lu 4~L 2 ~26
S n~g~s~e~ as a\ s 3?
40 56 f6~4:
sr'~ 591 53
The Science of Grassland Agriculture
"Take not too much of a land, were not out
all the fatnesse, but leave it in some heart."
-By Pliny the Elder, A.D. 23-79, from
his Historiae Naturalis, in 37 volumes
ience of Grassland Agriculture
UNDER THE EDITORIAL AUTHORSHIP OF
H. D. HUGHES
Iowa State College
MAURICE E. HEATH
Soil Conservation Service
DARREL S. METCALFE
Iowa State College
With 52 additional contributing authors,
selected for their recognized leadership
in the field of Grassland Agriculture
The Iowa State College Press Ames, Iowa
Copyright 1951 by The Iowa State College Press.
All rights reserved. Composed and printed in the
United States of America.
Second printing 1952
This Volume Is Respectfully Dedicated
To the Memory of Those gone on before, who, envisioning the
needs of the future and the possibility of better things,
lived purposefully, giving of themselves.
In Recognition of Those of our own day, who, endowed with
leadership ability in research and education, continue to
stimulate us to more productive effort.
For the Inspiration of Those who today follow on, but who to-
morrow, building upon established foundations, will be
charged with the responsibility of solving the new prob-
lems with which those of their day will be confronted.
Table of Contents
FORAGES AND A PRODUCTIVE AGRICULTURE
1. Forages in Our Advancing Civilization .
2. What Is Grassland Farming? . . .
3. Economic Aspects of Forage Production .
4. Forages and Soil Conservation . . .
5. Soil Fertility and the Nutritive Value of For-
6. Forage Statistics . . . .
FORAGE GRASSES AND LEGUMES
7. The Botany of Grasses and Legumes . .
8. Legume and Grass Seed Production . .
9. Forage Crop Breeding . . . .
10. The Inoculation of Legumes . . .
11. A lfalfa . . . . . . .
12. Red Clover and Alsike Clover . . .
13. Sweetclover . . . . . .
14. Ladino and Other White Clovers . .
15. Lespedeza . . . .
16. Crimson Clover . . . . . .
17. Birdsfoot Trceoil . . . . .
18. The Vetches . .
19. Other Legumes .
20. The Bluegrasss .
21. The Brome Grasses
22. Timothy . . . . .
23. Orchardgrass . . . .
24. Bermuda-grass . . . .
25. Dallisgrass, Bahiagrass, and Vaseygrass .
H. D. HUGHES
MAURICE E. HEATH
EARL O. HEADY
GEORGE M. BROWNING
R. L. LOVVORN and
W. W. WOODHOUSE, JR.
DARREL S. METCALFE
DARREL S. METCALFE
E. A. HOLLOWELL
I. J. JOHNSON
O. N. ALLEN
H. M. TYSDAL
C. P. WILSIE
W. K. SMITH
E. A. HOLLOWELL
C. A. HELM
E. A. HOLLOWELL
H. D. HUGHES and
H. A. MAC DONALD
ROLAND MC KEE
ROLAND MC KEE
E. N. FERGUS
L. C. NEWELL and
K. L. ANDERSON
MORGAN W. EVANS
W. M. MYERS
GLENN W. BURTON
HUGH W. BENNETT
( I I
26. Reed Canarygrass . . . . .. .MAURICE E. HEATH and
H. D. HUGHES
27. The Fescues . . . . . .. .R. Y. BAILEY
28. The Ryegrasses . . . . .. H. A. SCHOTH
29. Redtop and the Bentgrasses . . . J. A. DE FRANCE
30. The Wheatgrasses . . . . . CLYDE MC KEE
31. Johnsongrass, Carpetgrass, and Other Grasses
for the Humid South .. . . HUGH W. BENNETT
32. Other Grasses for the North and West . VIRGIL B. HAWK
33. Cereals as Forage . . .. . M. A. SPRAGUE
34. Sorghums for Forage . .. . J. R. QUINBY and
R. E. KARPER
35. Millets and Kochia .. . . w. W. WORZELLA
36. Rape, Kale, and Similar Forages . . C. s. DORCHESTER
FORAGE PRODUCTION PRACTICES
37. Soil, Climate, and Use in Choosing Forage
Crops . . . .
38. Establishment of New Seedings . . .
39. Fertilization of Forages . . . .
40. Weed Control in Forages . . . .
41. Hay and Pasture Seedings for the Northeast .
42. Hay and Pasture Seedings for the Central
and Lake States . . . . .
43. Hay and Pasture Seedings for the Humid
South . . . . . .
44. Hay and Pasture Seedings for the Northern
Great Plains and Intermountain States .
45. Hay and Pasture Seedings for the Southern
Great Plains . . . . .
46. Hay and Pasture Seedings for the Pacific
Coast States . . . . .
OLAF S. AAMODT
C. J. WILLARD
G. O. MOTT
C. J. WILLARD
VANCE G. SPRAGUE
HENRY L. AHLGREN
D. G. STURKIE
F. D. KEIM and
L. C. NEWELL
R. C. POTTS
A. L. HAFENRICHTER
47. What is Quality Hay? . . . .
48. Mechanization of Haymaking and Storage
49. Grass-Legume Silage . . . .
50. Dehydration of Forage Crops . . .
51. Emergency Hay and Pasture Crops . .
52. Permanent Pastures . . . .
53. Rotation Pastures . . . . .
. GUSTAV BOHSTEDT
E. L. BARGER
SC. B. BENDER
SRALPH E. SILKER
SALBERT C. ARNY
MASON A. HEIN
SD. R. DODD
54. Range Pasture . . . . .
55. Irrigated Pastures . . . . .
56. Forages for Dairy Cattle . . . .
57. Utilization of Forages With Beef Cattle .
58. Sheep Are Efficient Users of Forages . .
59. Forage Utilization by Hogs . . . .
60. Forage for Poultry . . . . .
D. A. SAVAGE
MAURICE L. PETERSON
RALPH E. HODGSON
R. F. FUELLEMAN
W. G. KAMMLADE
G. O. MOTT
D. C. KENNARD
AUTHOR INDEX . . . . . . . . .
SUBJECT INDEX . . . . . . . . ... .
The most important thing about this book is its authorship. Its title
page says ". .. 52 contributing authors selected for their recognized
leadership in the field of Grassland Agriculture." Many of the different
chapters are authored by the one person generally recognized as the very
best authority on a particular subject. Other chapters, however, perhaps
could have been written equally well by any one of three or four other
Each chapter is written by a person standing at the forefront in forage
knowledge. Interest in forage production and utilization is not confined
to agronomists and soil conservationists. The economist and farm man-
ager, the agricultural engineer, animal and dairy husbandry specialists,
and many others are as much concerned. The material included is the
information of the greatest concern and value to the largest number.
In the 60 chapters under which the material is presented, more sub-
jects are included than probably can be covered adequately in most or-
ganized classes. Some chapters will be of more interest and value for use
in a given part of the country than in others. Equal care has been given
to the selection of data and other kinds of information of interest and
concern to those in the Northeast, in the Deep South, and in the South-
west and West, as to those in the Corn Belt and in the Eastern Great
Plains. The coverage is sufficiently broad to permit considerable selec-
tion in order to emphasize production factors most applicable to a given
It sometimes will be desirable to give more attention to certain sub-
jects than has been possible within the limits of this volume. In this con-
nection, the reader will appreciate and find most helpful the extensive
citations to the best literature giving further details and results.
One of the responsibilities the editors have felt most important has
been the elimination of any undesirable repetition between the differ-
ent chapters and authors. The editors believe, however, that each sub-
ject unit (chapter) should give a complete picture within itself. Only
such limited and casual repetition in coverage as is definitely desirable
has been retained. The editors also have unified the style of organization
and presentation in the different chapters, while at the same time pre-
serving the individuality of expression of the respective authors.
FORAGES-The Science of Grassland Agriculture, has been pre-
pared especially for use by organized groups, but also will have great
value as a ready reference for farm managers and operators, soil con-
servation personnel, research workers and many others in related fields.
H. D. HUGHES
MAURICE E. HEATH
DARREL S. METCALFE
Forages and a Productive Agriculture
-p, ? 1d2
\ AND TWE EDITOR.
JUST GOT THROULrH
\ LLINCG ME HE
D DINTr WANT
C,/ur/t.yD / ANn MORE
Courtesy Des Moines Register and Tribune
The Only Kettle She's Got!
H. D. HUGHES
Iowa State College
Forages in Our Advancing Civilization
Early recognition of the high value of
grass is indicated by a writer in the Book
of Psalms some thousands of years back
-"He causeth the grass to grow for the
cattle." Moses promised the Children of
Israel, as their reward if they accepted
the commandments of God, that they
would have "Grass in their fields for
their cattle." Again, "In the habitation
of dragons shall be grass," and again,
"The Lord shall give to everyone grass
in the fields." The want of grass was
recognized as the symbol of desolation-
"The hay is withered away, the grass
faileth." The theme of grazing runs all
through the Books of Genesis and Exo-
"But grazing lands were vital to primi-
tive man long before cattle were domesti-
cated. Man's first attempts to control his
fate, to provide for future need instead
of remaining the victim of droughts or
other untoward circumstances, which
were the beginnings of civilization, must
have been in grasslands, where the young
calves, lambs, and kids he caught and
H. D. HUGHES, professor of farm crops at Iowa State
College, served the American Society of Agronomy as
its president in 1946. He is senior author of Crop Pro-
duction (Macmillan 1930), for many years used gener-
ally in colleges throughout this country, and to a consid-
erable extent abroad. In 1937 he was a delegate to the
International Grassland Congress in Great Britain and
spent the summer in a study of forages in Great Britain
and on the Continent. He was born and reared on an Illi-
nois dairy farm, had his undergraduate training at the
University of Illinois and his M.S.A. from the Univer-
sity of Missouri. Following three years on the staff of the
Missouri institution he went to Iowa State College in
1910 to head the Farm Crops work there.
tamed could find forage. It was on grass-
lands, too, that primitive man, after he
had reached the food-producing as dis-
tinguished from the food-gathering stage,
developed more rapidly . "
It is generally believed that in the dim
ages of the past, as man struggled with
his environment for better living, a
pastoral type of husbandry followed the
hunting stage. This in turn was followed
by the growing of cereal grains. The ex-
tensive cultivation of forage-producing
crops came still later in the evolutionary
GRASS PLAYS AN IMPORTANT ROLE
Making hay from harvested forage un-
doubtedly is a very ancient agricultural
practice. But the conversion of green
forage into cured hay, capable of being
stored and used through a considerable
period of time, is believed to have had
a more important part in the develop-
ment of civilization than most of us
realize. It is associated with a stabilized
type of agriculture.
It has been pointed out that in the
agricultural development of America the
pioneers depended to a considerable de-
gree on game as a source of food and
income. This was soon supplemented by
the returns from a limited number of
1 Smithsonian Scientific Ser. 11. Old and New Plant
4 1. Forages in Our Advancing Civilization
livestock, grazing the open prairies and
woods. As transportation facilities de-
veloped-and with the demand in con-
gested areas for such concentrated food
products as wheat-grain farming be-
came an important enterprise. This in
turn gave way in many areas to a type
of general farming, in which a consider-
able part of the cash grain crops was re-
placed by forage for livestock.
With a steadily increasing demand for
food products, both cereal and animal,
and in view of the greater acre produc-
tion obtained from harvested crops than
from pasture, an increasing acreage of
pasture land was plowed up to grow
harvested crops. However, the superior-
ity of a system of farming which utilizes
forage in the production of livestock, as
compared with specialized cash grain
production or other specialized crops, is
coming to be more generally recognized.
Such a system of farming tends not only
to maintain soil productivity but also
contributes to economic stability.2
UNIVERSAL BENEFICENCE OF GRASS
From the pen of John James Ingalls
there appeared in the Kansas Magazine
in 1872 certain inspired words and
thoughts under the title of "Bluegrass."
In the portion most often used Senator
Ingalls pictures grass at its best-its per-
sistence, its aggressiveness, its sod-form-
ing characteristics, and the true worth of
these characteristics to world civilization
Here is the picture with which Senator
Ingalls beguiles us and leads us out and
Attracted by the bland softness of an after-
noon in my primeval winter in Kansas, I
rode southward through the dense forest that
then covered the bluffs of the North Fork of
Wildcat. The ground was sodden with the
ooze of melting snow. . A tropical atmos-
2 Bunce, Arthur C. Economics of Soil Conservation.
Ames: Iowa State College Press. 1942.
phere brooded upon an arctic scene, creating
the strange spectacle of summer in winter,
June in January, peculiar to Kansas, which
unseen cannot be imagined, but once seen
can never be forgotten. A sudden descent
into the sheltered valley revealed an unex-
pected crescent of dazzling verdure. . It
was Bluegrass, unknown in Eden, the final
triumph of nature, reserved to compensate
her favorite offspring, in the new Paradise of
Kansas, for the loss of the old upon the banks
of the Tigris and Euphrates.
Next in importance to the Divine profu-
sion of water, light, and air-these three
great physical facts which render existence
possible-may be reckoned the universal
beneficence of grass.
Grass is the most widely distributed of all
vegetable beings, and is at once the type of
our life and the emblem of our mortality.
Lying in the sunshine among the buttercups
and dandelions of May, scarcely higher in in-
telligence than the minute tenants of that
mimic wilderness, our earliest recollections
are of grass; and when the fitful fever is
ended, and the foolish wrangle of the market
and forum is closed, grass heals over the scar
which our descent into the bosom of the
earth has made, and the carpet of the infant
becomes the blanket of the dead.
S. .Grass is The Forgiveness of Nature-
her constant benefaction. Fields trampled
with battle, saturated with blood, torn with
the ruts of cannon, grow green again with
grass, and carnage is forgotten. Streets aban-
doned by traffic become grass grown, like
rural lanes, and are obliterated. Forests de-
cay, harvests perish, flowers vanish, but grass
is immortal. Beleagured by the sullen hosts
of winter, it withdraws into the impregnable
fortress of its subterranean vitality, and
emerges upon the first solicitation of spring.
Sown by the winds, by wandering birds,
propagated by the subtle horticulture of the
elements, which are its ministers and serv-
ants, it softens the rude outline of the world.
Its tenacious fibers hold the earth in its
place, and prevent its soluble components
from washing into the wasting sea. It invades
the solitude of deserts, climbs the inaccessible
slopes and forbidding pinnacles of moun-
tains, modifies climates, and determines the
history, character and destiny of nations.
Should Its Harvest Fail
Unobtrusive and patient, it has immortal
vigor and aggression. Banished from the
thoroughfare and the field, it bides its time
to return and when vigilance is relaxed, or
the dynasty has perished, it silently resumes
the throne from which it has been expelled,
but which it never abdicates. It bears no
Our Historical Grass Cover Picture
Fi;. 1.1 "Originally . ou large prairie areas were covered with a great variety of
native grasses . big bluestem and the yellow Indiangrass held forth, with growths so
tall and with stands so thick that the cattle of the early settlers could be found only by
the tinkling of the cowbells and the waving of the grass." This is big bluestem grown
for seed increase. Ames, Iowa. S.C.S. photo.
blazonry of bloom to charm the sense with
fragrance or splendor, but its homely hue is
more enchanting than the lilly or the rose. It
yields no fruit in earth or air, and yet, should
its harvest fail for a single year, famine
would depopulate the world .... 3
OUR HISTORICAL GRASS COVER PIC-
Originally the land surface of our
large prairie areas was covered with a
great variety of native grasses, a few
legumes, and other flowering plants.
Most of the prairie east of the Missouri
was covered with so-called "tall-grass"
species and that to the west with "short-
grass" species. Along the sloughs the tall,
coarse prairie cordgrass and bluejoint
reedgrass were often found, practically
in pure stands. On the better drained
3 Ingalls, John James. Bluegrass. Reprinted in
Forage Crop Gazette. Div. Forage Crops and Diseases.
IT.S D A 3 I& 4 1939-40.
soils, big bluestem and yellow Indian-
grass held forth, in growth so tall and
with stands so dense that the cattle of
the early settlers could be found only
by the tinkling of the cowbells or the
waving of the grasses. Where moisture
conditions were less favorable, the
shorter grasses dominated-little blue-
stem, sideoats grama, blue grama, and
other similar grasses. So thick and tough
were the roots of these prairie grasses
that some farmers preferred not to break
the sod until after the stand had been
weakened by grazing and repeated mow-
Studies have indicated that 65 per
cent of the prairie grasses extended their
roots to a depth of five feet or more. It
is believed that the bulk of the prairie
was below and not above the soil sur-
face. When the farmer mowed the prai-
6 1. Forages in Our Advancing Civilization
Fic. 1.2 "... The growth and decay of these native grasses through thousands of years
resulted in deep, rich, black soil . will continue highly productive provided . sod
forming grass-legume combinations are grown. . ." Iowa State College photo.
rie in the fall, with yields of two or three
tons of dry hay per acre, he left a still
larger amount of living plant material in
The prairie cover broke the force of
the beating rains, even torrential down-
pours. Runoff water from these prairie
soils is known to have been slight, and
that which did run away was clear. Thus,
the soil surface was protected by litter
and leafy growth, with the soil particles
held firmly in place by dense, deep root
In general, our more fertile, deep soils
were formed under the vegetative cover
of the prairie. The growth and decay of
these native grasses through thousands
of years resulted in deep, rich black
soils. These soils will continue to be
highly productive provided sufficient
quantities of sod-forming grass-legume
combinations are grown-the very foun-
dation of a permanent, highly produc-
The Picture Changes
But what of the present in relation to
that ideal picture? As our pioneer farm-
ers pushed steadily westward those of
the advance guard always had more grass
than they could use. First, there was
4 Hughes, H. D., and Heath, Maurice E. Forage
crops that feed the livestock and save the soil. A Cen-
tury of Farming in Iowa; 1846-1946. Ames: Iowa State
College Press. 1946.
*. L .
*.. - -,
Fi,. 1.3 "So thick and tough were the roots of these native grasses that some farmers
preferred not to break the sod until after the stand had been weakened by grazing and
repeated mowing." (See p. 5.)
* ,' .-*>i
8 1. Forages in Our Advancing Civilization
more of the unimproved prairie grass
cover than was required to balance the
grain crops that could be produced.
Later, the aggressive, free-seeding, dense,
sod-forming newcomer-Kentucky blue-
grass-provided pasturage without any
effort on the farmer's part. Areas in pas-
ture were little appreciated and utterly
neglected. The result was that with the
passing of the years many of these areas
As our agriculture developed, with less
and less land in grass, the time came
when continuous close grazing from early
spring to late in the growing season, with
no opportunity for the accumulation of
root reserves, resulted in thin, weak sods.
Weedy, unpalatable grasses and other
plants with little or no feed value easily
penetrated these sods. Plant nutrients
were removed annually in the form of
milk, beef, and mutton, with no thought
of replenishment. Much of the land in
pasture came gradually to give smaller
and smaller returns.
Throughout most of the eastern
Wheat Belt and the Corn Belt, land had
been under the plow for upwards of
three quarters of a century before any
particular attention was given to meth-
ods by which the returns from permanent
pasture lands might be increased. A
somewhat similar condition developed
in other areas. It is believed that the his-
toric background of our pioneer fore-
bears is a factor in the difficulty experi-
enced in getting any great number of
farmers to take the steps necessary for
the improvement of pastures.
The picture is much the same for
rotation lands. Fields were intensively
cultivated, encouraging the rapid break-
down of organic matter and the libera-
tion and removal from the soil, both
in crops and by leaching, of the essential
The increased frequency of dust
storms and decreasing crop yields, with
more and deeper gullies in evidence,
has brought an increasing number of
land owners in the twentieth century to
a realization of the fact that a radical
change in the cropping pattern is im-
THREE THOUSAND GULLIES. In a single
Corn Belt county some three thou-
sand gullies 10 feet or more in depth
have been recorded, most of them out of
control except by the expenditure of
thousands of dollars of public funds.
The presence of these gullies proves
that the farm practices of the past under
which this critical condition developed
were wrong-the result of a grassless ag-
riculture. Too large a portion of the land
planted to row crops through a period
of years creates a serious soil conserva-
Growers in this area, and in many
other heavily cropped areas, are finding
to their dismay that many grass-legume
seedings fail to result in stands. The
soils have been cropped to such an ex-
tent, the topsoil has so eroded, the water
holding organic matter of the soil so
broken down and used and lost, the run-
off of rainfall from the surface so rapid,
that comparatively little water enters
the soil and is held. Such soil dries out
quickly with the result that grass seed-
lings fail generally. When we have no
sod-forming crops in our rotations the
productivity of our soils decreases rap-
Cornerstones in Conservation
That adapted grasses and legumes are
the chief tools in soil building, improve-
ment, and conservation is now generally
recognized. Fundamental research on
5 Hughes, H. D. The role of sod crops in produc-
tion and conservation programs. (Presidential address.)
Jour. Amer. Soc. Agron. 38:1035-48. 1946.
Our Historical Grass Cover Picture
FIG. 1.4 "In a single Corn Bell county some 3,000 gullies, 10 feet or more in depth, have
been recorded . The presence of these gullies proves that the farm practices of the
past . were wrong-the result of grassless agriculture." Iowa State College photo.
the improvement and production of the
grasses and legumes, together with stud-
ies on the soil factors relating to their
most successful growth and on the effect
of such crops upon the soil itself, has
provided the foundation upon which our
better land use program is built.
Widespread interest has developed in
the value and utilization of sod crops;
also some appreciation of the problems
to be solved in order that these grasses
and legumes shall contribute most to
abundant production, through soil im-
provement and conservation.6 The in-
clusion and right use of these sod crops
in the cropping picture apparently is
basic to the health and well-being of
both animal and man in a permanently
The direct benefit from the inclusion
of sod crops in the rotation, as this af-
fects the yield of crops which follow, has
6 Klages, K. H. W. "Appreciation of grasses and
grassland agriculture." Ecological Crop Geography. New
York: The Macmillan Co. 1942.
been recognized and evaluated under
a great variety of environmental con-
ditions and through a long period of
years. This represents a very real credit
to the sod crops.
Much evidence has been accumulated
on the extent to which sod crops in ro-
tation increase the permeability and the
water-holding capacity of a given soil.
We have been learning much of the ef-
fect of grass roots on the granulation of
the soil particles and the relation of this
characteristic to the resistance of a given
soil to destructive erosion.
Progress has been made in finding
strains and varieties and species of
grasses and legumes better suited to a
given environment and use than previ-
ously were known. It is recognized, how-
ever, that a mere beginning has been
made in this field. Perhaps no better
examples can be cited than the southern
type strains of smooth bromegrass, La-
dino clover, birdsfoot trefoil, the Ranger
and Buffalo alfalfas, and the improved
10 1. Forages in our Advancing Civilization
strains from several native grasses. In
like manner the acre production and
nutritive value of pastures and hay crops
have been increased by better soil man-
agement and cultural practices.'
All of these efforts have been impor-
tant as they bear upon the extent to
which an increasing number of farmers
may come to see the way to the more
generous use of sod crops in their crop-
ping plans. With the relatively low re-
turn which farmers have come to expect
from acres in pasture, and even to a
degree from hay crops, a vigorous pro-
gram to maximize the returns from land
in sod crops is essential.
It appears difficult for many farmers
to make an adequate expenditure of
labor and cash to increase materially
the returns from pasture and hay lands.
Even those who have been convinced
of the necessity of increasing their acre-
age in sod crops in order to save their
soils from ruin are confronted with a
problem of marketing their pasture and
hay after it is available. We not only
have the problem of increasing the acre
production of pasture and hay acreages,
but also the problem of satisfactory uti-
lization and marketing of this product.
FORAGE AND OTHER FEED RESOURCES
Of the estimated 367 million acres
from which crops were harvested in 1947
in the United States, approximately 70
per cent were used to produce feed for
livestock. In the broad sense all feed
consumed by livestock is classed as for-
age. In the more restricted sense usually
used, however, we think of forage as the
roughages, mostly hay and pasture. We
exclude the cereal grains and other con-
The foods produced in the United
7 Pieters, Mary Burr. Historical development of
grass research. Forage Crop Gazette. Div. Forage Crops
and Diseases. U.S.D.A. 5:5. 1941.
States which are used directly for human
consumption are produced on about
two-tenths of the harvested crop area.
The remaining one-tenth is devoted in
the main to fiber crops such as cotton,
and to specialized crops such as stimu-
lants, sugar, etc.
In addition to the acres from which
crops are harvested, there are some 230
million within the humid area which
are used for pasture. Also, there is an
area of some 800 million acres of semi-
arid grazing land and forest and cut-over
Livestock consume about three-fourths
of the production from improved land,
either in pasture or harvested crops,
plus also the pasturage provided by our
less productive acres.8 More than one-
third of the feed for livestock comes
from pasture and range land. When hay
is included, more than one-half of the
feed is from grassland.9
Pasture and range constitute the larg-
est acreage of land use-55 per cent of
the land area.10
But the land use picture is very differ-
ent as we move from one part of the
country to another. There is a direct
relationship between the extent to which
an area is used for the production of
forage and the climatic and soil condi-
tions which prevail."
In the eastern half of the United
States, about one-fourth of the area is
devoted to corn for grain, one-fourth
to product roughages such as silage,
fodder, and hay, with approximately 5
per cent devoted to other feed crops.
This area also has produced more than
one-half of the cotton of the world in
8 Bureau of the Census. Statistical Abstract of the
United States. 1946.
9 Piper, C. V., et al. Our forage resources.
U.S.D.A. Yearbook. 311-414. 1923.
1o Reuss, L. A., et al. Inventory of major land uses
in the United States. U.S.D.A. Misc. Pub. 663. 1948.
11 U.S.D.A. Will more forage pay? U.S.D.A. Misc.
Pub. 702. 1949.
Maximizing the Use of Forages
FIG. 1.5 "Pasture and range constitute the largest acreage of land use-55 per cent of the
land area. .. But the land-use picture is very different as we move from one part of the
country to another. There is a direct relationship between the production of forage and
the climatic and soil conditions. . ." (See p. 10.)
Hay crops occupy about one-third of
the crop land in the dairy and hay area
in the North and East, with corn fodder
and silage harvested from between 5 and
10 per cent.
In the corn and winter wheat region,
lying to the south and west of the dairy
and hay region, nearly three-fourths of
the crop land is used to produce forage
for livestock, and most of the remaining
one-fourth to produce human food. In
the Corn Belt proper, adjoining on the
north and west, about 85 per cent pro-
duces feed for farm animals, with only
about 15 per cent food for man.
In the Cotton Belt, a little more than
a half of the crop land has been used
to produce feed for livestock, with some-
thing less than one-third of the acreage
in cotton, tobacco, and other specialized
crops not used directly as feed or food.
This changed rapidly toward mid-cen-
tury, with more feed and less cotton.
On the whole, the western half of the
United States is largely arid or semi-arid
and consequently is used mostly for pas-
ture or range. Wheat, mostly used for
food, occupies nearly one-third of the
harvested crop land in this area, being
one of the best semi-arid crops.
MAXIMIZING THE USE OF FORAGES
A frequent query by farmers who are
trying to keep their soil at home and
improve its productivity is how far they
can go in maximizing the use of grass
12 1. Forages in Our Advancing Civilization
and hay in the production of market
livestock and livestock products. That
is a problem to which agricultural econ-
omists have been giving much thought
as well as those especially concerned
with the conservation of our soil (see
Chapters 3 and 4).
The relation of soil topography, sea-
sonal rainfall, transportation, market
demand, and many other factors must
have consideration. The extent and kind
of forage that can be utilized profitably
is related to the type of livestock. Of the
total feed consumed in the United States
by livestock, pastures provided 35 per
cent and hay land approximately 16 per
cent, or slightly more than half the
total. As heavy users of forage, sheep
and goats have ranked first, with 12 and
80 per cent of their feed consisting of
hay and pasture, respectively. Beef cattle
ranked second, with 13 and 60 per cent;
dairy cattle third with 26 and 38 per
cent; and horses and mules with 31 and
32 per cent.
In livestock use of total forage produc-
tion, dairy cattle have been consuming
53 per cent of the hay and 34 per cent of
the pasture; beef cattle 16 per cent of the
hay and 33 per cent of the pasture;
horses and mules 24 per cent of the hay
and 11 per cent of the pasture; with
sheep and goats 7 per cent of the hay and
20 per cent of the pasture.1"
In looking to an increased use of sod
crops in livestock production programs
in the Corn Belt, of great significance
are the acres of hay and pasture used by
different livestock to balance one acre of
corn. Data reported in 1934 from 600
Illinois farms 1 for a two-year period
shows that breeding sheep used 13.6 acres
of hay and pasture for each acre of corn;
12 Jennings, R. D. Feed consumed by livestock,
1941-42. Bur. Agr. Econ. U.S.D.A. 1946.
13 Rusk, H. P. Regional Forage Conference, Ames,
beef cattle used 4.6 acres; dairy cattle,
3.8; feeder lambs, 1.5; feeder cattle, .6
and hogs, .2 of one acre of hay and pas-
ture for each acre of corn consumed.
Any large shift from row crops to sod
crops tends to upset the established econ-
omy, so that prices that previously pre-
vailed may not hold under the new or-
der. Hay values and pasture rentals, for
example, may decrease rather quickly
and sharply with an increase in the
acreage devoted to these crops. Also, sig-
nificant increases in the proportion of
forages used in relation to grain crops in
feeding livestock may affect the quality
of the finished product. The quality of
dairy products usually is improved by
the extensive use of high quality pasture,
grass-legume silage, and the like. It is
recognized, however, that beef cattle
which go to market directly from pas-
ture do not reach the high finish at-
tained by grain-fed animals. Even beef
cattle fed grain on pasture usually sell
at a price somewhat below that of ani-
mals fed in the dry lot. This is in spite
of the fact that no valid reason can be
found for such differences, except per-
haps public prejudice to the yellow
tinge in the fat of cattle produced on
Both sheep and lambs frequently are
finished for market without the use of
grain. Early spring lambs finished on
pasture with little or no grain frequently
top the June market.
It is believed true that regardless of
the class or kind of livestock fed, the
lowest cost nutrients consumed come
from effectively utilized pastures, and
the next lowest from hay crops. But gen-
eral recognition of that fact alone is not
sufficient. In most parts of the country
the acres devoted to use as pasture must
tie into a well balanced program with
A Proposed Grassland Philosophy 13
Not a Single Simple Problem
No one problem is complete within
itself. Many of our agricultural prob-
lems are so complex that to consider one
phase without at the same time consid-
ering several others is likely to lead to
false conclusions. In the economics of a
grassland agriculture, it is recognized
that in addition to the feed value of the
grasses and legumes, there are other po-
tentials of perhaps as great importance.
Forage problems relate directly to the
research of the soil physicist and the soil
chemist; to the investigations in soil
management and soil fertility; to the re-
sults obtained by those who deal with the
problems of soil conservation through
erosion control; also to the cash grain
farmer, and to the livestock producer
with his summer grazing procedures and
winter feeding management problems.
They go even farther, in fact, and
must be given high priority in the think-
ing of the agricultural economist. They
influence to a significant degree not only
short time procedures but also the long
time national economy. It is believed
that the factual material contained in
the chapters which follow will prove of
value in the solution of some of these
Time Required for Changes
Some years back William Newton
Clark, writing about the time required
for the introduction of new ideas said:
First the idea must be seen in enthusiastic
vision by someone, and enunciated for the
world to hear. It must get abroad among
men, and be somewhat widely considered. It
must come to be deemed important. Then it
must be ignored, recognized, restated, ridi-
culed, refuted, denied, doubted, admitted,
discussed, affirmed, believed, accepted, taught
to aaults, taught to children, wrought into
literature, put into practice, tested by its
fruits, allowed to modify other ideas, em-
bodied in institutions; and in the course of
some generations it will sink in among the
certainties that are assured and acted upon
without question and without thought. For
this process two hundred years is but a short
But that statement was made before
the day of high-pressure sales programs,
before the air waves were crowded with
commercially sponsored news, informa-
tional, and educational programs; before
we had county agricultural agents in
practically every county; before state col-
leges had their agricultural extension di-
visions with their corps of specialists and
their well organized information bu-
reaus, with radio stations at their com-
mand. That was before profusely il-
lustrated informational booklets came
into every home; before the day of the
technicolor motion picture; before the
day of the Farm Security Administra-
tion, the Soil Conservation Service, and
other similar action agencies; before the
organization of watershed areas, with
funds, equipment, and trained person-
nel available to demonstrate the value of
proved conservation practices; and fi-
nally, before the day of Soil Conserva-
tion Districts, organized in nearly every
county in large parts of many states,
with farm planners available to work
with every individual farmer willing to
We are not willing today to accept
the idea that two hundred years is but a
short period in which to expect new
ideas to "sink in among the certainties
that are assured, to be acted upon with-
out question and without thought."
Progress toward a Grassland Agricul-
ture has been made; this progress will be
more apparent and rapid in the years
A PROPOSED GRASSLAND PHILOSOPHY
Dr. P. V. Cardon, formerly in charge
of the Division of Forage Crops and Dis-
14 1. Forages in Our Advancing Civilization
FIG. 1.6 A close-up, showing the effect of cover
as a protection against the eroding effect of rain
drops striking the soil surface. Each pillar (the
tallest two inches under the cap) is topped with
a small bit of stone. Grass and other growing
forage not only protect the soil from rain-drop
action but also resist erosion by improving the
soil tilth and in other ways conserving and in-
creasing the productivity of the soil. U.S.D.A.
eases, United States Department of Agri-
culture, and more recently heading up
the Agricultural Research Administra-
tion of the Department, is the author of
the following proposed grassland philos-
The ideal of soil conservation in America
will become a fact when farm practice gen-
erally accepts and includes in cropping sys-
tem grass as grass and not as an expedient.
When American farmers become truly grass-
conscious they will plant and manage grass
14 Cardon, P. V. Toward a grassland agriculture.
Jour. Amer. Soc. Agron. 31:229-31. 1931.
in rotation with other crops because they ap-
preciate its intrinsic value. Then soil con-
servation, in all its aspects, will follow as a
Farmers will accord grass its proper place
in American agriculture when they become
convinced that grass culture is economically
feasible not only as a dependable source of
food for livestock, but as a soil improving
crop to be reflected in the returns from other
crops and as an otherwise legitimate compo-
nent of cropping enterprises.
To this end, all research, educational, and
action agencies could well afford to align
their forces. In such alignment these forces
could view grass culture broadly and with re-
spect to its place in farm practice within wide
areas. They will give full consideration to
the economy of grass in current use, as well
as to its value in preserving soil for future
generations of society.
THE LAST OF THE VIRGIN SOD
We broke today on the homestead
The last of the virgin sod,
And a haunting feeling oppressed me
That we'd marred a work of God.
A fragrance rose from the furrow,
A fragrance both fresh and old;
It was fresh with the dew of morning,
Yet aged with time untold.
The creak of leather and clevis,
The rip of the coulter blade,
And we wreck what God with the labor
Of a million years had made.
I thought, while laying the last land,
Of the tropical sun and rains,
Of the jungles, glaciers and oceans
Which had helped to make these plains.
Of monsters, horrid and fearful,
Which reigned in the land we plow,
And it seemed to me so presumptuous
Of man to claim it now.
So when, today on the homestead,
We finished the virgin sod,
Is it strange I almost regretted
To have marred that work of God.
From Genesis to Revelation
And the earth brought forth GRASS . whose seed was in itself, after its kind:
and God saw that it was good.
They said moreover unto Pharaoh, for to sojourn in the land are we come; for thy
servants have no PASTURE for their flocks; for the famine is sore in the land of
Canaan. . .
And I will seed GRASS in thy fields for the cattle, that thou mayest eat and be full.
1 Kings 4-23:
Ten fat oxen and twenty oxen out of the PASTURES, and an hundred sheep, beside
harts, and roebucks, and fallow deer, and fatted fowl. ...
1 Kings 18-5:
And Ahab said to Obadiah, Go into the land, unto all fountains of water, and unto
all brooks; peradventure we may find GRASS to save the horses and the mules alive,
that we lose not all the beasts.
The PASTURES are clothed with flocks; the valleys also are covered over with corn;
they shout for joy, they also sing.
He causeth the GRASS to grow for the cattle, and herb for the service of man; that
he may bring forth food out of the earth.
The king's wrath is as the roaring of a lion; but his favor is as dew upon the GRASS.
For the waters of Nimrim shall be desolate: for the HAY is withered away, the GRASS
faileth, there is no green thing.
The GRASS withereth, the flower fadeth: but the word of the Lord shall stand
How do the beasts groan, the herds of cattle are perplexed, because they have no
PASTURE; yea the flocks of sheep are made desolate.
The beasts of the field cry unto thee; for the rivers of waters are dried up and the
fire hath devoured the PASTURES of the wilderness.
And he commanded the multitude to sit down on the GRASS, and he took the five
loaves and the two fishes, and looking up to heaven, he blessed and brake, and gave
the loaves to his disciples, and the disciples to the multitude.
And it was commanded that they should not hurt the GRASS of the earth, neither
any green thing, . .
-After E. W. HAMILTON
MAURICE E. HEATH
Soil Conservation Service
What Is Grassland Farming?
When row-crop and livestock production
are built around the grassland acres on
individual farms and ranches-that is
grassland farming. The grassland acres
include land devoted to the culture of
forage grasses and legumes grown alone
or in combination. The grassland farmer
takes into account soils, plants, animals
and their inter-relationships. Adequate
acreages of adapted grass-legume combi-
nations are provided, depending on soil
needs. High quality forages are empha-
sized in livestock production, with grains
supplementing rather than dominating
the feeding practices.
Grassland farmers are often craftsmen
in the culture and use of grass. When
grassland farming is practiced inten-
sively, organic matter is renewed, soil
erosion prevented, gulley formation ar-
rested, and soil tilth improved. Soil con-
servation is the inevitable result of grass-
land farming. It results in more bushels
of corn and other grains from fewer
acres. Less labor and machine costs per
unit of production are required.
As Myers 1 points out:
MAURICE E. HEATH, of the Soil Conservation Service,
U.S.D.A., conducts developmental work on grasses and
legumes in the 12 Northeastern states. He was born and
raised on an Iowa farm and received training in farm
crops and soils at Iowa State College. Since his gradua-
tion he has been with the Soil Conservation Service.
Until 1948 he worked on grassland problems in Mis-
souri, Iowa, Minnesota, and northern Illinois. During
that period he also conducted grass and legume develop-
mental work in Iowa in cooperation with Soil Con-
servation Districts and the Agricultural Experiment
Forage crops are still the orphan children on
the majority of farms in the United States.
In the earlier days, of course, forage crops
were relegated to the poorest areas of the
farm. The pasture land was considered to be
that land that was not useful for the growing
of other crops. . The farmer used the
very best land he had for the production of
corn and wheat and other cultivated crops
and used whatever land remained for the
production of grasses and legumes.
A GRASSLAND PHILOSOPHY
A sound national grassland philosophy
must be developed before grassland
farming will be generally practiced on
individual farms. When so practiced it
will result in a permanent, highly pro-
ductive agriculture. To accomplish this
will require the best thinking and efforts
of farmers as well as of all leaders and
workers in the applied phases of agricul-
It has been pointed out by Graber 2
that, "Grassland farming" is not a catch
phrase, it is a trend whereby farmers are
emphasizing the use and value of their
grass-legume crops in their over-all opera-
tions. The soil and climate, together with
those factors that govern the production
and utilization of grasses and legumes,
will determine the intensity of grassland
farming in different parts of the coun-
1 Myers, W. M. Forage crops in agriculture. Un-
published paper given at several mid-west seed con-
ferences. June 1950.
2 Graber, L. F. What is grassland farming? What's
New in Crops and Soils. April-May 1950.
A Grassland Philosophy 17
FIG. 2.1 "Grassland farmers are craftsmen organic matter is renewed, soil erosion
prevented, gully formation arrested, and soil tilth improved .... It results in more
bushels of corn and other grains from fewer acres. Less labor and machine costs per unit
of production are required." (See p. 16.)
try. Although the forage plants in the
range country may be quite different
from those of the humid south or north,
the principles to be followed are similar
regardless of location. These principles
have to do with the productivity of the
soil as measured by response to manage-
ment when the sod crops are made the
foundation of the farm and ranch opera-
tion. The Wisconsin College of Agricul-
ture Grassland Committee 3 believes:
Grassland agriculture is a long-time program
directed towards increased production from
improved grasslands and more efficient use
of high quality forage, rich in protein, min-
erals, and protective vitamins.
Shifts from a cash crop system, such as
cotton in the South, and grain in the
North and West, to one emphasizing for-
age production and utilization with live-
stock, require additional skills and a
3 Wisconsin College of Agriculture Grassland Com-
mittee. Turn to grassland farming now. Wis. Agr. Exp.
Sta. Stencil Bul. 4. Feb. 1948.
much higher type of management by the
farm operator. The ultimate in grass-
land farming requires the highest type
of farm management. It will result in
the greatest return possible over a long
period of years. It is balancing the physi-
cal factors of production at a high level
and at the same time giving us an ade-
The Bureau of Agricultural Econom-
ics of the U.S.D.A.5 states that if we
raised our per capital consumption 8 per
cent above that of 1946 to supply an ade-
quate diet, our 1955 population would
require 10 per cent more dairy products;
8 per cent more meat, poultry, and fish;
9 per cent more fats and oils, including
butter, bacon, and fat cuts; and 29 per
cent less grain products. The grassland
farming trend will provide for the neces-
4 Heath, Maurice E. The need for grassland hus-
bandry. Better Crops with Plant Food. Oct. 1948.
5 B.A.E., U.S.D.A. Will more forage pay? U S.D.A.
Misc. Pub. 702. 1949.
18 2. What Is Grassland Farming?
sary shifts to the kinds of foods needed.
Stapledon,6 after many years of re-
search and observation on grasslands,
Grass ( . grass and clover) properly used
insures soil fertility, grass marries the soil to
the animal and the solid foundation of agri-
culture is the marriage of animal and soil.
That spells humus. . Grass properly em-
ployed counters the devastating influence of
The outstanding feature of grassland is its
complexity. . Soil, climate, grazing ani-
mal. Which of these three is the most im-
portant factor? Most emphatically the graz-
ing animal: Manure right, sow right, and
manage the grazing animal wrong and you
are nowhere. Without the grazing animal
there would be no grassland worthy of the
name anywhere in the world. Management is
therefore the key to the solution of the whole
Cardon 7 observed that grassland farm-
ing is not necessarily an extensive farm
operation. In some places it is very in-
tensive-as much so as vegetable cul-
Inseparably linked with livestock produc-
tion, grassland agriculture under good man-
agement may equal or increase the produc-
tion of digestible nutrients to the acre and
reduce materially the labor needed to grow
and utilize a given amount of those nutri-
ents. It may also lower significantly the cost
of supplying the protein-often bought as a
concentrate-required for high levels of ani-
mal nutrition. Grassland agriculture envi-
sions the use of grasses and legumes alone or
in combination or rotation according to sys-
tems of management best suited to land use
under various environments, with ample pro-
visions for root crops, leafy vegetables, fruits,
fibers, forests, and specialty crops as needed.
Thus grassland agriculture differs from other
types of farming chiefly with respect to the
emphasis placed on grasses and legumes.
They are dominant in a flexible pattern de-
signed to conserve the land and its produc-
tivity but at the same time keep it adjustable
to emergency needs.
Cardon 8 also stated:
America today is definitely grass-minded,
6 Stapledon, R. G. Presidential Address. Fourth In-
ternational Grassland Congress. Proceedings. 1937.
7 Cardon, P. V. Our aim: An Introduction. Grass.
Yearbook. U.S.D.A. 1948.
8 Cardon, P. V. Toward a grassland agriculture.
Jour. Amer. Soc. Agron. 31:228-31. 1939.
but America still lacks the profound grass-
consciousness which prompts Europeans to
take advantage of favorable physical condi-
tions, to grow more and better grass, and to
utilize it to better advantage.
Grass-consciousness differs from grass-
mindedness. The one may be and probably
is an outgrowth of the other, but grass-
consciousness is the more profound. Grass-
mindedness inspires grass culture for specific
purposes, as, for example, a corrective of soil
erosion. Grass-consciousness, on the other
hand, regards such specific uses of grass as
incidental to its primary uses. It is grass itself
that is important-Grass is a farm crop
which is worthy of as good land and as in-
telligent culture as any other crop. Grass is a
crop around which to build profitable farm
enterprises; it conserves the land, it benefits
other crops grown in rotation with it, it is
the basis of a type of farming in which the
control of erosion, the protection of water
sheds, and the improvement of pastures and
ranges follow as matters of course. Thus,
grass-consciousness recognizes and utilizes the
intrinsic, greater value of grass without dis-
counting, but automatically providing for
the full play of its incidental values. The
culture of other crops fits into this grass-
land background and grassland agriculture
. Grassland agriculture represents a
definite advance towards stabilized agricul-
ture. It is not a reversion to pastoral practices.
It cuts across all phases of agricultural pro-
duction and therefore commands a high de-
gree of managerial ability. It calls for all of
the skill usually required in crop production
plus the application of that and other skills
in the production of crops in rotation with
grass. The successful establishment and main-
tenance of good grass cover requires skillful
application of the best agronomic informa-
tion available, and there is much still to be
learned about the breaking and preparation
of sodland for succeeding crops in rotation of
which grass is a part. Moreover, the utiliza-
tion of grass, if it is to be made profitable,
requires knowledge of a high order pertain-
ing to animal production. A successful grass-
land farmer, in other words, must be a very
good all-round farmer. ....
Complementary Benefits From Forages
In grassland farming the complemen-
tary benefits of the sod crop are many.
FEED FOR LIVESTOCK. One of the most im-
portant benefits of high quality, pro-
ductive forages is the fact that they
A Grassland Philosophy 19
FIG. 2.2 "Grassland agriculture represents a definite advance towards stabilized agriculture.
It is not a reversion to pastoral practices. It cuts across all phases of agricultural produc-
tion . calls for all of the skill usually required in crop production plus . knowl-
edge of a high degree pertaining to animal production." (See p. 18.)
provide the best and cheapest feed for
livestock. It is true that even idle grass
has value in soil protection and organic
matter renewal, but the value of the for-
age as a feed for livestock will largely de-
termine its use and extent of culture on
farms throughout the country. Forages
from the grassland acres supply both
winter and summer feed for livestock.
With an increasing number of forage
species and strains "all-year grazing" is
becoming a reality in an ever increasing
area in the South. For the same reason
the grazing season is being lengthened
in the more northern areas.
Through grassland farming the ani-
mal is in a soil conserving and soil im-
proving relationship to the land. Maxi-
mum use is made of high quality pas-
turage. The grassland farmer maximizes
high quality forages in his livestock feed-
ing enterprises. He has his livestock
working for him as much as possible be-
cause they are wedded to the soil by way
of grass. The grassland farmer knows
that meat and milk are the products of
grass-a soil improving and protecting
crop. The better the grass the better the
In grassland farming there is always
a reserve of forage at hand at all times
in the form of unused pasturage, grass
silage, or hay. This is one of the keys to
successful grassland-livestock manage-
ment. An adequate forage reserve of
from 30 to 50 per cent of normal needs
will bridge such emergencies as a severe
winter, a late spring, a summer drouth,
or a partial crop failure.
In the more humid parts of the coun-
20 2. What Is Grassland Farming?
FIG. 2.3 "The economy of pastures is due in large part to the saving in labor, equipment
use and power. The animals gather their own feed and spread the manure as they graze.
In grassland farming the best forages are utilized . ." Iowa State College photo.
try it is difficult to capture the nutrient
value of the forage crop as hay because of
rainy weather. Here the grassland farmer
is finding that he can conserve these val-
uable nutrients as silage. By making grass
silage instead of row-crop silage greater
soil benefits and feed value are derived
from the grassland acres. Grassland farm-
ers are finding that high quality grass
silage when fed to all classes of live-
stock is the nearest they can come to
good pasturage during the winter
The economy of pasture is due in
large part to the saving in labor, equip-
ment use and power. The animals gather
their own feed and spread the manure
as they graze. In grassland farming the
best forages are utilized with the market-
able classes of livestock or with produc-
ing dairy cows. The grassland farmer
tries to obtain as many feed units as pos-
sible from his fattening pastures. Cost
records in general show the following re-
lationship of digestible nutrients of dif-
ferent feeds from crops, listed in order of
economy of production per 100 pounds
of digestible nutrients:
Forages as pasture.......... I
Forages as hay..............2
Corn for grain ............. 3
O ats .................... 4
In grassland farming the emphasis is
on getting the most over-all benefit from
the grassland acres. This does not mean
putting the entire farm to grass. Ahl-
gren 9 points out the most restrictive con-
ception of grassland farming rules out all
cultivated crops. "All-grass" farming re-
quires a high degree of skill in keeping
forage stands highly productive. Seeding
the entire farm to grass through a period
of years may prove as unprofitable as
putting the whole farm continuously to
a row crop. In the forest the most vigor-
9 Ahlgren, G. H. Forage Crops. New York:
A Grassland Philosophy 21
ous growing part is the new wood. And
so it is with our forages. The first to the
third year of meadow crops are the most
vigorous in the humid areas of the
United States, depending upon the spe-
cies and mixtures. In most cases, where
land use permits, farmers will want to
set the stage for a new vigorous seeding
by taking advantage of this build-up
with a row or grain crop.
BEST FERTILIZER. The grassland farmer
looks upon the animal as a mecha-
nism for increasing soil fertility. He
recognizes that the animal removes nu-
trient elements from pasture crops and
harvested crops essential for its body
growth and maintenance. These must be
returned to the soil periodically in the
form of agricultural lime and commer-
The grassland farmer strives for a high
quality sod, one that results in high row-
crop yields. Such a sod is the cheapest
and best fertilizer for the crops which
follow. A high quality sod is one that re-
sults from the growth of a grass-legume
combination, the forage of which has
been so utilized through livestock that
maximum row-crop acre yields are ob-
tained when they follow the sod crop.
Lime and other plant food nutrients are
applied as needed for successful forage
production. The root quality should be
a plant character considered when de-
termining the species or strain of grass
that is to be seeded. Legumes are tap
rooted and decay rather quickly. The sod
effect is from the fibrous grass roots. The
grass roots are capable of sponging up
the nitrogen furnished by the legume.
They provide a much more stable type
of organic matter than do the legumes.
Decomposition of the grass roots is some-
what proportional to the summer tem-
peratures. Thus, the release of nitrogen
generally parallels the growth curve of
FIG. 2.4 "The grassland farmer strives for a high
quality sod . maximum row-crop acre yields
are obtained when they follow. . The sod
effect is from the fibrous grass roots . capable
of sponging up the nitrogen furnished by the
legumes . provide a more stable type of or-
ganic matter .. ."
summer growing crops, such as corn, as
the sod decomposes.
The quality of the sod can be im-
proved by utilizing the forage as pas-
turage rather than removing it as hay or
silage. Under pasturage only those nutri-
ents absorbed by the body of the animal
are removed. The voided material is
leached into the soil to be used again by
22 2. What Is Grassland Farming?
the forage plants, or by the row crop that
follows. To obtain maximum row-crop
yields the sod crop must be plowed while
the forage is still highly productive.
A high quality sod means a minimum
of tillage operations for the row crop
that follows. The cycle of most annual
weeds is completely upset by the develop-
ment of the perennial sod crop. The sod
crop provides the foundation and is
largely responsible for the success of such
supplemental conservation practices as
contouring and terracing.
BEST DRAINERS OF SOIL. In grassland farm-
ing the grasses are teamed with the
legumes wherever possible. They
supplement each other. Not only do le-
gumes penetrate the subsoil and improve
drainage, but the fibrous grass roots lit-
erally permeate the plow layer and grad-
ually diminish in quantity with depth.
The roots of some of the taller growing
grasses may extend to a depth of 6 to 8
feet. Thus, a high quality grass-legume
sod increases water percolation. Tile
lines made useless as a result of soil com-
paction by excessive row cropping have
been made to function again when the
proper ratio of sod crops to row crops
are used. Adequate use of forages is the
key to improved soil tilth and internal
GREATEST PROTECTOR OF SOILS. On the
non-forested acres, adapted grass-
legume combinations furnish the
greatest protection to soils on erodable,
sloping soil surfaces. This has been dem-
onstrated consistently throughout the
country by studies on the Soil Conserva-
tion Research Stations. Grass cover was
found to be from 200 to 2000 times more
effective in preventing soil loss when
compared to clean cultivated row crops'1
10 Enlow, C. R., et al. Grass and other thick-growing
vegetation in erosion control. Yearbook. U.S.D.A. 1938.
depending upon soil type and amount of
The forages protect the soil surface
from the beating action of rain. The
force of rain drops is broken by close
growing vegetation. Frequently, the run-
off from grass areas is crystal clear as
compared with silt laden run-off from
cultivated fields. The grass roots when
plowed for row-crop production furnish
protection to the soil surface by holding
and binding the soil particles together
and increasing percolation.
Forages Are the Hub or Pivotal Crop
The grassland farmer in planning his
farm operations starts with forage seed-
ing in balancing the soil-plant-animal
cycle. The choice of legumes is all impor-
tant. In general, it may be called the
starting point in grassland planning.
The appropriate companion grasses are
selected for the legumes. In grassland
farming the trend is toward more simple
mixtures with a higher degree of utiliza-
tion management. Such factors as lime,
seedbed preparation, method and depth
of planting, fertilizer needs, and ultimate
forage utilization are considered. If a
companion cereal crop is used with the
forage seeding, the rate of planting the
cereal crop and its best management to
insure the forage stand is dominant in
the mind of the grassland farmer.
It has been tradition in our crop pro-
duction and planning to start with the
row crop, for example: 1st year, Corn;
2nd year, Small grain and seeding; 3rd
year, Sod. Here the sod interval in the
rotation was used and referred to as a
fertilizer, to grow more corn and grain.
The emphasis was on the row crop. The
grassland farmer grows the sod crop be-
cause it is just as profitable, or more so,
than any other crop. He is familiar with
its complementary values. He starts with
the legume, adds the grass, and plans
I LEO SANTATION
LPvl 0 ,
mnOTE NO. CONTENTS ... PAG NO-.
FIG. 2.5 Forage Notes goes each month to the several hundred widely scattered members
of the Forage Club, organized in 1945 to dovetail the forage interests of crop and soil
specialists with those in animal and dairy production, agricultural economics, agricultural
engineering, soil conservation, and in other areas of activity. "Many of the grassland
problems . today are so broad as to be beyond the scope of any one specialist . the
soils, crops, beef cattle, farm management, and soil conservation specialists are teamed
together. . .They study the interacting factors and their effect on each other."
Io]ME-ROiW g PROTEIN
Itio 4T I
24 2. What Is Grassland Farming?
FIVE-YEAR CROPPING SYSTEM
2nd rear 3rd Year 4th rear
(Grass-legume seeding alone or with
1. Forage usage-Pasture, silage
2. Choice of legume-Superior strain.
3. Choice of companion grass-
4. Soil treatments-Kinds and
amounts of micro and macro
nutrients required for high yields of
quality forage (Lime and
5. Seedbed requirements-Method of
preparation, firmness and weed
6. Seeding-Seed viability, inocula-
tion, time, rate, depth, and method.
7. Management of small grain-To
be removed as hay, pasture or
grain. Straw removal and
8. Management of new legume-grass
stand-To be clipped, pastured,
cut for hay or seed.
1. For production of beef, pork,
milk, poultry, mutton, or seed.
2. Time of cutting or pasturing.
3. Supplemental fertilizer as top-
4. Mowing and grazing manage-
ment of grass to benefit legumes.
5. Insect and disease control in forage
6. Insect pollination in legume seed
production where bees are re-
7. Use of the animal as a forage
8. Types of equipment to harvest and
handle stored forage.
9. Methods of handling and storing
10. Ratio of sod crop to row crop that
will result in a sustained high level
of production, depending upon
the seeding. Some of the following fac-
tors are considered by the grassland
farmer in growing and using high yield-
ing and high quality forage in his farm
operation. A five-year cropping period
is used as an example in Table 2.1.
In grassland farming, forage stands ob-
tained on capability class I, II and III 1
lands usually have developed a high
quality sod by the end of the second or
third year. The row crop is used to cap-
ture the fertility accumulated by the sod
crop, as well as pave the way for the next
forage seeding. Class IV and VI lands
usually are in continuous grass except
for periodic re-establishment of legumes
Many of the grassland problems con-
fronting the grassland farmer today are
so broad as to be beyond the scope of any
one specialist. State and federal experi-
11 Hockensmith, R. D. The scientific basis for con-
servation farming. Jour. of Soil & Water Conservation.
2:1. January 1947.
ment stations in a number of locations
have started teamwork research, by as-
signing a number of specialists to work
together in studying and analyzing grass-
land problems. One such problem being
studied in the Midwest is that of how
best to utilize greater quantities of for-
ages called for by proper land use
through beef cattle feeding operations.
Here the soils, crops, beef cattle, farm
management, and soil conservation spe-
cialists are teamed together to pool their
resources. They study the interacting fac-
tors and their effect on each other. A
mixing of the sciences focused on the
problem spells the way to progress in
Hixon 2 observed a revolution in the
effectiveness of materials and methods
during the war period, the result of the
coordinated effort of men with widely
diverse training. He believes that similar
scientific teamwork on the forage prob-
lems would yield fundamental informa-
12 Hixon, R. M. The potentialities of coordinated re-
search for forage crops. Forage Notes 1:31. 1947.
A means of sod
Grain used to sup-
A Grassland Philosophy
tion of great value in forwarding the
more practical production and utiliza-
tion of grass and legume crops.
For example, perhaps much could be
done in solving the bloat problem in
ruminants if only the veterinarian, phys-
iological chemist, animal husbandryman,
soils and grassland agronomist could
work as a team. Certainly, many of the
applied problems of grass silage preser-
vation, storage, and utilization require
the combined efforts of specialists in the
fields of agricultural engineering, chem-
istry, animal nutrition and grassland
agronomy. And what of the feeding value
and utilization of many of the so-called
"edible weedy plants"? Could some of
these be used to advantage for pasturage
by including them in grass-legume mix-
tures? How can the "all-grass" farmer
keep his sod crops highly productive
without an intervening row crop?
Good grassland farming results re-
quire that grassland research results be
presented by specialist-teams. This would
tend to promote balance of farming op-
erations. Each specialist would find it
necessary to correlate his subject matter
FIG. 2.6 This up-lifted acre of corn, giving every indication of high production, stimulates
the imagination in an effort to visualize all that has contributed to make possible this
lower cost per unit. "The grassland farmer strives for a high quality sod; one that results
in high row crop yields . the sod must be plowed while the forage is still highly
productive." (See p. 21.) Pioneer Hi-Bred Corn Company photo.
26 2. What Is Grassland Farming?
responsibility to the whole grassland
farming operation of the individual
farm, as well as to the larger area prob-
A number of counties have pooled
their leadership, information, and other
resources to study and work on grassland
farming in all its aspects. In some in-
stances local county grassland commit-
tees have analyzed the potentials of a
grassland agriculture for their area and
planned a course of action. Such com-
mittees usually include various agricul-
tural workers, farm leaders, farm credit
representatives, farm equipment dealers,
farm editors, representatives of local in-
dustry and others. Such local teamwork
has been effective in speeding up the
trend toward grassland farming and at
the same time maintaining a well-
balanced over-all approach.
1. Explain how grass-consciousness differs
2. What is grassland farming?
3. Is grassland farming flexible? Explain.
4. How are grassland farming and a per-
manently productive agriculture re-
5. What are the benefits derived from the
sod crop in grassland farming? How
are these benefits complementary?
6. What is meant by a national grassland
7. Why is grassland farming so closely
linked with livestock production?
8. In general, why is the American farmer
not traditionally a grassland farmer?
9. What are the advantages of teamwork-
research and education in rendering
assistance to the grassland farmer?
What are the disadvantages?
10. Discuss how best to develop a county-
wide grassland farming program that
ultimately would result in a perma-
nently productive agriculture for your
EARL O. HEADY
Iowa State College
Economic Aspects of Forage Production
Climatic and soil conditions determine
where forages can be grown. They also
affect the yield obtained. But it is eco-
nomic considerations which finally de-
cide where, when and how much forages
should be grown. Economic considera-
tions determine whether forage, grain,
fiber, or other crops should be grown un-
der a given condition.'
FORAGE AMOUNT A FARM MANAGE-
Each individual farmer must consider
forage crops from the standpoint of how
they fit into the pattern of his farm.
Farmers ordinarily have limited re-
sources to work with. So they must de-
cide how they can use their labor, cap-
ital, and land most profitably. To maxi-
mize profits it is necessary that the farmer
use each unit of limited resources where
it will bring him the greatest return. He
must decide whether to invest scarce cap-
ital in legume seed, fertilizer, brood
sows, machinery or some other invest-
ment alternative. He must decide
whether a day of labor or an acre of land
EARL O. HEADY, Professor of Economics, Iowa State
College, is in charge of Farm Management and Produc-
tion Economics teaching and research. He was the
recipient of the American Farm Economic Association
award for distinguished research in 1949 and the Social
Science Research Council faculty fellowship award for
fundamental research for the years 1950-53. In 1947 he
was a United States delegate to the International Con-
ference for Agricultural Economists. Nebraska born,
he received the B.S. degree from the University of
Nebraska, followed by graduate work at the University
of Chicago and the Ph.D. from Iowa State College.
will bring in greater returns if used to
grow alfalfa, corn, peanuts, cotton,
wheat, or some other crop. He must
make similar choices between crops and
livestock enterprises, also between dif-
ferent kinds of livestock. For example,
he should use labor to produce pork in-
stead of forage only under one condition
-if the dollar return from a day's work
spent on hogs is greater than the return
from the same amount of labor spent on
alfalfa, clover, or some other hay crop.
Finally, he must decide whether, or con-
sider how, the different enterprises fit
into a pattern for his farm as a whole.
Some farm enterprises are in direct
competition with each other. Other crop
and livestock enterprises go together,
hand-in-hand. The best livestock enter-
prise for any one farm depends partly
on the crops which can be grown and
on the yield of these crops. At the same
time, however, the livestock program
which is most profitable under a given
condition helps determine which crops
should be grown. For example, a farmer
living in a certain milk shed may have
conditions which would make high yields
of corn and wheat possible. A high price
for whole milk and the returns from
1 Heady, Earl O. The economics of rotations with
farm and production applications. Jour. Farm Econ.
Heady, Earl O. et al. The right rotation for your
farm. Iowa Farm Science 3:9-12. 1948.
28 3. Economic Aspects of Forage Production
dairying, however, may lead him to pro-
duce only hay and pasture on his own
land. He does this to support as large a
number of dairy animals as possible. He
can buy concentrate feeds.
The questions of the most desirable
rotation or of the most profitable ration
to be fed a given class of livestock are
not distinct and separate problems. They
are problems that must be considered to-
gether if maximum farm profits are to
Some Questions To Be Answered
When forages are to be produced in
the farm program some of the questions
that must be answered are: (a) How
many acres should be grown? (b) What
type and variety? (c) What level of acre
yield should be attained through vary-
ing the rates of applying fertilizer, seed,
and other cultural practices? (d) Should
the forage be harvested as pasture, hay
or silage? (e) If harvested as hay should
a baler, chopper or hay loader be used? 2
Agronomy provides basic yield data
while engineering provides information
on machine performance in answering
these questions. Price and cost informa-
tion must be added to these data in ar-
riving at the final dollars and cents an-
swer. Each farmer must take the respon-
sibility for making the best use of the
soil resources, capital, labor, and man-
agerial ability at his command. There is
no "fixed recipe" which will tell all
farmers exactly the amount of forage to
produce. The amounts, kinds, and yields
of forages and the methods of harvest-
ing and utilizing them must be solved.
It is a problem peculiar to each indi-
2 For a more detailed discussion of these problems
and their solution refer to the following texts: Black,
J. D., et al. Farm Management. Chapters 1, 7, 8 and
13. (Macmillan Company, New York, 1947); Hopkins,
J. A. Elements of Farm Management. Chapters 9, 10
and 11. (Prentice Hall, New York, 1947); Forester,
G. W. Farm Organization and Management. (Prentice
Hall, New York, 1946).
There are certain economic principles
which apply. These determine the con-
ditions under which the production of
additional kinds and amounts of forages
will increase farm profits. They cannot
be developed in this one short chapter.
Only the broader and more general eco-
nomic aspects of forage production will
The average amount of forage pro-
duced per farm varies greatly between
different localities. In some areas nearly
all the land area is devoted to grasses
and legumes. Some regions grow very lit-
tle of these crops. In other areas a near-
even balance exists between forage and
grain or fiber crops. The areas which
can produce the highest acre yields of
grasses or legumes do not always spe-
cialize to the greatest extent in these
The principle of comparative advan-
tage is the economic law which helps ex-
plain this regional specialization.3 In
general, this principle or law indicates
that crops should not always be grown
where absolute yields and income per
acre are greatest. Rather they should be
produced where relative or comparative
yield and return are greatest.
For example, the yield per acre of both
forage and grain crops is greater in the
Corn Belt than in most of the Great
Plains area. Certain sections of the Corn
Belt, however, grow a greater acreage of
grain than of grasses and legumes. At
the same time in parts of the Great
Plains practically all the land is devoted
to grasses and livestock grazing. Here
the Corn Belt has an absolute advantage
in both forage and grain crops. Yet the
3 This principle can be better related to crop produc-
tion in a detailed discussion such as: Black, J. D. Loc.
cit.2 Chapters 5, 6, 7, 8 and 9. Hopkins, J. A. Loc.
cit.2 Chapters 2 and 3.
Comparative Advantage 29
Great Plains grazing area has a "com-
parative or relative advantage" for
grasses. The reason-its yield disadvan-
tage for grass is less than for grain crops.
In the same vein, the Corn Belt has a
comparative advantage for grain, since
its actual advantage for corn, oats and
soybeans is greater than for the forage
To illustrate: Suppose that in region
A an acre of land along with the neces-
sary capital and labor will yield either
2.5 tons of hay or 60 bushels of corn. In
region B the yields for hay and corn are
1.5 tons and 30 bushels, respectively. Re-
gion B has a comparative advantage in
hay because the yield is 60 per cent as
great as in region A while the corn yield
is only 50 per cent as great. Conversely,
A has the comparative advantage in
Here is another illustration of this
principle. Business executives, or pro-
fessional workers such as lawyers and
doctors, often are more adept at book-
keeping than their secretaries. Or, they
can dust office equipment at a more
rapid pace than the charwomen who per-
form these duties. Yet the business execu-
tive or medical specialist can make a
greater return by devoting his efforts to
professional duties, where he has an even
It must be borne in mind, also, that
consumers of commodities and services
help establish the comparative advantage
and the amount of specialization in any
one crop or enterprise. The prices con-
sumers are willing to pay tend to push
each region into producing the product
for which it has the greatest relative ad-
vantage. Market prices reflect the con-
sumers' desires for different products.
Aside from geographical variations this
is the same for all farmers. In effect, the
consumer thus indicates that the farmer
with the lowest relative costs (not always
FIG. 3.1 "... forages are produced in areas
where they have a comparative advantage over
other crops. There are important possibilities
for the substitution of forage for grain crops in
many of our agricultural regions." This is a
Dallis-Bermuda-carpetgrass-clover mixed low-
land pasture in Georgia. U.S.D.A. photo.
the lowest absolute costs) should produce
a given crop.
Historically, broad regions with vary-
ing degrees of specialization in grasses
and legumes have become established.
Some regions produce forages because
the topography and climate make it im-
possible to produce any other crop. But
mainly, forages are produced in areas
where they have a comparative advan-
tage over other crops. There are impor-
tant possibilities for the substitution of
30 3. Economic Aspects of Forage Production
forage for grain crops in many of our ag-
Changes in comparative advantage are
brought about especially by: (a) changes
in consumers' tastes for different things,
and hence the prices which they are will-
ing to pay for them as compared to
others; and (b) changes in the acre yield
or costs of one crop as compared to that
of other crops.
The American diet is fairly stable.
Therefore, the greatest opportunity for
increasing the comparative advantage of
forage crops relative to grain and fiber
crops is through increasing the relative
acre return as compared with that of
Best Combination With Other Crops
Very few farming regions in the
United States have such a distinct ad-
vantage in grain, fiber, fruit, or other
crops that they cannot afford to devote
any of their land to forage production.
Generally, the problem is to get the best
combination of forages with other crops.
The proper combination from a na-
tional economic standpoint is one which
gives both a maximum satisfaction to
consumers and a maximum profit to
farm operators. Once this balance has
been struck, any major shift away from
it is to the disadvantage of both farmers
ROLE FOR THE INDIVIDUAL FARM
Any farm manager has the problem of
deciding on the most profitable combina-
tion of crop and livestock enterprises.
The manner in which enterprises should
be combined depends partly on the rela-
tionships which they bear to each other.
Farm enterprises fall into three cate-
gories depending on their relationship
to one another. They are either competi-
tive, complementary or independent.4
The competitive and complementary
classifications best explain the economic
role of forage crops in the organization
of a farm in order to maximize profits.
These two general relationships help ex-
plain not only which farms should grow
grasses or legumes but also help deter-
mine how many acres of forage should
be grown on any one farm.
Enterprises are complementary with
each other when the production of one
increases the quantity of the other from
given resources. The complementary na-
ture of grasses and legumes is perhaps
the most important reason explaining
their place in the farm organization.
Forage crops are complementary with
grain crops when an increased acreage
and production of these forage crops also
increases the total production of grain
from a given farm or area of land.
The reasons why forage crops may
serve in a complementary relationship
to grain crops are outlined in otherchap-
ters. They are mainly these:
(1) Legumes add nitrogen to the soil.
This becomes a direct source of plant
food for later grain crops.
(2) Grasses and legumes add organic
matter to the soil. Thus they have a
beneficial effect on soil structure and
tilth. This may increase the per acre
yield of crops which follow in the rota-
tion. The better soil drainage brought
about permits more timely planting and
cultivation of the crop. Or grasses and
legumes may have direct yield effects
through the chemical and physical proc-
esses of the soil.
(3) Forage crops grown in rotation
4 See the following books for a complete discussion
of these relationships: Hopkins. Loc. cit.2 Chapter 3.
Black. Loc. cit.2 Chapters 16, 17, 18. Forester. Loc. cit.2
Role for the Individual Farm
Crun )milddr amn imll; r
lo w hcn )ou includr eu ___J_
fo inyour rotion. ~
Adde;n i ounr Iue Ir o. Ir .
Inun, rr. Ihr Ih A-1 1
outpuL One rouition pruoduoe B B ces W i .
rhe mia.l rte4, i
Grun oup1U n,- fall. a
)ou L. lude mom fc r'e
A. ,nu pro" ill rmor
forage in l re o u. ,. I.c
total feed outputI fall I
C.&iitnuoa gra i yeld '
differ ,oib oad types;
bhrt us.ully pioducat lesn J L
FIG. 3.2 "Forage crops are complementary with grain crops when an increased acreage and
production of these forage crops also increases the total production of grain from a given
farm or area of land." (See p. 30.)
may help control the corn root worm, or
other crop diseases and pests.
(4) Forage crops are especially effec-
tive in controlling erosion. Hence they
tend to increase the relative acre yield of
other crops over a period of time.
In order to maintain a perfect and di-
rect complementary relationship be-
tween forage and grain, the percentage
increase in yield per acre of the grain
must be greater than the percentage de-
crease in number of acres of grain, as
land is shifted from grain to forage. Let's
say a farmer has a four-year rotation
which includes two years of corn, one of
small grain and one of hay (75 out of
100 acres in grain). Now suppose he
shifts to a five-year rotation including
two years of corn, one of small grain and
two of hay (60 out of 100 acres in grain).
This shift increases total grain produc-
tion (a complementary effect) if the acre
yield of grain is increased by 25 per cent.
The shift will lower total grain produc-
tion (a competitive effect) if grain yields
go up only 15 bushels per acre.
During recent years there has been
some concern over methods of utilizing
and marketing the additional forages
produced under soil conservation adjust-
ment and production control programs.
There is little reason for this concern,
however, within the range in which for-
ages serve in a complementary capacity
to corn, tobacco, wheat or other crops.
If the grass or legume crop is comple-
mentary it always pays to produce these
crops regardless of the opportunities for
utilizing the hay or pasture through live-
stock. Also, it always pays to produce
forages irrespective of their prices or re-
turns relative to those of other crops, as
long as this complementary relationship
exists. It makes no difference whether,
for example, the return for forage is $20
per ton while the price of corn is 50
i .*rr- .pp
32 3. Economic Aspects of Forage Production
COSTS PER ACRE IN GROWING AND HARVESTING SPECIFIED GRAIN AND FORAGE CROPS, CORN
BELT AVERAGES, 1940-45 *
Kind of crop
Yield and cost items
Corn Oats Soybeans Alfalfa Red Clover
Yield per acre (bu. or ton) .................. 60.6 34.5 23.3 2.6 1.6
Growing cost .................. .......... $10.52 $6.27 $ 9.87 $ 5.98 $ 5.15
Harvestingcost ...... .................. $ 3.94 $3.10 $ 2.58 $16.80 $11.83
Total growing and harvesting cost t ......... $14.46 $9.37 $12.45 $22.78 $16.98
Source: Based on Corn Belt farm account and cost records.
t Cost items do not include interest on land, taxes and other items which are identical regardless of the
cents per bushel or whether the prices
are respectively $10 per ton and $2 per
bushel. As long as a greater acreage and
production of forage also results in an
increased output of other crops, the for-
age is profitable even if the direct return
from it were zero.
It is shown in Table 3.1 that the costs of
growing and harvesting the forages are
greater than for the grain crops listed.
However, the costs of growing forage are
less than the costs of growing and har-
vesting any single one of the other crops.
Thus, if fewer acres are devoted to grain
while more land is planted to alfalfa or
clover, total costs can be lessened even
if the forages are left unharvested or are
plowed under. Now it is evident that if
costs can be lessened while total grain
production is increased, profits must
necessarily increase. For example, a shift
from the continuous corn to the three-
year rotation shown in Table 3.2 would
increase grain production by the equiv-
alent of 1,279 bushels of corn. The shift
of 33.3 acres from corn to alfalfa hay
alone would save $282. (Additional cost
reductions would occur were an equal
acreage shifted from corn to oats.)
Yet profits can be increased even fur-
ther by utilizing the forage through live-
stock. If the farmer has the capital and
necessary fencing he can harvest his
crops as pasture and the only costs that
need be considered are the growing costs.
FIG. 3.3 ". . profits can be increased even
further by utilizing the forage through livestock
. he can harvest his crops as pasture. . He
can go even further in increasing profits if the
forage is harvested and fed to livestock which
add more to gross income than is added to har-
vesting and other costs . ." Iowa S.C.S. photo.
He can go even further in increasing
profits if the forage is harvested and fed
to livestock which add more to gross in-
come than is added to harvesting and
other costs. It should be emphasized
again, however, that utilization of forage
is not a necessary step in increasing prof-
its where the grass and legume crops are
complementary to the grain crops. Re-
Role for the Individual Farm
turns will always be greater as forage
acreage is increased.
Forage crops are competitive with
grain or other crops on any one farm if
an increased acreage of forage not only
results in a reduction in the acreage of
the non-forage crops but also results in
a reduction in the total output of the
latter. Thus, it is not sufficient that
grasses or legumes result in a per acre
yield increase of crops grown later on the
same land. The total yield increase must
be great enough to more than offset the
reduction in the number of acres planted
to the crops other than forages.
On some soils, the relationship be-
tween forages and other crops is only
competitive. This means that the acreage
and production of forage can be in-
creased only at the expense of produc-
tion of the non-forage crops. Here the
two do not go hand-in-hand. A competi-
tive relationship alone exists. This is
most common in those areas where mois-
ture rather than soil fertility is the lim-
iting factor in per acre yields. A rotation
including a legume might add nitrogen
and organic matter to the soil in the
wheat-producing area of western Kansas.
But it probably would not increase the
yield per acre in years when rainfall is
limited. Unless wind erosion were seri-
ous, the total output of wheat on a given
farm probably would be less if grasses or
legumes were included in the cropping
Similarly, there are soil areas in the
regions of more abundant rainfall where
soil structure, fertility, or erosion do not
limit the yield of non-forage crops.
There are also areas where the original
or virgin store of organic matter and
fertility was great, and where the supply
of these elements has not yet fallen
enough to make growing grasses and leg-
umes have a complementary effect on
the production of other crops.
Grasses and legumes do have a com-
plementary effect on a large number of
soils. But this relationship does not con-
tinue indefinitely, as more and more of
the land is shifted from grain crops to
forages on the same farm. When the
acreage of grasses and legumes has been
increased to a certain point, they become
competitive with other crops on all soil
types. This happens when a further shift
of land to forages necessarily reduces
total output of the non-forage crops.
Grain and forage crops can be both
complementary and competitive on the
same soil tract or farm. This is illustrated
by Ohio data from a rotation experiment
on Wooster-Canfield soils, for the period
1920-35 (see Table 3.2).
It will be noted that 100 acres con-
tinuously in corn would have produced
2,700 bushels of corn. A rotation includ-
ing 66.7 acres of grain (33.3 of corn and
33.3 of small grain) and 33.3 of alfalfa
would have produced 3,979 bushels of
corn equivalent and 90.4 tons of hay. A
rotation with 40 acres of grain and 60 of
alfalfa would have produced only 2,361
bushels of corn equivalent and 102.3
tons of hay. In the first case, adding hay
to the rotation has a complementary ef-
fect. Increasing hay acreage and produc-
tion further, however, had a competitive
effect. This is because it resulted in a de-
crease in total grain production.
The degree to which forage serves in a
complementary capacity to grain varies
from one soil to another. On some soils
the range of competition is reached with
rotations which include only a small pro-
portion of grass or legumes. On other
soils a greater proportion of forages can
be included before they become competi-
tive with other crops. In the case of
Wooster-Canfield soil, it is entirely pos-
sible that the full limit of forage as a
34 3. Economic Aspects of Forage Production
TOTAL EQUIVALENT PRODUCTION OF GRAIN AND FORAGE CROPS ON 100 ACRES OF WOOSTER-CANFIELD
SOILS, OHIO.* 1920-35.
Acres Total grain production Total hay production
Rotation t in
grain Lbs. Bus. ft Lbs. Tons
Continuous corn ................ 100 151,200 2700 0 0
C-SG-A ......................... 66.7 222,840 3979 180,800 90.4
C-SG-A-A-A ..................... 40.0 132,208 2361 405,600 102.3
Source: Handbook of Experiments in Agronomy, Ohio Agr. Exp. Sta. Sp. Circ. 53. The per acre yield
figures have been applied to 100 acres of land in arriving at the total production figures.
f C, SG and A refer to corn, small grain and alfalfa, respectively. The small grain in the three-year
rotation was wheat. The five-year rotation included oats.
ft Converted to bushels of corn equivalent on a weight basis. While feed grains average approximately
the same price per pound, wheat ordinarily sells at a greater price per pound than corn.
complementary crop to grain is met with
a C-C-SG-A, or similar, rotation.
Examination of rotation experiments
shows that rotations which include vari-
ous amounts of forage may affect grain
and feed production in the general man-
ner expressed by Figure 3.1. By the addi-
tion of some forage to the rotation both
total grain and total feed production is
increased. Adding more forage in the ro-
tation may increase total feed produc-
tion but decrease total grain production.
Finally, forage can be pushed to the ex-
tent that total feed production is de-
creased. All of these relationships may
be expressed on a single soil.
Price Relationships and Competitive
The relationship of grain and forage
prices, or the relative returns which can
be realized from grain-consuming as
compared to forage-consuming livestock,
becomes of first importance when for-
ages are competitive with grain crops.
As soon as an increase in the forage acre-
age in a rotation reduces total grain out-
put, an expansion of the grass-legume
acreage will increase gross returns only
if the ratio of forage prices or returns is
greater than the rate at which forage pro-
duction substitutes for grain production.
The arithmetic is simple. If a shift in an
acre of land and other resources from
corn to alfalfa and bromegrass, for ex-
ample, reduces total output of the former
by 50 bushels and increases output of
the latter by 2.5 tons (a forage-grain ratio
of 1 ton of forage to 20 bushels of corn),
the net price per ton realized from for-
age (either from sale on the market or
through livestock) must be more than
twenty times greater than the net price
from a bushel of corn.
Income actually will be at a maximum
when the forages and other crops are
combined on an individual farm in such
proportions that their substitution ratio
(1:20, above) is exactly equal to their
price ratio. The substitution ratio must,
of course, be figured from all the acres
in grain and forage under the cropping
systems being compared. The grain from
the acres shifted directly to forage is zero.
But the acre yield of the land remaining
in grain may be increased as a result of
the added soil nitrogen, improved soil
tilth, or erosion control that results from
the greater acreage of forages. This re-
fers to gross returns. The reason: relative
costs of labor, capital and other direct
expense items must also be considered
in figuring net returns. However, the
above ratio is a good rule-of-thumb pro-
cedure for determining the balance be-
tween forage and grain which will max-
imize net returns on any one farm. Thus,
the role of price relationships is entirely
Role for the Individual Farm
FIG. 3.4 "Problem of maximizing returns on most farms is one of getting the proper
combination of forages and other crops. On many of our soils . profits most often are
greatest if the forage acreage is expanded completely through the complementary range
-but not extended into the competitive range." In 1946, thirty-five cows of this herd,
seen here on orchardgrass-alfalfa-Ladino pasture in Pennsylvania, produced an average
of 522 pounds of butterfat with twice a day milking. U.S.D.A. photo.
different when forage is a competitive
rather than a complementary crop.
The problem of maximizing returns
on most farms is one of getting the
proper combination of forages and other
crops. On many of our soils there is both
a complementary and competitive range.
The rate of substitution of forages for
other crops is low on some soils. On such
soils, profits most often are greatest if the
forage acreage is expanded completely
through the complementary range-but
not extended into the competitive range.
This means a rotation which results in
maximum grain production for the farm
as a whole. This does not necessarily
mean a maximum in grain yield per
Where both relationships are present
and the forage-grain substitution rate is
high enough, maximum profits will be
forthcoming as forage acreage is in-
creased to the point where grain produc-
tion as well as grain acreage would be
decreased. This may mean in some cases
that the entire farm will be devoted to
forage. On soils where grain and forage
are competitive alone, some combination
of the two may be desirable. It is most
often here, however, that production of
forage to the exclusion of other crops
(and contrariwise) is most profitable.
In the small grain area of North Da-
kota, for example, grass as well as wheat
can be grown. But some farmers find it
more profitable over time to specialize
36 3. Economic Aspects of Forage Production
entirely in wheat. On the other hand,
production of both small grains and
grass is possible on many of the plateaus
of Wyoming. Yet many ranchers in this
area produce only grass for grazing pur-
poses. Whether one or the other ex-
treme will result in the greatest return
depends on (1) the rate at which these
crops substitute for each other (their
relative yields) and (2) the relationship
of prices or returns for one crop as com-
pared to the other.
OBSTACLES TO INCREASED FORAGE
Forages are complementary to other
crops only over time. Any increase in
production of grain resulting from the
nitrogen, organic matter or other con-
tributions of grasses and legumes to yield
must come from the grain crops which
follow the forages in rotation. Forages
are always competitive to other crops in
any single cropping season. A greater
acreage of grasses or legumes is possible
only as both the acreage and total pro-
duction of non-forages is cut within the
Herein lies a major reason why many
farmers produce fewer acreages of for-
ages than would be profitable over the
long period. As mentioned previously,
there are few if any instances where farm
profits can be at a maximum over time if
the acreage of forages is not extended en-
tirely through the range in which they
serve in a complementary capacity to
other crops. However, many farmers can
plan their cropping operations for only
a single year. Such farmers can view for-
ages only as competitive crops. This sit-
uation is especially true for (a) Tenants
who will be on a given farm for only one
year; (b) Tenants who always are faced
with the expectation that they may have
to move at the end of a year; and (c) Be-
ginning farmers, and others short on cap-
ital who plan largely in terms of the year
FIG. 3.5 "Herein lies a major reason why many
farmers produce fewer acres of forages than
would be profitable over the long period." (See
text.) U.S.D.A. photo.
ahead only, because of the uncertainty
of price and the future.
Improved leases, which protect both
the tenant and the landlord and allow
a longer view of the cropping system,
would encourage production of more
forages. Then, too, some landlords at-
tach such a high cash rent on pasture
and hay crops that the tenant cannot af-
ford to produce forage even where it is
a complementary crop. Here, both the
tenant and the landlord could make
greater returns were the forage acreage
increased at least to the point where the
forage becomes competitive. The land-
lord could actually have greater returns
were he to make no charge on the forage
acreage if this action resulted in the pro-
duction of grasses and legumes as com-
plementary crops. He would have more
grain from fewer acres and forage pro-
duction also would be greater. However,
the landlord is justified in charging rent
on forage which will equalize its return
with alternative crops when grass and
legumes alone are competitive, or if
their acreage is extended beyond the
complementary range into the competi-
There are other economic obstacles to
the production of more forages. One
stems from the money needed to finance
forage-consuming livestock. It should be
emphasized again, however, that utiliza-
tion is not a problem where forages are
complementary. Hence, capital limita-
tion is not really the obstacle here. Only
as forage and grain-or forage-consum-
ing and grain-consuming livestock-be-
come competitive does capital become a
Forage-consuming livestock generally
require a greater capital investment
than grain-consuming livestock. Usually
the time period required to return the
investment also is larger. Lack of knowl-
edge of the role and place of forages in
the cropping system is another important
deterrent, even in areas where more for-
ages should be grown.
Economics of Forage Utilization
Space does not permit a full discussion
of forage production economics. Utiliza-
tion economics has been but touched
Obstacles to Increased Forage 37
upon. Well-defined principles have been
established which set forth the major
considerations in the utilization of for-
ages through livestock. A statement of
these principles can be obtained through
agricultural production economists or
farm management specialists..
1. Why must each individual farmer decide
how much and what kind of forage he
should grow on his farm?
2. What factors should a farmer consider be-
fore he develops a forage program for
3. How does the principle of comparative
advantage explain why the amount of
forage produced varies so greatly be-
tween different localities?
4. From a national economic standpoint
what is the best combination of forages
and other crops for the United States?
5. List and discuss the reasons why forage
crops may serve in a complementary
relationship to grain crops.
6. During recent years there has been some
concern over methods of utilizing and
marketing the additional forages pro-
duced under soil conservation adjust-
ment and production control programs.
Under what conditions is this concern
7. Give a good "rule-of-thumb" for determin-
ing the balance between forage and
grain which may be expected to maxi-
mize net returns on any one farm.
8. List and discuss the major obstacles to in-
creased forage production.
GEORGE M. BROWNING
Iowa State College
Forages and Soil Conservation
When the white man came to this con-
tinent he found the land covered with
native grasses, legumes and timber. In
most parts there were few animals to con-
sume the forages. The Indians made lit-
tle use of the timber. As a result the
above-ground growth was returned to
the soil surface to decompose and be-
come incorporated with the soil. The
root systems of these plants also contrib-
uted to the accumulation of organic mat-
ter in the soil. The stems and leaves pro-
tected the soil surface from the beating
action of rain. The loose spongy condi-
tion of the soil was ideal for maximum
absorption of water. Soil erosion was not
a problem. But the white man needed
food for himself and feed for his live-
stock. The timber was needed for fuel
and shelter. He plowed the virgin prairie
and cleared the timber. Erosion took its
toll from intertilled crops such as corn,
tobacco, and cotton, grown without sup-
porting conservation measures. Modern
farming practices made possible the de-
velopment of a great agricultural and
industrial nation but destroyed nature's
blanket of protective vegetation. In gen-
GEORGE M. BROWNING is Associate Director of the Iowa
Agricultural Experiment Station. He had his under-
graduate training at the University of Missouri and re-
ceived the M.S. and Ph.D. degrees in Agronomy from
the Univeristy of West Virginia. From 1934-47 he
served with the Soil Conservation Service. In 1947 he
became a member of the staff of Iowa State College as
Research Professor of Soils. He has had a broad back-
ground in agronomy, especially in soil conservation and
eral, it was an exploitative system. We
could have done the same and even more
with conservation methods of farming.
But only within the last decade have the
farmer and the general public been
awakened to the real consequences of
misusing our farm land and our other
Today we are well started on a pro-
gram that will conserve and maintain
our soils. Bennett 1 has summarized the
over-all damages of erosion in the United
States. He estimates that erosion in the
United States already has ruined, or seri-
ously impoverished, approximately 282
million acres. From an additional 775
million acres erosion has stripped away
varying portions of the top soil. Consid-
ering only crop land, it is estimated that
erosion has ruined about 50 million
acres. An additional 50 million crop
acres are bordering on the same con-
dition. Nearly 100 million acres more,
still largely in cultivation, have been
severely damaged by the loss of one-
half to all the top soil. On at least an-
other 100 million acres of crop land ero-
sion is actively under way.
Measurements indicate that at least 3
million tons of solid materials are
washed out of our fields and pastures
each year. This soil contains some 92
1Bennett, H. H. Soil Conservation. New York:
McGraw-Hill Co. 1939.
Forages Reduce Runoff and Erosion
FIG. 4.1 "Wind erosion is estimated to be active . 200,000,000 acres . in the great
plains area . ." This view is not somewhere in the semi-arid West, but instead is a
roadside in the central Corn Belt after a spring blow. Iowa S.C.S. photo.
million tons of the five principal ele-
ments of plant food (phosphorus, potas-
sium, nitrogen, calcium, and magne-
Wind erosion is estimated to be ac-
tive in some degree over more than 200
million acres of farm and grazing land
in the Great Plains area from Texas to
North Dakota and in other parts of the
FORAGES REDUCE RUNOFF AND ERO-
The United States Department of Ag-
riculture in cooperation with various
state stations has reported the results of
studies on factors affecting erosion and
methods of control for important soil
and climatic areas throughout the
2 Bennett, H. H. and Chapline, W. R. Soil erosion
a national menace. U.S.D.A. Cir. 33. 1928.
3 U.S.D.A. Tech. Buls. 837, 859, 860, 873, 883, 888,
959 and 979.
A summary emphasizing the role of
forage in reducing runoff and erosion is
shown in Table 4.1. It is evident that
runoff and erosion vary widely for dif-
ferent soils and with the degree of slope.
The most outstanding differences, how-
ever, are between the runoff and erosion
from row crops and from sod crops. For
example, Muskingum silt loam in Ohio *
had a soil loss of 99.3 tons per acre from
corn and .02 from a bluegrass sod. From
row crops 40.3 per cent of the total rain-
fall was lost as runoff whereas only 4.8
per cent was lost from bluegrass sod. Ap-
proximately 7500 years would be re-
quired to erode one inch of soil under
bluegrass. In contrast, the loss of 99.3
tons per acre under continuous corn
would require 1.5 years to remove an
inch of soil by erosion.
The data in Table 4.1 are average an-
nual losses that include all types of rain.
But the real value of forages in control-
40 4. Forages and Soil Conservation
EFFECT OF ROW AND
SOD CROPS ON RUNOFF AND EROSION ON DIFFERENT SOILS
M marshall silt loam .............
Shelby loam ..................
Muskingum silt loam ..........
Stephenville fine sand loam.. ....
Cecil clay loam ...............
Kervin fine sandy loam.........
Kervin fine sandy loam.........
Nacogdoches sandy loam.....
Austin clay .................
Austin black clay..............
Fayette silt loam ..............
Soil loss T/A
crop 1 od
1 Row crop was continuous corn on Marshall, Shelby, Muskingum, Fayette, and Austin soils. Cotton
was grown on the Stephenville, Cecil, Kervin, and Nacogdoches soils. The sod crop was either Bluegrass
L 2 STALKS
8 & YOUNG STALKS
o WHEAT a YOUNG FALL
I RYE GROWTH
Co OF GRASS
Fic. 4.2 The effect of vegetative soil cover on
soil loss by erosion between corn harvest, Sep-
tember 29, and seedbed preparation time the fol-
lowing May 9. Missouri Soil Conservation Ex-
Speriment Farm, McCredie (Mo. Agr. Exp. Sta.
ling erosion is during rains of high in-
tensity. Most of these occur during May,
June, and July; the season when inter-
tilled crops leave the land vulnerable to
erosion. Sods give year-round protec-
tion. Soil and water losses from corn
and from sod for a single hard, driving
rain on two soils are shown in Table 4.2.
The erosion and runoff from corn was
of the same magnitude on the two soils.
The same is true for erosion under the
sod. But the percentage runoff under sod
varies widely between the soils; Marshall
2.3 per cent and Shelby 39.0 per cent.
Factors other than vegetative cover in-
fluence runoff. Part of the difference may
be explained by differences in the rate
and amount of rainfall. Even more im-
portant is the fact that the Marshall soil
is about seven times as permeable as the
Shelby under similar conditions. Even
with good vegetative cover, runoff occurs
when the rate of rainfall exceeds the
rate of its infiltration into the soil.
Anyone who has walked through a
field of grass, hay or corn after a rain
realizes that a considerable portion of
the precipitation clings to the leaves and
must later either pass down the stalks
of the plant to the soil or be lost by
evaporation. Horton's4 comprehensive
review of early investigations on rainfall
4 Horton, R. E. Rainfall interception. Monthly
Weather Review. 47:603-23. 1919.
FIG. 4.3 ". . investigations . show wide variation in rainfall intercepted by different
types of vegetation. . Forages, with their dense covering of leaves and stems, afford
maximum canopy interception of rainfall." S.C.S. photo.
42 4. Forages and Soil Conservation
RUNOFF AND EROSION FROM CORN AND SOD DURING A SINGLE INTENSE RAIN ON MARSHALL AND SHELBY
Shelby loam ..................
M marshall silt loam ..............
M o. .........
Soil loss T/A Runoff %
Corn Sod Corn Sod
46.0 .05 68.0 39.0
37.0 ......... 70.0 2.3
interception shows wide variation in the
percentage of rainfall intercepted by dif-
ferent types of vegetation. Haynes found
that 35.8 per cent of the 10.8 inches of
rain that fell between April 27 and Sep-
tember 15 was intercepted by alfalfa.5
Similar studies with corn for the period
May 27 to September 15 show that 15.5
per cent of the 7.1 inches of rain that fell
in 27 storms was intercepted by corn.
Oats intercepted 6.9 per cent of the 6.8
inches of rain that fell in 35 storms from
April 15 to June 30. His general con-
clusions are that interception of rainfall
increases directly with the increase of
vegetative cover. Forages with their
dense covering of leaves and stems af-
ford maximum canopy interception of
In 1874 Wollny observed that rye,
peas, and vetch protected the soil from
the raindrops to such an extent that the
non-capillary porosity of a shaded, humus
containing, calcareous sandy soil was
from 34 per cent to 53 per cent higher
than adjacent unprotected soil. He at-
tributed these differences to the protec-
tion of the soil from the dispersive ac-
tion of raindrops which destroyed the
5 Haynes, J. L. Ground rainfall under vegetative
canopy of crops. Jour. Amer. Soc. Agron. 32:176-84.
6 Wollny, E. Untersuchungen uher den Einfluss der
Streudecke auf den Erwarmung und Durchfeuchtung
des Bodens. Forchgn. Geb. Agrikult. Phys. 13:143-84.
surface structure. In unprotected soil the
percolating water which contained the
finer soil particles decreased the porosity.
Later work confirms the findings of
Although forages intercept an ap-
preciable amount of rainfall their great-
est benefit is in controlling erosion by
protecting the surface of the soil from
the beating action of raindrops.
Type and Amount of Vegetation Influ-
ence Runoff and Erosion
Numerous studies are available that
show the effect of protecting the soil sur-
face with vegetation or mulch in reduc-
ing runoff and erosion. Duley and Kel-
ley described and photographed the
formation of a compact surface layer
which greatly reduced the infiltration
rate and showed the effect of mulch in
preventing its formation.
The effect of forages on runoff and
erosion has been shown to be directly
related to the type and amount of
growth. Alderfer and Robinson 9 found
a rate of runoff in inches per hour of
7 Hendrickson, B. H. The choking of pore space in
the soil and its relation to runoff and erosion. Pro.
Amer. Geophysical Union, 15th Annual Meeting, Part 2.
8 Duley, F. L. and Kelley, L. L. Effect of soil
types, slope and surface condition on intake of water.
Neb. Agr. Exp. Sta. Res. Bul. 112. 1939.
9 Alderfer, R. B. and Robinson, R. I. Runoff from
pastures in relation to grazing intensity and soil erosion.
Jour. Amer. Soc. Agron. 39:948-58. 1947.
FIG. 4.4 The increased efforts being made to save and improve our soils center on the use
of hay and pasture crops. This use is supported by contour and strip planting, with well
planned and maintained grass waterways. The new cropping pattern for rolling and
erosive soils is well illustrated here by the area which surrounds one of the 12 "Great
American Churches" featured in 1950 by The Christian Century and Life magazines-
the Washington Prairie church in the Decorah, Iowa, area. Photo by William R. Wilson.
44 4. Forages and Soil Conservation
1.3 from a poor pasture sod heavily
grazed. On an adjacent site of poor sod,
not as heavily grazed but clipped, the
rate of runoff was about .8 inches per
hour. On a good sod heavily grazed the
rate of runoff was about .5 inches per
hour. On an excellent sod heavily ma-
nured, lightly grazed but clipped, less
than .1 inch per hour of rainfall was
lost as runoff. On the excellent sod no
runoff was observed until 30 minutes
after the rain started, whereas on the
other sites runoff started within a few
minutes. Heavy grazing not only reduced
vegetative cover but decreased the non-
capillary porosity and also decreased the
volume of the 0 to 1 inch layer of soil.
This is important. On most of our soils
the condition of the immediate surface
influences to a large extent the rate of
water penetration and, indirectly, the
rate of runoff and erosion. A direct re-
lationship was found between the rate
of runoff and compaction of the 0 to 1
inch layer of soil. This emphasizes the
importance of careful management of
pasture areas to prevent trampling and
puddling of the immediate surface soil
by livestock during periods when the
soil contains excessive moisture.
Duley and Kelley 10 found that grass-
land permanently in sod had an effect
similar to that of a heavy mulch in al-
lowing a high rate of intake of water.
When the grass and debris were re-
moved from the surface the rate of in-
take decreased rapidly.
Pasture management practices, includ-
ing the intensity of grazing and the use
of fertilizer practices such as a combina-
tion of fertilizer and lime to stimulate
the amount and density of cover grow-
ing, are important factors influencing
runoff and erosion. Gard et al." found a
10 Duley, F. L., and Kelley, L. L. Loc. cit.8
11 Gard, L. E., et al. Runoff from pasture land as
affected by the soil treatment and grazing management
and its relationship to mechanical and chemical com-
position and production. Jour. Amcr. Soc. Agron. 35:
soil loss of 3544 pounds per acre from
a treated and severely-grazed pasture.
This is in contrast to 339 pounds from
a treated and moderately grazed pasture.
The total percentage of rainfall loss as
runoff was 17.3 for the severely grazed
and 3.4 for the moderately grazed pas-
tures. These data are from four years of
study at the Dixon Springs Soil and
Water Conservation Experiment Station
in southern Illinois. The amount of run-
off from a rain of 4.02 inches on July 3
and 4, 1941, is an excellent example of
what may be expected during drought
periods. On the treated severely-grazed
plot, % of the rainfall, or 1.45 inches,
was lost as runoff. Only about %r,, or
0.17 inches, was lost from the treated
moderately-grazed area. These studies
also showed that the additional moisture
available for the moderately-grazed areas
was effective in stimulating growth for
greater forage production.
Browning and Sudds 12 found the rate
of water penetration in undisturbed or-
chard sods to be approximately five
times that from adjacent areas that had
been cultivated with little vegetation
present and subject to disturbance and
some compaction by spray rigs and farm
machinery. The unusually high infiltra-
tion rate of about five inches per hour
found on the sodded areas may be ex-
plained by the unusually loose and fri-
able condition that developed over a
period of years from vegetation that was
allowed to grow undisturbed and return
to the surface. Worm holes, insect bur-
rows, and channels left by decayed roots
also were factors in the development of
the unusually high infiltration rate.
Crop Residues Reduce Runoff and Erosion
In addition to their direct beneficial
effect in controlling runoff and erosion,
12 Browning, G. M. and Sudds, R. H. Some physical
and chemical properties of the principal orchard soils in
the eastern panhandle of West Virginia. W. Va. Agr.
Exp. Sta. Bul. 303. 1942.
Forages for Grass Waterways
FIG. 4.5 ". . forages also are effectively used as surface mulches to reduce runoff and
erosion." Shown are an erosive slope seeded without a mulch (left) and with a mulch
(right). Iowa S.C.S. photo.
forages also are effectively used as sur-
face mulches to reduce runoff and ero-
sion. The formation of a semipervious
layer at the immediate soil surface, often
only a few millimeters thick, can be
largely prevented with a cover of residue
or by a growing forage crop.
Duley and Kelley 1i found the average
infiltration rate for six widely different
soils to be .24 inches per hour on the
bare cultivated area. In contrast, adja-
cent areas covered with mulch had an
infiltration rate of .74 inches.
Borst and Woodburn concluded that
the beneficial effect of mulch on the sur-
face in eliminating the raindrop im-
pact, with its destructive effect on the
soil surface, rather than the reduction
of overland flow velocity was the major
contribution of the mulch in reducing
". Duley, F. L. and Kelley, L. L. Loc. cit.s
14 Borst, H. L., and Woodburn, Russell. The effect
of mulching and methods of cultivation on runoff and
erosion from Muskingum silt loam. Agr. Eng. 23:19-
FORAGES FOR GRASS WATERWAYS
A mat of grass and grass roots has no
equal in holding soil. Severe erosion and
gullies develop where natural drainage
ways are not maintained in sod. The
success of contouring, strip cropping,
and terracing depends on the safe dis-
posal of excess rainfall by the use of
grass waterways. Grass waterways may
well be considered the foundation of
such erosion control practices as effec-
tive rotation, strip cropping, contour
farming, terracing, gully control, and in-
telligent farming in general.
The plant cover protects the waterway
channel surface from the erosive action
of flowing water and hinders the move-
ment of soil particles from the channel
bed. This protective action varies with
the kind of vegetation and with the uni-
formity of cover. On individual kinds
of vegetation it varies according to the
age and condition of the plants, whether
the vegetation is cut short or left long,
and the season of the year. The type and
46 4. Forages and Soil Conservation
FIG. 4.6 "Severe erosion and gullies develop where natural drainage ways are not main-
tained in sod. The success of contouring, strip-cropping, and terracing depends upon the
safe disposal of excess rainfall by the use of grass waterways." (See p. 45.) Iowa S.C.S.
amount of vegetation in the waterway
have a marked effect on the capacity and
stability of these channels. Ree and Pal-
mer 15 have developed graphs for de-
termining the maximum conditions un-
der which different types of vegetation
are effective in resisting the erosive ac-
tion of runoff water in grass waterways.
A number of authors 16. 17, 18 outline
the steps in the preparation and seeding
of a grass waterway. They call attention
particularly to the size of the area to be
drained, the width of the waterway,
preparation of seedbed, manure and
fertilizer treatments, grass mixtures, seed-
ing rates, and maintenance.
15 Ree, W. 0., and Palmer, B. J. Flow of water in
channels protected by vegetative linings. U.S.D.A.
Tech. Bul. 967. 1949.
16 Tascher, W. R., and Clark, Marion W. Conserving
soil with natural grass waterways. Mo. Agr. Ext. Ser.
Cir. 438. 1942.
17 Leffler, Allan T. Contouring and grass waterways
made easy. Iowa Agr. Ext. Ser. 63 (Revised). 1945.
18 Zeasman, O. R. Grass waterways control and pre-
vent gullies. Wis. Ext. Ser. Cir. 320. 1941.
Strip cropping is the arrangement in
alternate strips of erosive intertilled
crops and small grain crops with con-
serving grasses and legumes, at right
angles to the natural slope of the land.
This has been shown to be effective in
reducing runoff and erosion. Close-
growing forage crops are the key to suc-
cessful strip cropping. The strip of
meadow serves as a buffer to slow down
and disperse the rate of runoff from the
intertilled area. The velocity of the silt-
laden water is reduced as it enters the
sod strip, causing the deposition of much
of the silt in the sod strip. It also pre-
vents concentration of water in low areas
which, if allowed to flow uncontrolled
from the field, would in time develop
gullies. Studies at the several soil erosion
experiment stations have shown that, on
the average, strip-cropped fields lose only
about one-fourth as much soil as com-
parable fields not strip cropped.19 The
different types of strip cropping, factors
to consider in developing a strip-crop-
ping plan and its effect on general farm
operation have been discussed by a num-
ber of workers.20, 21. 22
FORAGES AS COVER CROPS
The planting of cover crops is an im-
portant part of a good cropping system.
Such crops are planted in, or following,
erosive intertilled crops to help prevent
erosion and the leaching of plant nu-
trients. This is particularly true in those
sections where mild winters leave farm
land unprotected from the ravages of
erosion during the high-intensity rains
that frequently occur in those areas.
Studies by Copley et al. in North Caro-
lina 23 show the value of cover crops in
controlling runoff and erosion.
Soil and water losses from a desurfaced
Cecil Clay soil, cropped continuously to
cotton without a cover crop, were com-
pared with losses from a corn-cotton ro-
tation in which rye and vetch were
seeded as the cover crop in the corn, with
cowpeas as the cover crop in the cotton.
It has been found that approximately
the same amount of erosion occurs un-
der corn and cotton. In the cropping sys-
tem without a cover crop, 32.2 tons per
acre of soil and 11 per cent of the total
rainfall were lost. In the system with
cover crops, 18.2 tons per acre of soil
and 7.2 per cent of the rainfall were
19 Browning, G. M., Parish, C. L., and Glass, John.
A method for determining the use and limitations of
rotation and conservation practices in the control of
soil erosion in Iowa. Jour. Amer. Soc. Agron. 39:65-
20Tower, Harold E. and Gardner, Harry H. Strip
cropping for war production. U.S.D.A. Farmers Bul.
21 Peterson, J. B. and Clapp, L. E. Following the
contour. Iowa Agr. Exp. Sta. Ext. Ser. Bul. P53. 1943.
22 Thorfinnson, M. A. Contour strip cropping. Minn.
Agr. Ext. Ser. Ext. Fldr. 108. 1942.
23 Copley, T. L. et al. Investigations in erosion con-
trol and reclamation of eroded land at the Central
Piedmont Conservation Experiment Station, Statesville,
North Carolina. U.S.D.A. Tech. Bul. 873. 1944.
Forages in the Rotation 47
On a Dunmore silt loam soil in Vir-
ginia the use of a rye and vetch cover
crop materially reduced the amount of
water lost as percolate and the loss of
plant nutrients.24 On fallow land, 22.9
per cent of the rainfall was lost as per-
colate. When a rye and vetch cover crop
was used, only 16.2 per cent of the rain-
fall was lost as percolate, or a reduction
of 29 per cent as the result of the cover
crop. The percolate from the fallow
areas contained 37 per cent more mag-
nesium and calcium carbonate, 77 per
cent more potassium, and 126 per cent
more nitrate nitrogen than adjacent
areas on which cover crops were used.
The effects of cover on erosion after
corn harvest at the McCredie (Missouri)
Soil Conservation Experiment Farm are
shown in Figure 4.3.25
FORAGES IN THE ROTATION
If farmers could devote all of their
land to forest trees and properly man-
aged pastures there would be virtually
no erosion. But the average farm in this
country will not support a family if
the entire area is used for either timber
growing or for grazing. Food and fiber
requirements for our civilization neces-
sitate the production of intertilled crops.
This can be done and the productivity
of the land maintained providing the
right combination of depleting row crop
and conserving forages is supplemented
with supporting practices, such as con-
touring, strip cropping, and terraces,
adapted to the needs of the land.
Hays and Clark 20 developed a series
of rotations for Fayette soils in Wiscon-
sin that will minimize soil losses under
24 Hill, H. H. The effects of rye, lespedeza, and cow-
peas when used as cover crops and incorporated with
the soil on the leachings from Dunmore sub-loam soil.
Va. Agr. Exp. Sta. Tech. Bul. 83. 1943.
25 Smith, Dwight D., et al. Cropping systems for
soil conservation. Mo. Agr. Exp. Sta. Bul. 518. 1948.
20 Hays, Orville, and Clark, Noble. Cropping systems
that help control erosion. Wis. Agr. Exp. Sta. Bul.
48 4. Forages and Soil Conservation
FIG. 4.7 "Food and fiber requirements for our civilization necessitate the production of
intertilled crops . the productivity of the land can be maintained providing the right
combination of depleting row crops and conserving forages is supplemented with . .
contouring, strip cropping, and terraces adapted to the needs of the land." (See p. 47.)
It rained during the night. Part of the field was cultivated up and down the slope the
afternoon before. Iowa S.C.S. photo.
different land conditions. Similar recom-
mendations also have been developed for
Missouri 27 and Iowa.28
FORAGES AFFECT SOIL TEMPERATURE
Some of the highest rates of runoff
occur in early spring when the ground
is frozen. Erosion also can be serious at
this time unless the land is protected
with vegetation. Numerous investigators
have shown the effect of vegetation on
soil temperature. In addition to protect-
ing the surface from erosion a good
cover of forages may keep the soil from
freezing and thus allow greater percola-
tion of water. The effect of snow cover
and vegetation on Michigan soil tem-
perature at a three-inch depth is shown
in Table 4.3.29 Under Michigan condi-
tions, minimum January temperature
three inches below the surface for bare
27 Smith, Dwight D. et al. Loc. cit.25
28 Browning, G. M. et al. Investigations in erosion
control and the reclamation of eroded land at the
Missouri Valley Loess Conservation Experiment Sta-
tion, Clarinda, Iowa. U.S.D.A. Tech. Bul. 959. 1948.
29 Anonymous. Influences of vegetation and water-
shed treatment on runoff, erosion, and stream flow.
U.S.D.A. Misc. Pub. 397. 1940.
land was 7.50 F., for land covered with
snow 27.0 F., and for vegetative cover
with snow 32.0' F.
Bouyoucos o concludes from four
years study that in exceptionally cold
weather soil protected by vegetation and
a layer of snow may have 250 F. higher
temperature than bare soil at a three-
inch depth, and that the soil tempera-
ture fluctuates less under sod than where
the soil is bare.
Snow depth and frost penetration
studies were made during the winter of
1935-36 on the Big Creek watershed in
North Central Missouri (Table 4.4).31
Average frost penetration was 25 inches
on bare land, 12 inches with vegetative
cover not over 5 inches tall, and 5 inches
where the vegetative cover was over 5
inches tall. Average snow accumulation
was in reverse order. On bare land the
average snow depth ranged from 0-4
inches, whereas snow accumulated to
depths of from 10-24 inches where the
30 Bouyoucos, George J. Soil temperature. Mich. Agr.
Exp. Sta. Tech. Bul. 26. 1916.
31 Anonymous. Loc. cit.29
EFFECT OF SNOW COVER ON SOIL TEMPERATURE
Forages and Soil Tilth
AT 3-INCH DEPTH, JANUARY, 1915
M axim um .. .........................
Average maximum ...................
Average minimum .................
Soil temperature at depth of 3 inches
Bare Snow bare
( F.) ( F.)
DETERMINATIONS OF SNOW DEPTH AND FROST PENETRATION IN BIG CREEK
DIFFERENT COVER CONDITIONS
B arren ...............................................
Vegetative cover (not over 5 inches tall) ................ .
Vegetative cover (over 5 inches tall) ................... .
vegetative cover was over 5
It is apparent from these d
cover of vegetation and snow
portant effect on soil temper
absorption of water.
FORAGES AND SOIL TILTH
The main value of crop rot
the standpoint of erosion c
in the sod crop and the reduc
cultivation or soil tillage. It
pointed out by Bradfield 32 tha
and grass in particular, prod
cellent physical soil condition
this is essential in erosion coi
rotation alone will not contr
but it is fundamental to erosi
and a permanent agriculture.
seriously neglected and nov
given its place. The introduce
farms of this country of crol
32 Bradfield, Richard. Soil conserve
standpoint of soil physics. Jour. Amer
4 to 10
10 to 24
WATERSHED, Mo., UNDER
pen f absorption
25 Oto 50
12 50 to 90
5 90 to 100
nches tall. adequate for erosion control when sup-
ata that a plemented by supporting practices, fer-
has an im- tilizer and manure use, and good farm
rature and management will aid materially in
stabilizing crop production and in de-
veloping a sound and permanent agri-
ation from Crop rotations with adequate sod
control lies crops are the key to good soil tilth. Soils
tion in soil that contain a high percentage of large,
has been stable granules, as a result of sod crops
tt sod crop, in the rotation, are more resistant to the
uce an ex- erosive action of raindrops than soils
n and that depleted of organic matter through in-
itrol. Crop tensive cropping to intertill crops and
ol erosion, which contain few large, stable soil
ion control granules. Studies at erosion experiment
It has been stations show that, on the average, ero-
Smust be sion from corn following a sod crop is
ion on the only about one-half that from corn
p rotations which follows a clean-tilled crop in the
tion from the The effect on soil aggregation of crops
. Soc. Agron. s
_______ grown on Marshall silt loam for an
50 4. Forages and Soil Conservation
60 ----------60 _-
Corn Corn in Oats in Clover in Alfalfa Bluegrass
continuous corn-oats corn-oats corn-oats continuous continuous
clover clover clover
rotation rotation rotation
FIG. 4.8 "Crop rotations with adequate sod crops are the key to good soil tilth. Soils that
contain a high percentage of large stable granules as the result of sod crops in the rota-
tion are more resistant to the erosive action of raindrops than soils depleted of organic
matter through intensive cropping to intertilled crops . ." (See p. 49.) The effect of
different crops on the formation of soil aggregates on Marshall silt loam for the 11-year
eleven year period is shown in Figure
4.8.33 Clover turned down before corn
in the corn, oats, and clover rotation in-
creases the aggregates 27 per cent as com-
pared with continuous corn. This, in
33 Browning, G. M.. rt al. Loc. cit.28
addition to the smaller plant growth
available to protect the surface from the
beating action of raindrops when con-
tinuous corn is followed, explains the
38.3 ton per acre soil loss under con-
tinuous corn. And this is in contrast to
an 18.3 ton soil loss from corn that fol-
Plant Roots Form Channels
Fic. 4.9 The effect on soil loss and runoff of different crops, and different degrees and
lengths of slope, has been determined for different soils in different parts of the country.
The runoff water and soil from these plots are caught and accurate determinations of
loss are made. Iowa S.C.S. photo.
lows a clover crop in the rotation. In
all cases sod crops have almost doubled
the amount of stable aggregates present,
in contrast to the situation under con-
tinuous corn. The increased aggregation
that results from close-growing vegeta-
tion emphasizes the importance of in-
cluding sod crops regularly in the rota-
tion. This maintains a stable structure
that resists the action of tillage imple-
ments and the beating action of rain-
drops during the period when the land
is in intertilled crops.
Crops are known to differ materially
in the type and amount of residue they
leave in the soil.4' 35 The chemical com-
position and amount of residue has also
been shown to have an important in-
fluence on the amount and stability of
34 Woodruff, C. M. Variations in the state and
stability of aggregation as a result of different methods
of cropping. Soil Sci. Soc. Amer. 4:13-18. 1939.
35 Shively, S. E., and Weaver, J. E. Amount of un-
derground plant material in different grassland climates.
Neb. Cons. Bul. 21. 1939.
the aggregates."6 Materials which decom-
pose rapidly, such as legumes, bring
about aggregation in a relatively short
period of time-two or three weeks un-
der field conditions-but lose their ef-
fectiveness within two or three months.
On the other hand, the more carbona-
ceous materials require a longer period
of time to affect aggregation but have
a more lasting effect on soil structure.
PLANT ROOTS FORM CHANNELS
Channels left by decayed roots also
perform an important function in water
infiltration, storage of water, and soil
and water conservation. These roots
spread out through the soil in an amaz-
ingly complicated network, the dense-
ness of the roots depending on the type
and amount of the vegetation. This net-
6a Browning, G. M., and Milan, F. M. Effect of dif-
ferent types of organic material and lime on soil ag-
gregation. Soil Sci. 57:91-106. 1944.
work is particularly dense close to the
surface. Below two feet it is somewhat
less so. While the roots are alive their
growing tips force their way into minute
cracks in the soil granules, expand and
enlarge the opening, or break the gran-
ules into still finer particles. When the
roots die, as happens annually with one-
third or more of the roots, they soon
decay, leaving channels through which
water may penetrate into the soil. The
beneficial effects of roots of grass and of
such crop plants as alfalfa and sweet-
clover are much greater than most in-
tertilled crops. This is because of the
extent of their root system and the
size of the channels resulting from their
FORAGES AND SEDIMENTATION
It is recognized that silt accumulating
in natural and artificial reservoirs is
rapidly decreasing their storage capacity
and leaves the water unsuited for recrea-
The seriousness of the reservoir-silting
problem, particularly from an economic
and engineering standpoint, deserves
special consideration. There are more
than 8,400 dams and reservoirs in the
United States." A conservative estimate
would place the initial investment in
these at more than two billion dollars.
The usefulness of at least one-fifth of
them, representing probably three-
quarters of the total investment, is in
37 Anonymous. Loc. cit.29
FiG. 4.10 The camera lens and film of the Navy
Research Laboratory, much faster than the
human eye, catch and hold the image of a rain-
drop (top) as it is about to strike the surface of
a saturated soil. In sequence, the other photos
show the action a moment later as the drop
strikes the wet soil surface, dispersing surface
materials much as a small explosion would do.
The value and need of forage cover as a pre-
ventative of such action is coming increasingly
to be recognized. U.S.D.A. photos.
Forages and Sedimentation
water storage alone. When storage is
gone as a result of silting their value will
largely have disappeared.
Of 56 reservoirs examined by the Soil
Conservation Service in the southern
Piedmont region in 1934, 13 major reser-
voirs with dams averaging 29.8 feet in
height were found to have been com-
pletely filled by eroded material within
an average period of 29.4 years.
Numerous examples could be cited
showing the damage by siltation to reser-
voirs where the watershed was not ade-
quately protected by forages and other
conservation measures. The story of
Lake Decatur is typical.38 This story, in
a well-illustrated publication, shows how
the citizens of Decatur, Ill., more than
twenty-five years ago built a 2,800 acre
lake at a cost of two million dollars to
provide a water supply and recreational
facilities for the community. In twenty-
five years this lake lost more than a
fourth of its capacity by silting of pre-
cious topsoil from the fertile prairie soil
38 Walker, E. D. The story of a lake. Ill. Ext. Cir.
in the watershed. Damage to the reser-
voir as well as to the farmland of the
area would not have occurred if wise
land use and conservation measures had
been adopted on the entire watershed.
1. How many acres of land in the United
States have been damaged by erosion?
2. What is canopy interception, and how is
it related to soil conservation?
3. What is the relative effectiveness of
clean-tilled row crops and forages in
controlling runoff and erosion?
4. What forages, if any, are used for cover
crops, and how do they influence soil
5. Under what conditions is strip cropping
recommended? How effective is it as a
conservation measure? What deter-
mines its effectiveness?
6. Under what conditions would forages be
used as surface mulches, and what ef-
fect do mulches have on runoff and
7. What is soil tilth? What relation do crop
rotations have to it?
8. Discuss crop rotations in relation to soil
9. How does the type and amount of vegeta-
tive cover affect soil conservation?
10. What effect does vegetative cover have
on soil temperature, and how does this
relate to soil conservation?
R. L. LOVVORN
Bureau of Plant Industry, U.S.D.A.
W. W. WOODHOUSE, JR.
North Carolina State College
Soil Fertility and the Nutritive Value
The term soil fertility in its usual
sense refers to the broad combination
of factors affecting fertility. Such factors
as exchange capacity, per cent base
saturation, aggregation, type of colloid,
presence of toxic elements, organic mat-
ter content and level of essential ele-
ments are all components of soil fertility.
It is not possible, with present informa-
tion, to evaluate all of these factors as
they are related to the nutritive value of
forages. However, the nutrient level
factor has been studied rather exten-
sively, is fundamental to the growth of
nutritive forage, and probably is the one
that can be most readily improved in
farm practice. Consequently, this discus-
sion is confined largely to the nutrient
R. L. LOVVORN, head of the Division of Weed In-
vestigations of the Bureau of Plant Industry, Beltsville,
Maryland, was a professor of agronomy at North Caro-
lina State College until January, 1950. He is a native
of Alabama and took his undergraduate work at the
Alabama Polytechnic Institute. He was granted the
M.S. degree by the University of Missouri and the
Ph.D. degree by the University of Wisconsin. He en-
gaged in forage crop research for about 15 years, with
emphasis upon adaptation, management, and fertility
W. W. WOODHOUSE, JR. is associate professor of
agronomy at North Carolina State College. He is a
native of North Carolina, earned his B.S. and M.S.
degrees from North Carolina State College and the
Ph.D. from Cornell University. The past fifteen years
he has been engaged in soil fertility and management
research problems with pastures and forage crops.
The authors acknowledge the assistance of Robert P.
Unchurch in the preparation of this material.
level aspects of soil fertility as they re-
late to the nutritive value of forage.
Nutritive value must be considered
here in a restricted sense, i.e., chemical
composition of plants in terms of the
known requirements of animals for
plant constituents. The biological analy-
sis of plants has not progressed far
enough at this stage to provide much
data bearing directly upon the soil fer-
tility problem. However, the approxi-
mate minimum requirements and de-
sired amounts of protein, total digestible
nutrients, and minerals are known for
the various classes of livestock. These are
presented in Table 5.4 as a basis for
evaluating nutritive value. An increase
in any constituent beyond the level con-
sidered adequate in the animal diet has
not been proven to have nutritive value.
There is, however, some evidence to
indicate that nutrient levels may affect
the nutritive value of plants in a man-
ner not readily detected by chemical
methods now in use. An article from the
U. S. Plant, Soil and Nutrition Labora-
tory states: 1
1 Factors affecting the nutritive value of foods.
U.S.D.A. Misc. Pub. 664. 1948.
Factors Other Than Soil Fertility
AVERAGE PERCENTAGE OF NITROGEN, PHOSPHORUS, AND CALCIUM IN ALFALFA AND SMOOTH BROME IN
1948 AND 1949 WHEN GROWN AT 2 OR 3 FERTILITY LEVELS, ON 2 OR 3 SOIL TYPES, AND HARVESTED AT AN
INTERMEDIATE STAGE OF GROWTH *
M adison ...............................
M arshfield .................. ........ .
H ancock ...............................
M adison ... .. ................ ...
Marshfield ............... ..........
Miami silt loam
Spencer silt loam
Plainfield silt loam
Miami silt loam
Spencer silt loam
Differences for alfalfa are in most cases significant, but the comparisons for smooth brome do not differ
Fertilization of forages with superphos-
phate and lime produced crops of superior
nutritive value as measured by growth of
lambs and rabbits fed the forages, even
though the superiority of such fertilized for-
ages was not reflected-in their chemical com-
Burger 2 studied the effect of soil type
and fertilization on the total nitrogen,
calcium, and phosphorus content of
forages and of their nutritional value
when fed to guinea pigs. Alfalfa and
Ladino clover fertilized with 180 pounds
of P20, and 180 pounds of K,O per acre
produced significantly greater gains in
weight when fed to guinea pigs than
comparable unfertilized forage. Fertiliza-
tion of smooth brome failed to improve
its nutritional value. The effect that soil
differences may have on the composi-
tion of legumes and grasses is suggested
by Burger's data in Table 5.1.
It seems evident from this and other
work 3 that in some cases, at least, in-
creased soil fertility may enhance the
nutritive value of forage which is al-
ready adequate by present nutritional
standards. No generally accepted ex-
2 Burger, A. W. Chemical composition and biological
value of forages grown under different levels of mineral
nutrition and harvested at various stages of growth.
Unpublished data. Doctoral thesis. Library, Univ. of
3 McLean, E. O. et at. Biological assays of some soil
types under treatments. Soil Science Society of Amer.
proceedings. 8:282-86. 1944.
planation of the mechanisms involved in
this improvement in "quality" of forage
has been advanced. Certainly no method
other than that of feeding trial has as yet
been devised to determine relative value.
Consequently, it seems advisable to re-
strict our consideration largely to those
constituents known to have nutritional
significance, and to be readily determi-
nable by chemical methods.
Most experiments comparing nutrient
levels have depended upon the applica-
tion of nutrients to establish the dif-
ferent levels. This is to be expected,
since this usually is the most convenient
and positive way to assure valid com-
parisons. Consequently, most of the data
on which we have drawn are from ex-
periments of this nature.
FACTORS OTHER THAN SOIL FERTILITY
It should be kept in mind that in ad-
dition to soil fertility there are many
other factors that are of importance in
determining plant composition and nu-
STAGE OF MATURITY. As plants approach
maturity they almost always de-
crease in percentage composition of
protein and minerals and increase in
fiber, thereby becoming less desirable
56 5. Soil Fertility and the Nutritive Value of Forages
from a nutritive standpoint. Fertility
level may affect the nutritive value of
plants by influencing maturity. In fact,
it is quite likely that many of the dif-
ferences in nutritive value credited to
fertilizer application, actually are due to
differences in maturity. These changes
may be either up or down, since nutrient
level and balance may either speed up or
slow down maturity, depending upon
the circumstances. Deficiency of phos-
phorus frequently delays maturity, as
does an excess of nitrogen. An adequate,
balanced, soil fertility level usually
hastens maturity of plants having a de-
terminate type of growth. On the other
hand, such plants as Ladino clover prob-
ably can be kept in the vegetative stage
of growth much longer under high fer-
tility conditions than where a deficiency
of one or more nutrients exists.
CLIMATE. Climate or weather variations
may have a direct as well as indirect
effect upon plant composition. Dan-
iel and Harper 4 have shown that phos-
phorus content is increased and calcium
decreased under wet conditions, with
the reverse true during dry seasons.
DIRECT INFLUENCE OF SOIL FERTILITY
Soil fertility controls, to a large de-
gree, the nutritive value of the forages
generally grown in the humid regions.
This comes about through its control
over the type of plants that can be grown
with greatest success on a given soil. Le-
gumes such as alfalfa and Ladino clover
thrive only on soils well supplied (nat-
urally or artificially) with phosphorus,
calcium, magnesium, and potassium. In
the absence of adequate supplies of these
elements legumes having lower require-
ments must be substituted. These plants
4 Daniel, H. A., and Harper, H. L. The relation be-
tween effective rainfall and the total Ca and P in
alfalfa and prairie hay. Jour. Amer. Soc. Agron. 27:
almost invariably are lower in nutritive
value, or production, or both. Further-
more, continued production of these
without replenishment of the mineral
supply will sooner or later bring about
further reduction in both yield and
quality. Similarly, grasses such as smooth
brome, timothy, and orchardgrass grow
well only in the presence of a large ni-
trogen supply. At lower nitrogen levels
various high fiber-low protein grasses
may thrive but the nutritive value of
the forage suffers.
Soil fertility usually is overshadowed
by moisture as a controlling factor in
arid regions. However, the importance
of soil fertility in this respect through-
out the humid regions can scarcely be
Nutrient level in the soil usually,
though not always, affects the nutrient
level in the individual species.
Macy,5 in 1936, classified nutrient
levels in plants into the following three
1. Minimum percentage-yield in-
creased as the supply of the ele-
ment in question is increased, but
the nutrient concentration in the
plant remains static.
2. Poverty adjustment-both yield and
nutrient concentration increase as
the nutrient supply increases.
3. Luxury consumption-nutrient con-
centration increases but yield re-
mains static as nutrient supply in-
Actually, there is a fourth stage at
which increasing nutrient supply fails
to increase either nutrient concentration
or yield. Sometimes excessive applica-
tion may directly or indirectly depress
5 Macy, Paul. The quantitative mineral nutrient re-
quirement of plants. Plant Phys. 11:749-64. 1936.
Direct Effect of Major Nutrients
yield. As long as the nutrient supply
remains below the poverty adjustment,
or above the luxury consumption levels,
no change in nutrient composition can
It is difficult to find data from field
experiments that appear to fit this classi-
fication. Some of the reasons for this are
fairly obvious from an examination of
Figure 5.1. Most experiments have not
covered the entire range, and where they
have approached it the points deter-
mined have been entirely too far apart
to reveal the exact shape of the curves.
The data on which Figure 5.1 is based
would appear to fit this classification
rather well, if a sufficient number of
points were available near the lower
ends of both curves. At any rate, it helps
to explain the frequent failure of fer-
tilization to affect the chemical com-
position of the plant.
Conditions within the soil itself also
may prevent nutrient level changes in
the plant. Such nutrients as phosphorus
under some conditions may become so
rapidly and securely fixed as to have
little effect upon the nutrient supply.
Iron may be so firmly fixed by some
soils that this element must be applied
to the foilage if the plant is to get an
Nutrient balance also may play an im-
portant part in this process. For ex-
ample, Bear 8c Prince 6 have shown that
if theCa c Mg ratio in alfalfa exceeds
3.5, growth is limited. Yet below this
ratio normal growth is attained, with
these three cations being, to a consider-
able extent, interchangeable. Thus, an
increase in nutrient supply may be made
6 Bear, F. E., and Prince, A. L. Cation equivalent
constancy in alfalfa. Jour. Amer. Soc. Agron. 37:217
POUNDS P20 APPLIED PER ACRE
FIG. 5.1 The effect of phosphorus level on yield
and phosphorus content of Ladino clover. Un-
published data, N. C. Agr. Exp. Sta.
ineffective through an unbalance of nu-
trients. In a similar manner an increase
in the level of one nutrient may reduce
the uptake of another. The uptake of
several of the so-called "minor" ele-
ments, particularly cobalt, manganese,
zinc, and iron may be sharply curtailed
by excessive liming. Manganese defi-
ciency is thought to occur in most cases
only under conditions of overliming.
Thus, while an increase in the lime
level of a soil frequently leaves the pro-
tein, calcium and phosphorus contents
of the resulting forages unchanged, defi-
ciencies in some of the micronutrients
may be developed or accentuated.
DIRECT EFFECT OF MAJOR NUTRIENTS
Kobe lespedeza and carpetgrass are ex-
amples of plants that can exist under
quite low fertility levels. Data in Table
5.2 serve to illustrate the effect of in-
creasing nutrient level upon plant com-
position under low fertility conditions.
Comparison of these analyses with the
standards in Tables 5.4 and 5.5 reveals
that in several cases the phosphorus and
protein contents of the herbage were
well below standard. Even under the
best treatment shown some values re-
mained on the low side. Protein in car-
petgrass remains unchanged, perhaps in-
dicating that this may be the maximum
58 5. Soil Fertility and the Nutritive Value of Forages
EFFECT OF FERTILIZATION ON THE COMPOSITION OF LESPEDEZA AND CARPETGRASS
Treatment and crop
Kobe lespedeza *-Leon fine sand
No treatment ................................... ..
81 lbs. P205 + 37 lbs. K0. ....... ................
81 lbs. P206 + 1500 lbs. limestone .......................
Kobe Lespedeza f-Cecil gr. L.
No treatm ent .................................. .... .
60 lbs. P 20 ............ .................... .
4,000 lbs. lim estone .............................. ... .
60 lbs. P205 + 4,000 lbs. limestone ................... .
Carpetgrass f-Bladen fine sand
N o treatm ent ..................................
721bs. N ...................... .. ........... ..
NPKL-72 N, 144 PsOs, 100 KO0, 2,000 limestone. ........
Blaser, R. E., et al. Deficiency symptoms and chemical composition of lespedeza as related to fertili-
zation. Jour. Amer. Soc. Agron. 34:222-28. 1942.
t Stitt, R. E. The response of lespedeza to lime and fertilizer. Jour. Amer. Soc. Agron. 31:520-27. 1939.
1 Blaser, R. E., and Stokes, W. E. Effect of fertilizer on growth and composition of carpet and other
grasses. Fla. Agr. Exp. Sta. Tech. Bul. 390. 1943.
for this species under the condition of
The data in Table 5.2 represent
rather extreme conditions. However, the
literature, as shown by Beeson,7 contains
numerous analyses of forages that ap-
proach the danger zone from the nutri-
tional point of view. (See "Animal Re-
quirements" p. 62.)
In contrast to the situation described
above it is unusual to find the phos-
phorus, calcium, or protein content of
the plants having high nutrient require-
ments low enough to make their forage
value doubtful. This is due to the simple
fact that soil conditions for their normal
growth will insure automatically a rea-
sonable level of nutrient content. An
example of the operation of this factor
may be seen in Figure 5.1. This Ladino
clover was grown on a soil extremely
low in phosphorus
(trace by .002 NH2SO4).
Even without treatment the phosphorus
7 Beeson, K. C. The mineral composition of crops
with particular reference to the soils in which they are
grown. U.S.D.A. Misc. Pub. 369. 1941.
content was fairly adequate for the more
tolerant classes of animals. With the ap-
plication of sufficient phosphorus to per-
mit normal growth the content of this
element was readily adjusted upward,
bringing it well within the satisfactory
nutritional zone. In other words, if the
more nutritious forages grow well on a
given soil, there is likely to be little
doubt as to their nutritional quality.
The group of mineral elements re-
quired by animals in relatively minute
quantities, including manganese, copper,
zinc, cobalt, iodine, and iron, are often
called the "minor," trace, or micronu-
trient elements. Deficiencies of these oc-
cur in certain sods in various parts of the
world. In most cases their concentration
in plant tissue is quite low but may be
increased by applying them to the soil.
As has been previously mentioned, the
availability of several of them is ma-
terially influenced by liming. In some
cases it is necessary to by-pass the soil
and apply the element directly to the
Flexibility of Plant Composition
foliage in order to increase the content
in the plant. The addition of several of
these to the salt mixtures supplied to
animals is frequently resorted to in order
to assure an adequate supply.
It is true that plants growing on fer-
tile soils are likely to contain adequate
amounts of these micronutrient ele-
ments. However, the effects of soil fer-
tility levels on the plant content of some
of them have been studied only in a
limited way. Consequently, general rules
of behavior cannot be outlined at pres-
The effect of the soil upon the vita-
min content of plants has been of in-
terest to investigators for some time. It
is known that the vitamin content of
forages is quite variable. However, at
least at present, the vitamin content of
plants seems to depend upon such en-
vironmental factors as light and tem-
perature and upon heredity, rather than
the soil. There is no proof at present of
a direct effect of soil fertility level upon
vitamin content. Of course, since species,
varieties, and strains may differ in their
content of vitamins, soil fertility may
have an important indirect effect
through a change in the proportion of
different plants produced on a given
In brief, the inherent characteristics
of the plant plus the changes taking
place in processing and storage are the
important factors in determining the
FLEXIBILITY OF PLANT COMPOSITION
Some constituents of plants seem to be
more readily influenced by fertility level
than others. This may be due to limita-
tions imposed by the physiology of the
plants themselves, or in some cases by
their environment. At any rate, present
knowledge in this field suggests that
certain useful generalizations can be
NITROGEN. The total nitrogen (or crude
protein) content of forages is rather
readily influenced by fertility level.
The addition of nitrogen to nitrogen de-
ficient soils almost always results in an
appreciable increase in the level of this
constituent in grasses. Such treatment
may or may not affect the nitrogen con-
tent of legumes. The application of lime
to lime deficient soils, on the other hand,
usually improves the protein content of
the legumes growing on such soils. This
is generally believed to be due to a more
favorable environment for the nitrogen-
PHOSPHORUS. The phosphorus content
for a given forage frequently ap-
pears to be almost unchangeable.
As previously mentioned, this often may
be due to the position on the phosphorus
response curve of the particular soil un-
der consideration. On phosphorus de-
ficient soils, however, -the phosphorus
content of the plant usually is quite
readily increased by an increase in the
phosphorus level of the soil. The range
of values usually encountered in alfalfa,
for example, is from about 0.15 to 0.3
per cent phosphorus, with normal plants
seldom falling below 0.20 per cent.
Plants containing more than 0.40 per
cent are rare. Liming may, at times,
either increase or decrease the phos-
phorus content of the herbage.
CALCIUM. A given plant species tends to
maintain a relatively stable content
of calcium, although changes in the
calcium content of certain legumes
through an increase in calcium level of
the soil are fairly common. Alfalfa
usually varies between a low of slightly
60 5. Soil Fertility and the Nutritive Value of Forages
less than 1 per cent to as high as 2.5
per cent calcium, with more of the varia-
tion due to seasonal conditions than to
soil treatment. The general level of cal-
cium in the grasses is much lower-less
than 1 per cent-and less variable. The
addition of relatively large quantities of
calcium to the soil, and even fairly large
increases in exchangeable soil calcium,
may leave the calcium content of grasses
and many of the more tolerant legumes
The calcium content of some legumes
is quite readily affected by the potassium
supply. The calcium content of alfalfa
and Ladino clover often is appreciably
depressed by large increases in the
POTASSIUM. The content of some forage
plants is fairly flexible and readily
changed by applications of potas-
sium. This element probably is the prize
example of "luxury consumption." A
level of around 1.2 per cent potassium in
alfalfa or Ladino plants represents a soil
nutrient supply ample for normal
growth, yet liberal applications of this
element will frequently increase the con-
tent in these plants to above 3 per cent
and occasionally above 4 per cent. The
requirement of animals for this element
is quite low and since excessive con-
centration of it in the plant may repress
the uptake of other cations, such as cal-
cium, this luxury consumption of potas-
sium may be undesirable, and from more
than one viewpoint. In the case of potas-
sium, grasses frequently contain higher
concentrations than that of the legumes
growing in association with them, and
appear to be equally variable.
INDIRECT EFFECT OF SOIL FERTILITY
The direct effect of soil fertility upon
the nutritive value of forages can be
quite marked and at times may be vital.
On the other hand, the indirect effects
are in evidence on every farm and con-
sequently may have more over-all sig-
nificance from the nutritional point of
view than the direct effect. Soil fertility
exerts an influence, indirectly, upon nu-
tritive value in several different ways.
Only two of the major ones will be
Soil fertility is a significant factor in
determining the botanical composition
of sods. Legumes, generally speaking, are
benefited by high levels of phosphorus,
potassium, calcium, and magnesium,
while grasses respond principally to the
nitrogen level. Any shift between nu-
trient levels may change the proportion
of grass and legume.
In pasture renovation, soils depleted
of their fertility are limed and fertilized
with phosphate and potash-treatments
conducive to legume development. As a
result, the weeds are reduced and le-
gumes increased. The grass-legume stand
therefore is brought into balance with
the available nitrogen. As the nitrogen
level is increased through the legume
the grass increases at the expense of the
legume, until we have a type of vegeta-
tion in which grass predominates. As the
available nitrogen is exhausted by the
grass the shift in plant population is
back toward the legume.8
The rapidity with which the shift oc-
curs is governed by the various environ-
mental factors, the competitive ability
of the individual species, management,
and the presence of diseases. Any en-
vironmental factor, whether it be plant
nutrients, moisture, light or tempera-
ture, that is more favorable to one group
of plants than another will aid in their
8 Woodhouse, W. W., and Lovvorn, R. L. Establish-
ing and improving permanent pastures in North Caro-
lina. N. C. Agr. Exp. Sta. Bul. 338. 1945.
Indirect Effect of Soil Fertility 61
LIMESTONE LIMESTONE PHOS-
NO PHOSPHATE PHATE POTASH
TREATMENT POTASH AND NITROGEN
FIG. 5.2 "Soil fertility is a significant factor in
determining the botanical composition of sod. In
pasture renovation, soils . are limed and fer-
tilized . weeds are reduced and legumes in-
creased." (See p. 60.) N. C. Agr. Exp. Sta. Bul.
development. Interactions of species
with plant nutrients often are observed.
Such species as Bermudagrass are much
more aggressive than Dallisgrass and
tend therefore to be less tolerant of a
legume companion. Lespedeza, being
less aggressive than white clover, is much
less capable of maintaining itself as the
legume companion with grasses than is
white clover (Fig. 5.3). This relationship
may alter pasture fertilization recom-
mendations. If lespedeza is to maintain
itself in association with grasses the soil
nitrogen level must be reasonably low.
A vigorous legume such as Ladino
clover, on the other hand, may become
dominant at the expense of the grass as-
sociate unless the nitrogen level is high.
Since legumes are usually higher in
protein and minerals than are grasses
(Table 5.3) any change which causes a
shift in the grass-legume balance will in-
fluence the chemical composition of the
forage. Furthermore, the more desirable
A COMPARISON OF THE CHEMICAL COMPOSITION OF
KENTUCKY BLUEGRASS WITH THAT OF WHITE
CLOVER WHEN GROWN UNDER SIMILAR CONDI-
TIONS (DATA FROM VINALL AND WILKINS)
Crude Protein....... 17.37 29.98
Calcium ............. .56 1.41
Phosphorus. .......... .49 .55
plants usually are better able to utilize
higher fertility levels than are the weedy
plants. As a result, increases in fertility
levels usually will produce a sod contain-
ing a higher proportion of the more nu-
tritious plants. It is through such in-
creases in the proportions of nutritious
plants that increased soil fertility most
often improves the nutritional value of
Production of Energy
Another way in which fertility level
contributes to the nutrition of animals
may be seen in the yields of carpetgrass,
for which analyses were given in Table
5.2. The acre yields 10 of this grass were
No Treatment ....... 136 lbs. of dry grass
Nitrogen ............ 408 "
NPKL ........... .. 1058
This is evidence, perhaps extreme, in
support of the belief of many that more
animals are starved for lack of energy
than as a result of mineral deficiencies
in their diet. Obviously, from the data
presented above, most of our domesti-
cated animals would be hard pressed to
maintain an existence on the untreated
soil. Furthermore, it seems safe to as-
sume that the nearly eightfold increase
in yield resulting from liming and fer-
9 Vinall, H. N., and Wilkins, H. L. The effect of
fertilizer application on the composition of pasture
grasses. Jour. Amer. Soc. Agron. 28:562-569. 1936.
10 Woodhouse, W. W. and Lovvorn, R. L. Loc. cit.8
62 5. Soil Fertility and the Nutritive Value of Forages
ESTIMATED AVERAGE MINERAL REQUIREMENTS OF GROWING ANIMALS, EXPRESSED AS PERCENTAGES OF
THE DRY RATION UNLESS OTHERWISE SPECIFIED (FROM MITCHELL)
Mineral Pig Chicken Calf Lamb Horse
Calcium ..................... 0.40 0.66 0.27 0.18 0.23
Phosphorus ................... 0.30 0.40 0.19 0.15 0.21
M agnesium ................ .. ....... 0.04 0.07 ..........
Potassium ................... 0.15 0.17 ...... ..........
M anganese ................ ........... ... 0.004 ................
Cobalt ................................ ............ 0.07 t 0.07 t ..........
C opper ...................... 8 t ........... 3 t 5 t .....
Iodine. .................................. 1 0.09 t 0.11 ..........
These indicated requirements will not take care of the very young animal.
t Parts per million of the dry ration.
tilization would result in better fed ani-
mals on this land. This might well be
true even though the chemical composi-
tion of the forage remained the same.
According to the classification pro-
posed by Macy n the major effect of an
increase in nutrient level from a point
on the lower half of the response curve
is that of increasing plant growth. This
conclusion seems to be substantiated by
the data available. Although, as has been
shown, soil fertility is a major factor
in determining the nutritive value of
forage, it is even more important in
determining the number of animals that
may be supported on the land. In other
words, fertile soils usually produce more
nutritious forage, but what is more im-
portant, they also produce more forage.
It is not the purpose here to delve
deeply into the science of animal nutri-
tion. It is necessary, however, to provide
the reader with certain standards, in
order to give meaning to the chemical
data presented. It is for this purpose that
the following standards, accompanied by
a brief explanation, are presented in
11 Macy, Paul. Loc. cit.5
12 Mitchell, H. H. The mineral requirements of farm
animals. Journal of Animal Science. 6:365-77. 1947.
Mitchell x1 states:
The functions of the mineral nutrients are
varied and numerous, but they may be con-
veniently classified under four headings:
(1) They contribute to the structure of the
body. Calcium, magnesium and phosphorus
are important constituents of bone. This is a
(2) They aid in maintaining the status quo
of tissues already formed against the erosion
of the life processes. This is the maintenance
(3) They participate in the functional ac-
tivities of the body, such as muscular activity.
This may or may not lead to an increased
requirement in the food supply. Reproduc-
tion, lactation and egg production will in-
crease mineral requirements in proportion to
the mineral content of the products formed.
(4) As integral parts of the enzyme systems
in the tissues, they aid materially in metabo-
lizing the organic nutrients making up the
bulk of farm rations.
From this classification it may be seen
that the requirements of animals vary
considerably, depending upon their age
and activity. Young growing animals
have relatively high requirements as do
those in lactation or egg production.
Maintenance of mature animals on the
other hand requires a relatively low con-
centration of minerals.
It should be pointed out that the
above figures are stated as requirements;
recommended allowances would be
It should be emphasized that the wide
ranges shown are necessary in order to
Animal Requirements 63
RECOMMENDED ALLOWANCES OF CRUDE PRO-
TEIN, EXPRESSED AS PERCENTAGES OF THE DRY
Poultry Swine Sheep t
Dairy t Beef t
15-20 15-17 10-16 7.5-12 9-18
Calculated from recommended nutrient al-
lowances for domestic animals-National Re-
search Council Nos. 1, 2, 4 and 5, with assump-
tions as noted.
t Digestibility of crude protein by sheep and
beef cattle is assumed to be 50 per cent.
SCalculated from: Sherwood, F. W., et al.
Effect of fertilization on the nitrogen, calcium, and
phosphorus contents of pasture herbage. Jour.
Amer. Soc. Agron. 39:841-58. 1947. Digestibility of
crude protein assumed to be 50 per cent.
take care of extremes. The highest al-
lowances are for pregnant females, young
growing animals and animals in high
Available data indicate that the di-
gestibility of crude protein in roughages
varies roughly between 30 and 70 per
cent. The crude protein of most of the
better quality roughages are credited
with a digestibility of 50 per cent or
Numerous animal diseases are attrib-
uted to deficiencies of minerals in the
diet. Only a few will be mentioned here.
Cobalt deficiency is responsible for a
FIG. 5.3 "Numerous animal diseases are attributed to deficiencies of minerals in the diet.
Cobalt deficiency is responsible for a number of troubles. . Lack of copper also in-
spires an imposing list . phosphorus deficiency causes lameness, loss of appetite, and
. probably is one of the most common of deficiency diseases." N. C. Agr. Exp. Sta.
64 5. Soil Fertility and the Nutritive Value of Forages
FIG. 5.4 "Sick" because the hay eaten was from
soil low in calcium and phosphorus. Hay from
soil treated for deficiencies gave healthy sheep.
Mo. Agr. Exp. Sta. photo.
number of troubles including the "Bush-
sickness" of New Zealand, "pining" in
the United Kingdom, and "salt sick" in
Florida. Lack of copper also inspires an
imposing list, including Enzootic Ataxia
in Australia, Swayback, and Scouring
disease of the United Kingdom. Phos-
phorus deficiency causes lameness, loss of
appetite and a craving for bones and
probably is one of the most common of
deficiency diseases. Diseases of various
kinds are attributed to deficiencies of,
or imbalances between, those mentioned
minerals above plus iodine, sodium, po-
tassium, chlorine and excesses of sele-
nium, manganese, arsenic, and nitrate.
Russell 1 has published an excellent re-
view on this subject and the reader is
referred to this publication for a com-
plete listing and descriptions.
1. Why is it difficult to determine the effect
of soil fertility on the chemical compo-
sition and nutritive value of forages?
2. Under what conditions might an increase
in soil fertility level be expected to in-
crease the nutritive value of forages?
3. Is the direct or indirect influence of soil
fertility on nutritive value of forages
the more important in your state or re-
4. Explain the meaning of nutrient balance
and why it is important in plant
5. In the use of nutrients by plants what is
meant by luxury consumption? Is it
desirable or undesirable and why?
6. Why are trace element deficiencies found
only in certain areas?
7. Why is the carotene content of forages
8. Why does a shift in the nutrient level of
a soil tend to change the proportion of
grasses and legumes grown in associa-
9. Why are some constituents of plants
more readily influenced by soil fertility
10. Why is a knowledge of animal require-
ments necessary to discuss the relation-
ship of soil fertility to the nutritive
value of forages?
14 Russell, F. C. Minerals in pasture deficiencies
and excesses in relation to animal health. Aberdeen,
Scotland: Imp. Bur. of An. Nut. Tech. Pub. 15. 1944.
DARREL S. METCALFE
Iowa State College
An attempt is made here to bring to-
gether certain data of interest to the
student of forages which are not avail-
able in other chapters. These will serve
as a ready reference.
DARREL S. METCALFE, associate professor of agronomy
at Iowa State College, was born in Wisconsin. He at-
tended River Falls State Teachers College and had
secondary school teaching experience before becoming
a student at the University of Wisconsin. He later
was granted the M.S. degree by Kansas State College
and the Ph.D. by Iowa State College. On the Iowa
State College staff since 1946, he teaches courses in
forage crops and forage seed production and conducts
research on grass and legume seed production prob-
The trend is toward an increased use
of forage crop seed. The acreage seeded
to forage crops is being stepped up.
There is an increased appreciation of
forages to prevent erosion and maintain
SEED PRODUCTION AREAS
Table 6.1 gives the leading states in
the production of the more important
grass and legume seed. The acreages and
STATES LEADING (FIRST 10 OR LESS) IN THE PRODUCTION OF SEED OF SOME OF THE MORE IMPORTANT
LEGUMES AND GRASSES, ARRANGED IN ORDER OF ACREAGE HARVESTED FOR THE 10-YEAR PERIOD, 1938-
1947 (IN SOME CASES, 5-YEAR PERIOD, 1943-1947); ALso U. S. TOTAL *
Bus. yield per acre
Av. 1948 )
1 1 i I
Ind.. . . ......
Iowa. ........... ..
W is. . .. ......
M ich.. ...
M o. .. . .......
Idaho. . . . ...
Pa . .. .. .......
U. S.. .............
N eb.. ...... .....
O kla... ...........
M ich ................
66 6. Forage Statistics
Acreage harvested Bus. yield per acre
193847 1948 1950 1938 1948 1950
1938 47 1938 47
N D ................
U S ................
N C .. ..............
K y...... ... .. ......
K an.............. .
S C .................
V a ........ ..........
N eb .................
N D ................
S D ....... .......
M o. ................
C olo ................
U.S. .............. .
O re. .. ......... .
Ill. . .. . . ........
Ind. .. .............
U S ................
Acreage harvested Lbs. yield per acre
State A A
S19447 1948 1950 19447 1948 1950
Tenn................ 40,000 34,000 48,000 225 220 100
Ala................. 8,080 10,000 28,000 282 255 150
Ga .................. 6,200 13,000 29,000 214 210 145
Seed Production Areas
K y... ..............
U S ................
U S ................
F la .. . . . .........
A la .. ... ............
S C ................
In d .. ..............
P a .. . . .. .. .. .. .. .
U S ................
U S ... .. ...........
SUDAN GRASS ||
N eb .................
U S.. .............
Lbs. yield per acre
61,880 62,100 111,600 233 227 131
10,440 11,000 4,000 47 65 50
3,940 3,800 4,700 71 85 75
3,920 5,800 4,400 267 275 200
2,880 3,100 2,700 177 180 60
2,180 1,600 1,500 90 100 100
1,860 3,000 7,000 119 57 65
S 4,500 4,600 $ 85 40
25,620 32,800 28,900 107 119 82
6,600 13,000 35,000 72 90 120
5,020 5,500 20,000 64 100 150
600 1,500 4,400 75 135 85
12,220 20,000 59,400 68 98 127
13,040 23,000 145,000 938 700 970
5,840 10,000 16,000 800 580 650
5,840 5,000 25,000 1,065 650 970
1,000 22,000 1,000 1,000
24,720 39,000 208,000 934 669 948
189,700 50,000 142,000 176 167 167
65,300 21,000 144,000 137 117 180
51,300 24,000 83,000 145 122 131
36,300 10,000 35,000 122 126 119
30,650 9,000 14,000 168 158 153
14,500 4,600 10,000 151 113 126
13,000 5,000 25,000 131 126 135
5,680 5,100 7,800 124 126 131
366 401 480
~ I I
68 6. Forage Statistics
S D .. .. ..........
N D ................
U S ................
N eb .................
K an ... ........ ....
S D ... .. ...........
N D ................
U S ................
Lbs. yield per acre
* Field seed reports. Div. of Field Crop Stat., Bur. of Ag. Econ., U.S.D.A.
t Short-time average.
SNot estimated prior to 1947.
Not estimated prior to 1948.
S10-year average, 1938-47.
acre yields of forage seed crops vary
greatly from year to year. However, data
for a number of years indicate those
areas leading in the seed production of
any specific crop. See also Figure 6.1.
EXPORTS AND IMPORTS
Exports and imports of forage crop
seed fluctuate greatly from year to year
depending on the available supply in
this country and in other countries. Ex-
ports and imports also are restricted by
trade barriers, tariffs, staining regula-
tions, and other seed control legislation.
Table 6.2 gives the imports and ex-
ports of forage seed for the 6-year period,
1945 to 1950, inclusive. The movement
of seed during the period of years im-
mediately preceding was not representa-
tive of normal trade,
by war influences.
affected as it was
FUTURE SEED NEEDS
A survey on predicted forage seed use,
made by the Production and Marketing
Administration in 1949, indicates an in-
creasing need for forage seed-an in-
crease in use by 1955 of 140 per cent
above 1950 and by 1960 of 160 per cent.
Of particular interest is the indicated
demand for the different types of forage.
In some cases no increase in use is antici-
pated while in others the expected use
is 10 and 20 times as much in 1960 as in
1950. See Table 6.3.
SEED OF RANGE AND PASTURE SPECIES
The need for more information on the
seed production of a number of grasses
jc~m a n
.3\ u <
\ fe "!
70 6. Forage Statistics
UNITED STATES EXPORTS AND IMPORTS OF FORAGE CROPS SEED IN THOUSANDS
OF POUNDS, 1945-1950,
Red ............... .
Alsike .............. .
Kentucky bluegrass .....
Other grass seed..... ...
Other field seed.........
R ed .................
A like ................
White and ladino......
Other .............. .
H airy ...............
Kentucky bluegrass .....
M eadow............ .
Tall oatgrass ............
Other grass seed.........
. . . . .
Compiled from reports of the Bureau of Agricultural Economics, Division of Statistical and Histori-
cal Research, U.S.D.A.
If any, included with "other grass and field seed."
If any, included with "other clover seed."
If any, included with Hairy vetch.
# If any, included with "other grass seed."
and legumes, which are recognized for
their value in range and pasture seedings,
led to a special survey covering the years
1949 and 1950. Included were 20 native
and introduced grasses and 4 legumes.
For 16 of these, production estimates had
not previously been available. The more
complete coverage for the remaining 8
justifies the revision of previous seed pro-
duction estimates. The purpose of this
survey was ". . to aid in balancing seed
production with the anticipated require-
ments of a permanent grassland agricul-
tural program. .. ." (See Table 6.4.)
Tables 6.5 and 6.6 give the number of
seed per pound, weight per bushel, and
Future Seed Needs 71
ESTIMATED THOUSANDS OF POUNDS OF SEED OF THE MORE IMPORTANT LEGUMES AND GRASSES THAT FARM-
ERS IN THE UNITED STATES MIGHT BE EXPECTED TO USE FOR SEEDING IN THE YEARS 1950, 1955, AND 1960. f
Beggarweed (Tall Tick Clover)
Black Medic ...............
Bur Clover-California ......
Bur Clover-Spotted ........
Button Clover ..............
Clover-Field Hop .. ......
Clover-Large Hop ........
Clover-Small Hop ........
Clover-Sub ........... .
Crotalaria-Showy ....... .
Lespedeza-Tenn. 76 ......
Peas-Field ........... .
Peas-Rough ........... .
Sesbania or Hemp Sesbania.
Velvet Bean .......
A lfalfa .......... ........
Clover-Ladino ......... .
Clover-White .......... .
Indigo-Hairy .......... .
Ryegrass-Italian or common.
Sudangrass. ........ ......
Region of adaptation or use
S. Y/ of Cotton Belt
Corn and Soybean Belt
S. 4 of Cotton Belt
S. U. S. & Pacific N.W.
S. Y/ Cotton Belt & S. Pacific Coast
Cotton Belt & S. Pacific Coast
S.E. & S.W. U. S.
S. & S.E. U. S. & Pacific N.W.
S. U. S. & Pacific Coast
S.E. U. S. & S.W. Irrigated
S.-S.E. U. S. & Pacific Coast
S.E. U. S. & Pacific Coast
S. Y2 U. S. & S. Pacific states
S.E. U. S.
S.E. U. S.
S.E. U. S.
Corn Belt & N. Cotton Belt
S. 1 of S.E. Cotton Belt
S. Y of S.E. Cotton Belt
General U. S.
S.E. U. S. & Pacific N.W.
Tex., Pacific N.W., Cotton & Corn
S. & S.W. U. S.
S. Y of Cotton Belt
Pacific Coast & S.E. U. S.
General U. S.
S. Pacific Coast & S.E. U. S.
Pacific Coast & S.E. U. S.
Pacific Coast & S.E. U. S.
General U. S.
General U. S.
General U. S.
General U. S.
General U. S.
N. U. S.
General U. S.
General U. S.
Coastal Flains Fla. to Tex.
S.E. U. S.
Ore., Wash., Calif. & S.E. Coast
N.E. states, Corn Belt & Pacific Coast
Ore., Wash., Calif., N. Y.
Pacific Coast-E. U. S.
General U. S.
72 6. Forage Statistics
Bluestem-Little ......... .
Bluestem-Sand .......... .
Buffalograss.-. ... ..........
Region of adaptation or use
N. Great Plains & Pacific N.W.
N. M Humid U. S.
E. Great Plains
E. Great Plains
E. Great Plains
S. Great Plains
Rocky Mountain & Pacific Coast
N.W. Y4 U. S.
N. / U. S.
N. Vi Humid U. S. & N. Pacific Coasl
S. Coastal Plains
Pacific N.W.-Lake states
N.E. M U. S.; Irrigated W.
Pacific N.W., S. Corn Belt
S. Great Plains
E. Great Plains
Central & S. Great Plains
S. Great Plains
N. Great Plains
Central, N. & W. states
S. Y of N. Humid U. S.
S. Coastal Plains
S. & S.W. U. S.
N.E. 1V U. S.
S. Great Plains
Pacific & S. Corn Belt
Central & S. Great Plains
Corn Belt, N.E. U. S.
N. Great Plains, Intermountain
N. and Central Great Plains-Inter-
mountain, Pacific N.W. & S.W.
Intermountain, Pacific N.W.
N. & Central Great Plains
N. Great Plains
N. Great Plains
Species with less than 100,000 pounds estimate omitted.
f These figures are based on the assumption that reasonably priced seed would be available and that
educational programs would be continued on the same pattern as 1949. This report was submitted to the
Agricultural Conservation Programs Branch by State P.M.A. Committees in 1949.
seeding rate in pounds per acre of some
of the more important grasses and le-
gumes. Since seed vary greatly in size
from lot to lot, depending on seasonal
and other environmental conditions,
these figures vary greatly.
CHANGES IN HAY PRODUCTION
Although the acreage of all tame hay
harvested in the United States as a whole
has undergone only moderate changes,
there have been some significant changes
in different parts of the country, both
in the kinds of tame hays produced and
in their quantity and quality.1 In 1920,
nearly sixty per cent of the tame hay
acreage was clover and timothy, includ-
ing stands of timothy, of clover, and of
mixtures of the two. Now clover and
timothy represent but a third of the
1 Changes in hay production in war and peace.
B.A.E. U.S.D.A. F.M. 47. 1945.
Measurement of Hay in Stack and Mow
ESTIMATED ACREAGE, YIELD AND PRODUCTION OF SEED OF 24 GRASSES AND LEGUMES VALUABLE
IN RANGE AND PASTURE SEEDINGS *
Kind Acres Yield in lbs. Production in lbs.
of harvested per acre 000 omitted
seed 1949 1950 1949 1950 1949 1950
Bluestem mixtures .......... ........ 18,200 34,300 53 68 970 2,340
Bluestem, King Ranch ................ 2,800 10,300 79 58 220 600
Bromegrass, Mountain ................ 850 1,900 341 379 290 720
Bromegrass, Smooth .................. 74,200 143,950 158 204 11,720 29,310
Buffalograss . ................... 3,930 2,320 35 35 138 81
Dallisgrass ....................... 6,000 8,300 90 67 540 560
Fescue, Chewings ..................... 12,500 13,000 202 278 2,520 3,610
Fescue, Red. ........ ............... 7,300 7,150 126 264 920 1,887
Fescue, Tall (Alta and Ky. 31 or
Suiter's grass) ...................... 42,410 71,730 207 248 8,788 17,806
Grama, Blue.... ................... 2,200 11,000 25 50 55 550
Grama, Side-Oats .................... 4,100 7,900 38 47 155 370
Lovegrass, Sand ................... ... 6,100 12,500 58 55 355 690
Lovegrass, Weeping ................... 1,200 700 100 94 120 66
Wheatgrass, Crested .................. 51,300 67,300 107 87 5,480 5,860
Wheatgrass, Intermediate .............. 1,740 2,630 103 129 179 340
Wheatgrass, Slender .................. 160 600 275 267 44 160
Wheatgrass, Tall ..................... 220 600 132 155 29 93
Wheatgrass, Western .................. 750 1,250 80 92 60 115
W ildrye, Canada..................... 2,800 500 63 96 176 48
W ildrye, Russian..................... 200 200 150 150 30 30
Clover, Crimson...................... 90,950 119,110 209 132 18,970 15,688
Clover, Ladino .................. .... 26,820 59,840 140 127 3,765 7,623
Clover, White ........................ 29,900 40,100 77 80 2,290 3,210
Trefoil, Birdsfoot ..................... 3,600 7,000 30 67 108 470
Special Range and Pasture Grass Seed Report. Bureau of Plant Industry, U.S.D.A. February, 1951.
tame hay, while legumes, reported sep-
arately, total about 50 per cent of all
hay. Wild hay has declined from 16 to
11 per cent. See Table 6.7.
Measurement of Hay in Stack and Mow
The volume of a rectangular stack is
equal to its length (L) multiplied by
the area of the cross section.2 The length
can easily be measured but the exact
area of the cross section is not so readily
determined. A formula is necessary to
compute the area from the two measure-
ments width (W) and over (0). Width is
the width of the stack at the ground;
length is the average length of the stack;
and over is the distance from the ground
on one side over the stack to the ground
on the other side. Stacks are divided
into three types, based on shape. Factors
2 Hosterman, W. H. Measuring hay in stacks.
U.S.D.A. Leaflet 72. 1931.
have been developed for use in determin-
ing the volume of each type of stack.
(1) Low, round-topped stacks (Great
(0.52 x O) (0.44 x W) x WL = Volume
(2) High, round-topped stacks (Inter-
(0.52 x O) (0.46 x W) x WL = Volume
(3) Square, flat-topped stacks (Sacra.-
mento & San Joaquin valleys of
(0.56 x O) (0.55 x W) x WL = Volume
Another method of determining the
volumes of oblong or rectangular stacks
is the F-O-W-L method. In this method
a factor F is used which takes into ac-
count the varying shapes of stacks, and
it varies from 0.25 to 0.37. The factor F
is multiplied by the overthrow (0), by
the width (W), and this product by the
length (L). With ricks of different shapes
74 6. Forage Statistics
SEED PER POUND AND SEEDING RATE OF SOME OF THE MORE IMPORTANT GRASSES, ARRANGED ALPHA-
BETICALLY BY SCIENTIFIC NAME
Scientific and common name No. seed Seeding rate,
per lb. Ibs. per acre
Agropyron cristatum, crested wheatgrass ............................
Agropyron dasystachyum, thickspike wheatgrass ..................... .
Agropyron desertorum, desert wheatgrass ............................
Agropyron elongatum, tall wheatgrass............................ ..
Agropyron inerme, beardless wheatgrass ............................
Agropyron intermedium, intermediate wheatgrass.....................
A gropyron m ichnoi ..............................................
Agropyron repens, quackgrass (w) .................... .. .........
Agropyron riparium, streambank wheatgrass .........................
Agropyron semicostatum, drooping wheatgrass ........................
Agropyron sibiricum, Siberian wheatgrass ...........................
Agropyron smithii, western wheatgrass .............................
Agropyron spicatum, bluebunch wheatgrass .........................
Agropyron subsecundum, bearded wheatgrass .........................
Agropyron trachycaulum, slender wheatgrass .........................
Agropyron trichophorum, stiffhair wheatgrass ........................
Agrostis alba, redtop ............................................
Agrostis canina, velvet bent ......................................
Agrostis palustris, creeping bent ..................................
Agrostis tenuis, colonial bent .....................................
Alopecurus pratensis, meadow foxtail ...............................
Ammophila arenaria, European beachgrass ..........................
Ammophila breviligulata, American beachgrass ................... ...
Andropogonfurcatus, big bluestem .................................
Andropogon hallii, sand bluestem ..................................
Andropogon intermedius var. caucasius, Caucasian bluestem .............
Andropogon ischaemum, yellow bluestem ............................
Andropogon scoparius, little bluestem ...............................
Andropogon virginicus, broomsedge ................................
Anthoxanthum odoratum, sweet vernalgrass .........................
Aristida longiseta, red three-awn ..................................
Arrhenatherum elatius, tall oatgrass ...............................
Astrebla pectinata, Mitchellgrass ..................................
A vena sativa, oats ..............................................
Axonopus affinis, carpetgrass ......................................
Bouteloua curtipendula, side-oats grama .............................
Bouteloua eriopoda, black grama .................................
Boutelouafiliformis, slender grama ................................
Bouteloua gracilis, blue gram a ..................................
Bouteloua hirsuta, hairy grama .................................
Bouteloua rothrockii, Rothrock grama ............................ .
Briza maxima, big quakinggrass (o) ............................
Bromus arvensis, field brom e .....................................
Bromus catharticus, rescuegrass .. ..............................
Bromus erectus, m eadow brom e............................... ...
Bromus inermis, sm ooth brom e ...................................
Bromus marginatus, mountain brome ..............................
Bromus secalinus, chess (w)...................................
Bromus tectorum, cheatgrass brome (w) ...........................
Buchloe dactyloides, buffalograss. ..................................
Data on the seed and culture of common grasses and legumes. U.S.D.A. Yearbook. Grass. 743-58. 1948.
* = in burs or unhulled. w = weedy in character. o = ornamentals.
Scientific and common name
Calamagrostis canadensis, bluejoint reedgrass ...........
Calamovilfa gigantea, big sandreed ........... .....
Calamovilfa longifolia, prairie sandreed ...............
Chloris distichophylla, weeping chloris .................
Cynodon dactylon, Bermudagrass.. ............
Cynosurus cristatus, crested dogtail ............................
Dactylis glomerata, orchardgrass ................... .
Digitaria decumbens, pangolagrass ...................... .....
Digitaria sanguinalis, hairy crabgrass (w)...... ..................
Distichlis stricta, inland saltgrass .............. ...... ..
Echinochloa crusgalli var. frumentacea, Japanese millet.. .. ......
Elymus canadensis, Canada wildrye ............................. .
Elymus condensatus, giant wildrye. ... ....................
Elymus giganteus, Siberian wildrye ..................... ...
Elymus glaucus, blue wildrye .....................................
Elymusjunceus, Russian wildrye ............................. .
Elymus triticoides, creeping wildrye .......................
Elymus virginicus, Virginia wildrye ...............
Eragrostis chloromelas, Boer lovegrass. .
Eragrostis curvula, weeping lovegrass............. . .
Eragrostis lehmanniana, Lehmann lovegrass ................. ......
Eragrostis trichodes, sand lovegrass ................... ...... ....
Eremochloa ophiuroides, centipedegrass......................... .
Euchlaena mexicana, teosinte ... ...............
Festuca elatior, meadow fescue ... ...............................
Festuca arundinacea, tall fescue .........
Festuca idahoensis, Idaho fescue ... .
Festuca myuros, rattail fescue (w) ......
Festuca octoflora, sixweeks fescue (w) . .
Festuca ovina, sheep fescue .............
Festuca rubra, red fescue ....................................
Festuca rubra, var. commutata, Chewings fescue. ...................
Hilaria belangeri, curly-mesquite ...................... ........
Hilariajamesii, galleta .. ... ... . . . . . .
H ilaria mutica, tobosa ........................... . . ...
Hilaria rigida, big galleta .. . .. . . . . . . .
Holcus lanatus, velvetgrass ................................ ...
Hordeum bulbosum, bulbous barley ...............................
Hordeumjubatum, foxtail barley (w) ..............................
Hordeum nodosum, meadow barley (w) ..........................
Hordeum vulgare, barley ......
Hyparrhenia hirta ..........
Hyparrhenia rufa, jaragua .....
Imperata cylindrica, cogongrass.
Koeleria cristata, junegrass ....
Lolium multiflorum, Italian ryegrass ..............................
Lolium perenne, perennial ryegrass .............................. .
Muhlenbergia porteri, bush muhly ................ ..............
Oryzopsis hymenoides, Indian ricegrass.......... .................
Oryzopsis miliacea, smilograss ............ ........... ............
Panicum antidotale, blue panic ...................................
Panicum maximum, Guinea-grass ..................................
Panicum miliaceum, proso................... ....................
Panicum obtusum, vine-mesquite. ... .. .. .. . ........
Panicum purpurascens, Paragrass ...................................
. . . .
.. .. . .....
lbs. per acre
. . . . . . . I . . . . . .
. . . . . . . . . . I . . . . . .
. . . . . . . . . . I . . . . . . .
* = in burs or unhulled.
w = weedy in character.
o = ornamentals.
76 6. Forage Statistics
Scientific and common name
Panicum repens, torpedograss ....................................
Panicum virgatum, switchgrass .................................
Paspalum dilatatum, Dallisgrass ................................
Paspalum laeve, field paspalum (w) ..............................
Paspalum malacophyllum, ribbed paspalum .........................
Paspalum notatum, Bahiagrass ................................. .
Paspalum plicatulum, brownseed paspalum ................... .....
Paspalum stramineum, sand paspalum .............................
Paspalum urvillei, V aseygrass...................................
Pennisetum glaucum, pearlmillet ................................
Pennisetum purpureum, Napiergrass ..............................
Phalaris arundinacea, reed canarygrass ...........................
Phalaris canariensis, canarygrass ...............................
Phalaris caroliniana, Carolina canarygrass ........................
Phalaris tuberosa var. stenoptera, Hardinggrass ....................
Phleum pratense, timothy... ...... ........... ..........
Poa ampla, big bluegrass .....................................
Poa annua, annual bluegrass.......................... .........
Poa arachnifera, Texas bluegrass ...............................
Poa bulbosa, bulbous bluegrass ................................
Poa compressa, Canada bluegrass ...............................
Poa nevadensis, Nevada bluegrass ..............................
Poa pratensis, Kentucky bluegrass ..............................
Poa secunda, Sandberg bluegrass...............................
Poa trivalis, rough bluegrass...................................
Puccinellia nuttaliana, Nuttall alkali-grass ........................
Redfieldia flexuosa, blowoutgrass ................................
Saccharum officinarum, sugarcane................................
Secale cereale, rye ............................................
Setaria italica, foxtail millet ...................................
Setaria macrostachya, plains bristlegrass ..........................
Sorghastrum nutans, yellow Indiangrass ................. ........
Sorghum halepense, Johnsongrass ...............................
Sorghum vulgare, sorghum ......................................
Sorghum vulgare var. sudanense, Sudangrass .........................
Sporobolus airoides, alkali sacaton..............................
Sporobolus asper, tall dropseed ................................ .
Sporobolus asper var. hookeri, meadow dropseed ....................
Sporobolus cryptandrus, sand dropseed............................
Sporobolus giganteus, giant dropseed.............................
Sporobolus wrightii, sacaton .....................................
Stenotaphrum secundatum, St. Augustinegrass ......................
Stipa comata, needle-and-thread ...............................
Stipa pulchra, California needlegrass........................... .
Stipa viridula, green needlegrass .......................... ..... .
Trichachne californica, Arizona cottontop .......................
Tricholaena repens, Natalgrass .................................
Tridensflavus, purpletop ............................... ......
Tripsacum dactyloides, eastern gramagrass ........................
Trisetum flavescens, yellow trisetum ................................
Triticum aestivum, w heat .......................................
Uniola latifolia, broadleaf uniola (o) ............................ .
Uniola paniculata, sea-oats (o) ...................................
Zea mays, corn .......... ................................
Zizania aquatica, annual wildrice ................................
Zoysia japonica, Japanese lawngrass ..............................
Zoysia matrella, M anilagrass.................................. .
Zoysia tenuifolia, M ascarenegrass .............................. .
* = in burs or unhulled. w weedy in character. o = ornamentals.
lbs. per acre
w weedy in character.
o = ornamentals.
* = in burs or unhulled.
Seed Information 77
SEED PER POUND, WEIGHT PER BUSHEL AND RATE OF SEEDING OF SOME OF THE MORE IMPORTANT LEGUMES,
ARRANGED ALPHABETICALLY BY SCIENTIFIC NAME
Scientific and common name No. seed per rate, lbs.
per lb. bushel, per acre
Alysicarpus vaginalis, alyceclover ....................... 300,000 60 10-12
Anthyllis vulneraria, kidneyvetch ....................... 180,000 60 15-20
Arachis hypogaea, peanut .............................. 1,000 22 40 t
Astragalus cicer, cicer milkvetch ........................ 130,000 60 20-25
Astragalusfalcatus, sicklepod milkvetch ................. 130,000 60 20-25
Astragalus rubyi, Ruby milkvetch ...................... 240,000 60 10-12
Cajanus indicus, pigeonpea. ............................ 8,000 60 8-10 t
Cassia tora, sickle senna .............................. 22,000 60 40-45
Chamaecristafasciculata, showy partridge-pea ............. 64,000 57 20-30
Cicer arietinum, garbanzo ............................. 1,000 54 20-30 t
Coronilla varia, varia crownvetch ...................... 110,000 55 15-20
Crotalaria incana, chak crotalaria ....................... 85,000 60 15-18
Crotalaria intermedia, slenderleaf crotalaria ............... 100,000 60 10-15
Crotalaria juncea, sunn crotalaria ....................... 15,000 60 35-40
Crotalaria lanceolata, lance crotalaria .................... 170,000 60 7-10
Crotalaria mucronata, striped crotalaria .................. 75,000 60 10-15
Crotalaria spectabilis, showy crotalaria ................... 30,000 60 25-30
Cyamopsis tetragonoloba, guar .......................... 20,000 60 30-40
Dalea alopecuroides, foxtail dalea ....................... 150,000 60 10-15
Desmodium purpureum, tall tickclover .................... 200,000 60 8-10
Dolichos lablab, hyacinth-bean ......................... 1,400 60 20-25 f
Glottidium vesicarium, bagpod .......................... .1,500 56 20-30 t
Glycine soja, soybean ................................. 5,000 60 45-60
Hedysarum coronarium, sulla ............................ 100,000 60 20-25
Indigofera hirsuta, hairy indigo ......................... 200,000 55 8-10
Lathyrus cicer, flatpod peavine ......................... 8,000 60 60-70
Lathyrus hirsutus, roughpea ............................ 15,000 55 50-60
Lathyrus sativus, grasspea ............................. 5,000 60 70-80
Lathyrus sylvestris, flatpea ............................. 8,000 60 60-70
Lathyrus tingitanus, Tangier-pea ........................ 5,000 60 70-80
Lens esculenta, lentil .................................. 9,000 60 12-15 t
Lespedeza bicolor, bicolor lespedeza ..................... 82,000 60 1-2 t
Lespedeza cuneata, sericea lespedeza ..................... 350,000 60 10-15
Lespedeza cyrtobotrya, bush lespedeza .................... 65,000 60 1-2 f
Lespedeza hedysaroides, rush lespedeza ................ 300,000 60 10-15
Lespedeza latissima, decumbent lespedeza ................ 300,000 60 10-15
Lespedeza stipulacea, Korean lespedeza .................. 225,000 40 10-15 *
Lespedeza striata, common lespedeza var. Kobe.......... 190,000 25 10-15 *
Lespedeza striata, common lespedeza var. Tennessee #76. 310,000 25 8-10 *
Lotus corniculatus, broadleaf birdsfoot trefoil ............. 375,000 60 5-8
Lotus tenuis, narrowleaf birdsfoot trefoil .......... .... 400,000 60 5-8
Lotus uliginosus, big trefoil ............................ 1,000,000 60 3-5
Lupinus albus, white lupine ........................... 1,500 60 100-120
Lupinus angustifolius, blue lupine ....................... 2,500 60 70-100
Lupinus luteus, yellow lupine .......................... 4,000 60 50-80
Lupinus subcarnosus, bluebonnet ........................ 14,000 60 40-45
Medicago arabica, spotted bur-clover .................... 210,000 10 100 *
Medicagofalcata, yellow alfalfa ........................ 208,000 60 15-20
Medicago hispida, California bur-clover ................. 140,000 60 20-25
Medicago lupulina, black medic ........................ 300,000 60 10-15
t Planted in rows 3 to 4 feet apart.
78 6. Forage Statistics
Scientific and common name
Medicago minima, little bur-clover ............... .
Medicago orbicularis, buttonclover ............. ....
Medicago sativa, purple alfalfa. ....... ...... .
Medicago scutellata, snail medic .............. ........
Melilotus alba, white sweetclover ........... ..........
M elilotus indica, sourclover......... ...
Melilotus officinalis, yellow sweetclover .. ..... ..
Melilotus suaveolens, Daghestan sweetclover .......
Onobrychis viciaefolia, sainfoin ...................
Ornithopus sativus, serradella ..........................
Phaseolus aconitifolius, mat bean....... ........... .
Phaseolus acutifolius, Texas bean...................
Phaseolus angularis, adsuki bean........................
Phaseolus aureus, mung bean ........................
Phaseolus calcaratus, rice bean .......................
Pisum arvense, field pea........... ........
Pueraria phaseoloides, tropical kudzu .............. .. .
Pueraria thunbergiana, Thunberg kudzu ................
Sesbania exaltata, hemp sesbania ...... .....
Stizolobium deeringianum, Deering velvetbean .............
Strophostyles helvola, trailing wildbean ..................
Trifolium agrarium, hop clover ................
Trifolium alexandrinum, berseem. ... .......
Trifolium dubium, small hop clover ....... ..
Trifoliumfragiferum, strawberry clover. .. . ... . ....
Trifolium glomeratum, cluster clover .. ...... .. ...
Trifolium hirtum, rose clover....... . ... .
Trifolium hybridum, alsike clover .. .... ..
Trifolium incarnatum, crimson clover. .. . . . .
Tr folium lappaceum, lappa clover.. .
Trifolium nigrescens, ball clover ...... ......
Trifolium pratense, red clover ...... .........
Trifolium procumbens, large hop clover ..................
Trifolium repens, white clover .........................
Trifolium resupinatum, Persian clover ...................
Trifolium striatum, knotted clover ................... ...
Trifolium subterraneum, sub clover ................... ...
Trigonellafoenum-graecum, fenugreek .... ......
Vicia angustifolia, narrowleaf vetch .............. .
Vicia articulata, one-flower (monantha) vetch ............
Vicia atropurpurea, purple vetch ........................
Vicia cracca, bird vetch ..............................
Vicia dasycarpa, woollypod vetch. ..... ................
Viciafaba var. major, broadbean ........... . ..
Viciafaba, horsebean ........ ....... ..............
Vicia grandiflora, bigflower vetch...............
Vicia pannonica, Hungarian vetch................. .
Vicia sativa, common vetch ................
Vicia villosa, hairy vetch .............. ...
Vigna sinensis, cowpea............. ................
t Planted in rows 3 to 4 feet apart.
Changes in Hay Production
AVERAGE PRODUCTION IN THOUSANDS OF TONS OF ALL HAY IN THE U. S. AND RELATIVE IMPORTANCE OF
DIFFERENT KINDS BY 5-YEAR PERIODS, 1920-44
% of all hay
5-year average All hay Tame hay
Legumes Clover All other
reported and tame Wild
separately timothy hay t hay
% % % %
1920-1924......................... 90,503 25 46 13 16
1925-1929 ....................... 85,077 33 42 11 14
1930-1934. ............... ...... 73,801 40 33 15 12
1935-1939. .. ..... ............. 84,247 46 28 14 12
1940-1944. .......... .. . .. 96,430 48 : 28 1 13 11
Alfalfa, lespedeza, sweetclover, soybean, peanut-vine, and cowpea hay, exclusive of the clovers re-
ported in "clover and timothy" hay.
t Grains cut green for hay and production reported as miscellaneous tame hay.
$ The legume percentage would be increasingly greater in recent years and the "clover and timothy"
percentage considerably smaller if statistics on clover hays (grown alone) were available and included.
the following factors have been de-
A. For ricks three-fourths as tall as
they are wide: Narrow (cross sec-
tion nearly triangular), F = 0.25;
Moderately full, F = 0.28; Very
full-sided, F = 0.31.
B. For ricks as tall as wide: Very nar-
row (cross section nearly triangu-
lar), F = 0.28; Moderately full,
F = 0.31; Very full-sided, F = 0.34.
C. For ricks one and one-fourth times
as tall as wide: Very narrow, F =
0.31; Moderately full, F = 0.34;
Very full, F = 0.37.
ROUND STACKS.3 To measure round stacks
the stack is divided into two por-
tions. This division is made at the
shoulder of the stack. The base portion
of the stack may be cylindrical, or it may
be narrower at the bottom than at the top
of the base portion. For the cylindrical
base portion the formula is: Volume =
0.08 X height x circumference squared.
If the base is smaller at the ground than
at the shoulder the volume is calculated
3 Hughes, H. D., and Henson, E. R. Crop Produc-
tion. New York: Macmillan Co. 1930.
by the formula: Volume = 0.08 x height
x circumference at the base X circum-
ference at the shoulder. The volume of
the upper portion of the stack is found
by the formula: Volume = 0.04 x
height X circumference at the base of
the top portion squared. These formulas
give the volume of hay in the stack.
In order to find the number of tons it
is necessary to divide the volume of the
rectangular or round stacks by the esti-
mated number of cubic feet per ton.
CUBIC FEET PER TON. Many factors affect
the density of hay and therefore the
number of cubic feet required per
ton of hay. The factor that causes
the greatest variation probably is the
amount of moisture in the hay at the
time of stacking or placing in the mow.
Tough or slightly uncured hay will set-
tle and become more compact than very
dry or overcured hay. Other factors like
texture and foreign material may affect
the density also, but probably not to
the same extent as moisture. For these
reasons there often is a considerable
difference in the number of cubic feet
required per ton in different stacks and
80 6. Forage Statistics
ESTIMATED SILO CAPACITY IN TONS OF SETTLED CORN SILAGE
Inside Silage depth in ft.
in ft. 8 10 12 14 16 18 20 22 24 26 28 30 35 40 45
10 .......... 11 14 17 20 23 26 29 33 36 39 43 46 54 63 71
12 .......... 16 20 24 29 33 38 42 47 52 56 61 66 78 90 103
14 .......... 21 27 33 39 45 51 58 64 70 77 83 90 107 123 140
16.......... 28 35 43 51 59 67 75 84 92 100 109 118 139 161 182
18.......... 35 44 54 64 75 85 95 106 116 127 138 148 176 203 231
20 .......... 43 55 67 80 92 105 118 130 144 157 170 184 215 246 278
For immature corn add 10 to 15 per cent to the capacity given. If corn is unusually dry when ensiled,
deduct 10 to 15 per cent. If corn is rich in grain add 5 to 10 per cent. If very little grain is present, deduct
10 per cent.
AVERAGE WEIGHT PER CUBIC FOOT OF SETTLED UNWILTED ALFALFA SILAGE AND CAPACITIES OF SILOS OF
VARIOUS DIAMETERS *
(Alfalfa entering silo at 72-78% average moisture content)
Depth of settled silage in ft
6 ..................... .
28 ................... . .
3 0 . . . . . . . . . . . .
34 ................... . .
3 6 . . . . . . . . . . . .
per cu. ft.
in lbs. for
Quantity of settled silage in tons
Silo diameter (inside) in ft.
12 14 16 18
* Measured from the surface of the settled silage before any is removed from the silo.
mows. There is no simple method for
measuring variations in density.
The following figures are the averages
obtained from a large number of stacks
and may be used with fairly accurate re-
Length of time in stack
Kind of hay
30 to 90 days Over 90 days
Alfalfa........ 485 cu. ft./ton 470 cu. ft./ton
timothy mixed 640 cu. ft./ton 625 cu. ft./ton
Wild .......... 600 cu. ft./ton 450 cu. ft./ton
Figures used for estimating the ton-
nage of hay in the stack may be used for
estimating the tonnage of hay in the
mow. However, for hay stored in the
mow a volume for estimating tonnage is
a block 8 x 8 x 8 feet, or 512 cu. ft. as
equal to a ton of hay. For extremely
well-settled tame hay (i.e., in the bottom
of large mows) 343 cubic feet has been
used in some cases.
BALED AND CHOPPED HAY. A ton of baled
hay occupies from about 100 to 250
cubic feet, or 15 to 50 per cent of
the space occupied by loose hay.4 Bales
vary in size. The smaller bales, 50 to 60
pounds, are easily handled but com-
mercial hay is preferred in 70 to 80
pound bales. As a general rule for baled
hay, reduce the volume to one-fourth
and for chopped hay to one-half that re-
quired for loose hay. (See Chapter 48 for
variations from this rule.)
Measurement of Silage in Silo
CORN SILAGE. To determine the amount
of silage, the volume of the silo is
divided by the number of cubic feet
Measurement of Silage in Silo 81
per ton, the average being about 44 for
silage settled 30 days or more. The den-
sity is influenced- by several factors in-
cluding silage depth, diameter of silo,
per cent moisture, et al.5 Silo capacities
for corn silage are shown in Table 6.8.6
ALFALFA SILAGE. Table 6.9 gives silage
density and silo capacities for un-
4 Martin, John H., and Leonard, Warren H. Prin-
ciples of Field Crop Production. New York: Macmillan
5 Eckles, C. H. et al. Capacities of silos and weights
of silage. Mo. Agr. Exp. Sta. Bul. 164. 1919.
6 McCalmont, J. R. Silo types and construction.
Farmers' Bul. U.S.D.A. 1820. 1939.
SOtis, C. K. A look inside your silo. Minn. Agr.
Exp. Sta. Farm and Home Science 7(3):16-18. 1950.
Forage Grasses and Legumes
DARREL S. METCALFE *
Iowa State College
The Botany of Grasses and Legumes
Our principal forages are largely in the
two botanical families, the grasses,
Gramineae, and the legumes, Legu-
The grasses are grouped into about
600 genera, with close to 5,000 species.'
Of these, about 150 genera and 1,500
species are found growing in the
United States.2 They have a wider range
than any other family of flowering
plants. The grass family includes about
75 per cent of the cultivated forage
crops and all the cereal crops.
Economic Value of Grasses
The grasses excel all other seed-bear-
ing plants in their use by man and ani-
mals. They furnish the principal bread-
stuffs of the world and the bulk of the
feed of animals. Over one-half of the
farm income of the United States comes
from the grasses, including corn, wheat,
and other cereals. In addition to the
foods derived from their seed and fruits,
as in the case of cereals, and the forage
from their vegetative structures the
grasses are of value to man in many other
General Description of Grasses
Grasses are either annuals, winter
annuals, or perennials.3 Almost all are
See Chapter 6.
herbaceous (non-woody) plants. The
grasses are monocotyledons, as distin-
guished from legumes which are dicoty-
ledons. This distinction between the two
groups is based on the structure of the
embryo; the major root stem axis of the
embryo carries lateral members known
as cotyledons or seed leaves; monocoty-
ledons have only one cotyledon while
dicotyledons have two.
In size, the grasses range from a few
inches to seventy feet or more in height,
the greatest sizes being attained by the
bamboo. Corn, sugar cane, and sorghum
are representative of the larger species
of grasses. The organs of the grasses are
the stems, roots, leaves, inflorescences,
Morphology of Grasses
The organs of grasses undergo many
modifications from the usual or typical
structure. However, they have certain
LEAVES. The leaves are borne on the
stem, alternately in two rows, one
at each node. The leaf consists of
sheath, blade, and ligule (Fig. 7.1 G.J.).
The sheath surrounds the stem above the
1 Hitchcock, A. S. Manual of the grasses of the
United States. U.S.D.A. Misc. Pub. 200. 1951. (Re-
vised by Agnes Chase from original 1935 edition.)
2 Dayton, William A. The family tree of Gramineae.
Yearbook. Grass. U.S.D.A. 637-39. 1948.
3 Chase, Agnes. First Book of Grasses. New York:
The Macmillan Co. 1922.
The Grasses 87
node. The margins of the sheath usually
are overlapping (open), though they
sometimes are united (closed) into a cyl-
inder for a part or all of the distance to
The blades are parallel-veined and
typically flat, narrow, and sessile. Some
grasses have auricles or earlike append-
ages projecting from the leaf edges at
the junction of the sheath and blade.
The ligule is the appendage that clasps
the stem where the sheath and blade
join (Fig. 7.1 G). The ligule may be a
membrane, a fringe of hair, or a hard-
ened ring. The collar is the region on
the back of a leaf at the junction of the
sheath and blade.
STEMS. The jointed stem of a grass is
distinctly divided into nodes and
internodes. The internode may be
either hollow, pithy, or solid. The node
or joint is always solid. The leaves have
their vascular connections with the stem
at the node. Lateral buds arise in the axils
of the leaves. These lateral buds may be-
come vegetative (sucker) branches of
the stem or flower shoots. Brace roots
arise from the nodal meristem (keim-
ring), a zone just above the node, except
that at the second node the branches
arise just below the node. The cells of
the nodal meristem remain meristematic
until the stem has progressed well to-
ward maturity. It is because of the differ-
ential growth on the lower side of a
lodged stem that lodged stems are able
to turn upward and again attain a par-
tially erect position.
Many grasses have, in addition to the
vertical flowering stems or culms, hori-
zontal stems, called rhizomes, which are
characteristic of quackgrass, Johnson-
grass, bluegrass and many others (Fig.
7.11). The rhizome is, in most cases, the
over-wintering part of perennial grasses.
Creeping stems above ground are
called stolons (Fig. 7.1H). The stolons
resemble rhizomes in that they have defi-
nite nodes and internodes, nodal meri-
stems from which secondary structures
arise, and leaves. They are more "stem-
like" than rhizomes in that they lie
above ground and their leaves develop
and function normally. Two of the best
known stoloniferous grasses are buffalo-
grass and Bermudagrass. Certain grasses
have thickened lower internodes in
which food accumulates and from which
new shoots arise, thus serving to perpet-
uate the plants through the winter or
dormant season. These food storage
internodes usually are known as corms.
The timothy structure differs somewhat
and is called the haplocorm.
ROOTS. Grasses have fibrous root systems.
The primary grass root may persist
for only a short time after germi-
nation, as in corn. An extensive system
of secondary roots soon arises at the
lower nodes of the young stem and com-
prises the major part of the permanent
root system. Secondary roots sometimes
form at nodes above the ground, as in
the case of corn (prop roots), or at the
nodes of creeping stems (rhizome or
FIG. 7.1 Illustrations of characteristic growth of grass plants. (A) Flowers arranged as
several spikelets on a central axis, enclosed in two empty glumes or bracts. (B) The dif-
ferent parts of a grass flower. (C) The developed fruit or seed, a caryopsis. The caryopsis
is shown successively enclosed in the outer glumes, with the lemma and palea both closely
adhering and free. (D) Spikelets arranged in a terminal spike. (E) Spikelets arranged in a
panicle. (F) Spikelets arranged in a raceme. (G) The ligule, at the junction of the leaf
blade and leaf sheaf. (H, I, J) Means of propagating or spreading; stolon, rhizome, and
bulb, respectively. U.S.D.A. Yearbook photo. 1948.
88 7. The Botany of Grasses and Legumes
INFLORESCENCE. The unit of the grass
inflorescence is the spikelet. The
spikelets usually are in groups or
clusters, which constitute the inflores-
cence (Fig. 7.1A). There are several types
of inflorescence. The simplest is the ra-
ceme, in which case the spikelets are
borne along an unbranched axis (Fig.
7.1F). A typical raceme in grasses is rare.
The spike differs from the raceme in
having sessile spikelets (Fig. 7.1D). Wheat
and barley have spikes. The panicle is
the most common type of grass inflores-
cence. In a panicle the spikelets are
pedicelled in a branched inflorescence
(Fig. 7.1E). The panicle may be either
open, diffuse, or contracted. The flower
clusters of bromegrass, Kentucky blue-
grass, and redtop are panicles.
It is in the spikelet that specialization
usually takes place. The spikelet has a
variable number of flowers, ranging
from one to many, depending on the
species. The axis of the spikelet is the
rachilla. At the base of the spikelet two
glumes are attached, on opposite sides
of the rachilla. They enclose the florets
of the spikelet.
FLOWERS. The grasses usually have per-
fect flowers which are small, with
rudimentary perianth (Fig. 7.1B).
The flowers are arranged in spikelets
which consist of a shortened axis, the
rachilla, and two to many two-ranked
bracts, the lowest two being empty. The
one or more bracts above the empty
glumes are the lemmas. In the axils of
the lemmas are the flowers. Between each
flower and the rachilla is a two-nerved
bract called the palea. Stamens vary from
one to many, but three is the usual num-
ber. There is one pistil, and the pistil has
a one-celled ovary with one ovule. Com-
monly two styles are present, each with a
feathery plumosee) stigma. The perianth
consists of two or sometimes three mi-
nute blisters, called lodicules, located in-
side the lemma at the base of the flower.
These lodicules help to force open the
lemma and palea at the time of anthesis
and thus aid in pollination. The slender
filaments bear two-celled anthers. Most
grasses flower every year. However, some
perennials that spread by rhizomes may
cover extensive areas without flowering
regularly. Typically, the grasses are
adapted to cross pollination by wind
but many species are cleistogamous (self-
pollinating in the bud), as wheat, oats
FRUIT OR CARYOPSIS. The fruit of the
grasses usually is a caryopsis or
kernel (Fig. 7.1C). The single seed is
grown fast to the ovary wall, forming a
seed-like grain. The pericarp is the modi-
fied ovary wall while the seed is the devel-
oped ovule. The caryopsis may be free
from the lemma and palea, as in wheat,
or it may be permanently inclosed, as in
oats. The caryopsis may enlarge during
ripening and greatly exceed the glumes,
lemma and palea, as in corn. The peri-
carp closely adheres to the seed and thus
resembles a seed coat. A seed coat (testa),
however, is an ovular structure while the
pericarp is the modified ovary wall. The
pericarp protects the seed against the loss
of moisture, the attacks of organisms,
and injuries from fungicides and insecti-
cides. The embryo (germ) lies on the side
of the caryopsis next to the lemma and
can easily be seen as an oval depression.
The part of the caryopsis not occupied
by the embryo is the endosperm in which
food is stored. The embryo consists of a
plumule, radicle, and scutellum. Follow-
ing germination, the plumule develops
into the above ground portion of the
plant. The radicle develops into the pri-
mary root system, which anchors the
The Legumes 89
seedling and absorbs water. During
germination, the scutellum or cotyledon
of the germ secretes from its outer layer
of cells certain enzymes which dissolve
the stored food in the endosperm. This
makes possible the movement of food
materials into the plumule and radicle.
There are nearly 500 genera and some
11,000 species of legumes, with almost
4,000 species in America.
Economic Value of Legumes
The legumes are well known as soil
building plants. Among them are many
of value for hay, pasture, green manure,
nectar, and for the food value of their
seed and fruit. It is estimated that of the
acres of all legumes in the United States
40 million are cut for hay, 15 million
cut for seed, 5 million are used for cover
crop, and 40 million acres for pasture.4
It also is estimated that the nitrogen
added to the soil by growing legume
crops is greater than the amount added
by the use of commercial fertilizers. The
total nitrogen from this source would ap-
proximate 2 million tons.
General Description of Legumes
The legume family name, legumino-
sae, is derived from the term "legume,"
which is the name of the type of fruit
(pod) characteristic of the plants of this
family. A legume is a mono-carpellary
fruit, that contains only a single row of
seed and dehisces along both sutures or
As the legume plant grows the sym-
biotic bacteria responsible for the forma-
tion of the nodules on the roots are able
to use the nitrogen in the air and to
multiply in the nodules. The nitrogen in
turn becomes available to the legume
4 McKee, Roland. A general view of the Legu-
minosae. Grass. Yearbook. U.S.D.A. 701-03. 1948.
5 V 6 4
Fic. 7.2 Different types of legume leaves: (1)
sweetclover, (2) alfalfa, (3) vetch, (4) red clover,
(5) Korean lespedeza, (6) cowpea. (1 and 2
adapted from Isely, Iowa State College Journal of
Science, Vol. 25, No. 3.)
plant and aids in its nourishment and
Legumes are dicotyledons. They may
be annuals, biennials, or perennials.
Morphology of Legumes
The legumes have characteristics that
differ in many ways from those of grasses.
Although there are rather distinct mor-
phological differences between genera,
and between some species, there is much
uniformity in the characteristic growth
of the cultivated legumes.
LEAVES. The leaves of the legumes are
arranged alternately and have char-
acteristically large stipules. The
leaves usually are either pinnately or
palmately compound (Fig. 7.2).