuda, and Dal 
grasses are all relatively high in protein, phosphoric acid, and lime :5
the young stage of growth. Carpet grass, however, averaged sixth p
protein, ninth in phosphoric acid, and twelfth in lime content. The blu
stems (Andropogons), the principal native grasses of the area, were >_
relatively low in all of these constituents. Prairie three-awn, or nee
grass (Aristida-oligantha), was lowest of all the principal species =-
protein and phosphoric acid, but was fairly high in lime.

Comparison of dilferent species with Bermuda

A comparison of the average composition of all samples of the vario
species collected has been shown in Tables 2 and 3. The question is of J
asked as to how different species of grasses compare in chemical n,
position, when grown under the same conditions. Such a comparisof
cannot be made from previous tables, since i.t is valid only when 1-‘
between diiferent species collected at the same time and from the ~11
soil. Since not all of the species were found growing together on =i
locations, it is dsirable to select one species found rather generall
throughout the region and use this as a standard with which to compa ”

other species. Such a comparison is shown in Table 4, with the analys:

of the different species expressed as percentages of the correspondi

constituents found in samples of Bermuda grass collected at the m

time and place.

In the spring samples, protein was higher in Bermuda than in an.
other grass, in many grasses the protein was only slightly lower thv
in Bermuda, and it was considerably lower in the case of a few speci
averaging 68% of the Bermuda in silvery beardgrass and Panicum cap
larioides. Protein was higher in the fall samples of Johnson grass (113
and Dallis grass (105%) than in Bermuda, and considerably lower in 
remaining species, decreasing to only 62% in Panicum capillarioides. A

Phosphoric acid was higher in the spring samples of Johnson 
(108%), Dallis grass (105%), and silver beardgrass (101%) than 
Bermuda, slightly lower in Vasey, carpet, and flat-stemmed panic grass
and considerablyilower in the remaining species, decreasing to 58% 

 
 
 
  

 

CHEMICAL COMPOSITION OF FORAGE GRASSES 15
Table 4. Comparison of different grasses with Bermuda as 100
Spring Samples
Protein Phos horic acid Lime
ermuda . . . . . . . . . . . . . . . 100 ‘Johnson . .9 . . . . . . . . . . 10s P. pubescens . . . . . . . . . 133

lis . . . . . . . . . . . . . . . . . . 95 allis . . . . . . . . . . . . . . . 105 Flatstemrned panic. . . 110

Carpet . . . . . . . . . . . . . . . . . 91 Silver beard . . . . . . . . . 101 ohnson . . . . . . . . . . . . . 108

Vasey . . . . . . . . . . . . . . . . . . 90 Bermuda . . . . . . . ._ . . . . 100 Vasey . . . . . . . . . . . . . . . 105

Flatstemmed panic . . . . . . . 90 Flatstemmed panic. . . 93 Bermuda . . . . . . . . . . . . 100

' U. sessiliflora . . . . . . . . . . . . 90 Vasey . . . . . . . . . . . . . . . 92 Georgia .  ._ . . . . . . . . . 99

é Johnson . . . . . . . . . . . . . . . . 89 Carpet . . . . . . . . . . . . . . 91  capillarioides . . . . . . 96

 Silver beard . . . . . . . . . . . . . 85 Georgia . . . . . . . . . . . . . 81 allis._. _. . . . . . . . . . . . . 89

‘ Broomsedge . . . . . . . . . . . . . 81 P. pubescens . . . . . . . . . 81 U_. sessiliflora . . . . . . . . 89

g Georgia . . . . . . . . . . . . . . . . . 80 U. sessiliflora . . . . . . . . 81 Big bluestem . . . . . . . . . 86

; Little bluestem . . . . . . . . . . 75 E. lugens.. ._ . . . . . . . . . 79 E: lugens . . . . . . . . . . . . 85

- Big bluestem . . . . . . . . . . . . 74 P. capillarioides . . . . . . 77 Little bluestem . . . . . . . 81

i P. ubescens . . . . . . . . . . . . 70 Broomsedge . . . . . . . . . 75 Carpet . . . . . . . . . . . . . . 80

‘ E. ugens . . . . . . . . . . . . . . . 70 Big bluestem . . . . . . . . . 73 Silvery beard . . . . . . . . 78

P. capillarioides . . . . . . . . . . 68 Little bluestem . . . . . . . 72 Broomsedge . . . . . . . . . 77

v Silvery beard . . . . . . . . . . . . 68 Silvery beard . . . . . . . . 58 Silver beard . . . . . . . . . 70
1 Fall Samples
Fzihnson . . . . . . . . . . . . . . . . 113 ‘Johnson - - . - - - - - . - . -- 136

' allis . . . . . . . . . . . . . . . . .. 105 P. pubescens-----_---- 116

§ Bermuda . . . . . . . . . . . . . . . 100 Flalsfiimmed DQIIIQ- - - 104

‘ Carpet . . . . . . . . . . . . . . . . . 8 Georgia - - - - - - - - - - - - - 103

* E. lugens . . . . . . . . . . . . . . . 87 Bfifmllda - - - - - - - - - - - - 100

Vasey . . . . . . . . . . . . . . . . . . 85 B18 blllfistem - - - - - - - - - 99

Georgia . . . . . . . . . . . . . . . . . 80 E. lugens . . . . . . . . . . . . 81  sessiliflora . . . . . . . . 90

U. sessiliflora . . . . . . . . . . . . 77 U. sessilinora . . . . . . . . 76 allis . . . . . . . . . . . . . . . 85

L P. pubescens . . . . . . . . . . . . 74 P. capillarioides. ._ . . . . 75 Carpet . . . . . . . . . . . . . . 82

Broomsedge . . . . . . . . . . . . . 71 Flatstemmed panic. . . 73 Vasey . . . . . . . . . . . . . . . 75

' Flatstemmed panic . . . . . . . 71 Silver beard . . . . . . . . . 71 Little bluestem - - - - - . . 75

Little bluestem . . . . . . . . . . 67 Broomsedge . . . . . . . . . 69 E_. lugens . . . . . . . . . . . . 72

Big bluestem . . . . . . . . . . . . 66 Little bluestem . . . . . . . 65 Silver _bear_d_ . . . . . . . . . 64

Silvery beard . . . . . . . . . . . . 66 P. pubescens . . . . . . . . . 63 P. capillarioides . . . . . . 60

Silver beard . . . . . . . . . . . . . 63 Silvery beard . . . . . . . . 59 Broomsedge . . . . . . . . . 58

P. capillarioides . . . . . . . . . . 62 Big bluestem . . . . . . . . 57 Silvery beard . . . . . . . . 54

 
 
 

l-

 

  
 
 
 
 
 
 
 
 
 
 
 
 
  
 
   

silvery beardgrass. Phosphoric acid was higher in the fall samples of
Johnson grass (120%) than in Bermuda, the same in Dallis grass, slightly
lower in Vasey grass (92%), and considerably lower in the remaining
species, decreasing to 57% in big bluestem.

Lime was higher in the spring samples of Paspalum pubescens (133%),
flat-stemmed panic (110%), Johnson (108%), and Vasey (105%) grasses
than in Bermuda, slightly lower in Georgia grass (99%), and Panicum

icapillarioides (96%f-, and considerably lower in the remaining species,

decreasing to 70% in silver beardgrass. Lime was higher in the fall
samples of Johnson grass (135%), Paspalum pubescens (116%), fiat-
stemmed panic (104%) and Georgia (103%), grasses, slightly lower in
big bluestem (99%) and Uniola sessilifiora (90%), and considerably
lower in the remaining species, decreasing to 54% in silvery beardgrass.

In general, Johnson, Dallis, and Vasey grasses are about the same as

Vor a little better than Bermuda in protein, phosphoric acid, and lime.
Carpet grass and spring samples of flat-stemmed panic grass are slightly

lower than Bermuda, and the remaining species considerably lower than
‘Bermuda, with silvery beardgrass being the lowest.

16 BULLETIN NO. 582, TEXAS AGRICULTURAL EXPERIMENT STATION

Average feed constituents in species of forage

The average percentages of protein, ether extract, crude fiber, and
nitrogen-free extract in samples of different species at various stages
of growth are shown in Table 5. The usual feed analyses were made
on several samples of a number of species.‘ The averages given for
protein content are different from those given in Table 2, since only a
part of the samples are averaged in Table 5. In general, protein decreased

slightly, and crude fiber and nitrogen-free extract increased considerably A

with increasing age of the plants. White clover, lespedeza, the early
spring grasses (Bromus catharticus, Panicum helleri, and Poa annua),
and Bermuda grass were considerably lower in crude fiber than most
of the other species. In most of the samples of which a considerable
number were analyzed, the variation in nitrogen-free extract at the
same stage of growth is small, although at the young stage of growth
silver beard, Bermuda, and carpet grasses are‘slightly higher than other}
species. The crude fiber content is usually around 30 to 32 per cent,’
although a few samples contain much lower quantities, and a few others,
much higher quantities of crude fiber. Carpet grass, rescue grass, Ber-
muda grass, lespedeza, Panicum helleri, young‘ annual bluegrass and
young white clover are lower in crude fiber than the others and in
this respect are better than the other grasses.

Table 5. Average feed constituents in diflerent grasses at various stages of growth

Stage Number Nitro-
of of Protein Ether Crude gen-free
growth samples extract iibre extract
% % % %

Andropogon provincialis . . . . . . . . . . Young 23 6.68 2.11 31.61 41 80
(Big bluestem) Bloom 1 4.30 2.00 30.25 48 42
Mature 4 3.56 1.99 32.53 47 99

Andropogon saccharoides . . . . . . . . .. Young 5 4.39 2.49 29.89 47 62
(Silver beardgrass) Bloom 3 4.27 2.49 30.96 28
Mature 5 5.42 1.63 31.88 44 61

Andropogon scoparius . . . . . . . . . . .. Young 44 5.38 2.07 32.13 46 21
(Little bluestem) Bloom 12 5.13 2.05 31.41 46 95
Mature 6 3.61 H 1.86 31.34 48 23

Andropogon tener . . . . . . . . . . . . . . . . Young 4 5.88 1.89 32.80 45 75
(Texas bluestem) Bloom 3 3.88 1.57 30.74 47 73
Mature 2 3.93 1.66 31.55 48 06

Andropogon ternarius . . . . . . . . . . . .. Young 4 6.76 1.51 33.96 44 45
(bilvery beardgrass) Bloom 1 3.76 1.47 35.97 45 38
Andropogon virginicus . . . . . . . . . . .. Young 6 7.00 1.94 31.51 45 73
(Broomsedge) Bloom 1 3.95 1.09 35.08 47 24
Aristida longespica . . . . . . . . . . . . . . . Young 3 5.46 1.87 30.06 45 19
(Needle grass) Mature 1 4.64 1.67 33.75 48 47
Aristida oligantha . . . . . . . . . . . . . . . . Young 33 5.85 1.94 30.66 45 17
(Prairie three-awn) Bloom 2 5.75 2.11 31.66 45 77
Mature 51 4.99 1.71 32.00 46 03

Axonopus compressus . . . . . . . . . . . .. Young 23 6.95 1.73 27.14 46 45
(Carpet grass) Bloom 4 7.74 1.75 26.30 46 45
Mature 9 5.44 1.27 30.98 45 96

Bromus catharticus (Rescue) . . . . . . . Bloom 1 16.50 3.19 23.41 36 11
Cenchrus pauciflora . . . . . . . . . . . . . . Young 2 6.76 1.96 29.23 46 35
Cynodon daetylon . . . . . . . . . . . . . . .. Young 59 8.75 2.01 25.86 46 71
(Bermuda grass) Bloom 16 9.69 1.98 24.00 47 36
Mature 12 7.69 1.98 25.92 48 33

Digitaria sanguinalis . . . . . . . . . . . . .. Bloom 2 9.36 2.10 .87 45 99
Eragrostis elliottii . . . . . . . . . . . . . . .. Young 5 6.83 2.34 32.24 44 40
Mature 1 1 4.00 2.36 32.89 43 90

CHEMICAL COMPOSITION OF FORAGE GRASSES

Table 5 (continued).

17

Average feed constituents in different grasses at various stages of

growth
Stage Number _ Nitro-
of of Protein Ether Crude gen-free
growth samples extract fiber extract
% o % %

Eragrostis lugens . . . . . . . . . . . . . . . . . Young 6 6.10 1.61 32.39 43.95
Bloom 2 7.50 2.55 31.94 43.86

Mature 2 4.14 1.58 32 .94 47.85

Eragrostis pectinacea . . . . . . . . . . . . . Young 2 5.72 2.66 31.99 43,89
Eragrostis secundillora . . . . . . . . . . . . Young 1 8.10 1.90 26.78 46.33
’ Mature 3 4.92 2 .33 31.54 46.30
Eragrostis spectabilis . . . . . . . . . . . . . Mature 4 4.15 2.20 32.42 47.45
Lespedeza striata . . . . . . . . . . . . . . . . Young 9 12.92 3.04 26.21 43.22
(Lespedcza) Mature 2 11.55 2 .38 28 . 81 42 .05
Muhlenbcrgia capillaris . . . . . . . . . . . Young 1 6.30 1 .92 30.63 40.36
(Longawned hair-grass) Mature 2 4.05 1.71 34.79 45.31
Panicum anceps . . . . . . . . . . . . . . . . . . Young 4 8.25 1.83 27.72 44. 66
Bloom 2 6.69 2.66 28.95 43.32

Mature 2 4.54 1.48 30.40 46 .27

Panicum capillare . . . . . . . . . . . . . . . . Young 4 6.48 1.94 32.94 43.88
(Old Witch grass) Bloom 1 3 .98 1.72 33.13 44.48
Mature 2 4.80 1.57 33 .02 48 .02

Panicum capillarioidcs . . . . . . . . . . . . Young 8 6.87 2.02 32.81 40.89
Bloom 2 4.06 1.83 32.47 46 .82

Panicum hellcri . . . . . . . . . . . . . . . . . . Bloom 5 9.92 2.73 24.44 43.19
Paspalum dilatatum . . . . . . . . . . . . . . Young 10 7 .80 2 .08 31.71 41.41
(Dallis grass) Bloom 10 5.99 2.30 33.40 41.68
Mature 1 4 .04 1.61 33.83 43 .00

Paspalum floridanum . . . . . . . . . . . .. Young 4 6.25 1.77 30 36 44.51
Bloom 1 5 .96 1.45 26 .76 49 .34

Paspalum minus . . . . . . . . . . . . . . . . . Young 1 14.75 1.96 28.95 37.69
Paspalum notatum . . . . . . . . . . . . . . . Bloom 2 5 .85 1.53 30.90 48.21
Paspalum pubescens . . . . . . . . . . . . . . Young 14 6.56 1 .73 30.31 41.42
Bloom 2 5 .29 1.63 30.04 44 .85

Mature 2 3.73 1.42 29.87 47 .55

Paspalum stramineum . . . . . . . . . . . . Bloom 1 6. l0 1.44 31 .91 41.78
Paspalum urvillei . . . . . . . . . . . . . . . . Young 3 7.40 2.00 40.42 44.58
(Vasey grass) Bloom 5 5.74 1.56 32.84 44.73
Mature 1 5 .40 1.56 32.92 41.28

Poa annua . . . . . . . . . . . . . . . . . . . . .. Young 1 12.80 3.61 19.26 41.81
Setaria lutescens . . . . . . . . . . . . . . . . . Young 2 5.93 2.09 30.68 45.58
Mature 1 5.45 1.92 30.89 43 .95

Sorghastrum nutans . . . . . . . . . . . . . . Young 1 6.82 1.58 30.83 41.68
Sorghum halepense . . . . . . . . . . . . . . . Young 6 9.22 2.28 28.51 42.35
(Johnson grass) Bloom 3 5.43 1.87 30.00 43.19
Mature 2 5 .36 1.40 32.36 44.91

Sporobolus cryptandrus . . . . . . . . . . . Young 2 11.05 1.99 29.30 38 .26
Sporobolus poiretii . . . . . . . . . . . . . . . Young 4 6.76 1.87 29.21 46.25
_ (8mut grass) Mature 1 4.96 1.83 29.15 46.40
Trifohum repens . . . . . . . . . . . . . . . .. Young 5 21.91 2.70 14.83 42.24
Tripsacum dactyloides . . . . . . . . . . . . Bloom 2 6.83 1 .53 31.05 45 .43
Uniola sessiliilora . . . . . . . . . . . . . . . . . Young 9 6.53 2.11 31 .87 44.92
Mature 4 4.31 3.28 34.05 45 24

Grades of constituents of forage

In order to facilitate comparison of the composition of the samples,
we have grouped them into 5 classes or grades (Table 6), as was done with
soils (9) according to their content of protein, phosphoric acid, and lime.
These groups are to a certain extent empirical, and are intended to allow
comparisons to be made more easily than by use of the analytical figures
alone. We have tried to arrange the groups to carry as much meaning as
possible. The groups as decided upon are given in Table 6. The per-
centage requirements and grades of the different constituents are based
Some of the considerations

' on the requirements of range beef animals.
. involved in deciding on the limits of the, groups are discussed below.

18 BULLETIN NO. 582, TEXAS AGRICULTURAL EXPERIMENT STATION

Table 6. Grades for calcium, phosphorus, and protein in forage for range animals (all figures
as per cent on air dry basi)

Grade Interpretation
. Crude protein Protein
1 High . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 .00

2 Good . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 10.50 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 H‘gh . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. .45 + 1.01 +

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

3 Fair . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. .15 to .29 .33 t0 .66

4 Deficient“ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. .08 t0 .14 .17 to .32

5 Very deficient . . . . . . . . . . . . . . . . . . . . . . . . . . .. 0 to .07 0 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 to .15 .11 to .21

5 Very deficient . . . . . . . . . . . . . . . . . . . . . . . . . . .. O t0 .07 0 to .10

The quantity of a given constituent utilized by an animal depends upon
the percentage of that constituent in the ration, the quantity of the ration
consumed and the utilization of that constituent to the animal. The relative
utilization of the constituent is related to some extent to the quantity
of the constituent in the ration. For examples, according to data given
by Morrison (19) and Fraps (8), the protein in forage containing
less than 12% crude protein is digested only 56%; while the crude
protein in forage containing more than 12% crude protein is digested
78%. The ratio of the quantity of calcium and of phosphorus retained
by the animal to thatin the ration consumed has been variously estimated
by different investigators. Kellner (16) estimates that from 2 to 3 times
the quantity of calcium and phosphorus retained by the animal should
be supplied by the ration, while Mitchell and McClure (18) estimate that
1.43 parts in the feed is required for 1 part retained. Animals retain
a larger percentage of a mineral in the body when the quantity ingested
is low, than when it is high.

As the age and Weight 0f the animal increases through the first two
years, the pounds of dry matter required to furnish sufficient energy for
the animals increases, the Weight of calcium required decreases and the
Weight of phosphorus required remains practically constant (18). Conse-
quently, the percentages of calcium and phosphorus necessary in the feed
decrease as the animal gets older. In the case of female animals, preg-
nancy and lactation increase the quantities required.

Kellner (16) estimated the calcium and phosphorus retention of grow-
ing calves to be 15.0 grams of calcium and 8.3 grams of phosphorus daily.
Using data obtained by Lawes and Gilbert, Armsby (1) computed that
cattle retain 8.14 grams of phosphorus daily during the first year. Theiler,

CHEMICAL COMPOSITION OF FORAGE GRASSES 19

Green, and Du Toit (25) found that fair growth resulted from feeding 5
grams of phosphorus (in the form of phosphates) daily to heifers, while good
growth and reproduction was secured by feeding 13 grams daily. Huffman,
Duncan, Robinson, and Lamb (15) suggest for milk cows .75 grams of
feed phosphorus per pound of milk produced plus 10.0 grams of feed
phosphorus per 1,000 pounds of live weight for maintenance, while not
less than 17 grams of phosphorus should be fed during low production
or the dry period. Theiler, Green, and Du Toit (25) found that 2.23
grams of phosphorus and 4.99 grams of calcium per day was not suffi-
cient. Henderson and Weakley (13) estimate that the ration should not
contain less than 20% phosphorus. Archibald and Bennett (2) estimate
that 1.8 grams of phosphorus daily per 100 pounds of live weight during
the first year of life, 1.7 grams during the second year, and 1.2 grams
during the third year will produce average growth in dairy heifers.
Lindsey, Archibald and Nelson (17) found that an average daily intake
of 5.97 grams of calcium per 100 pounds live weight resulted in normal
growth and development, and that equally satisfactory growth was secured
with 3.17 grams, although there was a considerably lower storage of
lime by the latter group.

The grades classify the samples into 5 groups, high, good, fair, deficient
and very deficient. While not intended to be standards, these grades
have meaning.

A study of the available literature concerning the phosphorus content
of forage from areas which were known to be deficient in phosphorus, as
compared with areas on which the cattle showed no evidence of deficiency,
showed that grass samples from deficient areas contained an average of
.082% phosphorus, (Grade 5), while that from normal areas contained an
average of .170% (Grade 3). Of 53 samples of grass reported by Theiler
(23) from a “styfsiekte” area, 5 samples (collected in the early spring)
were in Grade 3, 17 in Grade 4, and 31 in Grade 5. Of 81 samples reported
from Florida by Becker, Neal, and Shealy (3), 14 samples from ranges
producing healthy animals averaged .167% phosphorus (Grade 3), while
67 samples from ranges supporting cattle suffering from “sweeny” or
“stiffs” averaged 103% (well down in Grade 4). Of 51 samples of prairie
hay reported by Eckles, Gullickson, and Palmer (7) from a phosphorus-
deficient area in Minnesota, 9 were in Grade 5 and 35 in Grade 4. Of
54 samples from Montana reported by Scott (21), samples of alfalfa,
timothy, and wild grass from areas supporting normal cows averaged
in Grade 3 with respect to phosphorus, while samples from areas sup-
porting cows with depraved appetites averaged in Grade 4. The available
data thus indicate that the limits of the grades as proposed have ‘some
meaning with respect to phosphorus.

Limits for grades of crude protein as given in Table 6 were estimated
by a series of calculations using as a basis standards and coefiicients
given by Morrison (19) and Fraps (9).

20 BULLETIN NO. 582, TEXAS AGRICULTURAL EXPERIMENT STATION

Distribution of samples according to grades of constituents

The distribution of samples of the different species, at various stages
of growth, in the different grades of protein, phosphoric acid, and lime
is shown in Table 7. A few of the samples are so low in protein that
they are classed as very deficient (Group 5), while in phosphoric acid
many are very deficient (Grade 5) and many more of them are deficient
(Grade 4). Lime was fair (Grade 3) to good (Grade 2). Only 3 samples
of broomsedge (in Grade 4) occurred below Grade 3. Many of the sam-
ples of Bermuda, Paspalum pubescens, and Johnson grass contained per»
centages of lime in Grade 1.

The distribution of the samples of a given species in the different
grades varied widely with the different species. A larger proportion of
the total number of samples of the bluestems (Andropogons) contained
percentages of protein and phosphoric acid occurring in the very deficient
and deficient grades (5 and 4) than was the case in any of the other
species. The bluestems and Paspalum floridanum were the only species
in which a significant proportion of the samples contained percentages of
protein and phosphoric acid in Grade 5. Many of the samples of Paspalum
pubescens and Bermuda, Dallis, and Johnson grasses at the young stage
of growth contained percentages of protein in Grade 2.

The distribution of the samples of each species at different stages of
growth is also shown in Table 7. The proportion of the samples of the
species containing percentages of protein and phosphoric acid in the
higher grades decreased as the plants became older. For example, at
the young stage of growth, 13 of the 79 samples of big bluestem contained
phosphoric acid in Grade 3 and only 5 samples were in Grade 5, while at
maturity, no sample contained sufficient phosphoric acid to be in Grade 3
and nearly two-thirds of the samples (9 of 14) were in Grade 5. The
lime content of some species increased with advancing maturity, decreased
in others, and in still others, remained practically unchanged. For exam-
ple, the proportions of samples containing lime in Grade 2 at the young,
bloom, and mature stages of growth were 43%, 50%, and 88% in
Uniola sessiliflora; 76%, 38%, and 25% in silver beardgrass; and 91%,
80%, and 95% in Bermuda.

The figures in Table 7 show that very few of the samples were deficient
in lime, but that practically all of the samples were from only fair to
very deficient in protein and phosphoric acid, and that as maturity
approached, there was a marked increase in the proportion of the
samples which were deficient or very deficient in protein and phos-
phoric acid.

 ~-

“we

Table 7.

Distribution of samples of different species of grasses at various stages of maturity in grades of constituents

Protein grade

Phosphoric acid grade

Lime grade

~ Stafge Nunfiber 5 4 3 | 2 | 1 5 4 3 2 4 3 2 1
o o r 1
growth samples 0— 3.00— 6.00—I10.50~ 15.00 0- .17~ .33— .67— .11—- .22— .43-
2.99 5.99 10.49 14.99 + .16 .32 .66 1.00 .21 .42 .82 .83+
Agrostis verticillata . . . . . . Young 1 . . . . . . . . . . . . 1 . . . . . . . . . . . . . . . . . . . . . . . 1 . . . . . . . . . . . . . . . . . . 1 . . . . . .

Water bentgras_s)_ Mature 3 . . . . . . 2 1 . . . . . . . . . . . . . . . . . 3 . . . . . . . . . . . . . . . . . . 1 2 . . . . . .

Andropogon provinciahs. . . Young 79 . . . . . . 33 46 . . . . . . . . . . . . 5 61 13 . . . . . . . . . . . . 21 57 1

(Big bluestem) Bloom 21 4 17 . . . . . . . . . . . . . . . . . . 10 11 . . . . . . . . . . . . . . . . . . 8 13 . . . . . .

_ Mature 14_ 4 1O . . . . . . . . . . . . . . . . .. 9 5 . . . . . . . . . . . . . . . . .. 3 11 . . . . ..

Andro ogon saccharo1des.. . . Young 21 . . . . . . 6 14 1 . . . . . . . . . . . 13 8 . . . . . . . . . . . . 4 16 1

Si ver beardgrass) Bloom 8 . . . . . . 6 2 . . . . . . . . . . . . 1 6 1 . . . . . . . . . . . . 5 3 . . . . . .

_ Mature 8 2 6 . . . . . . . . . . . . . . . . . . 2 6 . . . . . . . . . . . . . . . . . . 6 2 . . . . . .

Androppgon scoparius . . . . . . Young 112 . . . . . . 55 56 1 . . . . . . 8 81 23 . . . . . . . . . . . . 49. 63 . . . . . .

(Little bluestem) Bloom 47 3 36 7 1 . . . . . . 11 28 8 . . . . . . . . . . . . 19 26 2

Nlature 22 2 19 1 . . . . . . . . . . . . 14 7 1 . . . . . . . . . . . . 2 2O . . . . . .

Andropogon tener . . . . . . . . . . Young 1 1
(Texas bluestem) Bloom 2 3
Mature 2
Andropogon ternarius . . . . . . . Young 1
(Silvery beardgrass) Bloom 2
Andropogon virginicus . . . . . . Young
(Broomsedge) Bloom
Aristida fendleriana . . . . . . . . Young
(Fendler’s three-awn) Bloom
Aristida longespica . . . . . . . . . Young
(Needle grass) Bloom
Mature
Aristida oligantha . . . . . . . . . . Young
(Prairie three-awn) Bloom
Mature
Axonopus compressus. . .. . . . Young
(Carpet grass) Bloom
Mature
Axonopus furcatus . . . . . . . . . Bloom
Bromus cathart1cus..... . . . . Young
Cenchrus pauciflora . . . . . . . . Young
Cynodon dactylon . . . . . . . . . . Young
(Bermuda grass) Bloom
Mature

 

IZ SEISSVHD EIDVHOJ JO NOLLISOdWOO "IVOIWEIHO

Table 7 (continued). Distribution of samples of difierent species of grasses at various stages of maturity in grades of constituents

ZZ

NOLLVLS LNEIWIHEIJXEI "IVHHJJIIIOIHDV SVXELL ‘Z89 ‘ON NILLIETIIIH

Protein grade Phosphoric acid grade Lime grade
Stage N IIIIfIbQI‘ 5 4 r 3 2 1 5 4 3 2 4 3 2 1
o o
growth samples 0- 3 .00- 6 . 00- 10. 50- 15 .00 0- . 17- .33- .67- . 11- .22- .43-
2.99 5.99 10.49 14.99 + .16 .32 .66 1.00 .21 .42 .32 .83+
Digitaria sanguinalis . . . . . . . . Bloom 4 . . . . . . 1 1 2 . . . . . . . . . . . . 1 3 . . . . . . . . . . . . . . . . . . 4 . . . . . .

Eragrostis cil1anens1s . . . . . . . Young 1 . . . . . . . . . . . . 1 . . . . . . . . . . . . . . . . . . 1 . . . . . . . . . . . . . . . . . . . . . . . . 1 . . . . . .

(Stinkgrass) Bloom 1 . . . . . . 1 . . . . . . . . . . . . . . . . . . . . . . . . 1 . . . . . . . . . . . . . . . . . . 1 . . . . . . . . . . . .

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

Eragrostis elliottii . . . . . . . . . . Young 5 . . . . . . 2 3 . . . . . . . . . . . . . . . . . . 3 2 . . . . . . . . . . . . 1 4 . . . . . .

Mature 2 . . . . . . 2 . . . . . . . . . . . . . . . . . . 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 . . . . . .

Eragrostis intermedia . . . . . . . Young 2 . . . . . . 1 1 . . . . . . . . . . . . . . . . . . 2 . . . . . . . . . . . . . . . . . . 1 1 . . . . . .

Bloom 5 . . . . . . 3 2 . . . . . . . . . . . . . . . . . . 2 . . . . . . . . . . . . 2 3 . . . . . .

Eragrostis lugens . . . . . . . . . . . Young 25 . . . . . . 4 21 . . . . . . . . . . . . 2 12 11 . . . . . . . . . . . . 4 21 . . . . . .

Bloom 13 . . . . . . 3 10 . . . . . . . . . . . . . . . . . . 6 7 . . . . . . . . . . . . 7 6 . . . . . .

Mature 7 . . . . . . 3 4 . . . . . . . . . . . . 5 1 . . . . . . . . . . . . . . . . . . 6 1

Eragrostis pectinacea . . . . . . . Young 5 . . . . . . 2 2 . . . . . . 1 1 3 1 . . . . . . . . . . . . . . . . . . 5 . . . . . .

Bloom 4 . . . . . . 1 3 . . . . . . . . . . . . . . . . . . 3 1 . . . . . . . . . . . . . . . . . . 4 . . . . . .

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

Eragrostis secundiflora . . . . . . Young 4 . . . . . . 2 2 . . . . . . . . . . . . . . . . . . 3 1 . . . . . . . . . . . . . . . . . . 4 . . . . . .

Bloom 5 . . . . . . 2 3 . . . . . . . . . . . . . . . . . . 2 3 . . . . . . . . . . . . 1 4 . . . . . .

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

Eragrostis spectabilis . . . . . . . Young 4 . . . . . . . . . . . . 4 . . . . . . . . . . . . . . . . . . 3 1 . . . . . . . . . . . . 2 2 . . . . . .

(Purple lovegrass) Mature 4 1 2 1 . . . . . . . . . . . . 2 2 . . . . . . . . . . . . . . . . . . 1 3 . . . . . .

Lespedeza striata . . . . . . . . . . Young 14 . . . . . . . . . . . . 2 8 4 . . . . . . 3 11 . . . . . . . . . . . . . . . . . . . . . . . . 14

(Lespedeza) Bloom 3 . . . . . . . . . . . . 2 . . . . . . 1 . . . . . . 2 1 . . . . . . . . . . . . 1 . . . . . . 2

_ Mature 4 . . . . . . . . . . . . . . . . . . 4 . . . . . . . . . . . . . . . . . . 4 . . . . . . . . . . . . . . . . . . . . . . . . 4

Medlcago arabica . . . . . . . . . . Young 2 . . . . . . . . . . . . . . . . . . . . . . . . 2 . . . . . . . . . . . . 1 1 . . . . . . . . . . . . . . . . . . 2

Muhlenbergia capillaris. . . . . Young 3 . . . . . . 1 2 . . . . . . . . . . . . . . . . . . 3 . . . . . . . . . . . . . . . . . . 1 2 . . . . . .

_(Long-awned hair grass) Mature 2 . . . . . . 2 . . . . . . . . . . . . . . . . . . 2 . . . . . . . . . . . . . . . . . . . . . . . . 2 . . . . . . . . . . . .

Panlcum anceps. . . . ._ . . . . . . . Young 16 . . . . . . 1 15 . . . . . . . . . . . . . . . . . . 10 6 . . . . . . . . . . . . 4 11 1

(Flat stemmed panic grass) Bloom 12 1 8 . . . . . . . . . . . . . . . . . . 9 3 . . . . . . . . . . . . 2 10 . . . . . .

Mature 2 . . . . . . 2 . . . . . . . . . . . . . . . . . . . . . . . . 2 . . . . . . . . . . . . . . . . . . . . . . . . 2 . . . . . .

Panicum capillare . . . . . . . . . . Young 5 . . . . . . . . . . . . 5 . . . . . . . . . . . . . . . . . . 4 1 . . . . . . . . . . . . 2 3 . . . . . .

(Old Witch grass) Bloom 2 . . . . . . 1 1 . . . . . . . . . . . . . . . . . . 2 | . . . . . . . . . . . . . . . . . . 1 1 . . . . . .

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

Panicum capillarioides . . . . . . Young 22 . . . . . . 2 20 . . . . . . . . . . . . . . . . . . 7 | 12 3 . . . . . . . . . . . . 21 1

Bloom 5 . . . . . . 2 3 . . . . . . . . . . . . 1 3 1 . . . . . . . . . . . . 2 3 . . . . . .

Mature 12 . . . . .. 5 7 . . . . . . . . . . .. 10 2 . . . . . . . . . . . . . . . . . . . . . . .. 11 1

Panicum helleri . . . . . . . . . . . . Bloom 7 . . . . . . . . . . . . 6 1 . . . . . . 1 2 . . . . . . . . . . . . 4 . . . . . .

Panicum lindheimeri . . . .. . . . Young 4 . . . . . . 2 1 1 . . . . . . . . . . . . 2 2 . . . . . . . . . . . . . . . . . . 4 . . . . . .

Paspalum ciliatifolium . . . . . . Young 2 . . . . . . 2 . . . . . . . . . . . . . . . . . . . . . . . . 2 . . . . . . . . . . . . . . . . . . 2 . . . . . . . . . . . .

Bloom 2 . . . . . . 2 . . . . . . . . . . . . . . . . . . . . . . . . 2 . . . . . . . . . . . . . . . . . . . . . . . . 2 . . . . . .

Paspalum_ dilatatum.. . . . .. .
(Dalhs grass)

Paspalum distichum . . . . . . . .
(Joint grass)
Paspalum floridanum . . . . . . .

Paspalum minus . . . . . . . . . . .
Paspalum monostachyum. . .

Paspalum nqtatum . . . . . . . . .
Paspalum phcatulum . . . . . . .
(Georgia grass)

Paspalum pubescens . . . . . . . .

Paspalum setaceum . . . . . . . .
Paspalum stramineum . . . . . .
Paspalum unispicatum . . . . . .

Paspalum urvillei . . . . . . . . . .
(Vasey grass)

Poa annua . . . . . . . . . . . . . . . .
Setaria lutescens . . . . . . . . . . .
(Yellow foxtail)

Setaria viridis . . . . . . . . . . . . .

Sorghastrum nutans . . . . . . . .

Sorghum halepense . . . . . . . . .
(Johnson grass)

Sporobolus cryptqndrus. . . . .
Sporobolus poiretli . . . . . . . . .
(Smut grass)

Trifolium repens . . . . . . . . . . .
Tripsacum dactyloides . . . . . .
(Eastern gamagrass)
Uniola sessiliflora . . . . . . . . . .

Total . . . . . . . . . . . . .

49 12T
33 18
2 1
1 1
1 1
21 14
12 9
3 . . . . ..
1 . . . . ..
4 2
6 2
2 1
29 24
5 4
4 4
18 12
6 3
2 1
8 5
2 2
6 4
7 4
3 1
3 3
8 2
11 4
1 . . . . ..
2 . . . . ..
4 2
1 . . . . . ..
1 . . . . . ..
1 . . . . . ..
3 2
19 1
14 3
2 1
7 . . . . ..
16 7
7 4
8 4
5 1
3 1
2 . . . . ..
14 6
6 3
8 5
1432 763

‘SZ SHSSVHO HOVHO& d0 NOLLISOdWOO TVOINEII-IO

24 BULLETIN NO. 582, TEXAS AGRICULTURAL EXPERIMENT STATION

The chemical composition of the soils

Chemical analyses of the soil were made in order to ascertain the
relation between the composition of the soils and the composition of the
grasses. This knowledge would enable one to apply the results to the
various soils of Texas, as described in Bulletin 549.

The distribution by grades of constituents of 82 soils from which
forage samples were secured is given in Table 8. Nitrogen is deficient
or very deficient (Grades 4 or 5) in about one-fourth of the soils; the
permeable subsoil group is the only one in which any soils were very
deficient (Grade 5) in nitrogen. Total phosphoric acid was deficient or
very deficient (Grades 4 or 5) in over 80% of the samples. Active
phosphoric acid was very deficient (Grade 5) in 74 of the 82 samples,
and of the remaining 8, 6 were deficient (Grade 4) and 2 were only
fair (Grade 3). Active potash was deficient (Grade 4) in about one-
third of the samples and fair (Grade 3) in one-half of them. Active
lime was fair to very deficient (Grades 3 to 5) in '74 of the 82 samples.
Acidity (pH) averaged about the same for the soils of all- of the soil
groups. Since grasses are generally tolerant to soil acidity, it is doubtful
if any of the soils were suficiently acid to affect growth.

Table 8. Distribution by grades of constituents of soils of various soil groups from which
forage samples were secured

Imper-
Permeable meable Blackland
Subsoils Suhsoils Prairies Alluvial Total
(27) (30) (10) (15) (82)

Nitrogen

Grade 5, 0—.030% . . . . . . . . .. 2 0 0 0 2

Grade 4, .031—.060% . . . . . .. 11 8 0 2 21

Grade 3, .061—.l20% . . . . . .. 12 16 6 7 41

Grade 2, .121—.180% . . . . . .. 2 4 4 5 15

Grade 1, 181% and up. . .. O 2 0 1 3
Total Phosphoric Acid

Grade 5, 0—.025% . . . . . . . . .. 10 6 0 2 18

Grade 4, .026—.050% . . . . . .. 12 22 8 6 48

Grade 3, .051—.100% . . . . . .. 2 2 2 4 10

Grade 2, .101—.150% . . . . . .. 2 0 0 3 5

Grade 1, .151% and up. . .. 1 0 0 0 1
Active Phsophoric Acid

Grade 5, 0-30 p.p.m.. . . .. . .. 26 26 9 13 74

Grade 4, 31-100 p.p.m . . . . . .. 1 3 O 2 6

Grade 3, 101-200 p.p.m . . . . .. 0 1 1 0 2
Active Lime

Grade 5, 0-800 p.p.m . . . . . . .. 14 10 1 2 27

Grade 4, 801-1600 p.p.m.. .. 10 8 1 4 23

Grade 3, 1601-3200 p.p.m. .. 3 11 3 7 24

Grade 2, 320146000 p.p.m. . 0 1 4 2 7

Grade 1, 16,001 p.p.m. and up 0 0 1 0 1
pH

Grade 5, Below 5.0 . . . . . . . .. 1 2 0 2 5

Grade 4, 5.1—5.5 . . . . . . . . . .. 5 5 0 2 12

Grade 3, 5.6-6.0 . . . . . . . . . .. 8 10 4 2 24

' Grade 2, 6.1-7.5 . . . . . . . . . .. 11 12 4 9 36

Grade 1, 7.6 and up . . . . . .. 2 1 2 0 5

CHEMICAL COMPOSITION OF FORAGE GRASSES 25

Relation 0f the chemical composition 0f the soils to the
botanical composition of the forage

The figures in Table 8 show that a spread of two grades in the
several chemical constituents in the soils will cover most of the sam-
ples of soil collected. It is of considerable interest to know what the
principal species of forage were on soils which were above or below
the general average of the soils in the several constituents concerned.

Nitrogen in 3 of the 82 soils was in Grade 1; two of these were
Lufkin fine sandy loams which had been in cultivation at one time in
their history, and had probably received some fertilizer, while the_ third
soil was an Ochlockonee fine sandy loam, a bottomland soil. On all of
these areas, Bermuda was the principal forage grass, with small quan-
tities of needle, little bluestem, and Georgia grasses. Nitrogen in 15
of the soils was in Grade 2. All of these soils were from low-lying
locations or draws in which the moisture conditions were considerably
better than is common in the areas as a Whole. Seven of the soils were
of heavy texture. On 12 of the 15 soils, Bermuda was the principal
forage species, with Dallis, carpet, and Johnson grasses in varying pro-
portions. Bluestems provided most of the forage on the remaining 3
soils. Nitrogen was sufiiciently low in only 2 soils to be in Grade 5;
both of these soils were Norfolk fine sands supporting a very sparse and
spindly growth of sandburs, little bluestem, Paspalums of the setacea
group, and a little Bermuda.

Total phosphoric acid was in Grade 1 in only 1 soil, a Nacogdoches
fine sandy loam from a low area on which was a good stand for broom-
sedge and little bluestem. Total phosphoric acid in 5 of the soils was in
Grade 2. Three of these soils were heavy-textured bottomland soils
supporting forage consisting principally of Bermuda, Dallis, carpet, and

Vasey grasses, with small quantities of little bluestem and broomsedge,-

and 2 were fine sandy loams of the Kirvin and Nacogdoches series sup-
porting forage consisting principally of bluestems. Ten soils contained
total phosphoric acid in Grade 3, of which 4 were bottomland soils sup-
porting Bermuda, Dallis, carpet, Vasey, and Johnson grasses, and 6
were from areas well supplied with moisture because of the surround-
ing topography on which Bermuda, Dallis, big bluestem, ‘and little blue-
stem were the, principal grasses.

The agreement between the relations with respect to nitrogen and
phosphoric acid is probably caused in large measure by the fact that
soils which are high in nitrogen were also usually high in total phosphoric
acid. Most of the soils in which both nitrogen and total phosphoric acid
were high were soils in which moisture conditions were considerably better
than are usual in the area. These soils consequently presented better con-
ditions for plant growth than were usual in the area, from the stand-
points of soil fertility and soil moisture, and these resulted in the growth
of better species of forage.

26 BULLETIN NO. 582, TEXAS AGRICULTURAL EXPERIMENT STATION

Active phosphoric acid in most of the soils was in Grade 5. The
number of soils (8) containing active phosphoric acid above Grade 5 is
too small to make any general conclusions with respect to this con-
stituent, but on 6 of these 8 soils, a significant part of the forage was
provided by Bermuda.

Active lime was in Grade 1 in a sample of Houston black clay, on
which Bermuda and Dallis grasses were practically the only species. ()n
5 of the 7 soils in which active lime was in Grade 2, Bermuda fur-
nished an important part of the forage, while on the other two, the
principal species were big and little bluestem. Active lime was in Grade 3
in 24 soils, on about half of which Bermuda was important; on all of the
upland soils (17 of the 24), however, big and little bluestems and broom-
sedge provided most of the forage. With the exception of 5 bottomland
soils, on which the forage consisted principally of Bermuda, Dallis, and
carpet grasses, the forage growing on soils containing active lime in
Grades 4 and 5 consisted principally of big and little bluestems, broom-
sedge, and various native grasses in varying proportions. High lime con-
tent of the soils does not seem to be of as great importance as high
nitrogen and high phosphoric acid in determining which species grow
on a soil.

Average analyses of forage grasses as related to composition
of soils of dilferent series '

Comparisons of the average protein content of 15 species of forage
plants as related to 10 soil series are shown in Table 9, of the average
phosphoric acid in Table 10, and of the average lime in Table 11.

In general, the differences are small between the average analyses of
a given species grown on difierent soil series. In some cases, the differ-
ences between the averages for different soil series are less than might
be obtained in individual samples of the same kind of forage. For
example, the average lime in big bluestem ranged only from .5292; to
.59% in 6 of the 10 soil series, while the range between low and high
samples of this plant in bloom ranged from 0.18% to 0.73%. Many other
similar cases may be seen by inspection of the tables. Differences between
the analyses of different species from the same soil series may be greater
than those between samples of the same species from diiferent soil
series.

The average analyses of forage from some soil series, however, par-
ticularly the Norfolk and Ruston, are lower than those from other series.
This can be seen by comparing the averages of the samples from the
soil series near the bottom of Tables 9, 10, and 11 with each other.
The average for the forages can also be compared with the averages
for the corresponding constituent in the soils of the series. The forage
from soils of the Lufkin series averages 7.67% protein while the soil

Table 9. Average percentage of protein in principal species from soils of difierent series

All Ochlock- Susque- _ Nacog-
samples Lufkin onee hanna Bowie Crockett Tabor Wilson doches Ruston Norfolk
Bermuda . . . . . . . . . . . . . . . . . . . . . . . . .. 8.58 10.08 8.16 8.96 11.5 7.99 9.40 8.77 8.19 6.87 6 76

Johnson . . . . . . . . . . . . . . . . . . . . . . . . . .. 7.96 11.73 7.30 8.97 5.89 . . . . . . . . . . . . . . .. 7.36 8.43 . . . . . . . . . . . . . . ..

Dallis . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 7.93 10.00 8.02 7.62 7.03 7.58 6.30 7.82 . . . . . . .. 7.12 . . . . . . ..

Carpet . . . . . . . . . . . . . . . . . . . . . . . . . . .. 6.77 7.39 6.89 6.39 6.16 7.60 . . . . . . .. 7.01 . . . . . . .. 6.48 6.25

E. lugens . . . . . . . . . . . . . . .  . . . . . . . .. 6.75 7.18 . . . . . . .. 6.53 . . . . . . . . . . . . . . .. 7.18 7.59 7.05 7.02 5.99

P. capillarioides . . . . . . . . . . . . . . . . . . . . 6.70 6.70 . . . . . . . . 6.90 . . . . . . . . . . . . . . . . 7.33 . . . . . . . . . . . . . . . . 6.66 6.01

Broomsedge . . . . . . . . . . . . . . . . . . . . . .. 6.34 6.89 5.71 5.90 6.14 . . . . . . .. 6.00 . . . . . . .. 6.23 5.28 6 67

U. sessiliflora . . . . . . . . . . . . . . . . . . . . .. 6.31 6.03 . . . . . . .. 5.99 6.50 . . . . . . . . . . . . . . . . . . . . . . .. 5.42 6.01 . . . . . . ..

Georgia . . . . . . . . . . . . . . . . . . . . . . . . . .. 6.23 6.65 5.27 6.54 . . . . . . .. 6.32 6.27 6 29 . . . . . . .. 6.08 . . . . . . ..

P. floridanum . . . . . . . . . . . . . . . . . . . . .. 6.20 6.69 4.78 7.15 6 48 5.88 4.60 . . . . . . . . . . . . . . . . . . . . . . .. 7.15

Smut . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 5.81 7.12 5.02 7.33 ....' . . . . . .  8.12 7.10 . . . . . . . . . . . . . . .. 5.27

Big bluestem . . . . . . . . . . . . . . . . . . . . .. 5.81 6.38 6.22 5.87 6.06 6 91 5.38 7.23 4 82 4.97 4.98

Little bluestem . . . . . . . . . . . . . . . . . . .. 5.52 5.89 6.06 5.62 5.66 4 77 6.74 5.51 5 39 4.92 4.84

Prairie three-awn . . . . . . . . . . . . . . . . . .. 5.37 5.18 . . . . . . .. 6.41 4.91 5 47 5.50 . . . . . . . . . . . . . . .. 5.05 5.14

Silver beard . . . . . . . . . . . . . . . . . . . . . .. 4.91 6.70 5.22 4.96 . . . . . . . . . . . . . . .. 5.12 5 85 . . . . . . .. 4.36 4.29
Averages:
Protein in forage % . . . . . . . . . . . . . . . . . . . .. 7.67 6.92 6.70 6.68 6.35 6.34 6.30 6.22 5.85 5.71
Nitrogen in soils % . . . . . . . . . . . . . . . . . . . . . .105 .147 .080 .085 .119 .106 .111 .083 .066 .048
Relative order:
Protein in plants . . . . . . . . . . . . . . . . . . . . . .. 1 2 3 4 5 6 7 8 9 10
Nitrogen in soils . . . . . . . . . . . . . . . . . . . . . .. 5 1 8 6 2 3 4 7 9 10

LZ SEISSVHE) EIDVHOH e10 NOLLISOJWOO TVOIWIEIHO

Table 10. Average percentage of phosphoric acid in various species from soils of difierent series
All Ochlock- Nacog- Susque-
samples Lufkin onee doches hanna Tabor Wilson Bowie Norfolk Ruston Crockett
Johnson . . . . . . . . . . . . . . . . . . . . . . . . . .. .47 .40 .51 .63 .51 . . . . . . .. .45 .33 . . . . . . . . . . . . . . . . . . . . . . ..

Dallis . . . . . . . . . . . . . . . . . . . . . . . . . . . .. .38 .48 .41 . . . . . . .. .36 .29 .41 .27 . . . . . . .. .35 .25

Bermuda . . . . . . . . . . . . . . . . . . . . . . . . . . .37 .41 .39 .23 .39 .32 .46 .43 .33 .32 .35

P. capillarioides . . . . . . . . . . . . . . . . . . . . .34 .27 . . . . . . . . . . . . . . . . .34 .34 . . . . . . . . . . . . . . . . .38 .31 . . . . . . . .

E. lugens . . . . . . . . . . . . . . . . . . . . . . . . .. .31 .27 . . . . . . .. .33 .31 .28 .37 . . . . . . .. .36 .30 . . . . . . ..

U. sessiliflora . . . . . . . . . . . . . . . . . . . . .. .30 .18  .21 .31 . . . . . . . . . . . . . . .. .42 . . . . . . .. .32 . . . . . . ..

Broomsedge . . . . . . . . . . . . . . . . . . . . . . . .30 .34 .31 .38 .23 .26 . . . . . . . . .25 .29 .28 . . . . . . . .

Carpet . . . . . . . . . . . . . . . . . . . . . . . . . . . . .29 .26 .35 . . . . . . . . .26 . . . . . . . . .29 .26 .28 .24 .26

P. tloridanum . . . . . . . . . . . . . . . . . . . . .. .28 .31 .30 . . . . . . .. .40 .17 . . . . . . .. .27 .25 . . . . . . .. .23

Silver beard . . . . . . . . . . . . . . . . . . . . . .. .28 .31 .46 . . . . . . .. .24 .22 .30 . . . . . . .. .31 .18 . . . . . . . .

Smut . . . . . . . . . . . . . . . . . . . . . . . . . . . .. .27 .28 .36 . . . . . . .. .36 .35 .30 . . . . . . .. .36 . . . . . . . . . . . . . . ..

Georgia . . . . . . . . . . . . . . . . . . . . . . . . . . . .26 .27 .31 . . . . . . . . .25 .27 .23 . . . . . . . . . . . . . . . . .25 .25

Little bluestern . . . . . . . . . . . . . . . . . . . . .25 .33 .29 .30 .26 .25 .20 .22 .21 .21 .18

Big bluestem . . . . . . . . . . . . . . . . . . . . .. .23 .21 .21 .19 .25 .22 .32 .24 .20 .17 .26

Prairie three-awn . . . . . . . . . . . . . . . . . . .20 . 19 . . . . . . . . . . . . . . . . .23 .19 . . . . . . . . .20 .20 .18 .19
Averages:
Phosphoric acid in forage % . . . . . . . . . . . . . .36 .35 .31 .30 .29 .29 .27 .26 .25 .24
Active P205111 soils p.p.m . . . . . . . . . . . . . . .. 20 22 13 32 20 16 18 16 14 14
Total P205 in soils % . . . . . . . . . . . . . . . . . . . .032 .052 .129 .035 .038 .038 .030 .025 .036 .039
Relative order:
Forage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 2 3 4 5 6 7 8 9 10
Active P205 . . . . . . . . . . . . . . . . . . . . . . . . . . .. 3 2 10 1 4 7 5 6 8 9
Total P205 . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 2 1 7 4 5 9 l0 6 3

8K

NOICLVLS LNEIWIHCIdXEI TVHHIIIIIOIHDV SVXELL ‘Z89 "ON NLLHTIHH

 

  
  
  

 

Table ll. Average percentage of lime in various species from different soil series
All Ochlock- Susque- Nacog-
samples Lufkin Wilson Norfolk Crockett Tabor once hanna Bowie Ruston doches
Johnson . . . . . . . . . . . . . . . . . . . . . . . . . .. .81 .64 .92 . . . . . . . . . . . . . . . . . . . . . . .. .76 .77 .86 . . . . . . .. .67

Georgia . . . . . . . . . . . . . .. .67 .69 .61 . . . . . . . . .53 .77 .69 .67 . . . . . . . . 75 . . . . . . ..

P. floridanum. . . .. .61 .62 . . . . . . .. .61 .54 .59 .65 .62 .59 . . . . . . . . . . . . . . ..

Bermuda . . . . . . . . . - .60 .64 .68 .59 .62 .40 .63 .63 .60 .64 .47

P. capillarioides . . . . . . . . . . . . . . . . . . . .55 .77 . . . . . . . . .47 . . . . . . . . .64 . . . . . . . . .54 . . . . . . . . .51 . . . . . . . .

E. lugens . . . . . . . . . . . . . . . . . . . . . . . . .. .53 .61 .50 .66 . . . . . . .. .50 . . . . . . .. .49 . . . . . . .. .47 .69

Big bluestem . . . . . . . . . . . . . . . . . . . . . . .50 .52 .56 .54 .59 .53 .55 .47 .42 .47 .46

Carpet . . . . . . . . . . . . . . . . . . . . . . . . . . .. .48 .45 .50 .45 .64 . . . . . . . . .42 .52 .53 .56 . . . . . . ..

Dallis . . . . . . . . . . . . . . . . . . . . . . . . . . . .. .47 .50 ‘.54 . . . . . . .. .51 .42 .50 .46 .47 .48 . . . . . . ..

Silver beard . . . . . . . . . . . . . . . . . . . . . . . .47 .44 .65 .49 . . . . . . . . .42 .46 .46 . . . . . . . . .45 . . . . . . . .

Little bluestem . . . . . . . . . . . . . . . . . . . . .47 .61 .46 .48 .50 .54 .45 .47 .45 .39 .43

U. scssiliflora . . . . . . . . . . . . . . . . . . . . . . .47 .30 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .49 .52 .46 .54

Prairie three-awn . . . . . . . . . . . . . . . . . . . .46 .44 . . . . . . . . .49 .50 .44 . . . . . . . . .46 .47 .47 . . . . . . . .

Smut . . . . . . . . . . . . . . . . . . . . . . . . . . . .. .43 .61 .50 .44 . . . . . . .. .53 45 .36 . . . . . . . . . . . . . . . . . . . . . . ..

Broomsedge . . . . . . . . . . . . . . . . . . . . . . . . .38 .47 . . . . . . . . .37 . . . . . . . . .42 .44 .37 .36 .23 .34
Averages:
Lime in forage, % . . . . . . . . . . . . . . . . . . . .. .58 .55 .54 .54 .53 .53 .51 .50 .48 .46
Active lime in soils, p.p.m . . . . . . . . . . . . . . . . 1403 2356 650 2896 1710 2055 1127 1288 777 1308
Relative order:
Lime in forage . . . . . . . . . . . . . . . . . . . . . . . .. 1 2 3 4 5 6 7 8 9 10
Active lime in soils . . . . . . . . . . . . . . . . . . . . . 5 2 1O 1 4 3 8 7 9 6

SEISSVHD EIDVHOJ JO NOLLISOdWOO TVOINEIHO

63

30 ' BULLETIN NO. 582, TEXAS AGRICULTURAL EXPERIMENT STATION ,

averages 0.105% pitrogen; the forage of the Norfolk and Lufkin series
averages 6.22% and 5.88% protein, respectively, while the soils average
.066 and .048% nitrogen.

The relative order of the averages of the constituents in the forage
and the corresponding constituents in the soils are given at the bottom
of the tables. The agreement between the relative order for protein
(Table 9) in the forage and total nitrogen in the soil is good with
respect to the permeable subsoil group (Bowie, Nacogdoches, Norfolk,
and Ruston series) and the alluvial Ochlockonee series. The relative order
of protein in forage from soil of the impermeable subsoil group (Lufkin,
Susquehanna, and Tabor series) is considerably higher than the corre-
sponding order of nitrogen in the soils, while in samples from the Black-
land Prairies (Crockett and Wilson series), it is considerably lower. The
agreement with respect to phosphoric acid (Table 10) in the plants and
active phosphoric acid in the soils is good in all of the series except the
Nacogdoches. The relative order of phosphoric acid in the forage from
the Lufkin and Susquehanna series was much higher than the relative
order of total phosphoric acid in the soil. The agreement between lime
in the plants (Table 11) and the active lime in the soil was good with
the possible exception of soils of the Lufkin and Norfolk series, in which
the lime in the forage was relatively high.

In general, the agreement between the quantities of a given constituent
in the forage and the corresponding constituent in the soil was good
when comparisons were made among series of the same general soil
characteristics, but was not nearly so good when soils of different char-
acteristics were included in the comparison. The work indicates that
there is a relation between the active phosphoric acid, total nitrogen,
and active lime in the soil and the phosphoric acid, protein and lime
content of the grasses.

Relation of chemical composition of soils to that
of forage

The relation between the chemical composition of the soil and that of
the forage was studied by calculating the average protein, phosphoric
acid, and lime in samples of young Bermuda, Dallis, carpet, and big and
little bluestem grasses from soils with different grades for total nitrogen,
total phosphoric acid, and active lime. Active phosphoric acid in the soil
was not used in the comparisons because there was not suflicient range
in the grades of this constituent (Table 8). The averages are shown in
Table 12. Coefficients of correlation at the young stage of growth are
given in Table 13.

The percentage of protein in Bermuda and Dallis grasses did not vary
significantly with an increase in the grade of nitrogen in the soil (Table
12), and there was no correlation (Table 13). There was a significant
relation between protein in carpet, big bluestem, and little bluestem

. www-

CHEMICAL COMPOSITION OF FORAGE GRASSES 31

Table 12. Relation of percentage of protein in grasses to the grade of nitrogen in the soil;
phosphoric acid in plant to grade of total phosphoric acid in soil; lime
in plant to grade active lime in soil

   

   

 
  
  

Grade of constituent in soil
5 4 3 2 1
Percentage of protein and grade of nitrogen
ermuda . . . . . . . . . . . . . . . . . . . . . . . . . . .. 9.84 9.22 9.28 . . . . . . ..

Dallis . . . . . . . . . . . . .. 8.96 9.31 9.11 . . . . . . ..

Carpet . . . . . . . . . . . ..  6.69 7.17 8.01 . . . . . . ..

Big bluestem . . . . . . . . . . . . . . . . . . . . . . . . 5.82 6.50 7.39 . . . . . . . .

Little bluestem . . . . . . . . . . . . . . . . . . . . . . 5.81 6.04 7.32 . . . . . . . .
Percentage of phosphoric acid and grade of
total phosphoric acid _
Bermuda . . . . . . . . . . . . . . . . . . . . . . . . . . . . .39 .38 .45 .54
Dallis . . . . . . . . . . . . . . . . . . . . . . . . 35 .39 .54 .59
.25 .33 .43 51
Big bluestem . . . . . . . . . . . . . . . . . . . . . . . . .20 .27 .30 . . . . . . . .
Little bluestem . . . . . . . . . . . . . . . . . . . . . . . 17 .27 .32 .37
Percentage of lime and grade of active lime
Bermuda . . . . . . . . . . . . . . . . . . . . . . . . . . . . .62 .62 . 64 .66 1.00

Dallis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. .55 .49 .50 .58 1.26

Carpet . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .50 .44 .52 .64 . . . . . . . .

Big bluestem . . . . . . . . . . . . . . . . . . . . . . . . .45 43 .62 62 . . . . . . . .

Little bluestem . . . . . . . . . . . . . . . . . . . . . . .42 39 .49 57 . . . . . . . .
Table 13. Correlation between chemical composition of grasses and that of soils on
which they grew

Number Coef. Level of
of In In of signif- Inter-
forage soil plants c0rre— icance pretation
samples % % lation %
Protein of plant to nitrogen of soils
Bermuda. . ._ . . . . . . . . . . . . . . . . . . . . . 106 .095 9 25 .006 10 + None

Bluestem, big . . . . . . . . . . . . . . . . . . .. 70 .090 6 52 .576 1 High

Bluestem, little . . . . . . . . . . . . . . . . .. 91 .088 6 28 .318 1 High

Broomsedge . . . . . . . . . . . . . . . . . . . .. 29 .096 6 18 .432 2 High

Carpet . . . . . . . . . . . . . . . . . . . . . . . . . . 49 .095 7 39 .344 2 High

Dallis . . . . . . . . . . . . . . . . . . . . . . . . . . . 44 . 100 9 11 .045 10 + None

Eragrostis lugens . . . . . . . . . . . . . . . . . 22 .083 6 82 .436 4 High

Georgia . . . . . . . . . . . . . . . . . . . . . . . . . 28 .107 6 51 .330 9 Doubtful
Phosphoric acid of plants to total phosphoric acid of soils
Bermuda. . ._ . . . . . . . . . . . . . . . . . . . . . 106 .042 .40 .202 5 High

Bluestem, big . . . . . . . . . . . . . . . . . . . . 70 .034 .25 .355 1 High

Bluestem, little . . . . . . . . . . . . . . . . . . 91 .041 .27 .350 1 High

Broomsedge . . . . . . . . . . . . . . . . . . . . . 29 .051 .31 .455 1 High

Carpet . . . . . . . . . . . . . . . . . . . . . . . . . . 49 .039 .33 .429 1 High

Dallis. . ._ . . . . . . . . . . . . . . . . . . . . . . . . 44 .042 .42 .487 1 High

Eragrostis lugens . . . . . . . . . . . . . . . . . 22 .035 .30 .417 6 Probable

Georgia . . . . . . . . . . . . . . . . . . . . . . . . . 23 .033 .27 .422 3 High J

Lime of plants to active lime of soils

Bermuda. . ._ . . . . . . . . . . . . . . . . . . . .. 106 ‘ 1640 .40 .122 10 +i None j
Bluestem, big. . . . . . . . . 70 1455 .30 .442 1 High _
Bluestem, little. . . 91 1477 .44 .362 1 High
Broomsedge . . . . . . 29 i 1407 .38 ' .835 1 High

Carpet . . . . . . . . . . . 49 1208 .49 .343 2 High

D3lllS..._ . . . . . . .  . . . . . . . . .. 44 i 1664 .51 .151 10+ None i

Eragrostis lugens . . . . . . . . . . . . . . . . . 22 l 1255 .51 .384 10 + None

Georgia . . . . . . . . . . . . . . . . . . . . . . . . . 28 I 1690 .63 . 157 10 + None 1

32 BULLETIN NO. 582, TEXAS AGRICULTURAL EXPERIMENT STATION

grasses and the corresponding grade of nitrogen in the soil and there
was a high correlation (Table 13) with these grasses and also with broom-
sedge and Eragrostis lugens. Phosphoric acid in Bermuda, when the
latter was above Grade 4, Dallis, carpet, big bluestem and little bluestem
increase in grade with the total phosphoric acid in the soil. Table 13
shows significant correlation with all these grasses. The lime content of
Bermuda, Dallis, and carpet grasses did not change significantly until
the lime in the soil exceeded the lower limit of Grade 2; there was a
marked increase in lime in Bermuda and Dallis grasses when the lime
in the soil changed from Grade 2 to Grade 1. Big and little bluestem
grasses showed the effect of an increase in the lime in the soil only
when the latter exceeded the lower limit of Grade 3. These results are
in accord with those reported earlier by Fudge and Fraps (11). There
are high correlations (Table 13) between the active lime in the soil and
lime in the plant for big bluestem, little bluestem, broomsedge and
carpet grass, and no correlation with Bermuda, Dallis, Eragrostis lugens
and carpet grasses.

A statistical study of the relation of nitrogen phosphoric acid, and
lime in the soils of East Texas to those constituents in Bermuda and
little bluestem grassesat the young and mature stages of growth has
been published elsewhere (11). Since the conclusions reached are per-
tinent to the present discussion, they will be briefly stated here.

In Bermuda, a significant correlation with respect to nitrogen was
secured when the nitrogen content of the soil was less than .110%.
Correlations for phosphoric acid and lime were secured when all of the
soils were used in the comparison, but the correlations were not sig-
nificant when soils containing more than 30 parts per million of active
phosphoric acid or more than 5,000 parts per million of active lime were
excluded. In bluestem, the relation with respect to nitrogen in the soil
and protein in the plant was significant whether all of the soils were
included, or soils containing more than .110% were excluded. In young
bluestem, significant correlations were secured when all of the soils were
included. In mature bluestem, there was no significant relation between
the phosphoric acid in the plant and the active phosphoric acid in the
soil. In young bluestem, significant correlations with respect to lime were
secured in all comparisons. In mature bluestem, the correlation with
respect to lime was highly significant only when all of the soils were
included in the comparison. The relation between the chemical compo-
sition of the soil and that of the forage was much closer in the case
of little bluestem than in the case of Bermuda.

ACKNOWLEDGMENT

Chemical analyses and other work in the preparation of this Bulletin
have been taken part in by S. E. Asbury, T. L. Ogier, W. H. Walker,
George Smith, and other members of the staff of the Division of Chemistry.

CHEMICAL COMPOSITION OF FORAGE GRASSES 33

SUMMARY

A total of 1,432 samples of various species of forage at young, bloom,
and mature stages of growth, collected in the spring and fall of 1936
and 1937 at nearly 100 locations throughout the East Texas Timber
Country, were analyzed for protein, phosphoric acid, and lime. A con-
siderable number of these samples were also analyzed for ether extract,
nitrogen-free extract, and crude fiber. Wide differences were found in the
protein, phosphoric acid, and lime contents of dilferent samples of the
same species even at the same stage of growth. At the young stage of
growth, protein was highest in the legumes; in Johnson, Bermuda, and
Dallis grasses it averaged above 8%, while in most other species it was
less than that amount, as low as 6% in prairie three-awn or needle grass.
Phosphoric acid was highest in Johnson, Dallis, and Bermuda grasses
(above .40%), and lower in other species down to 0.20% in prairie
three-awn. Lime was highest (above .60%) in Johnson, Georgia, and
Bermuda grasses and lower in other species to broomsedge, with 39%.
Protein and phosphoric acid usually decreased as the plants became more
mature, but the tendency with lime was irregular.

In the spring, Bermuda had a higher content of protein than any other
principal species of grass, but in the fall Johnson and Dallis grasses
contained more protein than Bermuda. Spring samples of Johnson, Dallis,
and silver beard grasses were slightly higher than Bermuda in phos-
phoric acid; in the fall samples, phosphoric acid was considerably higher
in Johnson grass and the same in Dallis grass as in Bermuda. Several
of the species were higher than Bermuda in lime in both the spring
and the fall samples.

In general, crude fiber and nitrogen-free extract increased with the
age of the plants. The clovers, the early spring grasses, and Bermuda
grass were considerably lower in crude fiber than most of the other
species. Nitrogen-free extract was slightly higher in young silver beard,
Bermuda, and carpet grasses than in other species.

In order to facilitate comparison between the samples, a system of
grades, ranging from high (Grade 1) to very deficient (Grade 5), was
devised. The basis for the limits of the grades, and their significance, is
discussed.

The distribution of the samples of a given species in the diiferent
grades differed widely. A larger proportion of samples of the bluestems con-
tained percentages of protein and phosphoric acid occurring in the very defi-
cient and deficient grades (5 and 4) than was the case in any other species.
The proportion of the samples of a given species containing percentages
of protein and phosphoric acid in the higher grades decreased as the
plants became older. Protein and phosphoric acid in practically all of the
samples were from only fair to very deficient, and as maturity approached,
there was a marked increase in the proportion of the samples which

34 BULLETIN NO. 582, TEXAS AGRICULTURAL EXPERIMENT STATION

were deficient or very deficient in these constituents. Very few of the
samples were deficient in lime.

The chemical composition of 82 soils, from which forage samples
were collected, is shown by grades of constituents and also by the
various soil series to which they belong.

On most of the soils high in nitrogen and phosphoric acid, Bermuda,
Dallis, and Johnson grasses contributed largely to the forage, while on
soils low in these constituents needle grass, the bluestems, various
Panicums, and Paspalums of the setacea group were the most impor-
tant species.

The correlation between protein in the grasses at a young stage of
growth and nitrogen of the soils on which they grew was high for
carpet,_grass;"bigflbluestem, little bluestem, broomsedge and Eragrostis

“lugens. There was no correlation between the protein of the grass and
the nitrogen of the soil with Bermuda, Dallis and Georgia grasses.

There was a high correlation between the hosphoric acid content of
all the grasses and the total phosphoric acid of the soil with the
exception of the Eragrostis lugens in which there is a probable relation.

The correlation between the lime content and the active lime of the
soil was high for the big and little bluestem, broomsedge, and carpet
grass. With Bermuda, Dallis, Eragrostis lugens, and Georgia grass there
is no correlation.

Forages of East Texas appear to supply ‘sufficient lime (or calcium)
to grazing animals, but in general they do not supply enough phosphoric
acid (phosphorus) and at times they do not supply enough protein.

10.

11.

12.

13.

14.

15.

16.

17.

18.

19.

20.

21.

22.

23.

24.

25.

26.

CHEMICAL COMPOSITION OF FORAGE GRASSES 35

LITERATURE CITED

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Archibald, J. G., and Bennett, E. 1935. The phosphorus requirements of dairy heifers.
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Becker, R. B., Neal, W. M., Shealy, A. L. 1933.
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Carter, W. T. 1931. The Soils of Texas. Tex. Agr. Exp. Sta. Bul. 431.

Cory, V. L., and Parks, H. B. 1937. Catalogue of the flora of Texas.
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Eckles, C. H., Becker, R. B., and Palmer, L. S. 1926.
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Eckles, C. H., Gullickson, T. W., and Palmer, L. S. 1932.
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Fraps, G. S. 1932. The composition and utilization of Texas feeding stuffs.
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Fraps, G. S., and Fudge, J. F. 1937.
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Fraps, G. S., and Fudge, J. F. 1937. Phosphoric acid, lime, and protein in forage
grasses of the East Texas Timber Country. Proc. Amer. Soc. Soil Sci. 2:347-351.
Fudge, J. F., and Fraps, G. S. 1938. The relation of nitrogen, phosphoric acid, and
lime in soils of East Texas to those constituents in Bermuda and little bluestem

grasses. Proc. Amer. Soc. Soil Sci. 3389-194.

Hart, G. H., Guilbert, H. R., and Goss, H. 1932. Seasonal changes in the chemical
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Henderson, H. 0., and Weakley, C. E. 1930. The effect of feeding difierent amounts of
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Hitchcock, A. S. 1935. Manual of the grasses of the United States.
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Hufiman, C. F., Duncan, D. W., Robinson, C. S., and Lamb, L. W. 1933. Phosphorus
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Kellner, O. Die Ernahrung der Landwirtschaftlichen Nutztiere, 4th Ed. Berlin.

Lindsey, J. B., Archibald, J. G., and Nelson, P. R. 1931. The calcium requirements of
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Mitchell, H. H., and McClure, F. J . 1937. Mineral nutrition of farm animals. National
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Morrison, F. B.
Ithaca, N. Y .

Schmidt, H. 1924. Field and laboratory notes on a fatal disease of cattle occurring on
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Scott, S. G. 1929. Phosphorus deficiency in forage feeds of range cattle. Jour. Agr.
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Stanley, E. B. 1938. Nutritional studies with cattle on a grassland-type range in
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Theiler, A., et al. 1926. Lamsiekte (Parabotulism) in cattle in South Africa.
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Theiler, A., Green, H. H., and Du Toit, P. J. 1927.
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Stiffs or sweeny (phosphorus defi-

Tex. Agr. Exp.
A mineral deficiency in the
Phosphorus deficiency in the
Tex. Agr.

Chemical composition of soils of Texas. Tex.

U. S. D. A., Mis-

1936. Feeds and Feeding, 20th Ed., Unabr. Morrison Publishing C0.,

Union

( 1) The struc-
(2) Rickets and osteomalacia.

Minimum mineral requirements