qDIAMOND IN THE ROUGH
A History of the UC Sierra Field Station:
“Book” 5: Anatomy of a Grazing System
1
ABOUT THE COVER
The top image is taken from Livestock Feeding on Pasture, Occasional Publication No. 10 of the New Zealand
Society of Animal Production, published in 1987. I use it here as an excellent example of one of the two “end-limits”
of grazing system productivity. The bottom image, from the Lower Porter Field irrigated pasture on the SFREC,
illustrates one of the many examples of how grazing system productivity can be brought to a virtual halt. The New
Zealand example is an epitome of tightly-controlled processes of pasture establishment, sward growth rates and
standing crop mass amounts under regulated levels of grazer intake, and a balanced compromise between “maximum
potentials” and “economic optimums” attainable when grazing system stability over a period of years is an overarching mandate.
As one who has spent a lifetime avocation in photography I am keen on noticing little, mostly un-noticed by others,
points of interest in a picture. In setting up for the New Zealand picture the sheep obviously were distracted to look
away from the photographer, perhaps by a line of people along the fence just off the left margin of the image. They
(the sheep, that is) dutifully responded. Except for one, at some distance, and perhaps the reincarnation of a
photographer from another time, wondering who that guy is back there, standing by himself, and holding some kind of
little box up to his face.
The SFREC example is not quite so extreme, since options to gain useful productivity still exist, one of the more
obvious ones being taking a cutting for hay, which would allow an adequate amount of regrowth and pasturing in later
in the summer and in early fall. Much more can be said and written here about the simplicities and complexities of
linking plant growth and animal herbivory, but that’s what the rest of this book is about, isn’t it?
PREFACE
I am much indebted to the world’s best pasture managers and graziers, the New Zealanders and the Australians for first
doing the work, and then producing the manuals, that together, synthesize, integrate, and put into understandable order
the core knowledge that must undergird success in management of grazing systems.
A sterling example of such a manual is Livestock Feeding on Pasture, Occasional Publication No. 10 of the New
Zealand Society of Animal Production. 1987. The editor is A.M. Nicol. The manual consists of 11 Chapters, each
written by from one to four authors (including A.M. Nicol). In sum, twenty-three different individuals, all respected
researchers, contributed to its 145 pages A second is Grazing Management – Science into Practice. John Hodgson,
Massey University, Palmerston North, New Zealand. Longman Scientific & Technical Handbooks in Agriculture,
Longman Group UK Limited, London. 1990, 203 pages. A third is Agronomy of Grassland Systems. C.J. Pearson
and R.L. Ison. School of Crop Sciences, University of Sydney, Australia. Cambridge University Press. 1987, 169
pages. All are well illustrated.
I want also to mention three archival treatises about another, ancestral, quite different, yet also in many respects, quite
the same, “pasture”. It is the great prairies of central North America on which immense herds of buffalo once grazed
intensively, but which also roamed widely in patterns that allowed recovery and rehabilitation from close grazing of
these plant communities. In 1934 John. E. Weaver and T.J. Fitzpatrick wrote The Prairie (Ecological Monographs,
4:109-295) in which he described the “source of nutrients” for an entirely natural and un-managed (until America’s
expansion westward across the Mississippi and Missouri Rivers and the era of the buffalo hunters) a “pasture”
representing a much different climate, but characterized also by “how much”, “the pattern” (which in both cases would
include plant species composition), and “the factors that influence” the level of production. In 1944 Weaver wrote
North American Prairie (The American Scholar, pages 329-339). This quite brief volume seems to represent an effort
to extract from the lengthy and highly detailed The Prairie the highly-distilled essences of the volume of ten years
earlier. In 1954 (again, a decade removed) Weaver re-wrote North American Prairie. This time it comprised 348
pages in a hard-cover edition published by the Johnson Publishing Company of Lincoln, Nebraska. My copy came to
me, fortuitously, in a rather round-about way: I think it was the American Society of Agronomy that announced to its
readership that the residue of Weaver’s 1954 volume would be made available to the public at large, and at a
reasonable cost. I responded with alacrity, for which I am thankful. The first inside flap of the dust cover announces
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(with obvious pride) “This is the first comprehensive book ever written about the American Prairie. And it comes from
the pen of the one man who, more than any other, is qualified by training and experience to write it – Dr. John E.
Weaver. The dust cover narrative continues, and ends on the back flap with the following, written by Dr. L.A.
Stoddard, of Utah State Agricultural College, in reviewing an earlier work by Dr. Weaver:
“There comes occasionally to every scientific field a man who is so enthusiastic, and so
devoted to his work that it becomes his very life. To him nature seems to unfold her secrets in
response to his devotion; his ability to understand and communicate with nature becomes an
inspiration to students and fellow workers alike. Such a man is John Ernest Weaver in the
field of American grassland ecology.”
Such a person also resided in my theses mentor (at the University of Wisconsin – Madison) Dr. Dale Smith (he
steadfastly refused to accept a middle name or initial!), who, in turn, acquired it from his own major professor, Dr.
Larry (I suppose Lawrence, in actuality) F. Graber, a prolific researcher, writer, and absolutely fabulous teacher (I was
enrolled in his conduct of the Forage Crops course lab section the final time he taught, it as he retired thereafter). In a
manner similar to Dr. Harold Biswell’s acquisition of “Harry the Torch”, Larry Graber was known, not only in
Wisconsin, but throughout the Midwest, as “Mr. Alfalfa”.
In my own teaching at UC Davis, I always read a few quotes from Weaver and Fitzpatrick’s 1934 The Prairie
(it’s more effective to actually hold up the book and quote from it directly, rather than transfer the quote to a
printed handout). It now resides in my personal library bookshelves. And my page markers are still in it.
So also, as long as we’re at this kind of reminiscing, are my copies of Evangeline, A Tale of Acadie by Henry
Wadsworth Longfellow, and Snow Bound by John Greenleaf Whittier, tiny (5 x &1/4 inches) paperback volumes, both
part of the “Instructor Literature Series—of Supplementary Readers and Classics for all Grades” published by F.A.
Owen Publishing Company of Dansville New York.
Inside the front and back covers were lists of titles chosen by the company’s editors as deemed suitable for students of
grades one through eight, following the custom of the times, especially in rural areas, to function as 8-graded schools.
There was not a kindergarten. Various numbers of titles were suggested, specific to each grade, and chosen from the
overall categories of Fables and Myths, Nature and Industry, History and Biography, and Literature. These too
evidenced editorial decisions; for example the list for Seventh Grade was composed of 25 titles under Literature
(including the two above-mentioned), and two under Nature. I presume I read them as a seventh grader! Prepaid
Prices for these long-departed gems were: 7 cents per copy for 12 or more copies; 8 cents per copy for 6 to 11 copies;
10 cents per copy for 1 to 5 copies.
It is quite clear that education of the young was perceived differently then (the 1930s and ‘40s in my case) and there
(the “Middle Western” and Eastern states [Wisconsin in my case] ) than is the case in present times. Children learned
how to write, and to do so fluently and legibly in cursive text, instead of a clumsy string of awkward block letters.
Pages in these volumes (seventh grade, remember?) were generously footnoted, either to define a word or to explain the
meaning of an obscure statement. As an example, the narrative follows the beginning of a winter’s snow storm that
began in early evening and roared on through most of the night. In evening, the family had gathered around the
fireplace, well-stoked with burning logs that, besides warmth, provided light that filled the room. In order to illustrate
the footnoting I chose four lines from this scene:
“The house-dog on his paws outspread, Laid to the fire his drowsy head, The cat’s dark
silhouette on the wall, A couchant tiger’s seemed to fall” Silhouette is explained as
“The shadow of the cat. Many years ago people had silhouettes of themselves made
instead of photographs.” Couchant is defined as “Lying down, crouching, as an animal”
In like fashion, and more relevant to the work at hand, I consider myself most fortunate to have in my personal library
(at least for the time being) this treatise, penned by one of the historically most-prominent range science author and
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teacher. Copyrighted in 1952, but, as the author remarks at the beginning of his Preface, it was “…a long time in the
making”.
And that is all for the better, as the 570 pages contain not only a wealth of written information , but a series of
marvelous line drawings, exquisitely detailed, of range plants . These depict plants in full form, both above- and below
-ground, their inflorescences and their internal components (e.g., the panicle, spikelet, floret, and the five parts of a
grass flower.1 Further along in the Preface, Sampson writes
“This book--more than others(of his writing) before—aims to balance considerations of the care and
management of range lands and its grazing animals with the sciences upon which sound practices must
be based. For this reason the work should be as useful to stockmen and public range administrators as to
students of technical range management (hence inclusion in its title Principles and Practices).
The subject matter of the book is divided into four parts, as follows:
Part. 1. “Range Management in Perspective” defines range management, compares this subject with related fields,, and
evaluates the end products of the range; it reviews world grazing practices and problems; it discusses the application of
physiology and ecology to range problems; and it considers the physical and vegetal characteristics of United States
grazing lands as well as their historical development as grazing commons.
Part 2. “Native Range Forage Plants” points out why the livestock food plants are basic to range-livestock production,
and it illustrates, describes, and discusses a large number of the more important native western range forage grasses,
grasslike plants, forbs, and browse vegetation.
Part 3. “Improvement and Management of Range and Stock” considers artificial and natural reseeding, control of
noxious woody vegetation, and those management practices that are common to all range livestock, such as the water
requirements, water development, supplemental range feeding, and range sanitation. This is followed by specific
discussion of the husbandry and management of cattle, sheep, and goats on the range, including cattle grazing in the
southeastern states. Due consideration is given to range condition, forage utilization, and range surveys as well as to
the economic, physical, and social aspects of ranching.
Part 4. “Protection of Range Resources and Range Livestock” points out ways of avoiding serious damage by livestock
to timber reproduction; it recommends the use of shade trees and shelterbelts for the comfort and protection of
livestock; it describes and pictures in color plates the more troublesome poisonous range plants; and it tells how to
prevent livestock losses. Due consideration is also given to the foraging and predatory wildlife of the range; soil
erosion and its control; and to the administration of grazing on public lands, including highlights of the grazing
administration controversy between a few articulate stockmen and the United States Forest Service.2
1
On page 132 an illustration gives an array of these structures, with central location given to the ligule.
But I looked in vain for the ligule’s partner, the auricle, and it was nowhere to be found.
2
Shades of Cliven Bundy and the Bureau of Land Management!
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THE “MOTHER” OF ALL CONCEPTUAL PASTURE ECOSYSTEM MODELS!!
From: Sampson, A. W., Fig 1, page 6. A portrayal of the author’s concept of what is embodied in “range land”.
The Figure caption reads “A schematic “wheel” design of range (pasture) management and its integrating
organisms and disciplines. The range manager, like the ecologist, leans on many fields of basic and applied
science as background material in drawing plans for rational grazing-land use. Referring to this diagram in the
text Sampson comments “If the range-management “wheel” makes clear to the reader that many interwoven
subjects enter into the solution of range problems, it will have accomplished its primary aim.”
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THE ROLES, APPLICATIONS, AND CONSTRUCTION OF CONCEPTUAL MODELS
Conceptual models typically present a “core” zone of focus (see example below that draws attention to the contrasts
between pasturing and conservation harvesting) that is integrated with the remaining components of a grazing
management system. The components for convenience are depicted as little boxes (remember Pete Seeger and his song
about the “little boxes” of Daly City?) that can be identified, and characterized as to they represent, e.g., unit weight of
dry matter subtended by unit area of ground surface, and unit weight (or number) of grazing animals per unit land area
of a pasture.
“MY” MODELS
I developed this model for use in teaching in several undergraduate courses (back in the ‘70s and ‘80s!) and found it
quite effective. A few acronyms require definition:
“pS” = Photosynthesis; “ABS.” and “SURF” together = Absorptive surface; “GDM” = Green dry matter; “O.M” =
Organic matter, and “DEC.” = the Decomposer system, an often overlooked, but essential processor of detritus in
herbaceous plant communities
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ENVIRONMENT
A more or less standard form of
a “flow-thru” model, albeit one
that is intended to emphasize
the interactions between plant
and animal trophic levels in a
grazing method or system.
LIGHT, TEMPERATURE
WATER, 02, CO2, N2
SOIL PROFILE & SURFACE LAYER:
Click for other model examples.
MISCELLANEOUS EDAPHIC FACTORS
MISCELLANEOUS BIOTIC FACTORS
WATER & NUTRIENTS
ORGANIC MATTER: DETRITUS & ANIMAL WASTES
DECOMPOSERS
N2 & RHIZOBIA
HHERBACEOUS PLANT MASS
IMPORTS,
Including the
crucial element
MANAGEMENT
CONSUMING ANIMALS
AANIMAL PRODUCTS
EXPORTS
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TOXICS
An “import” here could be the management and costs of driving Valley cattle to high mountain ranges to take
advantage of environmental conditions that have provided forage in a different climatic zone.
In all such conceptual models the relationships between pasture supply and animal consumption, succinctly referred to
as “herbivory”, are based on fundamental states of the two trophic levels at any interval in time, the various factors that
independently influence each level, and the mutual interdependence between the two levels. I concocted the one above
decades ago, while I was still teaching Forage Crop (Agronomy 112) and Grassland (Range Science 133) Ecology
courses. The version below is a recent effort, which emphasizes that regardless of the type of environment, the key
focus must be on management of existing imports and available activity options, neither of which can be counted on to
remain stable from year to year.
It is arguable that management is the most important “Import” in a grazing management system.
Sometimes, though, “management” only goes as far as choosing the title of an already “canned” set of rules, e.g.,
“Rest-Rotation”, the rules for which may have been drawn up under substantially different environment and with
substantially different product output expectations. Application then, becomes a “crap-shoot”. The view taken here is
that, under grazing utilization, the seasonal balance between the progress of plant growth and regrowth coupled with
herbivory is so dynamic that it cannot be ignored. Possibly close attention is more important in pastures based on
perennial species (e.g., irrigated pastures) than in pastures based on annual species (e.g., foothill annual rangeland, but
at “ground level” similarities between the two outweigh the differences.
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SOME GENERALIZATIONS ABOUT ENVIRONMENTAL FACTOR INFLUENCES
Energy: Photosynthesis, Respiration, and the Leaf Area Index (LAI)
Plant growth processes are driven, following the intricacies of photosynthesis in chloroplasts, by simple sugars. The
determinants of energy accumulation are trifold: a) effectiveness of light energy interception by the leaf canopy, b)
efficiency of atmospheric CO2 capture, and c) efficiency of photosynthesis itself.
LAI is defined as the surface area of leaf lamina (one side only) subtended by its equal area of ground surface. The
so-called Critical Leaf Area represents a three-dimensional area in which leaf surface intercepts (for practical
purposes) all of the currently-incident light. For most well-managed grass-legume pastures the Critical Leaf Area
(CLA) is within or close to a range of 4 to 6. However, CLA varies. It (understandably) varies with solar angle, which
in turn varies with time of day and time of season. It varies with the angle of presentation of leaf surfaces, e.g., tending
to the horizontal in clovers, and toward the vertical in grasses. There is scattering of incident light within the plant
canopy, as strong rays of light bounce hither and you before they hit the ground. Under conditions of high light
intensity, this is advantageous. Moreover, smaller, and species-related variations occur. Young leaves are more
efficient than aging ones, and while grass leaves that have developed in environments of high light intensity are more
efficient that those developed in shade. Clover leaves have no such restriction.
The energy now resident in carbohydrates produced by photosynthesis is now mobilized for service in two areas.
First, CH2 moieties become the building blocks of cells, contents of cells, and structural tissues of future plants. But the
reduced C, which carried available energy through reduction, can now be oxidized to provide simple energy to
maintain and run current growth of new plant tissues and to maintain life processes. For the latter, CH 2 now reverts to
plain ‘ol CO2, from whence it came, and is released back into the atmosphere. “Helloooo, Respiration!”
Energy losses due to respiration can be assigned to a significant proportion of the energy initially produced through
photosynthesis, up to half in some situations. Respiration losses are positively associated with LAI increases, as the
accumulating weight of tissues in the plant extract increasing amounts of energy, simply for maintenance needs. In
pasture recovery growth after a bout of grazing, the net rate of carbon assimilation (photosynthetic gain minus
respiratory loss, will increase along with increasing LAI, but only to a certain point, after which it begins to decline,
even, with increasing LAI. Historically, support by grazing experts centered on management oriented toward
management of pasture LAI around the point of maximizing net carbon assimilation. Interestingly, the asymmetries
associated with pasture growth and pasture utilization by grazing barge in here. On pastures continuously grazed, or on
pastures cut and harvested very frequently, tiller populations are high, and close grazing increases frequency of
initiation of new leaves, which, in turn, are lower and displayed more horizontally, allowing greater capacity for
capturing incident sunlight . This scenario poses the prospect of an intricate dance in plant responses to defoliation,
where some amount of loss (lower net carbon assimilation) offers a compensatory gain (higher quality of grazer intake
plus a higher level of regrowth potential for new tillers.) and, perhaps most important, may extend the productive life of
the pasture. Insert drawing of intra-canopy display of clover leaves and grass leaves; perhaps refer to development of
a pseudostem.
Temperature and Photoperiod: regulates the rate of metabolic processes, which are increased by
approximately 2-fold for every 10 degrees C increase … Pasture production is higher the higher the soil temperature.
When soil temperature is between 5.5 to 10 degrees C in spring, each degree increases growth mass, on average, of 8
kg DM/ha/day. In autumn, a degree decrease in soil temperature, on average, of 4 kg DM/ha/day.”
All biological activity responds to changes in temperature. A general rule states that metabolic processes of aerobic
organisms, doubles, within limits, with every ten-degree increase. For example, annual ryegrass has a better growth rate
under cool winter conditions than does perennial ryegrass. As a general rule, grasses have a higher growth rate during
winter than do clovers. In clovers, the annual subterranean clover (T. subterraneum) has a better winter growth rate
than does the perennial white clover (T. repens). … Conversely, as might be expected, there are high-temperature
growth-rate limits among species. Ryegrasses may have an optimum at approximately 18 degrees C, while at the other
end of the range, Dallisgrass, Paspalum dilatatum, above, a summer-growing species, has an optimum at
approximately 30 degrees C, a spread of 22 degrees Fahrenheit.
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These two are mentioned here because both have demonstrated successful adaptation at SFS climatic conditions, hence
could be extrapolated to much of the western Sierran foothill zone in California. Further demonstrating the prominence
of temperature as an environmental variable, in this case, temperature of the soil profile, there are profound effects on
two fundamental soil compartments, the decomposer system and the Rhizobial-bacterial reduction of atmospheric
nitrogen to the soil nitrogen pool. The decomposer system appears to become active above a soil temperature above
approximately 6 degrees C. Little comparative information based on research studies for Rhizobial activity exists, but
it may be assumed to respond in similar manner to that of the decomposers. …
“In yet another temperature influence, the seasonal progress of plant growth from vegetative to
reproductive morphology coincides with seasonal increase in temperature. Parsons, A. J. and M. J.
Robson (1982. Annals of Botany 50: 167-177) concluded that growth rates under similar
temperature and solar radiation conditions increased by 85% after attainment of reproductivestage growth.”
This interpretation was applied to pasture growth rates as a whole, not taking into account the proportions of grass and
legume extant. Obviously, ambient temperature has an impressive array of influences, given that the shift from
vegetation to reproductive status has important bearing on both plant nutrient content and intake by grazing animals.
Nz 10
Nz 10, 11 Soil moisture, dependent on seasonal precipitation: Soil moisture storage (as a function
of soil-texture class and effective rooting depth) can become the critical limiting factor to plant growth potential.
Pasture plant species vary considerably in their inherent rooting structures; notable examples of which are the taprooted alfalfa vs. many if not most fibrous-rooted grasses. The growth vigor displayed by such as tall fescue (Festuca
arundinacea) and cocksfoot (Dactilis glomerata) includes greater tolerance to soil moisture stress as well as faster
recovery following droughty conditions, which may be a reflection of physiological as well as morphological
adaptations. The combination could well be involved in the tendency of these species to result in early clumpiness of
sown pastures under lax grazing management. Use diTomoaso’s references when mentioning species
Soil moisture, dependent on supplementary irrigation: in the Sierran foothills can be justified
only by use of 1) the time-honored practice of “wild-flooding”, with the assumption that a competent irrigator is
available at nominal expense). Costs are minimal, especially where only the areas most easily accessible are watered
and ignoring what that distribution pattern might look like from an airplane. 2) application to intensively-managed
“irrigated pastures” located on good soils with respectable depth on modest slopes. The complexities and costs of
suitable conveyance and application systems may be defeating when compared with the opportunities for livestockproduct yields; 3) Seasonal application on rangeland in the fall, e.g., mid-October +/- a week or two. This might be
favored when combined with a new seeding or renovation project and justified as getting a better sward development
prior to overwintering, which in turn would enable higher pasture yields during the first full year of production.
Sometimes, new stand establishments in spring, as opposed to fall, are debated, partly on the basis of utilizing a
favorable level of both a surface and sub-surface amount of carryover moisture content. Here again, costs such as
fencing and irrigation equipment may raise cost-benefit questions, as well as the risks of stand failure caused by
protracted periods of high spring temperatures and drying winds. The latter assumes that seedbed preparation is
involved, as contrasted to use of the rangeland drill with deep placement in a stable sod surface.
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Nz 11 Soil fertility: It may be safe to say that attention to native soil fertility is of greatest importance when newpasture establishment is the issue at hand, most especially when the new pasture is to contain both grasses and
legumes. In California, as well as in parts of Australia and New Zealand, the list will begin with nitrogen (use aerial
photos). Under San Joaquin Valley conditions (e.g., early research at the USFS San Joaquin Experimental Range),
sulfur may be next.
In northern California phosphorous will be added to sulfur. If soil acidity is of concern (e.g., % or lower), lime
(pulverized “limestone”, which contains both calcium [Ca] and magnesium [Mg]), and one or more trace elements
might be needed. Trace element content may also have importance at the animal level, particularly in situations of
potential toxicity. In the context of this section, molybdenum (Mo), which is necessary to the intra-rhizobial reduction
of N2 by laeghemoglobin. In the long term, there also is the scenario, often referred to, that, if the sown legume
attains dominance in the establishing pasture3, the abundance of N2 being fixed, then seasonally transferred to the
adjoining and competitively fibrous-rooted grasses, leads to aggressive completion for dominance by the grass
component, which in turn potentially eliminates the legume component. Soon the “flush” of soil nitrogen has been
depleted and we are back to “Square One”4.
Nz 12 Plant species composition: Apart from the issue of grass vs. grass-legume, it is sometimes argued that
a complex species and/or species-cultivar mixture will boost productivity. In reality, beyond a (grass-legume) pasture
consisting of four (at most five or a distant six) compatible species, the limiting factor is very apt to be utilization
management, and simply adding more species is unlikely to add product yield at the animal level. In bygone decades
mixed species mixtures up to a total of a dozen or more also were recommended with the assumption that one or more
would “fill in” where soil physical or nutritional limitations would not support the high-yielding members of the mix.
However, be that as it may, there are few rules that do not have exceptions. In the Sierran foothills, when sowing a
new pasture on a prepared seedbed, and as a fall seeding, it is useful to add annual ryegrass to the mix because of its
early, rapid, and vigorous growth. It fills up spaces that would otherwise be filled with weeds or, on slopes, susceptible
to soil erosion. It provides some protection to the more-slowly establishing perennials, is palatable, and will mostly
fade away after the first full-season year. A minor add-in might be the legume birdsfoot trefoil. Although not high on
the list of productivity, it does seem to persist here and there, perhaps because it tolerates less-fertile sites.
Nz 12, 13 Insect pests, plant diseases, and weeds: Of these, the first two generally are simply tolerated.
The costs in time, purchase of chemicals, and custom application (or acquisition of suitable equipment) are simple too
great There is a huge set of difference between a typical foothill rangeland site or irrigated pasture and a valley
commercial-production alfalfa field whose annual economic value supports the almost unending battle against both
“old friends” and newcomers in all three categories. On small acreages mechanical clipping where slopes are gentle, or
occasional hand weeding, especially of newly-invading species, there is but one opportunity to do battle: Initial pasture
seeding on cultivated ground, or following a renovation sequence that virtually eliminates serious weed ingress on the
renovated site. An effective sequence might be fall clipping and cultivation followed by over-sowing with a winter
annual; followed by spring cultivation and a densely-sown summer Sudangrass crop. At summer’s end the Sudangrass
is harvested as hay (or greenchop, if that option exists) and the new-pasture seeding made into the Sudangrass stubble.
The vigorous summer growth of Sudangrass (might have to add a tiny bit of fertilizer here!) also aids in “evening out”
some of the existing soil fertility differences, thus helping to ensure uniformity in early growth of the new pasture.
PASTURE PLANT MORPHOLOGY
3
When I was in my “working” years I observed striking cases of Ladino clover dominance occurring in the first full production year
following a grass-legume seeding the previous fall. Once I polled a number of “old-timer” Farm Advisors in the Sacramento Valley
and found that they had observed these occurrences too. In such situations, even though the legume is supposed to contribute
“free” nitrogen from the atmosphere through “fixation” by its root-borne nodules, judicious applications of nitrogen fertilizer are
warranted at that time, in order to ensure a suitable grass-legume balance. It might be argued that clover dominance is the result of
inappropriate species proportions in the seed mixture sown, and that viewpoint has merit. But the “other side of the coin” is the
knowledge that such pastures inevitably end up grass-dominant.
4
Some time back in about the 1970s or so, visitors from the U.K. to the Davis campus would chide us for attempting to make grasslegume pasture, given the several difficulties involved. “Why not simply add nitrogen as necessary and make life simpler” was their
conviction. Of course, during those times the British government subsidized the cost of fertilizer N to the farmers.
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Seed structure, germination, and emergence-type compared for small-seeded
legumes and grasses typically used in perennial rain-fed or irrigated pastures
At left:
Emergence of the entire (planted) “seed”, which is in fact its tiny embryo nestled between two alreadydeveloped leaves (the cotyledons) commits the seedling either to successful continuation of its growth, or, instant death if
severed below the cotyledons (red line).
At right:
Primary grass-tiller (the first one emerging from its buried seed-borne embryo). Only its leaf sheath and
emerging blade are evident at this stage
Small-seeded
Legume seedling
Grass
seedling
First trifoliolate leaf
Unifoliolate leaf
Cotyledons
Hypocotyl arch
(The arch, like the second knuckle
on a finger, aids in emergence, and
also aids in stripping off any remainder
of the seed coat.
The developing grass tiller is aided in
Emergence by a sharp point on the
Shoot apex called the coleorhiza
Epigeal emergence
Hypogeal emergence
Insert photo(s) of legume seedlings showing cotyledons, unifoliate and first trifoliate leaves
Emergence is epigeal (epi = above; geal = earth). The hypocotyl, a part of the embryo, elongates and elevates the
above-ground part of the embryo above the soil surface. The (two) cotyledons unfold to present two horizontallydisplayed surfaces with photosynthetic capability. It is worth noting here that for both grasses and small-seeded
legumes the processes of germination and emergence are “fed” by metabolic conversion to energy of the “food” stored
in the endosperm part of the embryo. Quantitatively, there is a substantially larger endosperm in grasses than in smallseeded legumes. Anthropomorphically speaking, the legume takes a greater risk of survival; if the hypocotyl is severed
there is no means left to re-establish growth. On the other hand, if the first leaf or more of the grass is damaged, there
are many more left to “send into battle”, as the basal meristem is still safely below ground and further “sorties”, amply
fed by the abundant energy of the endosperm.
The legume, however, has expended its meager supply and must rely on its photosynthetically-functional cotyledons
to support growth of its unifoliolate5 and its first “true” (trifoliolate) leaf (or leaves) to the stage where the seedling is
self-sustaining energy-wise.
5
As an undergrad at the University of Wisconsin back in the 1950s, I had the privilege of taking a first course in Agronomy as taught
by Professor L. F. Graber in historic Moore Hall just steps away from the administrative building of the College of Agriculture. I give
12
Cotyledon condition, i.e., plump, a bright green, and obviously healthy vs. shriveled, brown, and perhaps even missing
provides a reliable and easy to read indicator of early seedling vigor and even with significant competition from
surrounding plants cotyledons can remain active recipients of and extra bit solar energy well after the parent plant has
become energetically self-sufficient.
here a nod to a revered and kindly gentleman who was nonetheless firm in his expectations for grammatical precision. Thus, a true
leaf of alfalfa or red clover was “Tri-foliolate”, not “Tri-“foliate”.
13
Plant-growth morphology of common “Cool Season” perennial erect bunchgrasses:
[ Smooth bromegrass (Bromus inermis), Orchardgrass (or “Cocksfoot”), (Dactylis
glomerata), Tall fescue (Festuca arundinacea), and Perennial ryegrass, Lolium
perenne)
Plant-growth morphology of a cool-season perennial erect bunchgrass (Timothy,
Phleum pratense):
Emergence is hypogeal (“hypo = below; geal = earth),
The individual above-ground growth units of a grass plant are produced from three zones of cell division that
originate, already differentiated, from microscopic aggregations of cells on the embryo portion of a seed. These zones
are called “meristematic zones”, or simply, “meristems”. Early in the seasonal life history of a growth unit (now
referred to as a “tiller”) it will produce one to many leaves. Each leaf arises from a meristem located at the base of the
plant (near, at, or slightly below ground surface level) and is displayed as a tubular sheath that branches out into a flat
to V-shaped blade. A single tiller will have one to several leaves. Perennial ryegrass, for example, produces three
leaves on each tiller. This is the grass plant’s vegetative phase.
As the growing season progresses, environmental cues, e.g., daylength changes or ambient temperature conditions
some basal meristems will elongate become apical meristems that will be located at the top of a tiller,. At the base of
each tiller, the minute and tightly-packed stacks of node and internode pairs expand and provide height to the
maturing tiller. During further growth of the plant the apical meristem becomes differentiated into the tiller’s
inflorescence, a plant part morphologically very different from earlier structures. The still-growing plant has now
committed its resources to producing seeds, and is in its reproductive phase.
14
At left: A drawing showing the “jointing”
stage of development in Smooth
Bromegrass (Bromus inermis), a perennial
pasture and hay species used widely in
the Midwest, but also in California at
higher elevations. Illustrated is the
location of a new tiller within the sheath
of the preceding leaf, as the plant move
from its vegetative to its reproductive
stage of seasonal development. Where
used, the point of the illustration was to
note that at the “jointing” stage of this
species, cutting for hay or hard grazing
would sever the growing point, resulting
in death of the emerging tiller. It would
be advantageous to have emergence of
new tiller buds from the grass plant crown
staggered over time, such that in a hayharvest system, cutting top growth for a
high level of hay yield would be done after
release of new growth from crown tiller
buds, allowing some to be sacrificed as
shown in Fig. xx, but with a sufficient
number left to provide a satisfactory yield
from regrowth (sometimes called
“aftermath”.
15
of Orchardgrass (Dactylis glomerata),a common perennial
bunchgrass widely used in the U.S. and known for its competitive ability.
REGROWTH CAPABILITY
In this example, despite a simulated “over-grazing”
more destructive than any herbivore could
command, a sufficient number of new tiller
meristems remain to make a respectable showing.
Given the advanced stage of maturity of the
sacrificial plant, recovery may have been aided by
carbohydrate reserves in the former stem bases.
Obviously, the recovery achieved is weak, and its
limited tolerance to repeated grazing inadequate to
ensure its survival. The surrounding open space also
encourages invasion by aggressive species in its
immediate environment.
16
Growth morphology of a cool season annual erect bunchgrass; Annual ryegrass,
(Lolium multiflorum)
Growth morphology of a rooted warm season perennial stoloniferous/rhizomatous
grass, Bermudagrass (Cynodon dactylis)
Growth morphology of a rooted erect cool season perennial erect legume Red clover
(Trifolium pretense)
Growth morphology of a rooted perennial erect cool season legume (Birdsfoot
trefoil (Lotus corniculatus)
Growth morphology of rooted perennial and stoloniferous legumes [ White (or
Ladino) and “Salina” strawberry) clovers (Trifolium repens and Trifolium
fragiferum, respspectively) ]:
The prostrate-growing stolon is the equivalent of the grass plant’s erect tiller, complete with nodes and internodes.
Leaves, roots, and inflorescences occur, as usual, at the nodes. Depth of rooting is shallower than in grasses, and wellrooted grass plants, two years or more in the stand, will better tolerate droughty conditions or inadequate irrigation
regimes, especially if a lax stocking rate leading to selective grazing of the legume has reduced its vigor as compared to
the grasses.
Taking into consideration also the symbiotic N2 fixation system emphasizes the need to recognize that a crucial
management zone of about six vertical inches exists, three inches above, three inches below, the soil surface. Issues of
defoliation intensity and frequency, uniformity of soil moisture availability, an effective N2-fixation system, and
livestock treading damage combine to “make or break” a potentially productive pasture system.
Photo C.A. Raguse
17
LEGUMES AND NITROGEN FIXATION
18
19
5 tprz z A brief account of how atmospheric nitrogen (about 78.1% of
the total atmosphere) then becomes the soil N that causes the grasses in
your pasture to crowd out the legumes that you so carefully tended.
Photosynthesis; Respiration; Leghaemoglobin; Nodule; Nod factor; Rhizobia; Symbiosis Root hair infection;
Metabolism; Oxidation; Reduction; Decomposition
Leghaemoglobin In some legume plants, Leghaemoglobin is a cellular protein contained in root nodules that owns
the peculiar ability to be able to bind with atmospheric (gaseous) nitrogen. It is central to the conversion of
atmospheric nitrogen (N2 to NH3 to ammonium [NH4] ) This process had to happen some time during evolution
because the atmosphere is full of nitrogen, almost 80% in fact. But both oxygen and nitrogen like to be left by
themselves rather than mess around with hooking up with other atoms, so it wasn’t easy.
The reason leghaemoglobin is so important is that atmospheric N just hates to be reduced when atmospheric oxygen is
around (just another oxidation vs. reduction battle, right? So, legoglobin steps up and creates an oxygen-free
environment for the hive workers (an enzyme called [you guessed it] “Nitrogenase”)..
To add to the already sufficient difficulties, a part of nitrogenase called the “heme group” is what actually grabs the
oxygen molecule. But heme contains iron (Fe), and oxygen is sensitive to Fe so if it is present in excess the nitrogenase
enzyme’s work is thwarted. And nitrogen remains free. This surly attitude on the part of oxygen resulted in the
evolution of several, differing mechanisms by which N2-fixing organisms can allow the presence of sufficient oxygen
to allow adequate oxidation when it is needed in the presence of Fe.
The Nodule
The root nodule, as illustrated and described above, represents the formation of a new, and heretofore foreign, organ in
its biological system. In actuality, a biological factory with the capability of capturing O2 and N2 and, using the
processes and machinery contained in the nodule, provide reduced N for protein synthesis in a clover leaf and release
NH4 to the soil solution for use by neighboring plants.6
In conventional industry, it would be a brick, mortar, and steel factory. Which, of course, exists, credit due to Fritz
Haber, a German chemist. His incentive is considered to be the Allied naval blockade of shipments of sodium and
potassium nitrates to Germany. The nitrates were used in the manufacture of explosives necessary to conduct of the
ongoing war. Although WWI (sort of) began in 19XX, the first demonstration of the Haber Process was shown in the
summer of 1909, when Haber “created” ammonia, a drop at a time from air. The rate of production is quoted as being
something in excess of 100 ml per hour (less than 4 US fluid oz). A German chemical company then purchased the
process and brought it to factory industrial scale in 1913. By the following year production had been upgraded to as
much as 20 (metric) tons per day of ammonia, which as nitric acid, became a precursor to munitions production.
Albeit vanishingly small in size compared to those used for the production of nitrogenous fertilizes by the Haber
process, the reduction of N2 within a fully functional nodule7 is at least as complex, if not more so. But right here
emerges the most fundamental reason to react (in “shock and awe”) in unfettered admiration that this can happen at all:
First, the means for biding must all be at hand (yes, even Mo), and the factory itself must be constructed.
6
I happen to like footnotes instead of the more commonly-used “Notes”, which are located at ends of chapters or of the whole
document, because footnotes are “closer to the source” of their relevance. Here, it is a reminder that a bane of successful nitrogen
fixation is attributed to the copious provision of soil N (via organic matter decomposition) to the grasses in a mixed grass-legume
sward, which leads to aggressive competition by the grasses and potential elimination of the legume. It can happen. I guess.
7
Not by any means are all fully-formed nodules fully effective, and their efficiency ranges from near zero upwards. It is this very
fact that brought Anthony (“Tony”) Holland, a microbiologist from Australia to the Department of Agronomy at UC Davis to
cooperate with Joe Burton of the Nitragin Company of Milwaukee, WI, James E. (“Jim”) Street, a Cooperative Extension Specialist in
the Department, and a host of additional agricultural companies and C E Farm Advisors to provide a creditable solution for that
region in those times.
20
THE BUSINESS OF BEING A PASTURE
The managed grazing of various species of livestock, singly or in various combinations is the basis of much of the
world’s pastoral agriculture. Areas of prominence include New Zealand, Australia, and the United Kingdom (UK).
Farmers and ranchers generally have, largely through their own trial and error experience, learned how to integrate
their animal and pasture resources. The decisions they make include choice of stocking rate, time of calving and
lambing, how much hay to make and how long groups of livestock stock should stay in an area of a specific size. The
skills required to balance the feed supply and demand of grazing livestock include knowledge of the seasonal feed
requirements of grazing animals and the ways in which these can be met from pasture. Differences in the way
different species of pasture plants grow and how they contribute nutritionally to the grazer also influence pasture
production. (It must be noted here that the New Zealand pastures consist of mainly perennial ryegrass and white
clover. ) While this combination of one grass and one legume arguably is the premium two-species mixture the
world over, interpretation of research results on its management, and extrapolation to locations of differing
climatic and soils conditions must be made with aforethought and caution. Thus, for an adequate understanding of
pasture production an appreciation is required of the various contributions made by pasture growth, nutritive value in
relation to the plant growth cycle, and harvesting (“herbivory”) by the animal to the integrated value of pasture to the
farming or ranching enterprise as a whole
21
This section will consider the HERBACEOUS PLANT MASS part of the Summary Model in more detail, not as a
static system, for it is never that. It is always changing, in response to morphological changes tied to initial growth and
regrowth of individual plants, in response to its physical environment, and in response to utilization. But it is helpful to
isolate the two main physical compartments of a sward (“Green forage” and “Dead forage”)in conjunction with the
processes that combine to make the sward into a cohesive unit (Growth, Senescence and Decay), subject to be thought
of and quantitatively measured mostly independent of utilization, as done by grazers or by mechanical harvesting. This
can be portrayed as shown in Figure . So, for the moment at least, we can ignore cattle and sheep!
Growth adds new tissue to existing pasture plant mass, in small increments over time. Plant mass can be defined as
the weight of dry matter8 per unit ground area, with the sample being cut at ground level, at the instant of sampling.
Plant growth rate extends this concept forward over a defined period of time, i.e., becoming weight of dry matter per
unit ground area per day (or other, more appropriate, unit of time). It should now be said that an understanding of
what factors control or influence plant growth rate, is one of the fundamental necessities in successful pasture
management, if for no other reason (and there are others) than that it is a function of plant mass (“Fig. 8a”)
Having laid the above “ground work” the very heart of “the business of being a pasture” can be stated: Net pasture
production, which is defined as the amount of plant mass that can be removed per unit time, as consumed by grazing
animals, or mechanically harvested. (“Fig 8b”).
Although simple in execution, field sampling of plant mass is time consuming, dreadfully tedious, subject to pointed
questions about the statistical validity of the sampling design, and, when the numbers are in hand, of questionable value
except to fill Tables in a publication manuscript.
The tenacity of the visual approach to dealing with pasture mass related to livestock management given in
(citation) supports the notion that an experience pasture manager’s eye trumps most, if not all “cut, dry, and
weigh” methods.
8
Dry matter (DM) is used as a basis for estimating mass by subjecting a cut sample to set temperatures in a drying facility, which
may be a simple oven or a small building equipped with heating, fans, and specialized racks to enhance the uniformity of
temperature applied and air flow circulation. Basically, the intent is to reduce moisture content and plant cell respiration quickly
enough to shut down metabolic activity and reduce plant moisture content to a very low level. If the sample is destined to be
analyzed for metabolically active components, e.g., individual sugars, whose identity and concentration can change quickly following
cutting, or when placed in poorly designed drying facilities, samples can be immediately be frozen as they are cut (e.g., use of dry ice
in an insulated container) and subjected to moisture removal by lyophilization (vacuum removal of moisture in its vapor phase
(sublimation). The latter is a laboratory procedure used in basic studies of some aspect of plant physiological processes and is listed
here only to indicate that there is a wide range of methods used in the simple objective of drying plant samples.
22
Ten “Rules” for Irrigated Pasture Management
1. Treat newly-established pastures plants as though they were tender, shallow-rooted annuals
2. After full establishment (e.g., second year following fall seeding), graze uniformly and completely, but
now below a 3 to 5 inch stubble height.
3. Do not allow excessive accumulation of forage, especially in early stages of new-pasture development.
4/ Irrigate immediately following grazing.
5/ Allow a 7 to 10 day recovery period after grazing and irrigation.
6. Irrigate at 7 to 10 day intervals if recovery between grazings exceeds two weeks.
7. Allow at least enough time between irrigation and resumption of grazing for the soil surface to support
livestock treading without pugging damage.
8. During the stand life of the pasture, remove excessive, ungrazed growth by increasing stocking rate (use
of “mob” stocking), conservation harvesting as hay, greenchop, or silage, or, clipping in place. If the latter,
use a chopper with blower to lessen compaction from clipped forage accumulated in place.
9. Consider timely and judicious fertilization of older pastures, especially grass-legume mixtures when
legumes begin to fail. Single-element (nitrogen) fertilizer generally is adequate. Sward condition and
vigor must be such that new growth by grass tillers and legume stolons can readily occur.
10. Renovate when necessary, or move to a different crop if managing in a multi-crop rotation sequence.
23
Ch5,p.65Successful grazing management depends on knowledge of feed requirements and pasture availability,
integrating the requirements of different animal classes and having the ability to control grazing animals.
Five important rules must be followed for successful grazing management:
1. Match pasture supply and demand as closely as possible. Identify pasture deficits and periods of high
nutritional priority and attempt to transfer/allocate pasture into these periods through the use of long rotations.
Identify priority stock classes and give them preference in grazing sequences. During “production periods”
(e.g., lactation) encourage maximum intakes by providing high levels of high quality pasture.
2. Generate desirable pasture composition. Pasture management must encourage the full potential of the
pasture species that fertility and climate will support. Over-grazing during dry conditions and under-grazing
during surplus periods should be avoided. Encourage more erect, productive species (e.g., ryegrass) into the
pasture.
3. Ensure a high pasture density and thus active leaf cover. Avoid extremes of low and high pasture mass. Low
pasture cover/density will reduce pasture growth rates. This is most relevant during late spring-summer.
Severe pasture through excessive winter pugging should also be avoided.
4. Maintain nutritional quality of pasture. Ensure that clover and green leaf content of the pasture are as high
as climate etc., will allow. Under-utilization is the major constraint; its impact is minimized by integrating stock
classes and where possible conserving surpluses as hay or silage.
5. Remain flexible. Optimum grazing management is always a compromise (e.g., pasture density v pasture
rationing). Identify the primary objective of management for specific times, pastures and animals and develop a
compromise that satisfies that objective without jeopardizing other components to the extent that they limit
production (e.g., excessive rotation length). The corollary is that management must rectify the factor most
limiting to current production. This is likely to differ for each situation.
24
Think about this, and look back to the comparison
of two quite different pasturing systems shown on
the cover of this book
It’s not how much you grow, but how much pasture
(plus in some cases, supplements) your cattle and/or
sheep convert into milk, meat, and wool, versus how
much of this potential you forego by managing
pastures at less than their productive capability?
Note that the pasture-height (target post-grazing
height) metric to English conversion values shown
on the “calibrator boot” are: (8 to 10 cm equals 31/8
inches to 4 inches, and 6 to 8 cm equals ½ inch to 31/8
inches.
Compare those values with the conventional
recommendation (in California) of maintaining
(continuously-grazed in this case) pastures within a
range of 4 to 6 inches, which is equal (roughly) to 10
to 15 cm. For those readers who graze cattle on pastures (rangeland or irrigated), I ask “How do you
approach the key pasture-side management question illustrated here?
25
THE BUSINESS OF BEING A GRAZER
26
27
THE BUSINESS OF BEING A MANAGER
“The first aim of pasture management must be to maintain pasture quality by
avoiding extremes of pasture mass for long periods, especially overgrazing
following drought, or allowing accumulation of rank pasture during the spring
and summer periods. Desirable pastures for high rates of pasture production
should be leafy and densely-tillered, and with a low content of weeds. Such
pastures will produce at a maximum level when they are maintained at a mediumlevel mass. (Then, a caveat): Even so, experience proves that an occasional hard
grazing will be required in order to maintain this level of quality.” Nicol et al
“The average level of output from grassland is normally only about half that achieved by the best grassland farmers,
and their performance n turn is only about half that shown to be theoretically possible. This indicates the scope for
improvement in production from grassland systems. The objective of management will not necessarily be an increase in
output either per animal or per unit land area, though often it is. Greater predictability or uniformity of production, or
greater management convenience, may be more important objectives on many farms, and the ultimate practical test of
any farming enterprise is its financial viability. However, appreciation of the scope for improvement and of the
financial implications of any planned changes in management depends upon an understanding of the biological
principles which determine plant and animal production (emphasis mine)”.
“The fundamental engine that drives all conventional food production systems is a combination of solar radiation
(energy source), the soil sub-system (source of water, within which essential plant nutrient are supplied), and the
existence of communities of plants that combine these into carbon-based stable sources that can be consumed directly
Examples would include wheat, rice, or corn by man or non-ruminant animal; or herbaceous plants consumed by
ruminant animals. In the case of either non-ruminant or ruminant, and in matters of digestive metabolism there are few
differences between plants and animals, save for the costs of processing through what is often referred to as the second
trophic level. An exception is made by the symbiotic relationship between the ruminant animal and the microbial
populations of its rumen.
28
Twenty-five percent of the total land area of the earth’s surface is given over to the production of herbaceous plants
suitable for consumption by grazing animals. In New Zealand, positioned at one extreme in any thoughtful
consideration of the world’s grasslands, about 90 percent of the total nutrient requirements of its ruminant population is
derived from grazing. Many species of these plants have evolved structural components that double as resistance to
being eaten, e.g., cellulose, hemicellulose of cell walls, and lignified tissues. Ruminants evolved (?) to overcome these
barrier to consumption by two mechanisms, the rumen as a plant disassembly vat, and regurgitation to a secondary
digestive system through “cud” chewing, the latter an event given “center stage” several times daily.
Problems of Enterprise Management: A reflective essay
I was born and raised on a small dairy farm in north-central Wisconsin. Milk, livestock, and eggs were common
products and sold for cash. Added were products from the garden, principally strawberries in season and a tiny acreage
of cucumbers (the latter only lasted a couple of years; too hard to pick often enough to get the tiny ones that brought
more money, and they had to be driven into town, six miles away, to be sold). A major supplement to crops harvesting
during summer months came from the 30-acre woodlot. Oak and maple veneer logs, pine logs for construction lumber
paid well. Left-over limb and upper trunk of hardwoods got cut down into firewood length, and enough was produced
each winter to not only heat the house with the living room heater, but cook all meals and heat water for laundry
washing, hand-washing, and “bathing”. Along with dairy cattle, many farmers also raised hogs. Mostly one or two or
a few, to be used for butchering for home use, or sold for the same purpose. A local area generally had a farmer who
also doubled as a butcher, and would travel, much as a horseshoer (my Word 2010 spell checker didn’t like
“horseshoer”, but it is a valid noun; if the reader would prefer “farrier” that’s fine with me!) . .
As an old adage goes: “In the proper butchering of a hog, nothing is wasted but the squeal”.
My maternal grandfather’s farm had a stone-walled smokehouse, within which hung huge hams and slabs of bacon, the
elegance and flavor of which no longer exists in ordinary grocery stores. One of my favorite breakfast treats was blood
sausage. It was baked in a pan and cut into slices, more or less like a batch of chocolate brownies might be today. I
couldn’t say what the recipe was, but it was delightful in texture, somewhat on the sweet side, and contained raisins. In
summer, usually after a rain that preclude working with hay-making, it was off to the blueberry woods, found on
properties held by absentee owners. Mosquitoes would be rampant, and were combated by wearing long-sleeved shirts
with the collars turned up, and anointing hands and parts of the head not protected by a hat with ordinary cattle fly
spray, dispensed out of the same sprayer used in the barn. We three (Dad, Mother and Me) picked furiously. I was
given a small “syrup pail” which, when partly filled, was dumped into my mother’s larger milk pail. Dad had the
largest one, I think it was a 16-quart capacity. Every now and then Dad would hustle off, looking for “richer
pickings”. If found he would return, just within earshot, and stage whisper C’mere, C’mere! The urgency of his tone of
voice, and lowered decibels meant that his new find was really much better than where we were, and, hurry up, before
someone else finds it.
When back home, the three of us would sit around the dining room table, pour out quantities from the pails, and sort, to
remove debris, green or mashed berries and put into other containers. Of course, a fantastic blueberry pie would be
made, and a kettle-full cooked and transferred to Mason jars for storage on a set of shelves in the cellar, for tasty treats
next winter. Some were also sold, in town. My Dad would take delight in changing into a clean pair of Oshkosh, b’
Gosh striped bib overalls, and head off to peddle his wares, usually to housewives whose husbands would, dependably,
be off at work
In summer of 1964, I arrived at Davis to take up my new career. I was dutifully shown around the agriculture of the
state, mostly by the very knowledgeable Cooperative Extension Specialists who resided on campus. I came to realize
that “farming” (sometimes, oddly to me, called “ranching”) was done quite differently in the Great Central Valley. I
looked in vain for silos; there simply weren’t any. True, some dairies in the area operated with pastures, but mostly on
edge-of-valley poorer soils and in the small valleys interspersed among the foothills. The principle forage was, and still
is, alfalfa. And from start to finish, its production and utilization was enterprise-based. Some person or entity owned
the land, another leased the land for alfalfa production, another prepared the seedbed and sowed the crop, another,
owning the proper machinery, baled, chopped, or cubed the crop at the proper times; still another, a broker, purchased
29
the now “ready-to-eat” dairy feed and sold it to out of valley dairies, with yet one last enterprise, distance bulk
trucking, making the deliveries.
The point of this is simply a considerable range of variation in how, when writing about pasture, to regard it. By
definition and by actuality, “pasture” in inextricably joined with grazing livestock, mostly either sheep or cattle, and the
interrelationships between the two can be explored in great detail, even to the point of researching and then describing
the differences in plant growth, management and utilization influenced differently by the two classes of livestock. But
“Pasture” can also be mechanically harvested, with seasonal portions of the growth cycle fed as hay, greenchop, or
even (though unlikely) put into a blue glass-lined Harvestor silo, whereupon it becomes part of an enterprise.
Mechanical harvesting can serve well to capture an excess of growth in a conventional six-field rotation system. ( Nicol
et al write “…even so, an occasional hard grazing may be necessary.”)
In current times, and especially in large operations (certainly much unlike my multi-“enterprise” dairy farm), the
“farm” itself is divided From one of my “get to know California” excursions (about 1965), I vividly recall a stop at a
pasture-fed dairy. His pastures were magnificent, almost elegant, and obviously quite productive. He said “I can hire
someone to milk my cows. But I can’t hire anyone who can manage my pastures.”
The Los Angeles Times article that accompanied the picture of what had to be a large pasture, of long-standing, and in excellent
condition in a dairy that operates in a year-around location in the U.S., had as its focus the obvious difficulties embedded in
immigration policy related to Mexico, Central America, and even upper South America. The situation, as described in the article was
nearly a direct analog. But in reverse: “I can manage my pasture, but I can’t hire someone to milk my cows. A couple of days later, a
flurry of letters to the editor appeared, in general accusing the pasture owner of a refusal to pay decent wages, in order to encourage
unemployed Americans to work in his milking barn. The man had been quoted as saying he had tried that, but to no avail. What the
article lacked was an interview with the milker, pictured in an immaculate, high-tech, and thoroughly ergonomically designed and
constructed milking unit. Simply looking at that picture I imagined that it was possible that this young man was proud of his
occupation and the skills required and being competent in them, was well-paid and likely sending money to his family home on a
regular basis. All in all, the picture evoked the image of a competent and satisfied worker, and certainly well worthy of American
citizenship.
The moral, if any, might be that, in any complex situation, unless all facts are known, judgments that made too quickly can miss the
true mark.
30
THE BUSINESS OF BEING AN IRRIGATOR
31
AN EXAMPLE RESPONSE TO MY FAVORITE GRAZING-METHOD
An experiment conducted by the author in cooperation with the Department of Animal Science at UC Davis.
The grazing methods compared were continuous, five-field rotation, and two-field rotation. Beef steers were
used as grazers.
Experience in California’s Central Valley ranked Orchardgrass as by far the most competitive of the four
species (Tall Fescue not included in this comparison), in many instances becoming the dominant species
(certainly so against perennial ryegrass) following several years of grazing a newly-established pasture.
Likewise, Ladino clover a stronger competitor than strawberry clover, largely because of its taller stature and
greater leaf area.
32
ALTERMATIVES TO GRAZING PASTURES
In the heart of America’s Dairyland, alongside a highway between Milwaukee and Green Bay. The two concrete
stave silos were built first, then he/she/more likely they, went to the Cadillac of such structures, the Harvestor
blue steel, glass-lined beauties. They are not cheap, but they are “wicked good”, as might be said if they were
sold in an L. L. Bean catalog. And, they are not farming on the Auburn, Argonaut, Sobrante, and Las Posas
fractured-rock soils of the Sierran foothills at the SFREC either.
33
WHAT’S IMPORTANT?
When compiling a seed mixture to order a special mix at the seed dealer, avoid saying something like “Gee, I really
like perennial ryegrass; let’s put in twice, maybe three times as much. Then, I’ll get that much higher percentage of in
my pasture.” Back in the 1930s and ‘40s, in the Middle West complex mixtures of up to a dozen different species
combinations of perennial grasses and legumes were sometimes recommended. What happened? The most coarse and
aggressive two or three species (usually perennial grasses) took over and eliminated the nutritious and palatable “little
guys”. Just like tall fescue and orchardgrass do in California.
In many enterprises forage is cut, harvested, and stored before it is fed, and this makes the stages of plant growth and
animal utilization independent of each other. Not so in grazing systems as animal utilization must be coordinated with
plant growth stages. The ensuing interactions set up important influences on the eventual output of animal product. As
a consequence, management decisions that improve efficiency at one side of the” plant to anima product ” equation
may reduce it at the other and vice versa. If such changes in management are many, and randomly occur on each side,
eventual output may suffer, but the system won’t collapse. That said, the essence of grassland management is to
achieve a reasonable balance of the three production stages: plant growth, plant consumption, and digestive
conversion to animal product. If pasture is just one enterprise in the total farming or ranching system it is better to err
on the side of stability than to risk the costs of correcting an error that diminishes any of the three efficiencies.
In grassland plant species that have become valued in grazing systems, two components of growth morphology are
present. For one, the meristematic regions from which new buds arise are held close to, at, or slightly below surface of
the ground. Protection of new growth following defoliation is key. Secondly, the production of new growth units from
this location is virtually continuous over the climatically-defined growth season. The nature of such growth and
regrowth, however, is altered by progression of the plant from its vegetative to its reproductive stage. Defoliation
management can have an influence in that the removal of reproductive growing point to the extent possible will
encourage a return to the vegetative expression. This is often referred to as “aftermath” growth, and is more likely to
be observed in regions of long, summer-occurring growing seasons than in the so-called “Mediterranean Annual”
seasons of the Sierran foothills rangelands, but could easily become part of a management-option for adjacent irrigated
pastures
If you are pasturing a mixture of white clover and perennial ryegrass, you are located in a region with a climate
significantly different from that of the Sierran foothills on the western edge of the Great Central Valley. However, this
fact is sometimes forgotten when a discussion is primarily focused on the mechanics of grazing system management.
I believe that a fully-competent pasture manager must understand growth morphology and the locations of
meristematic zones and stem nodes on the three principal types of stem growth: tillers, stolons, and rhizomes. Note that
stolons and rhizomes confer the equivalent of mobility, a feature sadly lacking in “bunchgrass” species like
orchardgrass and tall fescue. (Consider the tenacious mobility of Bermudagrass, which has both stolons and rhizomes;
it stands alone as a paragon of energy-use efficiency and growth morphology that not only tenaciously holds its original
space but aggressively acts to expand it, both above and below ground level.) And, although quite different from
Bermudagrass, it helps to compare these structures and their functions with the “crown” of a developed alfalfa plant.
There exists an almost endless array of choices in pasture and grazing management schemes and alternatives, but in the
selection of one of these options, or some modification of your own, it is necessary to defend that management choice
by referral to the basics of pasture plant growth as it interacts with utilization by herbivory.
An argument for placing limits on sward height and mass, whether it be the initial growth of the season or successive to
it in the following harvests: Leaf growth of most perennial pasture plants under intensive management takes place
from the bottom of a sward, and must grow up through older plants of greater height before it can participate in its
necessary function of photosynthesis. Given a large concentration of basal growth buds, new growth continues as,
unless grazed or otherwise defoliated, older, neighboring plants mature, senesce, and experience death and decay of
previously green (and previously nutritious) forage. Typically, the major portion of the mass of a growing sward
canopy is located close to ground level. A key concept here is “turnover”, as cycles of basal meristem activation,
34
growth in height and maturity followed by senescence, death, and decomposition, all under lax grazing, severely limit
the daily levels of net forage production. See Fig., Pg.
The strategic growth strategies, if you will, of Ladino clover and Salina strawberry clover (both stoloniferous) provide
an interesting contrast if it is assumed they are both present in a grass-legume mixture. In the large-leafed, tallergrowing Ladino, a larger portion of its canopy weight is at the soil surface, in its stolons. Conversely, in the upper
layer of the canopy, a larger proportion of that canopy layer’s weight and leaf area is in the clover, not the grass.
One now has a choice in how a grazing animal chooses what it will remove. The choice (made by the grazer, of
course) is whether to graze uniformly across the two-dimensional offering, with successive grazing doing the same. In
this case the height of the forage canopy is successively and uniformly lowered. Alternatively, if the same sward is
grazed selectively, the grazer always making a choice, the choice may well be the more nutritious (and possibly more
tasty) Ladino clover. In both cases, the clover loses, and the grass wins, and this can very well be part of a scenario to
explain how clover fixed-nitrogen acts to its own host’s detriment by stimulating growth of the grasses in the mixture,
which then crowd out the clover. So, anthropomorphically speaking, Ladino clover had that all figured out, and put
hefty, high energy storage stolons where their integrity is maintained. If the grazing pressure is really, really great, the
grasses will also be grazed severely, and their regrowth capacity reduced to minimum. So, hey! The clover has got
another chance! Grazed sward ht; p. 11, 3.5 cm
35
REFERENCES
Sampson, Arthur W. 1952. Range Management, Principles and Practices. John Wiley & Sons, Inc. New
York. 570 pp.
36
A GLOSSARY OF TERMS AND CONCEPTS
Efficiency The ratio of an input (or the summation of inputs) to a process, e.g., herbage growth over a defined
time interval, as a proportion of output from that process, taking into account all external influences on herbage
growth rate as influenced by environmental variables and management practices. It is usually expressed as a
percentage. Accurate and useful application of the concept can be difficult in a pasture grazing system due to
ongoing (time-wise) interactions between plant growth and animal utilization (herbivory). Hodgson resolves
these difficulties by stating: “The essence of grassland management is to achieve an effective balance (emphasis
mine) between the efficiencies of the three main stages of production: herbage growth, herbage consumption,
and animal production.” Diagrammatically then, instead of three separated boxes connected by uni- or bidirectional arrows, it is more useful to visualize the three as a single “process” whose “efficiency” is secondarily
modified by the influence of environmental variables and temporal as well as long-term pasture management
decisions instead of blind adherence to some “canned” year-long- or multi-yearlong system bound by an
arbitrary set of rules designed for an entirely different soil-plant-climate geographical region, and perhaps also
for markedly different set of management concept and result expectations. (See page for an example of such
reasoning).
37
“TEST” QUESTIONS
On what month and day in what year was P.J. L’Huilier born?
You’re not a rancher. But you’ve always wanted to be a rancher and raise those beautiful Black Angus cattle that
Carl’s Jr. guarantees they always use in their high-class burgers. So, you just came into a very large inheritance, and
you went out and bought a ranch. A big one. It has 160 acres of absolutely run-down, impoverished irrigated pasture
on highly-compacted soil (which looks like it isn’t very fertile, either). The pasture is overrun with weeds, and has
virtually no quality pasture-plant species on it (maybe there weren’t any to begin with). But now, no matter; you have
to start from the beginning. As we said, your inheritance was substantial, so you can hire local owners of landpreparation, seeding, and pasture-management equipment to perform all necessary services. But it is you who (or
“whom, your choice) will need to decide what plant species you will choose for the new pasture, the number of
different plant species you will use in your seeding mix (include both grasses and legumes – your choice of how many
annuals and perennials) , and the per cent proportion of each species component in the mix. Oh yes, what will be the
seeding rate of the mix, in lbs. per acre? And don’t forget any needed fertilizer(s). Please “give reasons” for any of the
choices wherever appropriate. Finally, keep track (write it all down) of what you did, ‘cause when your pasture
outshines all others in the Valley, you can expect CE Farm Advisors to come from miles around, asking “Now just how
did you do that?”
38
INDEX
39
APP. A. NEW ZEALAND, AUSTRALIA, AND THE UNITED KINGDOM (UK)
A sterling example of such a manual is Livestock Feeding on Pasture, Occasional Publication No. 10 of the New
Zealand Society of Animal Production. 1987. The editor is A.M. Nicol. The manual consists of 11 Chapters, each
chapter written by from one to four authors (including A.M. Nicol). In sum, twenty-three individuals, all respected
researchers, contributed to development of a manual whose depth of technical information integrated with an
understanding of a host of emergent complexities of “The Plant looking up vs. The Grazer looking down”.. 145 pages
A quote from the Introduction:
“Use of pasture by grazing animals is the basis of New Zealand pastoral agriculture. Farmers
generally have through experience learned to integrate their animal and pasture resources. The
decisions they have to make include choice of stocking rate, time of lambing and calving, how
much hay to make and how long mobs of stock should stay in a paddock. The shills required
to balance the feed supply and demand of grazing livestock include a knowledge of the
seasonal feed requirements of grazing animals and the ways in which these can be met from
pasture.
Early research work in New Zealand helped to define the appropriate pasture intake for many
classes of livestock at stages of their annual production cycle and described the consequences
to animal production of not meeting appropriate feeding levels. However, little of this work
defined the pastures required to give a particular feed intake. Over the last ten years this has
changed and many experiments defining pasture parameters such as ‘pasture allowance’ have
identified the amount and type of pasture that must be supplied to meet the seasonal
requirements of animal production systems.
Recommendations from these trials have led to the development of ‘feed budgeting’ at the
farm level and through this, planned pasture feeding to ensure that an appropriate supply of
pasture is provided for grazing livestock. This quantitative approach to planning grazing
makes feeding livestock on pasture more feasible for the beginner and yet permits a high level
of sophistication in feed planning by experienced operators.”
A second is Grazing Management – Science into Practice. John Hodgson, Massey University, Palmerston North, New
Zealand. Longman Scientific & Technical Handbooks in Agriculture, Longman Group UK Limited, London. 1990, 203
pages.
A quote from the Preface:
“It has been conventional to describe grazing management as an art rather than a science,
despite a substantial input to grazing research over many years. This has been due in no small
measure to the difficulties of achieving an understanding of the inter-relationships between
plants and animals under grazing conditions, and the ways in which these inter-relationships
might influence output from grazing systems.”
Excerpts from Chapter 1 Grassland and grazing management:
“As a method of land utilization, grazing is of enormous importance on a world scale.
Approximately 25 per cent of the total land area of the world is classified as grazing lands, and
grazing animals also make substantial use of cropping lands, which occupy a further 10-15 per
cent of the land area. …
In New Zealand, with a predominantly pastoral agriculture, around 99 per cent of the total
nutrient requirements of ruminants come directly from grazing.”
…
“The average level of output from grassland is normally only about half that achieved by the
best grassland farmers, and their performance in turn is only about half that shown to be
40
theoretically possible. This indicates the scope for improvement in production from grassland
systems. The objective of management will not necessarily be an increase in output either per
animal or per unit area of land, though it often is. Greater predictability or uniformity of
production, or greater management convenience, may be more importantobjectives on many
farms, and the ultimate practical test of any farming enterprise is its financial viability.”
A third is Agronomy of Grassland Systems. C.J. Pearson and R.L. Ison. School of Crop Sciences, University of
Sydney, Australia. Cambridge University Press. 1987, 169 pages. Excerpts from Chapter 1 An overview:
1.2 Grassland productivity
“Net primary productivity (NPP) is the net change in weight of grassland plants between any
two points in time, usually over a year. … models show that productivity is highest in the
tropics, where NPP is likely “to be of the order of 9 t per ha per year in those regions where
grasslands are the predominant use of farmland.”
1.3 Efficiency
”Efficiency is most meaningful when assessed in terms of transformations within the system.
Measures include:
(i) Efficiency of NPP as a percentage of energy from solar radiation incident on
the grassland
(ii) Efficiency of recovery of fertilizer as the amount of extra mineral element
that is recovered in herbage, expressed as a percentage of the amount of
fertilizer added to the grassland.
(iii) Efficiency of grazing or harvesting as the amount of herbage consumed at
each grazing as a proportion of the herbage mass present, or the herbage
consumed as a proportion of herbage accumulation, i.e., the change in herbage
mass between successive measurements, over the same time interval
(iv) Efficiency of “consumption”, i.e., efficiency of conversion of eaten
herbage into animal product.
(v) Efficiency of support energy use, generally of the energy derived from nonrenewable (mostly fossil fuel) sources.”
1.4 Stability
…”Stability of a grassland system is indicated by the amount of variation experienced by a
community of both plants and grazing animals around their dynamic equilibrium following
disturbance. … These variations maintain plant populations within a range, except in extreme
situations of flood, drought or overgrazing.
Stability, defined thus as resilience or homeostasis, is measured either by the variation in
productivity about its long-term mean or by the time taken for the community to return to its
equilibrium state following a catastrophe. This differs from the population ecologist’s
definition of stability as constancy in population size or the physicist’s definition, as resistance
to displacement.”
1.5 Sustainability
“Vegetation in any ecosystem changes gradually as one population succeeds another. This is
what Tansley (1920) defined as succession. Tansley’s paper was published in the Journal of
Ecology, 8, 118-49, and titled The classification of vegetation and the concepts of
development. The gradual change may be progressive and associated with increased structural
complexity and species diversity or it may be regressive and involve loss of species.
41
Succession ends, or more correctly, pauses, with the creation of a ‘climax’ community
within which plant reproduction and environmental factors are relatively balanced so
that the species composition and productivity fluctuate in response to seasonal changes
in weather and other factors, without long-term trend. This climax community is an
equilibrium composition of species. …
Grasslands have varying degrees of sustainability in response to stress. Agronomic
manipulation may enable us to sustain grassland systems that might otherwise be degraded,
e.g., legume-based grassland degradation associated with soil acidification is combated using
tolerant rhizobia, liming and gypsum.
… Appreciation of the dynamic nature of climax grassland communities will cause
agronomists to be relatively unconcerned by seasonal or short-term perturbations in
population structure and productivity.
42
APP B Arthur W. SAMPSON, M.A., Ph.D. Professor of Forestry (Range
Management) University of California at Berkeley
I consider myself most fortunate to have in my personal library (at least for the time being) this treatise, penned by
one of the historically most-prominent range science author and teacher. Copyrighted in 1952, but, as the author
remarks at the beginning of his Preface, it was “…a long time in the making”. And that is all for the better, as the 570
pages contain not only a wealth of written information , but a series of marvelous line drawings, exquisitely detailed,
of range plants . These depict plants in full form, both above- and below -ground, their inflorescences and their
internal components (e.g., the panicle, spikelet, floret, and the five parts of a grass flower. 9
Further along in the Preface, Sampson writes “This book--more than others(of his writing) before—aims to balance
considerations of the care and management of range lands and its grazing animals with the sciences upon which
sound practices must be based. For this reason the work should be as useful to stockmen and public range
administrators as to students of technical range management (hence inclusion in its title Principles and Practices).
The subject matter of the book is divided into four parts, as follows:
Part. 1. “Range Management in Perspective” defines range management, compares this subject with related fields,,
and evaluates the end products of the range; it reviews world grazing practices and problems; it discusses the
application of physiology and ecology to range problems; and it considers the physical and vegetal characteristics of
United States grazing lands as well as their historical development as grazing commons.
Part 2. “Native Range Forage Plants” points out why the livestock food plants are basic to range-livestock production,
and it illustrates, describes, and discusses a large number of the more important native western range forage grasses,
grasslike plants, forbs, and browse vegetation.
Part 3. “Improvement and Management of Range and Stock” considers artificial and natural reseeding, control of
noxious woody vegetation, and those management practices that are common to all range livestock, such as the
water requirements, water development, supplemental range feeding, and range sanitation. This is followed by
specific discussion of the husbandry and management of cattle, sheep, and goats on the range, including cattle
grazing in the southeastern states. Due consideration is given to range condition, forage utilization, and range
surveys as well as to the economic, physical, and social aspects of ranching.
Part 4. “Protection of Range Resources and Range Livestock” points out ways of avoiding serious damage by livestock
to timber reproduction; it recommends the use of shade trees and shelterbelts for the comfort and protection of
livestock; it describes and pictures in color plates the more troublesome poisonous range plants; and it tells how to
prevent livestock losses. Due consideration is also given to the foraging and predatory wildlife of the range; soil
erosion and its control; and to the administration of grazing on public lands, including highlights of the grazing
administration controversy between a few articulate stockmen and the United States Forest Service. 10
9
On page 132 an illustration gives an array of these structures, with central location given to the ligule.
But I looked in vain for the ligule’s partner, the auricle, and it was nowhere to be found.
10
Shades of Cliven Bundy and the Bureau of Land Management!
43
APP C
HISTORICAL DEVELOPMENT OF GRAZING IN AMERICA
IN:Sampson, Arthur W. 1952. Range Management, Principles and Practices. John Wiley & Sons, Inc.
New York. 570 pp
Early Handicaps:
Despite the favorable foraging conditions, pioneer stockmen were confronted with many drawbacks. The Indians, by
thievery of livestock and continual resistance to the settler, constituted the most dreaded early handicap. Even so, by
1830 cattle and sheep of Texas were spreading northward and contacting herds and bands in the Mississippi Valley.
Although the industry lacked transportation and satisfactory markets, expansion continued because of abundant
pasturage. Within the next three decades two events greatly stimulated livestock markets and production: namely,
the California gold rush and the Civil War.
Gold Rush and Texas Trail Herds
Early in the nineteenth century Texans began marketing their cattle in growing Midwestern cities. In 1846 many
cattle were trailed to Ohio, and during the gold rush large herds were driven to California where tey competed with
native beef and with stock fro Mexico, Arizona, and New Mexico. Regardless of attacks by Indians, natural hazards,
and hostilities of ranchers along the way, increasing numbers of steers from Texas reached California. Soon an
excessive supply of meats and hides cause so sharp a drop in the California market as to greatly curtail livestock
imports. This situation brought about a decline in livestock numbers in the state for more than a decade.
During, and for some time after the Civil War, there was again great demand for meat and animal products, and
hundreds of thousands of stock were driven to market from Texas. Many animals were on the trail from 2 to 3 years,
having grown out and been fattened on the way. Breeding herds were trailed as far as Canada. By 1883, when
fencing and railroad transportation all but ended these trailings, more than 5,000,000 cattle had been driven from
Texas.
Livestock Boom
The inflationary period after the Civil War caused tremendous expansion in livestock. Pamphlets promising enormous
profits in livestock resulted in investment of millions of dollars from the eastern states and the Old World. The boom
affected much of the West and was the chief factor in the sharp upswing in livestock populations (26,650,000 cattle in
the 17 western states in 1890 as compared with 4,630,000 in 1870. Soon overexpansion, poor management,
homesteading, and periodic droughts resulted in conspicuous shortage of feed and In range depletion. Thousands of
livestock perished, and untold numbers were thrown on the market at ruinous prices. Bankruptcy of companies and
individuals was the rule.
Range Wars
By 1890 the last western open range was fully stocked. At that time there were 20,000,000 sheep in the 17 western
states as compared with 514,000 in 1850. The resulting competition for forage between cattle and sheep was
intense, for stockmen of both factions felt they had established prior right to range they had used. The period from
1890 to 1905 was marked with many better struggles in which cattle raisers and sheep growers contested the right to
use range. Sheepmen set fire to ranges when departing in the fall, cattlemen declared “open season” on sheep and
herders alike. In several localities many lives were lost on both sides.
44
In the early period of this factious fury, cattlemen constructed barbed-wire fences around lands that they had
acquired or were merely using, to conserve forage and water for their own animals. Usually the fences enclosed far
greater acreage of free range than of privately-owned land
The practice of precluding starving herds and bands of competing stockmen brought about a renewed struggle
between nomadic herdsmen and settled operators and led to extensively organized “wire snipping”. Although the
fencing of public range was most widespread in Texas, it was also a common practice in several other states, notably
the Dakotas, Montana, Colorado, Wyoming, Kansas, and Nebraska. The struggle for free range was most severe and
savage in years of drought. When requests to remove illegally place fences went unheeded, the wire cutters would
take the law into their hands. In Custer County, Nebraska, in 1884, when the Brighton Ranch Company failed to
remove a fence around many sections of “no-man’s land”, the snippers severed the wire fences and used the posts as
rafters in their sod houses.
Although the Federal government enacted laws forbidding fencing of public domain lands, these laws were seldom
enforced. Eventually, the illegally erected barbed-wire fencing proved beneficial in discouraging nomadic grazing and
in promoting permanent settlement. According to Gard (9): ‘The barbed-wire fence played a major role in the taming
of the western plains, a task in which the fence-cutters were only a momentary impediment. It opened the plains to
homesteading, encouraged improvement of the land, and gave rise to thriving cities on what had been a few decades
earlier the range of the buffalo.’
One of the most effective measures adopted by cattle and sheep graziers during the struggle for free range was the
eventual establishment, by mutual agreement, of “dead-lines’> These lines constituted boundaries mutually agreed
upon by the two stockmen factions in setting aside areas that could be grazed unmolestedly by these groups. Where
dead-lines were not respected the molester would pay dearly for his temerity. Losses of human lives and of livestock
declined sharply soon after dead-lines were extensively adopted.
Another highly stabilizing livestock event was the expansion, in 1905, of the national forests, a measure that virtually
ended the range wars.
History of Acquisition and Administration of Public Lands
The Unite States government was concerned first with the acquisition and later with the parceling out of small,
productive land units to qualified individuals. But judicious procedure in administration of arid western grazing lands
had to await a relatively later date. Since little of the nation’s land was surveyed and none was classified to indicate
its best uses, it is remarkable that so many persons found suitable areas to operate.
Admittedly, glaring administrative errors were made, yet few politicians or administrators became rich; millions of
citizens found peace and contentment on the land; and a struggling nation became powerful.
By definition, “public domain” includes all lands not privately or corporately owned. More concretely, the term
embraces al areas federally owned that have not been set aside, or appropriated, for some specific uses. There were
no public domain lands in the original thirteen states of the East, nor in Indiana, Kentucky, Ohio, or Tennessee, a few
small parcels of Federal lands still exist in the Lake States and in the South. Nearly all the remaining public domain is
located in the arid West and is useful chiefly for grazing, timber, and watershed protection. A large acreage is desert
waste. Acquisition was obtained by treaty, cessions by states, capture, conquest, and/or purchase.
The history and philosophies pertaining to the public domain concern three outstanding measures: acquisition,
disposal, and conservation.
Acquisition of Public Domain: In Colonial days there were in existence two general forms of land policies. In the
northern rich farm land colonies, where organized protection from Indians was essential, a system of “township
45
planting (sic)” was used: a plot of land was divided among the colonists, who has to reside upon and improve the land
allotted to them. In the southern colonies, where large-scale farming prevailed and where Indians were less
troublesome, each settler could choose an unclaimed area of any size, shape, and in any location. But the policy of
land acquisition adopted in the North ultimately became nation-wide.
The following events chiefly account for the acquisition of the public-domain lands:
1783. Through cessions of state claims and by treaty with England, public lands of nearly 350,000 square miles were
acquired between the boundaries of the original states and the Mississippi River. This acquisition clarified boundaries
and administrative problems pertaining to these lands.
1803. The Louisiana Purchase from France, for 15 million dollars, of nearly 1 million square miles of territory, virtually
doubled the area of the United States. Although the original aim of the buyers was merely to gain control of the Port
of New Orleans, Napoleon demanded that the entire area be purchased.
1819. Purchase from Spain, for 5 million dollars, the territory that now is Florida. This purchase was deemed
administratively and strategically desirable.
1846. Acquisition of Oregon Territory from Great Britain, involving more than 250,000 square miles of territory and
including the states of Idaho, Oregon, and Washington. Purchase made for administrative and strategic reasons.
1848. Cession by and ultimate purchase from Mexico, for 15 million dollars, of an area in excess of 500,000 square
miles of territory, embracing what is now California, Nevada, Utah, western Colorado, northern Arizona, and Western
New Mexico. The ports of San Diego and San Francisco were the chief inducements for purchase.
1850. Purchase from Texas, for 16 million dollars, of all lands then controlled by that state that lay outside its
boundaries. Included were southwestern Kansas, eastern New Mexico, part of Wyoming, central Colorado, and the
Panhandle of Oklahoma – an area of 123,270 square miles. Purchase made to establish more satisfactory boundaries
to enhance development of that region.
1853. Gadsden purchase from Mexico, for 10 million dollars, involving some 30,000 square miles of territory in
southern Arizona and southern New Mexico. Purchase made to improve boundaries and to facilitate building of
railroads in the Pacific region.
1867. Purchase of Alaska from Russia for $7,200,000, involving more than 500,000 square miles. Purchase made for
protection of the fur trade and to “improve national welfare”.
By these transactions the United States secured title to 2,809,000 square miles of territory. Today there remain only
some 37 million acres of vacant, unappropriated, and unreserved public lands in the states outside of Federal grazing
districts. There are, however, 132,000,000 acres under a system of administration within Federal grazing districts.
The states formed from the various acquisitions were given no title to the public lands within their boundaries, and
they had no voice in their administration. Until disposed of, the public lands belonged to the nation, with Congress
alone responsible for their administration or disposal
Disposition of Public Domain
Hamilton was the first to initiate sales of public lands to obtain revenue. This practice continued until about 1840,
when the Jeffersonian principle of land disposal to encourage settlement was adopted, as follows”
46
Military Bounties. Originally designed to favor Royalist soldiers who fought in the Revolutionary War, this measure
was later adopted by the Federal government to encourage war veterans to develop the land. The total acreage
disposed of by this means was 68 million.
Ordinance of 1785. This provided for public sale of domain lands in the Northeastern Territory, in 640-acre units, at a
minimum price of $1.00 per acre. The act failed of its purpose the farm acreage was too large and funds for purchase
were not available.
Harrison Act of1800. Provided for credit to purchase the lands and for reduction of units to 320 acres.
Act of 1820. Discontinuance of the credit system, establishment of the minimum price of $1.25 per acre, and
reduction of the minimum unit to 80 acres.
Disposal to Encourage Settlement
Act of 1841. Provided that preference be given to the settler over the land speculator and the squatter.
Homestead Act of 1862. Termed the most workable land law of all, it provided for title to 160 acres per family after 5
years’ residence, or for a shorter period upon payment of $1.25 per acre. This act accomplished outstanding results
in the fertile Midwest – though not without speculative hindrance – but prove unsuitable in the drier western range
country where much larger acreage was needed ot support a family.
Timber Culture Act of 1871. Designed to avert an impending ‘timber famine’ by providing for tree planting on onefourth of individual 160-acre units. In 1891 the act was repealed because of its virtual failure.
Desert Land Act of 1877. An act adapted to arid western states, by which 640-acre units (later revised to 320 acres)
could be obtained for $1.25 per acre after reclamation by irrigation. The act was a complete failure because of
unavailability of water.
Enlarged Homestead Act of 1909. Concerning only the far western range states, this act provided for acquisition of
320 acres of non-irrigable land, one-fourth to be cultivated. This act inadvertently resulted in segregating the arid
public domain into small, uneconomic units and I breaking up valuable forage sod.
Stock-raising Homestead Act of 1916. This applied to non-irrigable grazing lands by which 640-acre units could be
homesteaded. The acreage proved too small to support a family. Almost of the 30 million acres claimed under the
act by 1923 are now owned by large stock operators.
Homesteading under the Taylor Grazing Act of 1934. This act provides for filing on agricultural land up to 320 acres,
lying within Federally administered public land areas. Since this territory contains little farm acreage, the act is
relatively unimportant.
Disposal for Internal Improvements
In the interest of education and related improvements, more than 200 million acres of Federal lands were granted to
the various states when they were admitted to the Union. In the West, a large proportion of these lands eventually
became the property of stockmen through sales by the states.
Most conspicuous among the land grants were those made to railroads to compensate for aiding in settlement and
development of the country. Because of the large outlay of funds for railroad construction, the land subsidy measure
seemed justified. Generally, alternate sections of land were granted along a strip from 10 to 40 miles wide on each
side of the railroad right-of-way. These railroad grants amounted to 91 million acres exclusive of reverted areas. The
main purpose of granting alternate sections was to stimulate uniform settlement. Such scattered land ownership,
47
however, proved unwise: stockmen could not make a living on 640 acres, nor could railroad officials readily sell the
dispersed land sections. Eventually the railroad companies sold much of this land’ also they purchased or exchanged
lands partly to consolidate their holdings.
Other Land Acts
Among other major land acts, though of lesser significance to the grazing industry, were the Swamp Land Act of 1849,
the Free Timber Act of 1878, and the Timber and Stone Act of 1878. These acts were accompanied by much fraud
and resulted in consolidation of large land holdings in private hands.
Conservation of Federal Lands
After the Civil War exploitation of land resources was rapid. Between 1870 and 1890 many watershed lands passed
into private hands; extensive timber and grazing resources were being depleted; and soil erosion was accelerated.
These conditions awakened the public, particularly in the eastern states, to the idea of conserving the remaining
public domain resources. This, it was felt, could best be accomplished by retention of land ownership and skillful
administration by the Federal government. The acts that primarily resulted in setting up the conservation
movements are:
National Forests Act of 1891
Under this act President Harrison set up the first forest reserve, the Yellowstone Park timberland reserve. Although
small tracts containing springs and seeps, an a considerable acreage of Indian lands had been reserved earlier, the
decade of the 1890s witnessed the turning point from free, unmanaged public domain to conservation and planned
use of critical areas. As early as 1876 a special Congressional act resulted in appointment of Dr. F.B. Hughes as
Commissioner of Forestry, with instructions to gather facts on forest and watershed conditions
Act of 1897. Despite the adverse reports by Hughes and others of conditions of the public lands, there was no
administration of them because, up to 1891, there were no forests or other lands legally set up to manage. The Act of
1891 marks the initial effort at establishing a policy for the lands that had then been proclaimed or which were later
acquired. Between 1891 and 1897 Presidents Harrison and Cleveland had set aside in the West 40 million acres of
“forest reserves”, and between 1901 and 1909 Theodore Roosevelt set aside additional tracts totaling some
148,000,000 acres. Since that time boundary adjustments and small additions and deductions have been made. In
1949 there were 158,471,270 acres of national forest land in continental United States, an area large than the state of
Texas. In that year the states west of the 100th meridian contained about 87 percent of the total thane federally
acquired. Some 85 million acres of the forests in the western states are grazing annually – in 1948, by 1,153,246
cattle and 3,321,993 sheep. IN 1901 the Forestry Division was established in the U.S. Department of Interior, where
its administration continued until 1904.
Act o f 1905-1907. This act provided for transfer of the forest reserves to the U.S. Department of Agriculture under
the title Forest Service. Legal machinery was then set up for detailed administration of these lands. For the first time
grazing fees were collected and the need for range improvement was realized. In 1907 the name “National Forest”
was substituted for “Forest Reserve”, and two range technicians were appointed – J.T. Jardine and A. W. Sampson.
Court Decision of 1911. Affirmative decision was rendered by U. S. Supreme Court for collection of livestock-grazing
fees on the national forests.
Act of 1915. Provided for the setting up of an organization for forest and range research. At that time research as a
function was separated from National forest administration by the formulation of a branch of research. The scope
was broadened to include study of problems on both private and public lands. Three of the earlier experiment
stations established on national forests were taken over in the reorganization process.
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As a matter of record it may be recalled that 1912 marks the year when the first range experiment station of the
Forest Service was established. This station was located on the Manti National Forest in central Utah under the name
Utah Experiment Station and was later renamed Great basin Experiment station. The author served as its first
director for 1912 to 1922
Grazing Districts – Bureau of Land Management
The Taylor Grazing Act of 1934 marked the termination of long-time struggle to place under management lands that
had been heavily punished by un-regulated grazing. In the beginning, only 80 million acres were included in the
grazing districts, but the following year the amended law resulted in including additional lands, to make a total of 142
million acres under such Federal ownership.
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APP D AMERICA’S TALL-GRASS PRAIRIES & J. E. WEAVER
(Sometimes it is helpful to set up contrasts between two or more disparate grassland ecosystems as a backdrop
against which the usefulness of conceptual models can be more properly evaluated as to the extent of their
usefulness.).
. In this case it is the great prairies of central North America on which immense herds of buffalo once grazed
intensively, but which also roamed widely in patterns that allowed recovery and rehabilitation of these plant
communities.
In 1934 J. E. Weaver and T.J. Fitzpatrick wrote The Prairie (Ecological Monographs, 4:109-295) in which he
described the “source of nutrients” for an entirely natural and un-managed (until America’s expansion westward across
the Mississippi and Missouri Rivers and the era of the buffalo hunters) “pasture” representing a much different climate,
but characterized also by “how much”, “the pattern” (which in both cases would include plant species composition),
and “the factors that influence” the level of production.
In 1944 Weaver wrote North American Prairie (The American Scholar, pages 329-339). This quite brief volume
seems to represent an effort to extract from the lengthy and highly detailed The Prairie the highly-distilled essences of
the volume of ten years earlier.
In 1954 (again, a decade removed) Weaver again wrote North American Prairie. This time it comprised 348 pages in a
hard-cover edition published by the Johnson Publishing Company of Lincoln, Nebraska. My copy came to me,
fortuitously, in a rather round-about way: The American Society of Agronomy that announced to its readership that the
residue copies of Weaver’s 1954 volume would be made available to the public at large, and at a reasonable cost. I
responded with alacrity, for whic1h I am thankful. The first inside flap of the dust cover announces (with obvious
pride) “This is the first comprehensive book ever written about the American Prairie.” It came from the pen of the one
man who, more than any other, was qualified by training and experience to write it – Dr. John E. Weaver.” The dust
cover narrative continues, and ends on the back flap with the following; written by Dr. L.A. Stoddard, of Utah State
Agricultural College, in reviewing an earlier work by Dr. Weaver
“There comes occasionally to every scientific field a man who is so enthusiastic, and so devoted to
his work that it becomes his very life. To him nature seems to unfold her secrets in response to his
devotion; his ability to understand and communicate with nature becomes an inspiration to students
and fellow workers alike. Such a man is John Ernest Weaver in the field of American grassland
ecology.”
It is entirely appropriate here to also comment on a respected contemporary, and student of, Dr. Weaver, Laurence
Alexander Stoddart. Following attainment of his B.S. and M.S. degrees at Colorado State University, “…he studied
under the storied J.E. Weaver at the University of Nebraska, where he earned his doctorate in 1934. From here, he
accepted the challenge to initiate a Range Management program at Utah State.” Stoddart served as the Range
Management Department Head until his “untimely” death in July of 1968. The book titled Range Management, coauthored by Stoddard, and Arthur D. Smith, a contemporary at Utah State, was copyrighted in 1943 and published by
the McGraw-Hill Book Company. A third edition was published posthumously for Stoddart in 1975, and was claimed
to be the most widely used text in the field.
The copy of Stoddart and Smith’s Range Management in my collection is a First Edition, and still in almost-new
condition. Inside the front cover is inscribed: “Maurice L. Peterson, Farm Crops Department, Iowa State College”. It
is an authentic signing, as I recognize Dr. Peterson’s meticulous hand. What remains unknown is what Maurice
Peterson’s position was, e.g., student, or faculty, at the time the volume was purchased.
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The West is a land of livestock grazing. Roughly, the 100th meridian marks the division
between the area of cultivated crop production in the East and the area of range land in the
West. Despite the many large and important irrigated farm sections and the occasional
important dry-farm lands, western United States is largely uncultivated. It is characterized by
precipitation generally too low for crop production unless supplemented by irrigation and soil
too shallow and rocky or to alkaline for successful crop production. Exceptions to the lowprecipitation rule are the high mountain regions and parts of the Pacific coast area. Although
timber production is a vastly important industry in these areas, by far the major part of the
West is too low in precipitation to support trees or supports only small trees, which are of but
marginal value as lumber
Essentially, then, these western states are range states not from choice but from necessity.
Range land is their heritage, and they will always be dependent upon it. Proper management
of range land and the conservation of range resources are of major importance in each of these
states, a fact realized, unfortunately, by few.
This is an age of conservation. America is but now awakening to her duties as a protector of
natural resources. In some respects, ‘conservation’ is an unfortunate term, for, sometimes, it
implies disuse. Resources may be classified as replaceable, as, for example, growing things,
or non-replaceable, as, for example, minerals. This reasoning led to the selection of the title
“Range Management”, for this book in preference to “Range Conservation”, because the aim
of the range guardian is maximum use, so long as that use is compatible with protection from
permanent injury. The goal of the range manager is no conservation alone but maximum
sustained production of forage, the backbone of the livestock industry, an industry that is
second in importance to none in the West
Shades of Merton Love, in his description of what “range land” really is.,
In my own (undergraduate) teaching at UC Davis, I always read a few quotes from Weaver and Fitzpatrick’s 1934 The
Prairie (it’s more effective to actually hold up the book and quote from it directly, rather than transfer the quote to a
printed handout). My page markers are still in it.
From: the Introduction: “The prairie covers a vast area. It appears almost monotonous in the
general uniformity of its plant cover. The absence of trees, the paucity of shrubs and half-shrubs,
the dominance of grasses, and a characteristic xeric flora constitute its main features. Neither
geological formation, topography, nor soil determines the character of the flora that develops under
the master hand of climate. In varying the water relations of soil and air they merely bring about
changes in the groupings of the dominant grasses and accompanying segregations and
rearrangements of the forbs. Over the hills of loess with their deep mellow soils, across the hills,
ravines, and valleys of the areas of glacial drift, far out on the level loess plain, and extending
across the well-drained alluvial lowlands along the Missouri and Platte Rivers and a thousand
tributaries, extends the carpet of the prairie. It is a sea of waving grasses dotted with splendid
flowers that nod gently before the summer breeze.” (pg. 113)
From: Complexity of the Prairie: “The prairie offers problems of great complexity. It presents
many changes in both major and minor variations. Responses to major changes in habitat are more
striking, since more pronounced, but of no greater interest than the more minute ones that recur
again and again in response to slight differences in the factors. Moreover, as the seasons advance,
the panorama of the landscape varies to an extent that is almost kaleidoscopic in character. Major
variations in the plant cover are determined in part by the amount of precipitation. They result also
from differences in topography through their effect upon run-off and exposure and consequent
water relations. On low ground, the depth of the water table is a determining factor. … Local
variations are brought about by the nature of the soil, chiefly its water-retaining capacity but to
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some degree by its fertility as well. Only rarely is the soil so shallow that the presence of
underlying rock modifies the character of the plant cover.
Within the prairie cover one finds the conditions of life severe. Though the soil is rich and deep,
water is frequently scarce and the plants sharing it are legion. Deficiency of water usually occurs
when the air too is driest, the temperature high, and the prairie perhaps swept by desiccating winds.
The grasses respond by increasing their osmotic pressure, folding or rolling their leaves, and in
other way [citation]. The changes are most marked on upland where conditions are most severe. …
So numerous are the individuals tht those of greater stature shade the shorter ones, often to the
extent that seedlings and lower leaves die for lack of food. Through thousands of years there has
resulted an adjustment of the species to the environment. The plants, with few exceptions, are
remarkably free from disease, regardless of the weather; they are little injured by high winds or
extreme heat. They may be harmed by late freezing or infrequently stripped of their leaves and
battered to the ground by hail, but rarely or never killed. Those that were unfitted have
disappeared; those that remained have reacted to the factors of the environment so thoroughly that
as species they successfully meet the most severe conditions.
The problem of an adequate water supply has been met by the development of deeply penetrating,
usually widely branching, and thoroughly efficient root systems. The perennial life habit is
exhibited by all of the dominant species as well as by practically all of those that a rare secondary
and subdominant. Reproduction is largely vegetative.
Although seedlings are found distributed widely, certain species meeting conditions favorable to
germination and early growth almost every season, yet studies now being completed indicate that
the survivors are extremely few [citation]. The underground plant parts are storehouses of food
during the long period of winter dormancy and account for the rapid growth of the plants following
their early awakening in spring.
The roots do not all draw upon the same soil level for their supplies of water and nutrients. In fact
the root habit is so fixed in this respect that the various species may be grouped according to the
layer or layers of soil occupied by them. Moreover, the species on a single square meter of soil
surface frequently obtain their water and nutrients from a volume of 3 or more cubic meters of soil.
…
This segregation of the root systems into several more or less distinct levels for absorption is one
of the chief adaptations of plants of the prairie to their environments [citations]. Because of the
extensive development of the absorbing organs, the soil is thoroughly occupied by the various root
systems, especially the fine fibrous roots of the grasses, even to one-half inch of the surface. The
entire water supply is laid under tribute, and competition beneath the surface is so severe during
times of stress that the available water supply at all depths approaches, but rarely reaches, the point
of complete exhaustion [citation]. The balance between species is so well adjusted that a
considerable increase of one at the expense of another rarely occurs except in case of serious
disturbance.
Just as roots occur at different levels, so too are found the underground parts that serve primarily
for food accumulation and propagation. Corms, bulbs, tubers, and root offshoots abound, but much
more frequently the rhizomes of grasses and forbs. These occur in dense masses, mostly within a
very few inches of the soil surface or just below it. Roots and rhizomes form a dense network
below the bunches and mats of sods. Between the plants or plant masses the water-absorbing
system extends in so complete a network that invaders in the apparently bare areas cannot
successfully compete. The effect of this community habit and the excellent condition of tilth
resulting from it is such that the soil rarely cracks with consequent exposure of large surfaces to
evaporation as is frequently the case after the vegetation has been removed or seriously disturbed as
in overgrazing.
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Just what adjustments the species have made to live and successfully compete with their neighbors,
to endure the conditions imposed upon them by the dominants, or to profit by the presence of their
fellows are problems of great complexity but of extreme interest. The beauty and the quiet calm of
the grassland should not obscure the fact that the prairie is a field of battle centuries old in which
the conflicting species, never wholly victorious nor never entirely vanquished, each year renew the
struggle. It is the bitter struggle for mere existence, for light, water, nutrients, etc., eagerly sought
by numerous competitors. Each species would increase its holdings; but parent plants must
compete with their own offspring; as a result the population becomes enormously overcrowded for
the best development of the individual. Consequently. all are reduced in size and underdeveloped
compared to the stature they could attain. They often fruit sparingly rather than abundantly, and
take years to accomplish what, unhindered by their fellows, might be accomplished in a single
season. Such is the picture of the prairie in its condition of stabilization. (Pages 121-125)
A full two decades later, Weaver concluded what was largely a “wrap-up’ book, writing briefly on its last page a bit of
musing about it all, under the title “In Retrospect”:
“The disappearance of a major unit of vegetation from the face of the earth is an event worthy of
causing pause and consideration by any nation. Yet so gradually has the prairie been conquered by
the breaking plow, the tractor, and the overcrowded herds of man, and so intent has he been upon
securing from the soil its last measure of innate fertility, that scant attention has been given to the
significance of this endless grassland or the course of its destruction. Civilized man is destroying a
masterpiece of nature without recording for posterity that which he has destroyed.
The prairie provides us with a background against which we may measure the success or failure of
our own land use and management. [citations]. Before the western prairies disappear as gradually
and completely as have those of the east, let us follow the judicious plan of the conservationists in
the great prairie state of Iowa and preserve some representative tracts forever for ourselves and for
posterity [citation].
Nature is an open book for those who care to read. Each grass-covered hillside is a page on which
is written the history of the past, conditions of the present, and predictions of the future. Some see
without understanding; but let us look closely and understandingly, and act wisely, and in time
bring our methods of land use and conservation activities into close harmony with the dictates of
nature.
As formerly expressed by the author [1944], the prairie itself is an intricately constructed
community. The climax vegetation is the outcome of thousands of years of sorting of species and
adaptations to soil and climate. ‘Grassland soils through untold centuries have been thoroughly
protected by the unbroken mantle of prairie vegetation. The vegetation and soil are closely related,
intimately mixed, and highly interdependent upon each other and upon the climate. Hence, prairie
is much more than land covered with grass. It is a slowly evolved, highly complex organic entity,
centuries old. It approaches the eternal. Once destroyed, it cannot be replaced by man.’ “
And before leaving John Weaver’s 1954 volume, it is noteworthy for its inclusion of over four pages of single-spaced
text listing the common and “scientific” names of prairie grasses and forbs (Did you know there was a “Venus’
looking-glass”, Latin binomial Solidago mollis, and a “White prairie clover”, Latin binomial Petalostemmum candidum
? I thought so! But Beecher Crampton surely would have. And finally, spread over eight pages there are over 200
references, mostly from the 1920s, ‘30s, and ‘40s, with a scattering ranging between 1871 and 1954. Rich pickin’s for
someone looking to do an authentic (meaning authentic authors), historical review of Middle America ‘historical’
grasslands.
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APP EA SIMPLIFIED KEY TO SELECTED FORAGE PLANTS
Two of the “Bread & Butter” courses I taught for many years
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