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Eliot in 1747 wrote of a type of marl which he tried and "found it equal to good
dung."!"^ The use of this material on grasslands was mentioned as early as



Wllbid.. 36th Annual Report (1888). p. 517.
^"^ibid., 46th Annual Report (1898), p. 189.
lO^Mass. Agric. Expt. Sta.. Bui. 355 (1939), p. 19.
'"^Field Husbandry, p. 17.



30 MASS. EXPERIMENT STATION BULLETIN 380

ITdl.^"^ During the latter part of the eighteenth century- the use of gypsum or
land plaster was initiated with much success and it was used extensively through-
out most of the nineteenth century. The use of limestone was common by 1820
in sections where it was abundant, but its general use was not extensive until
later on in the nineteenth century when processing and transportation facilities
were improved and costs had been lowered. In 1838 Colman reported that the
cost of lime in Massachusetts prevented its use to any considerable extent except
in the limestone regions. Many of the principal benefits of lime were recognized
by the same author when he spoke of its use as "neutralizing the acids which
render a soil sour and unproductive; in converting insoluble into soluble matter
and in thus preparing the vegetable matter in the soil for the food of the plants
and bringing it into condition by which it can be taken up by their roots. "'"^

Recent studies by Albrecht^"^ indicate that calcium is even more important in
the nutrition of plants than was formerly thought. Not only must calcium
be considered as a very essential element in itself, but plentiful supplies of calcium
in the soil are essential for the efficient utilization of other nutrient elements such
as potassium and phosphorus. These same studies have shown that available
calcium is the important consideration and that soil pH to a large extent is more
or less incidental. Therefore the use of materials which supply available calcium
in adequate quantities is of utmost importance. Limestone is probably the
cheapest and most effective source of calcium, and in Massachusetts where soils
are also deficient in magnesium, a dolomitic limestone is preferable. It must
also not be overlooked that man}' fertilizer materials carry calcium as an incidental
part of their composition and that calcium in this form may serve a very useful
purpose in supplying the needs of the crop.

Potash and Phosphates. — The early and extensive use of wood ashes as a
"manure" indicates an early recognition of a deficiency of soil potassium in
Massachusetts. Jared Eliot in 1747 observed "Ashes is allowed on all hands to
be some of the best Dressing or Manure for Land; it enriches much and lasts long
but the misery is we can get but little."^"* A hundred years later Colonel Wilder
declared, "I have never used any manure on my soils that would produce such a
wonderful effect as ashes. ... I am of the opinion that there is no mineral manure
that we need so much upon our soils here in New England that have been long
under cultivation as potash. "^"^ Recent experimental results on the beneficial
effects of potash in stimulating the growth of white clover in permanent pastures,
in greatly benefiting stands of alfalfa and Ladino clover, and in increasing the
yields of hay mixtures, merely substantiate the keen observations of Colonel
Wilder.

Historical references to the importance of phosphates are not nearly so fre-
quent as they are for potash and lime. However, the use of "bone manure"
before the middle of the nineteenth century is evidence that the addition of
phosphates was beneficial. More recently crop responses from phosphate fertili-
zation have not been so pronounced as they have from potash fertilization prob-
ably because of the comparatively light, or sandy nature of most Massachusetts
soils. Such soils invariably respond to potash fertilization before they do to
phosphate fertilization. Moreover, the phosphorus content of most commercial
fertilizers has been proportionately high ever since they came into extensive use
so that phosphorus needs in general have been met. It must not be construed,



lOSpield Husbandry, p. 160.

106Agriculture of Massachusetts, 2d Report (1838). p. 11.

^"^Soil Science Society of America Proceedings V (1940), 1-16.

lOSpield Husbandry, p. 43.

l^^Mass. State Bd. Agric. 17th Annual Report (1869). Pt. I, p. 47.



PASTURE CULTURE 31

however, that liberal applications of phosphate fertilizers need not be continued,
for many of our most desirable forage crops, particularly the legumes, are raven-
ous consumers of phosphorus as well as of calcium, magnesium, and potassium
and they must have adequate supplies of all of these elements.

Nitrogen. — Organic matter is the natural repository of soil nitrogen. The
original reserve of nitrogen in Massachusetts soils was contained in the accumu-
lated layer of organic matter or vegetable mold and as long as appreciable quanti-
ties of this original supply of organic matter persisted in the soil, there was no
great need for additional nitrogen. As soon as the supply was exhausted, how-
ever, another source of nitrogen was necessary. For many years this need in
pastures was supplied principally by the legume, white clover. Where legumes
constitute a substantial part of the vegetation today, they can still be relied upon
to supply a considerable portion of the necessary nitrogen. Where grasses pre-
dominate, on the other hand, the use of nitrogen fertilizers is obligatory, since
grasses to be productive must have large quantities of this element.

Minor Elements. — The lack of some of the minor elements is indicated by the
more frequent occurrence in recent years of a number of different "deficiency
diseases." To prevent this occurrence, it now appears that, in addition to mag-
nesium, boron and perhaps other elements must be supplied to many Massachu-
setts soils.

Organic Matter. — Soil organic matter, the material which played such an
important soil fertility role in the past in Massachusetts, is at the present time
a very important factor in soil fertility relationships. The principal difference
between present and former times is that today the nature of organic matter and
its behavior are better understood and the desirability of periodically replenishing
the organic matter supply of cultivated soils is more widely appreciated.

Soil organic matter is one of the most active constituents in the soil. If present
in adequate quantities in soils well supplied with plant food it serves to hold
certain of the more soluble nutrients in such a way as to make them readily
available to growing plants but yet to prevent excessive losses through leaching.
This function is also carried on by colloidal clay, an inorganic material, but since
the clay content of most Massachusetts soils is quite low, the action of organic
colloids in this respect is of much greater importance.

A great many of the favorable effects of organic matter result not from its mere
presence in the soil but from its being continually broken down into its simpler
constituents. Under favorable circumstances complete breakdown of this material
releases quantities of plant food nutrients which can be readily taken up by grow-
ing plants. In this way not only nitrogen is released but also calcium, potassium,
magnesium, and many other essential elements.

The relationship of decomposing organic matter to the development and
maintenance of good soil structure is important, but this subject will receive fuller
treatment in the discussion on tillage.

In spite of the many "positive" effects of soil organic matter, Albrecht.i^** in
a recent enlightening discussion on this subject, points out that organic matter
under certain conditions may be injurious to plant growth. Such can be the
case if plant nutrients are physically held through absorption so securely as to be
unavailable to growing plants. Injurious effects can also result if, during the
process of complete breakdown, the microorganisms which bring about this
transformation are not supplied with a "well-balanced bacterial ration." The
microorganisms may withdraw nutrients from the soil solution and from the



ll'Soil Science, LI (1941), 487-494.



32 MASS. EXPERIMENT STATION BULLETIN 380

organic material itself to such an extent that the crop plants actually suffer from
an unbalance or a deficiency of one or more essential elements. A temporary
nitrogen deficiency is frequently induced when large quantities of carbonaceous
materials are plowed under without sufficient nitrogen to promote both the
decomposition of the organic matter and the satisfactory growth of the crop.
If available supplies of other elements are limited, deficiencies or perhaps an
unbalance of essential plant food nutrients may also be induced as a result of
the decomposition process. This is likely to be the situation in soils which had
been badly depleted of their available essential minerals before a quantity of
organic matter was plowed under.

The need for supplementary nitrogen to promote the decomposition of certain
types of organic matter is generally recognized and steps are usually taken to
provide it; but the need for additional quantities of supplementary mineral
elements to promote decomposition is not generalK" recognized and this may
account for some of our now unexplainable difficulties in crop production. For a
number of years many farmers in Massachusetts have frequently had difficulty
in producing satisfactory tilled crops following immediately on land which has
lain for several years in hay or pasture. Since the common hay and pasture
species are capable of reducing fertility of a soil to a low level and since the general
practice has been to let such a condition develop, immediate difficulties in pro-
ducing crops on "run out" hay or pasture land might be expected. Unless the
needs of both the microorganisms and the crop can be satisfactorily met, the
crop will certainly suffer. The succeeding crop may be adequately fertilized,
but it may require a considerable period of time for the fertilizers to act and re-
establish satisfactory soil fertility relationships.

The most satisfactory solution of this problem would be to prevent such a
condition from developing. If satisfactory levels of soil fertility are maintained
in hay and pasture lands, not only will greatly increased yields of better hay or
pasture herbage result but the succeeding crops in rotation will benefit from the
"positive" effects of decomposing organic matter instead of suffering from its
"negative" effects. In fact, one of the most satisfactory means of replenishing
the supply of organic matter in a cultivated soil is through the periodic produc-
tion of a well-fertilized sod crop. Stapledon has recently written that, "It is
an axiom to my mind to say that a ley [sod ] is a good preparation for any crop,"'!!
but this will only be true when the fertility levels maintained in sod lands are
comparable to those maintained in other crop lands.

Tillage. — Over three hundred years ago Lord Bacon wrote that "Old ground,
that hath been long unbroken up, gathereth mosse; and therefore husbandmen
use to cure their pasture grounds, when they growe to mosse, by tilling them for a
yeare or two."'i2 Since the time of Bacon, much evidence has accumulated which
definitely indicates that grasslands, at least on soils similar to those in Massachu-
setts, must be periodically plowed and reseeded if high levels of productivity are
to be maintained. Jared Eliot, in describing grasslands in Connecticut, noted
that, "The Experienced Farmers say that their Grass Ground thus Ploughed
Once in Five Years mends the Land in this way."ii^ Bordley, writing about
grasslands in eastern Pennsylvania in 1801, said, "It is of great advantage to turn
up the ground, shift its surface, and bury the sods of grass. "i'^ This is in direct
contradiction to the idea now occasionally expressed, though not proved, that a
layer of organic matter at the surface of the ground is necessary for some of the



!!!piough-Up Policy and Ley Farming (London, 1939), p. 75.

I'^storer, Agriculture III, 612.

!!*Fie!d Husbandry, p. 64.

^'''Bordlcy's Husbandry (Philadelphia, 1801). p. 10.



PASTURE CULTURE 33

shallow-rooted permanent pasture plants — principally native white clover — to
thrive. Bordley continued, "The expense of seed for renewing grass is thought
too much of by farmers. It is a trifle, when opposed by the advantages gained."

Many observations on the benefits of tillage to grasslands have also been
recorded in Massachusetts. Henry Colman in 1841 wrote:

Without a question, where land has become, as it is termed, 'bound
out', the sward matted, and the herbage fine, small and stunted, much
would be gained by simply turning it over, keeping the sward unbroken,
harrowing it and freely sowing grass seed upon it, especially with the
application of ashes or plaster, or some other alkaline substance ... to
get the greatest yield, an occasional manuring, and the cultivation of the
soil so as to break up its tenacity and expose it freely to the influence of
sun and air are indispensable. The coarse grasses will soon come in again
if the land is not cultivated and manured. ^^

The following quotation, taken from the Massachusetts State Board of Agri-
culture report for 1871, on the necessity of periodically plowing grasslands is
typical of a number which appear from time to time from 1853 through to 1906:

If land is moist and thoroughly stocked, it may be kept in good condition
for several years by a judicious top-dressing. But my own experience is
that top-dressing cannot be applied to high lands with so good a result.
Manage as we may, in from three to five years the crop grows less, the
wild grass begins to creep in, and from five to eight years the land needs
turning over and reseeding.ii^

Many experiments in top-dressing both hay lands and pasture with fertilizers
have been carried on from time to time in Massachusetts. A marked improve-
ment has usually been obtained in both quality and quantity of feed produced,
but in no instance have the results indicated that top-dressed applications of
fertilizer materials were nearly as effective as plowing, fertilizing, and reseeding.
In experiments reported by W. P. Brooks^i^ from the Massachusetts Station in
1903, hay top-dressed with manure yielded something over 5,600 pounds per
acre; while hay land which was manured, plowed, and reseeded, yielded 10,000
pounds per acre. Although much encouraged by his first results from the use of
top-dressed fertilizers, he finally concluded that their use could extend the useful
life of hay sods only a year or two.

Levi Stockbridge, one of the keenest agricultural men of his day, whose judg-
ment concerning practical agricultural matters in Massachusetts was unsur-
passed, declared in 1872: "... my experience and observations are, that there
is no grass-land in Massachusetts but what ought to be ploughed once in ten
years. "11* There is a striking similarity in Stockbridge's statement to one made
in 1939 by Sir George Stapledon, one of the world's leading pasture authorities,
discussing the grasslands of England. Sir George writes:

In this country, and even on the very best grassland soils, I do not
believe there is a single field that would not benefit from periodic breaking.
I do not say that it would be possible or desirable, to plough into every
single acre of permanent grass in the country: but this is my point.

The sods below all permanent grass, if not becoming actually matted,
at least attain to a sort of "pot bound" condition after the lapse of a suffi-
cient number of years; on the best soils and under the best and most
intelligently grazed swards this condition may take thirty, forty, fifty or
sixty years to develop. On poorer soils, and under less intensive grazing
ten to fifteen years will be long enough for an advanced pot-boundness
to show itself. Some soils cannot carry decent grass for longer than four
to six years . . . the concensus of opinion everywhere is that animals are



^1 ^Agriculture of Massachusetts, 4th Report (1841), p. 239.

ll^Mass. State Bd. Agric. 19th Annual Report (1871), Pt. II, p. 22.

ll'^Hatch Expt. Sta. (Mass. Agric. College), 16th Annual Report (1904), p. 145.

ll^Mass. State Bd. Agric. 20th Annual Report (1872), Pt. I, p. 197.



34 MASS. EXPERIMENT STATION BULLETIN 380

healthy in proportion as the pastures are kept tolerably near to the plough —
are not, in short, of too great age in sward. ii^

John Orr, another prominent British authority on grass farming, writes:

Nothing will establish British agriculture on such a sound basis as the
use of the plough for the growth of grass. . . . For the quick and eflfective
introduction into the soil of raw materials from which grass is made, and
for its speed}' production in finished form, the plough is necessary. i^o

Such expressions of expert opinion concerning the best grasslands of England,
for years regarded as models of perfection in grassland management, are certainly
interesting if not revolutionary. If permanent pastures do not represent the best
pastures of England where soil and climatic conditions are generally favorable
for their best development, then prospects are indeed poor for making first-rate
permanent pastures out of the large area of run-down pasture land in Massachu-
setts, where both soil and climate are far less congenial.

The Case jor Tillage in Pasture Culture. — Why is tillage essential to high
productivity levels in grasslands? If both historical evidence and present-day
expert opinion agree that the periodic plowing and reseeding of grasslands are
prerequisite to high productivity levels, then there must be some good funda-
mental explanation. In recent 3'ears experimental work has been carried out in
various parts of the world which has supplied some scientific evidence to support
early observations. Although still more scientific evidence may be necessary
to provide a full explanation, the following discussion in the light of present in-
formation supplies a plausible if not a totally correct interpretation.

It was early observed in Massachusetts that adequate soil tillage for cultivated
crops was directly associated with soil moisture relationships. "The very Dews
will enter his pulverized Fields, with a larger Blessing than a large Shower can
give his Slovenly Neighbour because his ground is not fit to re».eive it or Retain
it," '21 wrote one Nathan Bowen, in 176L Later it was observed that moisture
relationships in grasslands become steadily poorer as the character of the sod
itself depreciates. The surface becomes hard and rather impervious to rainfall,
the water-holding capacity is reduced, and even the moisture already present in
the soil appears to be lost from the surface more readily by evaporation. 122 To
substantiate some of these observations, experiments reported recently from
New Jerseyi23 showed that the water loss, as total run-ofT, from a continuously
grazed pasture plot was four times as great as that from a grass-legume seeding
and even greater than that from the corn plot. Recent work on the evaporation
of water from bare soil surfaces, carried on at the Missouri Station, 124 indicates
that, for some soil types at least, moisture from below the surface may be con-
tinually lost through evaporation until the available moisture supply is depleted
to a considerable depth. It appears, therefore, that, as a sod becomes older,
particularly on sandy soils, certain physical relationships of the soil become pro-
gressively less and less favorable to plant growth.

In order to determine just what factors were responsible for reduced yields
from aging sods, experiments were carried out in Germany on soils similar to
those in Massachusetts. In one series of experiments'^s certain physical prop-
erties of the soil were measured in natural meadowland and similar areas which
had been plowed and reseeded. It was found that in the plowed land the water-



119piough-Up Policy and Ley Farming, p. 21.

I20Scottish Journal of Agriculture, XX (1937), 3-40.

12lField Husbandry, p. 208.

122Mass. State Bd. Agric. 58th Annual Report (1910). p. 12.

123Soil Conservation, V (1940), 256-258.

124pfjya(g Communication from C. M. Woodruff, Dept. of Soils, Mo. Agric. Expt. Sta., 1941.

l^^Zeitschrift fiiV Pflanzenernahrung Dungung und Bodenkunde, A XXXII (1933), 278-301.



PASTURE CULTURE 35

holding capacity of the soil was increased, particularly on mineral soils naturally
low in organic matter; the air content was over 50 percent greater; and the organic
matter content was appreciably lower. In another series of similar experiments, '26
some of these same measurements were taken over a period of years and the results
correlated with yields of hay. The hay yields on the plowed and reseeded areas
fell off progressively as the values for water-holding capacity, soil structure, and
content of soil air of the reseeded areas approached those for natural meadow soils.
It is difficult to say just which factor was the most important in raising the
production of the reseeded plots because it is difficult to separate the effect of
improved nutrient relationships and water-holding capacity in the newly seeded
areas from the effects of better aeration or some other changed relationship.
It is likely that in the case of light, mineral soils, greater supplies of plant nutrients
and increased water-holding capacity were important factors, but improved soil
aeration may also have been very important. Recent investigations on the
importance of oxygen in plant nutrition definitely suggest this possibility. Hoag-
land and Arnon believe that, "the factor of oxygen supply and of carbon dioxide
removal from around the roots may sometimes limit nutrient absorption by
plants, even when availability of nutrients, in a chemical sense, is not limiting."'"''^
Similar views have recently been expressed by Shive.^^s

In the second series of German experiments, efforts were made to increase the
yield of the natural meadowland by the use of various fertilizer top-dressing ma-
terials. There w'as some increase in yield from several of the treatments, but in
no instance did the yield even approach that obtained from the reseeded plots.
The fact that factors other than a lack of plant food nutrients were important in
limiting yields, explains why simply supplying these nutrients did not restore
hay yields. Perhaps lack of an adequate supply of available oxygen and an
excess of carbon dioxide were important.

Further light is thrown on the subject of tillage by results from Russian ex-
periments which have been reviewed by Russell. 129 The Russians have found
that the structure of a soil is improved not b\' the presence of raw organic matter
in the soil but by its decomposition, and that the greater the rate of decomposition
the greater will be the improvement in soil structure. This explains why, although
a large amount of organic material accumulates in a soil under a continuous sod
cover, soil structure actually deteriorates together with other factors influencing
plant growth, such as moisture-holding capacity and soil aeration. It also shows
why a well-developed sod, when plowed under, may produce so many desirable
effects. As Lindsay-Robb writes —

The age-old implement the plough is still the most efficient cultivator
on the farm. ... It is the only implement that enables a farmer to
release and cash the 'frozen' fertility that has accumulated since the
pasture was established. The effect of cultivation on arable land — which
incidentally commences with the plough — is well known, and it is equally
true of established grassland. i^"

Fertility Improvement and Maintenance in Permanent Pastures

Although one might conclude from the foregoing discussion that it is practically
impossible to maintain satisfactory fertility levels in a grass sod for more than
a few years, such an interpretation is not altogether correct. By following suitable
practices, fair yields of moderately good feed can be produced in permanent



126pflanzenbau, XIV (1938), 241-264.

127Soil Science, LI (1941), 431-444.

128lbid., pp. 445-458.

"^Imperial Bureau of Soil Science, Tech. Communication No. 37, (1938).

'^University of Pretoria (South Africa), Series No. 1. BuK 36, p. 29.



36 MASS. EXPERIMENT STATION BULLETIN 380

pastures, provided natural soil conditions are favorable. Following is a critical
discussion of certain widely publicized "systems" for bringing about permanent
pasture improvement.

Factors Influencing the Growth of Natural White Clover. — Since the success of



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