DRAINAGE 237-246
Underdrainage 237
Counting the cost 238
Where returns are largest 239
Material for the drains 239
The outlet 240
Locating main and branches 240
The laterals 241
Size of tile 241
Kind of tile 242
The grade 243
Establishing a grade 243
Cutting the trenches 244
Depth of trenches 245
Connections 245
Permanency desired 246
ILLUSTRATIONS
Alfalfa and Corn in Indiana _Frontispiece_
Facing Page
A Good Crop for a Poor Soil 4
Red Clover on Limed and Unlimed Land 20
Turning down Organic Matter with a Gang Plow 36
Red Clover on the Farm of P. S. Lewis & Son,
Pt. Pleasant, W. Va. 51
Alfalfa on the Ohio State University Farm 61
Curing Alfalfa at the Pennsylvania
Experiment Station 68
A Heavy Grass Sod in New York 73
Good Pasture Land in Chester County, Pa. 90
Sheep on a New York Farm 96
The Cowpea Seeded at the Last Cultivation of Corn
in the Great Kanawha Valley, W. Va. 106
Texas Calves on an Ohio Farm 121
In the Fertile Miami Valley, Ohio 126
Concrete Stable Floors 131
Corn in the Ohio Valley 140
Penn's Valley, Pennsylvania 151
In the Shenandoah Valley 155
Plat Experiments 167
In the Lebanon Valley, Pennsylvania 189
On the Productive Farm of Dr. W. I. Chamberlain
in Northwestern Ohio 210
Deep Tillage 222
Making an Earth Mulch in a New York Orchard 233
Drain Tile 239
The Lure of the Country 246
CROPS AND METHODS FOR SOIL IMPROVEMENT
CHAPTER I
INTRODUCTION
In Lieu of Preface.--This book is not a technical treatise and is
designed only to point out the plain, every-day facts in the natural
scheme of making and keeping soils productive. It is concerned with the
crops, methods, and fertilizers that favor the soil. The viewpoint, all
the time, is that of the practical man who wants cash compensation for
the intelligent care he gives to his land. The farming that leads into
debt, and not in the opposite direction, is poor farming, no matter how
well the soil may prosper under such treatment. The maintenance and
increase of soil fertility go hand in hand with permanent income for
the owner when the science that relates to farming is rightly used.
Experiment stations and practical farmers have developed a dependable
science within recent years, and there is no jarring of observed facts
when we get hold of the simple philosophy of it all.
Natural Strength of Land.--Nearly all profitable farming in this
country is based upon the fundamental fact that our lands are
storehouses of fertility, and that this reserve of power is essential
to a successful agriculture. Most soils, no matter how unproductive
their condition to-day, have natural strength that we take into
account, either consciously or unconsciously. Some good farm methods
came into use thousands of years ago. Experience led to their
acceptance. They were adequate only because there was natural strength
in the land. Nature stored plant-food in more or less inert form and,
as availability has been gained, plants have grown. Our dependence
continues.
Plant Constituents.--There are a few technical terms whose use cannot
be evaded in the few chapters on the use of lime and fertilizers. A
plant will not come to maturity unless it can obtain for its use
combinations of ten chemical elements. Agricultural land and the air
provide all these elements. If they were in abundance in available
forms, there would be no serious soil fertility problem. Some of their
names may not interest us. Six or seven of these elements are in such
abundance that we do not consider them. A farmer may say that when a
dairy cow has luxuriant blue-grass in June, and an abundance of pure
water, her wants are fully met. He omits mention of the air because it
is never lacking in the field. In the same way the land-owner may
forget the necessity of any kind of plant-food in the soil except
nitrogen, phosphoric acid, potash, and lime. Probably the lime is very
rarely deficient as a food for plants, and will be considered later
only as a means of making soils friendly to plant life.
Nitrogen, phosphoric acid, and potash are the three substances that may
not be in available form in sufficient amount for a growing crop. The
lack may be in all three, or in any two, or in any one, of these plant
constituents. The natural strength of the soil includes the small
percentage of these materials that may be available, and the relatively
large stores that nature has placed in the land in inert form as a
provision against waste.
The thin covering of the earth that is known as the soil is
disintegrated rock, combined with organic matter. The original rock
"weathered," undergoing physical and chemical change. A long period of
time was required for this work, and for the mixing and shifting from
place to place that have occurred. Organic matter has been a factor in
the making of soils, and is in high degree a controlling one in their
production of food.
Organic Matter.--Nature is resourceful and is constantly alert to
repair the wastes and mistakes of man. We may gain fundamental truth
about soil fertility through observance of her methods in restoring
land to a fertile condition. Our best success comes only when we work
with her. When a soil has been robbed by man, and has been abandoned on
account of inability to produce a profitable crop, the first thing
nature does is to produce a growth of weeds, bushes, briers, or aught
else of which the soil chances to have the seeds. It is nature's effort
to restore some organic matter--some humus-making material--to the
nearly helpless land. Vegetable matter, rotting on and in the soil, is
the life-giving principle. It unlocks a bit of the great store of inert
mineral plant-food during its growth and its decay. It is a solvent.
The mulch it provides favors the holding of moisture in the soil, and
it promotes friendly bacterial action. The productive power of most
farming land is proportionate to the amount of organic matter in it.
The casual observer, passing by farms, notes the presence or absence of
humus-making material by the color and structure of the soil, and
safely infers corresponding fertility or poverty. Organic matter is the
life of the soil.
[Illustration: A good crop for a poor soil.]
A great percentage of the food consumed by Europe and the Americas
continues to come out of nature's own stores in the soil, organic and
inorganic, without any assistance by man except in respect to selection
of seeds, planting, and tillage. The percentage grows less as the store
of original supplies grows less and population increases. Our science
has broadened as the need has grown greater. We have relatively few
acres remaining in the United States that do not require intelligent
treatment to insure an adequate supply of available plant-food. The
total area that has fallen below the line of profitable productiveness
is large. Other areas that never were highly productive must supplement
the lands originally fertile in order that human needs may be met.
When soils have been robbed through the greed of man, nature is
handicapped in her effort to restore fertility by the absence of the
best seeds. Man's intelligent assistance is a necessity. Successful
farming involves such assistance of nature that the percentage of
vegetable matter in the soil shall be made high and kept high. There
must be such selection of plants for this purpose that the organic
matter will be rich in fertility, and at the same time their growth
must fit into a scheme of crop production that can yield profit to the
farmer. Soils produce plants primarily for their own needs. It is a
provision of nature to maintain and increase their productive power.
The land's share of its products is that part which is necessary to
this purpose. Skill in farming provides for this demand of the soil
while permitting the removal of a large amount of animal food within
the crop-rotation. Lack of skill is responsible for the depleted
condition of soils on a majority of our farms. The land's share of the
vegetation it has produced has been taken from it in large measure, and
no other organic matter has been given it in return. Its mineral store
is left inert, and the moisture supply is left uncontrolled.
Helplessness results.
Drainage.--Productive soils are in a condition to admit air freely. The
presence of air in the soil is as necessary to the changes producing
availability of plant-food as it is to the changes essential to life in
the human body. A water-logged soil is a worthless one in respect to
the production of most valuable plants. The well-being of soil and
plants requires that the level of dead water be a considerable distance
below the surface.
When a soil has recently grown trees, the rotting stump roots leave
cavities in the subsoil that permit the removal of some surplus water,
and the rotted wood and leaves that give distinctive character to new
land are absorbents of such water. As land becomes older, losing
natural means of drainage and the excellent physical condition due to
vegetable matter in it, the need of drainage grows greater. The
tramping of horses in the bottoms of furrows made by breaking-plows
often makes matters worse. The prompt removal of excessive moisture by
drains, and preferably by underdrains, is essential to profitable
farming in the case of most wet lands. The only exception is the land
on which may be grown the grasses that thrive fairly well under moist
conditions.
Lime.--The stores of lime in the soil are not stable. The tendency of
lime in most of the states between the Missouri River and the Atlantic
seaboard is to get out of the soil. There is no evidence that lime is
not in sufficient quantity in most soils to feed crops adequately, but
within recent years we have learned that vast areas do not contain
enough lime in available form to keep the soil from becoming acid. Some
soils never were rich in lime, and these are the first to show evidence
of acidity. In our limestone areas, however, acid soil conditions are
developing year by year, limiting the growth of clover and affecting
the yields of other crops.
The situation is a serious one just in so far as men refuse to
recognize the facts as they exist, and permit the limiting of crop
yields, and consequently of incomes, through the presence of harmful
acids. The natural corrective is lime, which combines with the acid and
leaves the soil friendly to all plant life and especially to the
clovers and other legumes that are necessary to profitable farming.
Nature is largely dependent upon man's assistance in the correction of
soil acidity.
Crop-rotation.--A good crop-rotation favors high productiveness. One
kind of crop paves the way nicely for some other one. The land can be
occupied by living plants without any long intermissions. Organic
matter can be supplied without the use of an undue portion of the time.
The stores of plant-food throughout all the soil are more surely
reached by a variety of plants, differing in their habits of
root-growth. The injury from disease and insects is kept down to a
minimum. There is better distribution of the labor required by the
farm, and neglect of crops at critical times is escaped. The
maintenance of fertility is dependent much upon the use of a legume
that will furnish nitrogen from the air. A permanently successful
agriculture in our country must be based upon the use of legumes, and
crop-rotations would be demanded for this reason alone if none other
existed.
Fertilizers.--When a crop is fed to livestock, and all the manure is
returned to the land that produced the crop without loss by leaching or
fermentation, there is a return to the land of four fifths of the
fertility, and a good form of organic matter is supplied. A portion of
the crops cannot be fed upon the farm, or otherwise the human race
would have only animal products for food. The welfare of the people
demands that a vast amount of the soil's crops be sold from the farms
producing them. This brings about a dependence upon the natural stores
of plant-food in the soil, which become available slowly, and upon
commercial fertilizers.
There has been a disposition on the part of many farmers to regard
fertilizers only as stimulants, due to the irrational use of certain
materials, but a good commercial fertilizer is a carrier of some or all
of the necessary elements that we find in stable manures. They may
carry nitrogen, phosphoric acid, or potash,--any one or two or the
three,--and the three are the constituents that usually are lacking in
available forms in our soils. Examples of the best modern skill in
farming may be found in the rational selection and use of commercial
fertilizers.
Tillage.--Man's ability to assist nature in the work of production
finds a notable illustration in the matter of tillage. Its purpose is
to provide right physical condition of the soil for the particular
class of plants that should be produced, while destroying the
competition of other plants that are for the time only weeds. Most
soils become too compact when left unstirred. The air cannot enter
freely, plant-roots cannot extend in every direction for food, the
water from rains cannot enter easily, there is escape of the moisture
in the ground, and weathering of the soil proceeds too slowly. The
methods used in plowing, harrowing, and later cultivations fix the
productive power of a soil for the season in large measure.
Control of Soil Moisture.--The water in the soil is a consideration
that has priority over plant-food in the case of agricultural land. The
natural strength of the soil is sufficient to give some return to the
farmer in crops if the moisture content is right throughout the season.
The plant cannot feed unless water is present; the process of growth
ceases in the absence of moisture. One purpose of plowing is to
separate the particles of soil to a good depth so that water-holding
capacity may be increased. When the soil is compact, it will absorb and
hold only a very limited amount of moisture. We harrow deeply to
complete the work of the plow, and the roller is used to destroy all
cavities of undue size that would admit air too freely and thus rob the
land of its water. Later cultivations may be given to continue the
effect of the plow in preventing the soil from becoming too compact,
but usually should be required only to make a loose mulch that will
hold moisture in the ground, and to destroy the weeds that would
compete with the planted crop for water, food, and sunshine.
CHAPTER II
THE NEED OF LIME
The Unproductive Farm.--When a soil expert visits an unproductive farm
to determine its needs, he gives his chief attention to four possible
factors in his problem: lack of drainage, of lime, of organic matter,
and of available plant-food. His first concern regards drainage. If the
water from rains is held in the surface by an impervious stratum
beneath, it is idle to spend money in other amendments until the
difficulty respecting drainage has been overcome. A water-logged soil
is helpless. It cannot provide available plant-food, air, and warmth to
plants. Under-drainage is urgently demanded when the level of dead
water in the soil is near the surface. The area needing drainage is
larger than most land-owners believe, and it increases as soils become
older. On the other hand, the requirements of lime, organic matter, and
available plant-food are so nearly universal, in the case of
unproductive land in the eastern half of the United States, that they
are here given prior consideration, and drainage is discussed in
another place when methods of controlling soil moisture are described.
The production of organic matter is so important to depleted soils, and
is so dependent upon the absence of soil acidity, that the right use of
lime on land claims our first interest.
Soil Acidity.--Lime performs various offices in the soil, but farmers
should be concerned chiefly about only one, and that is the destruction
of acids and poisons that make the soil unfriendly to most forms of
plant life, including the clovers, alfalfa, and other legumes. Lime was
put into all soils by nature. Large areas were originally very rich in
lime, while other areas of the eastern half of the United States never
were well supplied. Within the last ten years it has been definitely
determined that a large part of this vast territory has an actual lime
deficiency, as measured by its inability to remain alkaline or "sweet."
Many of the noted limestone valleys show marked soil acidity. There has
been exhaustion of the lime that was in a state available for union
with the acids that constantly form in various ways. The area of soil
thus deficient grows greater year by year, and it can be only a matter
of time when nearly all of the eastern half of this country will have
production limited by this deficiency unless applications of lime in
some form are made. When owners of soil that remains rich in lime do
not accept this statement, no harm results, as their land does not need
lime. On the other hand are tens of thousands of land-owners who do not
recognize the need of lime that now exists in their soils, and suffer a
loss of income which they would attribute to other causes.
Irrational Use of Lime.--Some refusal to accept the facts respecting
soil acidity and its means of correction is due to a prejudice that was
created by an unwise use of lime in the past. Owners of stiff limestone
soils learned in an early day that a heavy application of caustic lime
would increase crop production. It caused such flocculation of the fine
particles in their stiff soils that physical condition was improved,
and it made the organic matter in the soil quickly available as
plant-food. The immediate result was greater crop-producing power in
the soil, and dependence upon lime as a fertilizer resulted. The
vegetable matter was used up, some of the more available mineral
plant-food was changed into soluble forms, and in the course of years
partial soil exhaustion resulted. The heavy applications of lime,
unattended by additions of organic matter in the form of clover sods
and stable manure, produced a natural result, but one that was not
anticipated by the farmers. The prejudice against the use of lime on
land was based on the effects of this irrational practice.
There are land-owners who are not concerned with present-day knowledge
regarding soil acidity because they cannot believe that it has any
bearing upon the state of their soils. They know that clover sods were
easily produced on their land within their remembrance, and that their
soils are of limestone origin. As the clovers demand lime, these two
facts appear to them final. The failures of the clovers in the last ten
or twenty years they incline to attribute to adverse seasons, poor
seed, or the prevalence of weed pests. They do not realize that much
land passes out of the alkaline class into the acid one every year. The
loss of lime is continuous. Exhaustion of the supply capable of
combining with the harmful acids finally results, and with the
accumulation of acid comes partial clover failure, a deficiency in rich
organic matter, a limiting of all crop yields, and an inability to
remain in a state of profitable production.
Lime deficiency and its resulting ills would not exist as generally as
is now the case if the application of lime to land were not expensive
and disagreeable. These are deterrent features of wide influence. There
continues hope that the clover will grow successfully, as occasionally
occurs in a favorable season, despite the presence of some acid. The
limitation of yields of other staple crops is not attributed to the
lack of lime, and the proper soil amendment is not given to the land.
Where Clover is not Wanted.--The ability to grow heavy red clover is a
practical assurance that the soil's content of lime is sufficiently
high. When clover fails on account of a lime deficiency, the work of
applying lime may not be escaped by a shift in the farm scheme that
permits the elimination of clover. The clover failure is an index of a
condition that limits the yields of all staple crops. The lack of lime
checks the activity of bacteria whose office it is to prepare
plant-food for use. The stable manure or sods decompose less readily
and give smaller results. Soil poisons accumulate. Mineral plant-food
in the soils becomes available more slowly. Physical condition grows
worse.
The limitations of the value of manure and commercial fertilizers
applied to land that has a lime deficiency have illustration in an
experiment reported by the Cornell station:
The soil was once a fertile loam that had become very poor. A part was
given an application of lime, and similar land at its side was left
unlimed. The land without lime and fertilizer of any kind made a yield
of 1824 pounds of clover hay per acre. A complete fertilizer on the
unlimed land made the yield 2235 pounds, and 15 tons of manure on the
unlimed land made the yield 2091 pounds.
Where lime had been applied, the unfertilized land yielded 3852 pounds
per acre, the fertilized, 4085 pounds, and the manured, 4976 pounds.
The manure and fertilizer were nearly inactive in the acid soil. The
lime enabled the plants to obtain benefit from the plant-food.
Determining Lime Requirement.--It is wasteful to apply lime on land
that does not need it. As has been said, the man who can grow heavy
clover sods has assurance that the lime content of his soil is
satisfactory. This is a test that has as much practical value as the
analysis of a skillful chemist. The owner of such land may dismiss the
matter of liming from his attention so far as acidity is concerned,
though it is a reasonable expectation that a deficiency will appear at
some time in the future. Experience is the basis of such a forecast.
Just as coal was stored for the benefit of human beings, so was lime
placed in store as a supply for soils when their unstable content would
be gone.
The only ones that need be concerned with the question of lime for
soils are those who cannot secure good growths of the clovers and other
legumes. Putting aside past experience, they should learn whether their
soils are now acid. Practical farmers may judge by the character of the
vegetation and not fail to be right nine times out of ten. Where land
has drainage, and a fairly good amount of available fertility, as
evidenced by growths of grass, a failure of red clover leads
immediately to a strong suspicion that lime is lacking. If alsike
clover grows more readily than the red clover, the probability of
acidity grows stronger because the alsike can thrive under more acid
soil conditions than can the red. Acid soils favor red-top grass rather
than timothy. Sorrel is a weed that thrives in both alkaline and acid
soils, and its presence would not be an index if it could stand
competition with clover in an alkaline soil. The clover can crowd it
out if the ground is not too badly infested with seed, and even then
the sorrel must finally give way. Where sorrel and plantain cover the
ground that has been seeded to clover and grass, the evidence is strong
that the soil conditions are unfriendly to the better plants on account
of a lime deficiency. The experienced farmer who notes the inclination
of his soil to favor alsike clover, red-top, sorrel, and plantain
should infer that lime is lacking. If doubt continues, he should make a
test.
The Litmus-paper Test.--A test of fair reliability may be made with
litmus paper. A package of blue litmus paper can be bought for a few
cents at any drug store. This paper will turn pink when brought into
contact with an acid, and will return to a blue if placed in
lime-water. A drop of vinegar on a sheet of the paper will bring an
immediate change to pink. If the pink sheet be placed in lime-water,
the effect of the lime in correcting the acidity will be evidenced by
the return in color to blue.
To test the soil, a sample of it may be put into a basin and moistened
with rain-water. Several sheets of the blue litmus paper should be
buried in the mud, care being used that the hands are clean and dry.
When one sheet is removed within a few seconds and rinsed with
rain-water, if any pink shows, there is free acid present. Another
sheet should be taken out in five minutes. The rapidity with which the
color changes, and the intensity of the color, are indicative of the
degree of acidity, and aid the judgment in determining how much lime
should be used. If a sheet of the paper retains its blue color in the
soil for twenty minutes, there probably is no lime deficiency. The test
should be made with samples of soil from various parts of the field,
and they should be taken beneath the surface. One just criticism of
this test is that while no acidity may be shown, the lime content may
be too low for safety.
[Illustration: Red clover on limed and unlimed land.]
A Practical Test.--The importance of alkalinity in soils is so great,
and the prevalence of acidity has such wide-spread influence to-day,
limiting the value of the clovers on a majority of our farms, that a
simple and more convincing test is suggested here. Every owner of land
that is not satisfactorily productive may learn the state of his soil
respecting lime requirement at small expense. When a field is being
prepared for seeding to the grain crop with which clover will be sown,
a plat containing four square rods should be measured off, and
preferably this should be away from the border to insure even soil
conditions. A bushel of lump-lime, weighing eighty pounds, should be
slaked and evenly distributed over the surface of the plat of ground.
It can be broadcasted by hand if a spreader is not available, and mixed
with the surface soil while in a powdered state. The plat of ground
should be left as firm as the remainder of the field, so that all
conditions may be even for the test. The appearance of the clover the
following year will determine whether lime was needed or not. There is
no reason why any one should remain in doubt regarding the lime
requirement of his fields. If income is limited by such a cause, the
fact should be known as soon as possible.
Duration of Effect.--Soil acidity is not permanently corrected by a
lime application. The original supply failed to prove lasting, and the
relatively small amount given the land in an application will become
exhausted. The duration depends upon the degree of acidity, the nature
of the soil and its crops, and the size of the application. Experiments
at the Pennsylvania experiment station have shown that an application
only in sufficient amount to correct the existing acidity at the time
of application will not maintain an alkaline condition in the soil,
even for a few months. There must be some excess at hand to unite with
acids as formed later in the crop-rotation, or limings must be given at
short intervals of time to maintain alkaline conditions.
Experience causes us to assume that enough lime should be applied at
one time to meet all requirements for a single crop-rotation of four,
five, or six years, and, wherever lime is cheap, the unpleasant
character of the labor inclines one to make the application in
sufficient amount to last through two such rotations. It is a
reasonable assumption, however, that more waste results from the
heavier applications at long intervals than from light applications at
short intervals. In any event need will return, and soil acidity will
again limit income if applications do not continue to be made.
CHAPTER III
APPLYING LIME
Forms of Lime.--There is unnecessary confusion in the mind of the
public regarding the forms of lime that should be used. If amounts
greatly in excess of needs were being applied, the form would be a
matter of concern. There would arise the question of soil injury that
might result from the use of the lime in caustic form. Again, if
pulverized limestone were used, a very heavy application would bring up
the question of coarseness in order that waste by leaching might be
escaped. Most farms needing lime do not have cheap supplies, and the
consideration is to secure soil alkalinity at a cost that will not be
excessive. Freight rates and the cost of hauling to the fields, added
to first cost of the lime, limit applications on most farms to the
necessities of a single crop-rotation which includes clover, or, at the
most, to two crop-rotations. Under these circumstances it is best to
let cost of correction of soil acidity determine the form of lime to be
used.
The material that will render the soil friendly to clover for the least
money is the right one to select. We need to be concerned only with the
relative efficiencies of the various forms of lime, as measured in
terms of money. That which will most cheaply restore heavy clover
growths to the land is the form of lime to be desired. The contentions
of salesmen may well be disregarded as they produce confusion and delay
a work that is important to the farmer.
Definitions.--The use of the various forms of lime will become general,
and the terms employed to designate them should be understood. They
vary in their content of acid-correcting material, and their correct
names should be used with accuracy.
_Stone-lime_, often called lump-lime or unslaked lime, or calcium oxide
or CaO, is a form widely known, and may be taken as a standard. It is
the ordinary lime of commerce, and is obtained by the burning of
limestone. One hundred pounds of pure limestone will produce 56 pounds
of stone-lime (CaO).
_Pulverized lime_, often called ground lime, is stone-lime after being
pulverized to permit even distribution. When it is fully exposed to the
air or moisture, it slakes and doubles in volume.
_Hydrated lime_, often called slaked lime, is a combination of
stone-lime and water. The water causes an increase in weight of 32 per
cent, 56 pounds of stone-lime becoming 74 pounds of the hydrate.
_Pulverized limestone_, often called carbonate of lime, is the unburned
limestone made fine so that good distribution may be possible.
_Air-slaked lime_, often called carbonate of lime, is stone-lime or
hydrated lime combined with carbonic acid from the air, and thereby
increased in weight. Fifty-six pounds of stone-lime, or 74 pounds of
hydrated lime, become 100 pounds of air-slaked lime.
_Agricultural lime_, or land-lime, may embrace anything that the
manufacturer of lime chooses to market. It may be reasonably pure
unslaked lime, or it may have less value than a finely pulverized pure
limestone. There is a custom of grinding the core, or partially burned
limestone of the kiln, together with impurities removed from builders'
lime, and with this may be put some air-slaked lime. Some manufacturers
market under this name a lime of excellent value. There is no standard,
and one should not pay more than a finely pulverized pure limestone
would cost unless he knows that the content of fresh burned lime is
high.
The element with which we are concerned in any of these forms of lime
is calcium. It is the base whose union with the acids destroys the
latter. It should be obvious that the addition of water to stone-lime,
which adds weight and causes 56 pounds of the stone-lime to become 74
pounds of hydrated lime, adds no calcium. Likewise the change to the
air-slaked condition adds no calcium, but again adds weight.
The Kind to Apply.--If a soil contains free acid, the amount of calcium
needed is definite. The form of lime that can supply the need in that
particular field at least expenditure of money and trouble is the one
to be selected. A ton of stone-lime, or pulverized lime, can correct as
much acid as 2640 pounds of hydrated lime or 3570 pounds of pulverized
limestone, if all the original material was pure.
In other words, if the value of a given weight of pulverized limestone
is placed at 100, the value of the same weight of hydrated lime would
be 132 and the value of stone-lime would be 180, when each was finely
divided and distributed throughout the surface soil.
The Fineness of Limestone.--Experiments at the Pennsylvania experiment
station have shown that limestone has practically immediate
availability in an acid soil if all of it has ability to pass through a
screen having 60 meshes to the linear inch. Much of the limestone
meeting this test doubtless is fine enough to pass through an 100-mesh
screen. The requirement that a 60-mesh screen be used in testing is a
satisfactory one to the buyer that wants immediate results in the
field. A coarser product must be used in larger amount per acre, as
only the fine particles are available at once, and the object of the
application is to correct all the acidity. Where a coarse product,
containing some fine particles, can be used at such a low price per ton
that the application may consist of a large number of tons per acre,
the practice may be commended, but the essential thing is immediate
results, and only finely divided limestone can give them. Any long
railway or wagon haul makes a heavy application of coarsely pulverized
limestone inexpedient.
Hydrated Lime.--Many salesmen are too enthusiastic in their claims for
hydrated lime. It has advantages over pulverized limestone, stone-lime,
and pulverized lime, and there are disadvantages. The buyer of
pulverized limestone pays for the haul on 100 pounds of material to get
the 56 pounds of lime carried, while 74 pounds of the hydrate furnish
the same amount of actual lime, if all of it is a hydrate. While the
hydrate contains less strength than the stone-lime, it is in good
physical condition for distribution, and the stone-lime must be slaked.
The buyer will bear in mind, moreover, that much of the stone-lime
which is burned on farms comes from limestone that is not very pure,
and all impurity is waste. Most manufacturers of the hydrate locate
their costly plants where the limestone is relatively pure. Prudent
business reasons dictate such a course. A careful manufacturer of
hydrated lime takes out imperfectly burned and other faulty material
with screens. These advantages have some weight, but the fact remains
that a ton of pure stone-lime has considerably more acid-correcting
power than a ton of the hydrate.
Stone-lime.--Stone or lump-lime is composed of the 56 per cent of a
pure limestone that gives value to the limestone. Forty-four pounds of
waste material were driven off in the burning. Where railway or wagon
hauls are costly, the purchase of stone-lime is indicated. There is
advantage in getting this lime in pulverized form, provided it can be
distributed in the soil before moisture from the air induces slaking
and consequent bursting of the packages. The necessity of rapid
handling has limited the popularity of pulverized unslaked lime, but no
other form is equal to it when it is wholly unslaked. Some
manufacturers grind the partially burned limestone often found in
kilns, and furnish goods little better than pulverized limestone.
The slaking of stone-lime should be done in a large pile, and the
distribution may be made with lime-spreaders. When the application is
fairly heavy, a manure-spreader does satisfactory work. A good
lime-spreader is to be desired, but care must be used to remove any
stones or similar impurities in the slaked lime when filling it. Such
spreaders are on the market.
The practice of slaking lime in small piles in the field is wasteful.
It is difficult to reduce all the lime to a fine powder and to make
even distribution over the surface. Any excess of water from rains
puddles some of the lime, destroying practically all its immediate
effectiveness. Distribution with shovels is necessarily imperfect.
The labor of slaking stone-lime and the difficulty in distribution are
two factors to be considered when selecting the form of lime to be
used. They may counter-balance in some instances the higher percentage
of actual lime when comparison is made with the hydrate. That is a
question to be decided by the buyer. He must be willing to use methods
that will secure even distribution. The prevailing practice, however,
of marketing the hydrate at a much higher price per ton than the
stone-lime should prevent sales to farmers. The price paid for ease of
handling is too great when purchase of the hydrate is made under such
circumstances. It is better to do the slaking at home, furnishing the
added weight of 32 per cent in water on the farm.
Ashes.--Hard-wood ashes have ceased to have much importance as a source
of lime for land, but their use is held in high esteem even by those
who regard fertilizers as mere stimulants and doubt the efficiency of
lime. Hard-wood ashes, unleached, clean and dry, are valuable for acid
soils. Their content of potash, which is variable and averages about 4
per cent, formerly was given all the credit for the soil improvement
and increased clover growth that resulted from their use. Tests with
other carriers of potash have shown that the potash probably produced
only a small part of the effect noted, and the benefit is attributable
to the lime in the ashes which exists in an effective form. The content
of lime is variable, and largely so on account of the percentage of
moisture and dirt that may be found in most ashes, and when no analysis
has been made, the estimate of value should not be based on more than
30 to 40 per cent of carbonate of lime. The price of ashes runs so
high, as a result of prejudice in favor of this well-known kind of soil
amendment, that it rarely is advisable to buy them. Pure lime is a
cheaper means of correcting the soil acidity, and the sulphate or the
muriate of potash is by far the cheaper source of potash.
Marl.--Marls vary widely in composition. When quite pure, they contain
90 or more per cent of carbonate of lime, and have a value per ton
about equal to finely pulverized limestone, and near half the value per
ton of stone-lime. There are marls that are carriers of potash and
phosphoric acid, and are to be valued accordingly as fertilizers.
Magnesian Lime.--Some limestone is a nearly pure calcium compound, and
yields a pure lime, while much limestone contains a high percentage of
magnesia. The latter is preferred by manufacturers who furnish
pulverized lime because it does not slake readily, and is less liable
to burst the packages before required for use. A pound of magnesian
lime will correct a little more acid than a pound of pure lime, and no
preference may be shown the latter on that score. There are soils in
which the proportion of magnesia to pure lime is too great for best
results with some plants, as plant biologists assure us, but there is
too little definite information respecting these soils to justify one
in paying more for a high calcium lime than for a magnesian lime when
it is to be used on acid land. The day may come when more will be
known, but the rational selection to-day is the material that will do
the required work in the soil for the least money.
Amount per Acre.--The amount of lime that should be applied to an acre
of land depends upon the degree of its acidity, the nature of the soil,
the cheapness of the lime, and the character of the crops to be grown.
The actual requirement for the moment could be determined by a chemical
test, but the application should carry to the soil an amount in excess
of immediate requirement. When clover has ceased to grow within recent
years, it is a fair inference that the deficiency, if it exists, has
not become great. When sorrel and plantain have gained a strong
foothold, indicating that good grasses are unable to replace clover,
the degree of acidity probably is higher. The results of tests at
experiment stations and on farms show that 1000 pounds of pulverized
lime, or one ton of pulverized limestone, evenly distributed throughout
the surface soil, can restore clover to the crop-rotation on much land.
This is an application so light that a state of alkalinity cannot be
long retained. It is better to apply the equivalent of a ton of
stone-lime in the case of all heavy soils that have shown any acidity.
Where lime is low in price, 3000 pounds of stone-lime, or its
equivalent in any other form of lime, is advised, the belief being that
such an application will maintain good soil conditions through two
crop-rotations, or eight to ten years. This amount can be applied quite
successfully with a manure-spreader, and meets the convenience of the
man who burns his own lime and does not want to screen it for use in a
lime-spreader. The man who must buy his lime, and pay a freight charge
upon it, will find it better to use only a ton per acre. This advice
applies to heavy soils. A light, sandy soil should be given only a
small application, as otherwise physical condition may be injured. The
lime, used in excess, has an undue binding effect upon the sand. An
application of 1000 pounds of stone-lime per acre can be made with
safety.
Time of Application.--The use of lime on land should be associated in
the land-owner's thoughts with the growing of clover. It does help soil
conditions so that more grain can be produced, but if it is permitted
to displace the use of fertilizers, and does not lead to the growth of
organic matter, harm will result in the end. Lime should be applied to
secure clover, and therefore it should be mixed with the soil before
the clover is sown. The application may be made when fitting the
seed-bed for the grain with which clover usually is seeded, or may be
given a year or two years previous to that time. The important point is
to have the soil friendly to plant life when a sod is to be made.
Lime should be put on ground always after the plowing, and it should be
well mixed with the surface soil. Even distribution is just as
important in its case as in that of fertilizers. A good practice is to
break a sod for corn, harrowing and rolling once, and then to put on
the lime. A cut-away or disk harrow should be used to mix the lime with
the soil before any moisture causes it to cake. When large crumbs form,
immediate efficiency is lost.
If the application is light, and may barely be equal to immediate
demand, it is better practice to put on the lime when preparing the
seed-bed for the wheat or other small grain in which the clover will be
sown. It should never be mixed with the fertilizer nor applied with the
seed. The lime should go into the soil a few days, or more, prior to
the seeding. The soil having been put into a condition favorable to
plant life, the seeding and the use of commercial fertilizers should
proceed as usual.
Lime should never be mixed with manure in the open air, but it is good
practice to plow manure down, and then to use lime as indicated above,
if needed. If manure and lime must be used after the land has been
plowed, the lime should be disked well into the soil before the manure
is applied, and it is advisable that the interval between the two
applications be made as long as possible.
CHAPTER IV
ORGANIC MATTER
Office of Organic Matter.--The restoration of an impoverished soil to a
productive state usually is a simple matter so far as method is
concerned. It may be a difficult problem for the individual owner on
account of expense or time involved, but he has only a few factors in
his problem. Assuming that there is good drainage, and that the lime
requirement has been met, the most important consideration is organic
matter. A profitable agriculture is dependent upon a high percentage of
humus in the soil. Average yields of crops are low in this country
chiefly because the humus-content has been greatly reduced by bad
farming methods.
[Illustration: Turning down organic matter with a gang plow.]
Nature uses organic matter in the following ways:
1. To give good physical condition to the soil. The practical
farmer appreciates the importance of this quality in a soil. Clayey
soils are composed of fine particles that adhere to each other.
They are compact, excluding air and failing to absorb the water
that should be held in them. The excess of water finally is lost
by evaporation, and the sticky mass becomes dry and hard. The
incorporation of organic matter with clay or silt changes the
character of such land, breaking up the mass, and giving it the
porous condition so essential to productiveness. Improved physical
condition is likewise given to a sandy soil, the humus binding the
particles together.
2. To make the soil retentive of moisture. Yields of crops are
limited more by lack of a constant and adequate supply of moisture
throughout the growing season than by any other one factor. Decayed
organic matter has great capacity for holding moisture, and in some
measure should supply the water needed during periods of light
rainfall.
3. To serve, directly and indirectly, as a solvent of the inert
plant-food in the soil that is known as the "natural strength" of
the land. Its acids do this work directly, and by its presence it
makes possible the work of the friendly bacteria that are man's
chief allies in maintaining soil fertility.
4. To furnish plant-food directly to growing plants. Even when it
has been produced from the soil supplies alone, there is great gain
because the growing crop must have immediately available supplies.
Many of the plants used in providing humus for the soil are better
foragers for fertility than other plants that follow, sending their
roots deeper into the subsoil or using more inert forms of
fertility.
The Legumes.--Any plant that grows and rots in the soil adds to the
productive power of the land if lime is present, but plants differ in
value as makers of humus. There are only ten essential constituents of
plant-food, and the soil contains only four that concern us because the
others are always present in abundance. If lime has been applied to
give to the soil a condition friendly to plant life, we are concerned
with three constituents only, viz. nitrogen, phosphoric acid, and
potash. The last two are minerals and cannot come from the air. They
must be drawn from original stores in the soil or be obtained from
outside sources in the form of fertilizers. The nitrogen is in the air
in abundance, but plants cannot draw directly from this store in any
appreciable amount. The soil supply is usually light because nitrogen
is unstable in character and has escaped from all agricultural land in
vast amounts during past ages.
Profitable farming is based upon the great fact that we have one class
of plants which can use bacteria to work over the nitrogen of the air
into a form available for their use, and the store of nitrogen thus
gained can be added to the soil's supply for future crops. These
plants, known as legumes, embrace the clovers, alfalfa, the vetches,
peas, beans, and many others of less value. They provide not only the
organic matter so much needed by all thin soils, but at the same time
they are the means of adding to the soil large amounts of the one
element of plant-food that is most costly, most unstable, and most
deficient in poor soils. Their ability to secure nitrogen for their own
growth in poor land also is a prime consideration in their selection
for soil improvement, assuring a supply of organic matter where
otherwise partial failure would occur.
Storing Nitrogen.--Man needs protection from his own greed, and
nature's checks are his salvation. An illustration is afforded in the
case of legumes grown for the maintenance of soil fertility. The
clovers and some other legumes are seeded primarily for the benefit of
the soil. The need of organic matter is recognized, and a cheap supply
of nitrogen is wanted for other crops in the rotation. The purpose of
the seeding is praiseworthy, but if all of the product were available
for use off the land, observation teaches that the soil producing the
crop probably would fare badly. The crops grown prior to the season
devoted to legumes proclaim their need of better soil conditions, more
organic matter, and more nitrogen, but the legumes, appropriating
nitrogen for themselves, give to the land a more prosperous appearance,
and the disposition to harvest everything that is in sight prevails.
There is the excusing intention to return to the soil the residue from
feeding, which should be nearly as valuable as the original material,
while the fact usually is that faulty handling of the manure results in
heavy loss, and the distribution of the remainder is imperfect. There
is no happier provision of nature for the guarding of the soil's
interests than the unavailability for man's direct use of a
considerable part of most plants, thus saving to the land a portion of
its share of its products. The humus obtained from plant-roots,
stubble, and fallen leaves forms a large percentage of all the humus
obtained by land whose fertility is not well guarded by owners. This
proportion is large in some legumes, amounting to 30 or 40 per cent in
the case of red and mammoth clover.
The Right Bacteria.--The word "bacteria" has had a grudging admission
to the vocabulary of practical farmers, and the reason is easily
stated. The knowledge of bacteria and their work is recent and limited.
They are many in kind, and scientists are only in the midst of their
discoveries. The practical farmer does well to let bacteriologists
monopolize interest in the whole subject except in so far as he can
provide some conditions that have been demonstrated to be profitable.
The work of bacteria must come more and more into consideration by the
farmer because nature uses them to produce a vast amount of the change
that is going on around us.
In consideration of the value of legumes we must take into account the
bacteria which they have associated with them, and through which they
obtain the atmospheric nitrogen. This would be a negligible matter, it
may be, if all legumes made use of the same kind of bacteria. It is
true that the bacteria must have favorable soil conditions, but they
are the same favorable conditions that our plants require. A fact of
importance to the farmer is that the bacteria which thrive on the roots
of some legumes will not serve other legumes. This is a reason for many
failures of alfalfa, crimson clover, the soybean, the cowpea, hairy
vetch, and other legumes new to the region.
Soil Inoculation.--The belief that the right kind of bacteria may be
absent from the soil when a new legume is seeded, and that they should
be supplied directly to the soil, has failed in ready acceptance
because examples of success without such inoculation are not uncommon.
Even if the explanation of such success is not easy, the fact remains
that legumes new to a region usually fail to find and develop a supply
of bacteria adequate for a full yield, and some of these legumes, of
which alfalfa is an example, make a nearly total failure when seeded
for the first time without soil inoculation. Experiment stations and
thousands of practical farmers have learned by field tests that the
difference between success and failure under otherwise similar
conditions often has been due to the introduction of the right bacteria
into the soil before the seeding was made.
Explanations offered for any phenomenon may later become embarrassing
in the light of new knowledge. We do not really need to know why an
occasional soil is supplied with the bacteria of a legume new to it. We
have learned that the bacteria of sweet clover serve alfalfa, and this
accounts for the inoculation of some regions in the east. We believe
that some bacteria are carried in the dust on the seed, and produce
partial inoculation. Other causes are more obscure. The cowpea trails
on the ground, and carries its bacteria more successfully than the
soybean. Most legumes require a soil artificially inoculated when
brought into a new region, failing otherwise in some degree to make
full growth.
Method of Inoculation.--The bacteria can be transferred to a new field
by spreading soil taken from a field that has been growing the legume
successfully. The surface soil is removed to a depth of three inches,
and the next layer of soil is taken, as it contains the highest
percentage of bacteria. They develop in the nodules found on the
feeding roots of the plants. The soil is pulverized and applied at the
rate of 200 pounds per acre broadcast. If the inoculated soil is near
at hand and inexpensive, 500 pounds should be used in order that the
chance of quick inoculation may be increased. The soil should be spread
when the sun's rays are not hot, and covered at once with a harrow, as
drying injures vitality. The soil may be broadcasted by hand or applied
with a fertilizer distributer. The work may be done at any time while
preparing the seed-bed. The bacteria will quickly begin to develop on
the roots of the young plants, and nodules may be seen in some
instances before the plants are four weeks old.
Pure cultures may be used for inoculation. Some commercial concerns
made failures and brought the use of pure cultures into disrepute a few
years ago, but methods now are more nearly perfect, and it is possible
to buy the cultures of all the legumes and to use them with success.
Prices continue too high to make the pure cultures attractive to those
who can obtain inoculated soil with ease. If land has been producing
vigorous plants, and if it contains no weeds or disease new to the land
to be seeded, its soil offers the most desirable means of transferring
the bacteria.
The claim is made by some producers of pure cultures that their
bacteria are selected for virility, and should be used to displace
those found in the farmer's fields. The chances are that, if soil
conditions are good, the bacteria present in the soil are virile, and
if the conditions are bad, the pure cultures will not thrive. All
eastern land is supplied with red clover bacteria, just as some western
land possesses alfalfa bacteria, and partial clover failure has causes
wholly apart from the character of its bacteria.
We do not have definite knowledge concerning duration of inoculation
nor the manner in which it is maintained when legumes are not growing,
but we do know that when a legume has once made vigorous growth in a
field, the soil will remain inoculated for a long term of years.
CHAPTER V
THE CLOVERS
Red Clover.--Wherever red clover thrives there is no more valuable
plant than this legume for making and keeping soils productive under
ordinary crop-rotations. The tyro in farming finds his neighbors
conservative in thought and method, and may rightly see room for
improvement. He naturally turns to new crops that are receiving much
exploitation, but should bear in mind that the world nowhere has found
a superior to red clover as a combined fertilizing and forage crop for
use in short rotations. Farmers turn aside from it because it turns
aside from them. There has been increasing clover failure in our older
states for a long term of years. It has become the rule to seed to
timothy with the clover in the short crop-rotations as well as in the
longer ones, and chiefly for the reason that clover seeding has become
no longer dependable. In many regions the proportion of timothy seed
used per acre has been made large because the clover would not surely
grow. In the winter-wheat belt, where the custom has been to make such
seedings with wheat, timothy being sown in the fall and clover the next
spring, this increase in the timothy has made matters worse for the
clover, but it has helped to insure a sod and a hay crop. "Clover
sickness," supposedly resulting from close clover rotations, and the
prevalence of plantain and other weeds, have been assigned as a partial
cause of clover failure. It is only within recent years that the true
cause of much failure has been recognized.
Clover and Acid Soils.--There are limited areas in which some clover
disease has flourished, and in some years insect attacks are serious.
Barring these factors which have relatively small importance when the
entire clover area is taken into account, the causes of clover failure
are under the farmer's control. The need of drainage increases, and the
deficiency in organic matter becomes more marked. The sale of hay and
straw, and especially the loss of liquid manures in stables, have
robbed many farms. These are adverse influences upon clover seedings,
but the most important handicap to clover is soil acidity. There is sad
waste when high-priced clover seed is put into land so sour that clover
bacteria cannot thrive, and there is ten-fold more waste in letting
land fail to obtain the organic matter and nitrogen clover should
supply. When land-owners refuse to let their soils remain deficient in
lime, clover will come into a prominence in our agriculture that it
never previously has known.
Methods of Seeding.--It is a common practice to sow clover in the
spring, either with spring grain or with wheat or rye previously seeded
in the fall. This method has much to commend it. The cost of making the
seed-bed is transferred to the grain crop, and there is little outlay
other than the cost of seed. Wheat and rye offer better chances to the
young clover plants than do the oat crop which shades the soil densely
and ripens later in the summer. The amount of seed that should be used
depends upon the soil, the length of time the sod will stand, and the
purpose in growing the clover. When soil fertility is the one
consideration, 12 to 15 pounds of bright, plump medium red clover seed
per acre should be sown. A fuller discussion of the principles involved
in making a sod and of seed mixtures is given in Chapters VII and VIII.
Fertility Value.--Attempts have been made to express the actual value
of a good clover crop to the soil in terms of money. The number of
pounds of matter in the roots and stubble has been determined, and
analyses show the percentage of nitrogen, phosphoric acid, and potash
contained. The two crops harvested in the second year of its growth
likewise have their content of plant-food determined. If the total
amounts of nitrogen, phosphoric acid, and potash have their values
fixed by multiplying the number of pounds of each ingredient of
plant-food by their respective market values, as is the practice in the
case of commercial fertilizers, a total valuation may be placed upon
the clover, roots and top, as a fertilizer. Such valuation is so
misleading that it affords no true guidance to the farmer. In the first
place, the phosphoric acid and potash were taken out of the soil, and
while some part of these materials may have been without immediate
value to another crop until used by the clover, no one knows how much
value was given to them by the action of the clover. Again, no one
knows what percentage of the nitrogen in the clover came from the air,
and how much was drawn from the soil's stores. The proportion varies
with the fertility of the land, the percentage of nitrogen taken from
the air being greater in the case of badly depleted soils.
A big factor of error is found in the valuations of the ingredients
found in the crop. All plant-food is worth to the farmer only what he
can get out of it. He may be able to use 50 pounds of nitrogen per acre
in the form of nitrate of soda, at 18 cents a pound, when growing a
certain crop, but could not afford to buy, at market price of organic
nitrogen, all the nitrogen found in the clover crop, and therefore it
does not have that value to him.
On the other hand, these estimates do not embrace the great benefit to
the physical condition of the soil that results from the incorporation
of a large amount of vegetable matter.
Discussion has been given to this phase of the question in the interest
of accuracy. Values are only relative. The practical farmer can
determine the estimate he should put upon clover only by noting its
effect upon yields in the crop-rotation upon his own farm. It is our
best means of getting nitrogen from the air, it provides a large amount
of organic matter, it feeds in subsoil as well as in top soil, bringing
up fertility and filling all the soil with roots that affect physical
condition favorably, and it provides a feed for livestock that gives a
rich manure.
[Illustration: Red clover on the farm of P. S. Lewis and Sons, Point
Pleasant, W. Va.]
Taking the Crops off the Land.--The feeding value of clover hay is so
great that the livestock farmer cannot afford to leave a crop of clover
on the ground as a fertilizer. The second crop of red clover produces
the seed, and, if the yield is good, is very profitable at the prices
for seed prevailing within recent years. The amount of plant-food taken
off in the hay and seed crops would have relatively small importance if
manure and haulm were returned without unnecessary waste. Van Slyke
states that about one third of the entire plant-food value is contained
in the roots, while 35 to 40 per cent of the nitrogen is found in the
roots and stubble. Hall instances one experiment at Rothamstead in
which the removal of 151 pounds of nitrogen in the clover hay in one
year left the soil enough richer than land by its side to produce 50
per cent more grain the next year. He cites another experiment in which
the removal of three tons of clover hay left the soil so well supplied
with nitrogen that its crop of Swede turnips two years later was over
one third better than that of land which had not grown clover, the
application of phosphoric acid and potash being the same. When two tons
of well-cured clover hay are harvested in June, removing about 80
pounds of nitrogen, 45 to 50 pounds are left for the soil. The amounts
of potash are about the same, while phosphoric acid is much less in
amount.
Physical Benefit of the Roots.--While the roots and stubble contain
less than two fifths of the total plant-food in a clover crop, one may
not safely infer that the removal of the crop for hay reduces the
beneficial effect of the clover to the soil fully 60 per cent, or more.
The roots break up the soil in a way not possible to a mass of tops
plowed down. They improve the physical condition of the subsoil as well
as the top soil. The amount of the benefit depends in part upon the
nature of the land. Its value cannot be surely determined, but the
facts are called to mind as an aid to judgment in deciding upon the
method of handling the clover crop.
Used as a Green Manure.--Where dependence must be placed upon clover as
a fertilizer, little or no manure being returned to the land, at least
one of the two clover crops within the year should be left on the land.
The maximum benefit from clover, when left on the land, can be obtained
by clipping it before it is sufficiently heavy to smother the plants,
leaving it as a mulch. When the cutter-bar of the mower is tilted
upward, the danger of smothering is reduced. Truckers, remote from
supplies of manure, have found it profitable to make two such clippings
just prior to blossoming stage, securing a third heavy growth. The
amount of humus thus obtained is large, and the benefit of the mulch is
an important item.
Some growers clip the first crop for a mulch, and later secure a seed
crop. The early clipping and the mulch cause increase in yield of seed.
A common practice is to take one crop off for hay, and to leave the
second for plowing down the following spring. Early harvesting of the
clover for hay favors the second crop.
When to turn Down.--When the maximum benefit is desired for the soil
from a crop of clover, the first growth should not be plowed down. Its
office should be that of a mulch. In its decay all the mineral
plant-food and most of the nitrogen go into the soil. The second crop
should come to maturity, or near it. As a rule, there is gain, and not
loss, by letting the second crop lie on the ground until spring if a
spring-planted crop is to follow. Some fall growth, and the protection
from leaching, should equal any advantage arising from rotting the
bulky growth in the soil. In some regions it is not good practice to
plow down a heavy green crop on account of the excessive amount of acid
produced. When this has been done, the only corrective is a liberal
application of lime.
Mammoth Clover.--When clover is grown with timothy for hay, some
farmers prefer to use mammoth clover in place of the medium red. It may
be known as sapling clover, and is accounted a perennial, though it is
little more so than the red. It is a strong grower and makes a coarse
stalk but, when grown with timothy, it has the advantage over the red
in that the period of ripening is more nearly that of the timothy. It
inclines to lodge badly, and should be seeded thinly with timothy when
wanted for hay. The roots run deep into the soil, and this variety of
clover compares favorably with the medium red in point of fertilizing
power, the total root-growth being heavier. While its yield of hay,
when seeded alone, is greater than the first crop of the red, its
inclination to lodge and its coarseness are offsets. It produces its
seed in the first crop, and the after-growth is small, while red clover
may make a heavy second crop. Its use should become more general on
thin soils, its strong root-growth enabling it to thrive better than
the red, and the lack of fertility preventing the stalks from becoming
unduly coarse for hay. The amount of seed used per acre, when grown by
itself, should be the same as that of red clover.
Alsike Clover.--A variety of clover that may have gained more
popularity than its merit warrants is alsike clover. It is more nearly
perennial than the mammoth. The roots do not go deep into the subsoil
like those of the red or the mammoth, and therefore it is better
adapted to wet land. It remains several years in the ground when
grazed, and is usually found in seed mixtures for pastures. It is
decumbent, and difficult to harvest for hay when seeded alone. It is
credited with higher yields than the red by most authorities, but this
is not in accord with observation in some regions, and it is markedly
inferior to the red in the organic matter and the nitrogen supplied the
soil in the roots.
The popularity of this clover is due to its ability to withstand some
soil acidity and bad physical conditions. In regions where red clover
is declining on account of lack of lime, one may see some alsike. The
rule is to mix alsike with the red at the rate of one or two bushels of
the former to six bushels of the latter. As the seed of the alsike is
hardly half as large as that of the red, the proportion in the mixture
is greater than some farmers realize. The practice is an excellent one
where the red will not grow, and the alsike adds fertility, but when
the soil has been made alkaline, the red clover should have nearly all
the room. Alsike is a heavy producer of seed.
Crimson Clover.--Wherever crimson clover is sufficiently hardy to
withstand the winter, as in Delaware and New Jersey, it is a valuable
aid in maintaining and increasing soil fertility. It is a winter
annual, like winter wheat, and should be seeded in the latter half of
summer, according to latitude. It comes into bloom in late spring. The
plant has a tap-root of good length, but in total weight of roots is
much inferior to the red. This clover, however, compares favorably with
red clover in the total amount of nitrogen added to the soil by the
entire plant when grown under favorable conditions. It is peculiarly
fitted for a cover crop in orchards and wherever spring crops are
removed as early as August, or a seeding can be made in them, as is the
case with corn. Even when winter kills the plants, a successful fall
growth is highly profitable, adding more nitrogen before winter than
red clover seeded at the same time. Where the plants do not
winter-kill, they are plowed down for green manure when in bloom in
May, or earlier in the spring to save soil moisture and permit early
planting, although a good hay for livestock can be made, and the yield
is about the same as that of the first crop of red clover.
In the northern states a large amount of money has been wasted in
experimental seedings with crimson clover, and it is only in
exceptional cases that it continues to be grown. There is reason to
believe that many of these failures were due to lack of soil
inoculation. The Pennsylvania experiment station is located in a
mountain valley where winters are severe. Crimson clover is under test
with other cover crops for an experimental orchard, and success with it
has increased as the soil has become fully inoculated. This view is
supported by the experience of various growers in the North, and while
crimson clover can never make the success in a cold climate that it
does in Delaware, there is a much wider field of usefulness for it than
is now occupied. Experiments should be made with it under favorable
conditions respecting moisture and soil tilth. Fifteen pounds of seed
should be used, and the seed should be well covered, as is the case
with all seeds sown in mid-summer.
CHAPTER VI
ALFALFA
Adaptation to Eastern Needs.--The introduction of alfalfa into the
eastern half of the United States will prove a boon to its depleted
soils, encouraging the feeding of livestock and adding to the value of
manures. It will affect soils directly, as does red clover, when
farmers appreciate the fact that its rightful place on their farms is
in rotation with grain. Under western conditions, where no other crop
can compete with it in value, as is the case in semi-arid belts, its
ability to produce crops for a long term of years adds much to its
value, but in eastern agriculture this characteristic is not needed. On
most soils of the east it will not remain productive for more than four
to six years, and that fact detracts little from its value. It should
fit into crop-rotations, adding fertility for grain crops. When grown
in a six-years rotation with corn and oats or other small grain, it
furnishes a rich sod for the corn, and the manure made from the hay
helps to solve the farmer's fertility problem.
Fertility and Feeding Value.--Vivian says that "the problem of the
profitable maintenance of fertility is largely a question of an
economic method of supplying plants with nitrogen." The greatest value
of alfalfa to eastern farming lies in its ability to convert
atmospheric nitrogen into organic nitrogen. It has no equal in this
respect for relatively long crop-rotations, storing in its roots and
successive growths of top far more nitrogen within three or four years
than is possible to any other of our legumes. A good stand of alfalfa,
producing nine crops of hay in the three years following the season of
seeding, will produce from nine to twelve tons of hay. Good fields,
under the best conditions, have produced far more, but the amounts
named are within reach of most growers on land adapted to the plant. A
ton of hay, on the average, contains as much nitrogen as five or six
tons of fresh stable manure. Thus there comes to the farm a great
amount of plant-food, to be given the land in the manure, and in
addition the roots and stubble have stored in the ground enough
nitrogen to feed a successive corn crop, and a small grain crop which
may follow the corn. Moreover, the roots have filled the soil with
organic matter, improving the physical condition of the soil and
subsoil.
[Illustration: Alfalfa on the Ohio State University Farm.]
Another gain is found in the content of phosphoric acid and potash in
the manure, much of which was drawn from soil supplies out of reach of
the other farm crops. The profit from introduction of alfalfa into a
region's agriculture is very great.
Alfalfa makes a nutritious and palatable feed for livestock. A ton
contains as much digestible protein as 1600 pounds of wheat bran.
Climate and Soil.--The experimentation with alfalfa by farmers has been
wide-spread, and the percentage of failure has been so large that many
have believed this legume was unfitted to the climate and soil of the
country east of the Missouri River. Successful experience has shown
that it can be made to take a considerable place in eastern
crop-schemes. The climate is not unfavorable, as is evidenced by large
areas of good alfalfa sods on thousands of farms. The abundant rainfall
brings various weeds and grasses into competition with it, and that
will remain a serious drawback until growers learn to clean their
surface soils by good tillage before seeding.
Any land that is sufficiently well drained to produce a good corn crop
in a wet summer can grow alfalfa if the seed-bed is rightly made. The
loose soils are more difficult to seed successfully than is the land
having enough clay to give itself body, although most experimenters
select their most porous soils. All farms having good tilth can bring
alfalfa into their crop-rotations.
Free Use of Lime.--The conditions requisite to success in
alfalfa-growing are not numerous, but none can be neglected. Alfalfa
should be given a calcareous soil when possible, but an acid soil can
be made favorable to alfalfa by the free use of lime. There must remain
a liberal amount after the soil deficiency has been met, and when the
use of lime is on a liberal scale, the pulverized limestone makes the
safest carrier. However, 50 bushels of stone-lime per acre can be used
safely on any land that is not distinctly sandy, and that amount is
adequate in most instances.
Inoculation.--The necessity of inoculation has been discussed in
Chapter IV. Eastern land would become inoculated for alfalfa if farmers
would adopt the practice of mixing a little alfalfa with red clover
whenever making seedings. Some alfalfa plants usually make growth,
securing the bacteria in the dust of the seed, presumably. The addition
of one pound of alfalfa seed per acre would assist materially in
securing a good stand when the day came that an alfalfa seeding was
desired.
Fertilization.--The ability of alfalfa to add fertility to the farm,
and directly to the field producing it when all the crops are removed
as hay, does not preclude the necessity of having the soil fertile when
the seeding is made. The plants find competition with grass and other
weeds keen under eastern skies where moisture favors plant-life. In
their first season this is markedly true. There should be plenty of
available plant-food for the young plants. Stable manure that is free
from the seeds of pernicious weeds makes an excellent dressing. It is
good practice to plow down a heavy coat of manure for corn and then to
replow the land for alfalfa the next season. A top-dressing of manure
is good, affording excellent physical condition of the surface for
starting the plants. Eight tons per acre make a good dressing.
If land is not naturally fertile, mineral fertilizers should be
applied. A mixture of 350 pounds of 14 per cent acid phosphate and 50
pounds of muriate of potash is excellent for an acre of manured land.
In the absence of manure, 100 pounds of nitrate of soda and 50 pounds
of muriate of potash should be added to the mixture. If the materials
are wet, a drier must be used. The fertilizer should be drilled into
the ground prior to the seeding.
A Clean Seed-bed.--Much failure with alfalfa is due to summer grasses
and other weeds. The moisture in our eastern states favors plant-life,
and most soils are thoroughly stocked with the seeds of a large number
of weeds. The value of blue-grass and timothy would be comparatively
small if they were not capable of monopolizing the ground when well
started and given fertility. Alfalfa plants are less capable of
crowding out other plants, and especially in their first season. Their
habit of growth is unlike that of grass. Rational treatment of alfalfa
demands that the surface soil be made fairly clean of weed seed, and
this applies with peculiar force to annual grasses, like fox-tail. If
attention were paid to this point, failures would be far less numerous.
Old grass land should not be seeded until a cultivated crop has
followed the plowing. The land should be in good tilth, and capable of
producing a good crop of any sort. Alfalfa is not a plant for poor
land, although it does add organic matter and nitrogen.
Varieties.--There is only one variety of alfalfa in common use in this
country, and the western-grown seed sold upon the market is known
simply as alfalfa. Bound up in this one so-called variety are many
strains differing in habit of growth, and their differentiation will
occur, just as it has in the case of wheat, and is now proceeding
slowly with timothy. The eastern grower at present should use the
variety of the west that is furnishing nearly all the seed produced in
this country. There is a variety known as Sand Lucerne that has shown
value for the light, sandy soils of Michigan. The Turkestan variety was
introduced for dry, cold regions, but does not produce much seed.
Clean Seed.--Care should be exercised to secure seed free from
impurities. If one is not a competent judge, he should send a sample to
his state experiment station for examination. The practice of
adulteration is decreasing, but the seed may have been taken from land
infested with pernicious weeds.
The impurity most to be feared is dodder. There are several varieties,
the seeds varying in size and color. The same pest may be found in
clover fields, but the injury is less because the clover stands only
two years. The dodder seed germinates in the soil, and the plant
attaches itself to the alfalfa, losing its connection with the soil and
forming a mass of very fine vines that reach out to other alfalfa
plants. In this way it spreads, feeding on the sap of the host plants
and killing them.
When the infestation is in only a few spots in the field, the remedy is
to cover with straw, soak with kerosene oil, and burn. All the
infestation at the edges of these spots must be destroyed.
When the dodder is too widely distributed throughout the field to
permit of this treatment, the only course is to plow the field at once,
and to grow cultivated crops for two or three years. It is believed
that no variety of dodder produces seed freely in the eastern states,
and that the hay made from the first crop of alfalfa or red clover will
not contain any seed of this pernicious plant.
The Seeding.--When alfalfa has become established on eastern farms, the
difficulties in making new seedings will be smaller. The experience of
growers will save from mistakes in selection of soils and preparation
of the ground, and the thorough inoculation with the right bacteria
that can come only with time will do much to insure success. The
unwisdom of making seedings in ground filled with grass and other weed
seeds will be appreciated. It is quite probable that much successful
seeding will be made in wheat and oats, where the alfalfa is to stand
only one or two years. These practices are not for the beginner. His
land is not thoroughly supplied with bacteria, and every chance should
be given the alfalfa.
If there are no annual grasses, such as appear so freely in some
regions in mid-summer, spring seeding is excellent. A cover crop is
then desirable, and nothing is better for this purpose than barley at
the rate of 4 pecks of seed per acre. In all experimental work 25
pounds of bright, plump alfalfa seed per acre should be sown. The
seeding should be made as soon as spring comes, the barley being
drilled in, and the seed-spouts of the drill thrown forward so that the
alfalfa will fall ahead of the hoes and be covered by them.
Seeding in August.--Much land is infested with annual grasses and other
weeds, and in such case seedings should be made in August, as described
in Chapter VIII.
Subsequent Treatment.--If the alfalfa plants find the bacteria at hand,
they will begin to profit from them within the first month of their
lives. A large percentage of the plants may fail to obtain this aid in
land which has not previously grown alfalfa, and within a few months
they indicate the failure by their light color, while the plants
liberally supplied with nitrogen through bacteria become dark green.
Where there are no bacteria, the plants turn yellow and die.
There are diseases that attack alfalfa, causing the leaves to turn
yellow, and when they appear, the only known treatment of value is to
clip the plants with a mower without delay. The next growth may not
show any mark of the diseases.
[Illustration: Curing alfalfa at the Pennsylvania Experiment Station.]
When alfalfa is seeded in the spring on rich land, a hay crop may be
taken off the same season. If the plants do not make a strong growth,
they should be clipped, and the tops should be left as a mulch. The
clipping and all future harvestings are made when the stalks start buds
from their sides near the ground. This ordinarily occurs about the time
some flowers show, and is the warning that the old top should be cut
off, no matter how small and unprofitable for harvesting it may be. The
exception to this rule is found only in the fall. An August seeding may
make such growth in a warm and late autumn that flowering will occur,
and lateral buds start, but the growth should not be clipped unless
there remains time to secure a new growth large enough to afford winter
protection. This is likewise true of a late growth in an old alfalfa
field.
Owners of soils that are not well adapted to the alfalfa plant will
find top-dressing with manure helpful to alfalfa fields when made in
the fall. The severity of winters in a moist climate is responsible for
some failures. If the soil is not porous, heaving will occur. A
dressing of manure, given late in the fall, and preferably during the
first hard freeze, will prevent alternate thawings and freezings in
some degree. The manure should have been made from feed containing no
seeds of annual grasses or other weed pests.
Rolling in the spring does not serve to settle heaved alfalfa plants.
The tap-roots are long, and when they have been lifted by action of
frost, they cannot be driven back into place.
It is believed that the permanence of an alfalfa seeding may be
increased by the use of mineral fertilizers in the early spring. In the
case of one alfalfa field of fifteen years' standing in the east, the
fertilizers were applied immediately after the first hay crop of the
year was removed. Three hundred and fifty pounds of acid phosphate and
50 pounds of muriate of potash per acre is the mixture recommended.
When old alfalfa plants do not stand thickly enough on the ground,
grasses and other weeds come in readily. They can be kept under partial
control by use of a spring-tooth harrow, the points being made narrow
so that no ridging will occur. The harrow should be used immediately
after the harvest, and will not injure the alfalfa.
It does not pay to use alfalfa for pasturage in our eastern states
because the practice shortens the life of the seeding.
Alfalfa makes a seed crop in profitable amount only in our semi-arid
regions. No attempt to produce a seed crop in the east should be made.
CHAPTER VII
GRASS SODS
Value of Sods.--The character of the sods is a faithful index of the
condition of the soil in any region adapted to grass. The value of
heavy sods to a soil cannot be overestimated. They not only give to a
farm a prosperous appearance, but our country's agriculture would be on
a much safer basis if heavy coverings of grass were more universal. We
do not hold the legumes in too high esteem, but the emphasis placed
upon their ability to appropriate nitrogen from the air has caused some
land-owners to fail in appreciation of the aid to soil fertility that
may be rendered by the grasses. One often hears the statement that they
can add nothing to the soil, and this is serious error. They add all
that may be given in the clovers, excepting nitrogen only, and that is
only one element of plant-food, important though it be. A great part of
the value of clover lies in its ability to supply organic matter to the
soil and to improve physical condition by its net-work of roots. Heavy
grass sods furnish a vast amount of organic matter which not only
supplies available plant-food to succeeding crops, but in its decay
affects the availability of some part of the stores of potential
fertility in the land.
[Illustration: A Heavy Grass Sod in New York.]
Prejudice against Timothy.--Timothy, among the grasses, is especially
in disrepute as a soil-builder, and yet its value is great. The belief
that timothy is hard on land is based upon observation of bad treatment
of this grass. There is a common custom of seeding land down to timothy
when it ceases to have sufficient available plant-food for a profitable
tilled crop, and usually this is the third year after a sod has been
broken. The seeding is made with a grain crop that needs all the
commercial fertilizer that may chance to be used. Clover may be seeded
also, and on a majority of farms it fails to thrive when sown. If
clover does grow, the succeeding crop of timothy may be heavy. If
clover does not grow, the timothy is not so heavy. The seeding to grass
is made partly because a tilled crop would not pay, and partly because
a hay crop is needed. It comes in where other crops cannot come with
profit, and it produces fairly well, or very well, the first year it
occupies the ground by itself. With little or no aid from manure or
commercial fertilizer, it adds much to the supply of organic matter in
the soil, and it produces a hay crop that may be made into manure or
converted into cash.
If the sod were broken the following spring, giving to the soil all the
after-math and the mass of roots, its reputation with us would be far
better than it is. This would be true even if it had received little
fertilizer when seeded or during its existence as a sod, not taking
into account any manure spread upon it during the winter previous to
its breaking for corn. But the rule is not to break a grass sod when it
is fairly heavy. The years of mowing are arranged in the crop-rotation
to provide for as many harvests as promise immediate profit. On some
land this is two years, and not infrequently it is three. Where farms
are difficult of tillage, it is a common practice to let timothy stand
until the sod is so thin that the yield of hay is hardly worth the cost
of harvesting. Then the thin remnant of sod is broken for corn or other
grain, and the poor physical condition of the soil and the low state of
available fertility lead to the assertion that timothy is hard on the
soil. This is a fair statement of the treatment of this plant on most
farms.
Object of Sods.--The land's share of its products cannot be disregarded
without loss. The legumes and grasses come into the crop-rotation
primarily to raise the percentage of organic matter that the land may
appropriate to itself within the rotation. Some of the crops usually
are for sale from the farm. Most of the crops require tillage, and that
is exhaustive of the store of humus. A portion of the time within the
rotation belongs to a crop that increases the supply of vegetable
matter, unless manure is brought from an outside source. Sods lend
themselves well to this purpose because they afford some income, in
pasturage or hay, while filling the soil with vegetation. The tendency
is to forget the primary purpose of sods in the scheme, and to ignore
the requirement of land respecting a due share of what it produces.
Attention centers upon the product that may be removed. The portion of
the farm reduced in productive power for the moment goes to grass,
while the labor and fertilizers are concentrated upon the fields that
are broken for grain and vegetables. The removal of all the crop at
harvest, and probably the pasturing of after-math, are the only matters
of interest that the fields, depleted by cultivation and seeded down to
grass, have for the owner until the poor hay yield and the need of a
sod for corn draw attention again to them.
Seeding with Small Grain.--The usual custom is to sow grasses with
small grain, and there is much to commend it. The cost of preparing the
seed-bed rests upon the grain crop, and the conditions are favorable to
fall growth and winter protection, if the seeding is made in the fall.
Wheat and rye are good crops with which to seed. In the case of fertile
land there is the danger that the timothy will establish itself too
well in a warm, moist autumn to permit clover to get a foothold the
following spring, and clover should always be seeded for the sake of
fertility. In northern latitudes clover cannot be seeded successfully
as late in the season as wheat should be sown, as it fails to become
well rooted for winter. The overcrowding of clover by timothy is met in
part by reduction in amount of timothy seed sown with the wheat.
The oat crop is less satisfactory for seedings to grass and clover. The
leaves near the ground are too thick, shading the young plants unduly,
and the late harvest exposes the grass and clover when the season is
hot, and usually dry. Some reduction in the amount of seed oats used
per acre helps to save from injury.
Seeding in Rye.--When thin land is desired for pasture, and available
fertility cannot well be applied, a sod may be formed more surely by
seeding with rye, using the rye for pasture and a mulch, than,
probably, in any other way. The ground should have good tillage and
then be seeded to rye in September at the rate of six pecks of seed per
acre. Timothy and red-top should be seeded with it, and in the spring
red and alsike clover should be added. Whenever the ground is dry
enough in the spring to permit the tramping of cattle without injury,
the rye should be pastured, and preferably by a sufficient number of
animals to hold the rye well in check. When the usual time for heading
comes, all stock should be removed, and when heads do appear, the
growth should be clipped with a mower and left as a mulch on the
surface. A second clipping will be required later, with cutter-bar
tilted well upward. When the usual summer drouth is past, livestock can
again be turned into the field. This method is suggested only for thin
fields that have failed to make catches of grass, and that for some
reason cannot well be given the fertility that all thin soils need. The
application of lime before seeding to the rye is an expense that
usually must be met in the case of such fields, and fertilizers should
be used.
Good Soil Conditions.--When the grasses and clovers desired for a sod
are sown with small grain, there is competition between them and the
grain crop for fertility, moisture, and light. The grain crop is the
one that will produce the income the following summer, and naturally is
given right of way. The amount of seed is used that experience teaches
is best for a maximum yield of grain. Usually this gives a thicker
stand of plants than is best for the tiny grass and clover plants that
often are struggling for existence down under the taller grain. If the
farmer could see his way clear to cut down the quantity of seed wheat
or oats used on a fertile soil, the catch of grass would be better, but
the small-grain crop is not very profitable at the best, and the owner
does not like deliberately to limit it.
A greater amount of failure is due to an inadequate supply of
fertility. The grass does not suffer so much from over-shading as it
does from starvation, both during the growth of the grain and after
harvest. The stronger grain plants appropriate the scanty stock of
available fertility, and leave the grass and clover nearly helpless.
This condition is especially noticeable in dry seasons when there is
less opportunity to obtain food in solution. Plants which are expected
in another season to fill the ground with vegetable matter are starved
in the beginning and die. Plant-food is needed, and should be mixed
with the soil when the seeding is made. The fertilizer needs are
discussed in another chapter.
When manure is available, it should be spread on the plowed ground and
mixed with the surface soil. If a soil is thin, or heavy, or light, the
use of a ton of manure in this way can bring greater returns than under
any other circumstances in general farming. It supplies some fertility,
and it puts the surface soil into good physical condition for young
plants. Land deficient in humus forms a crust after a rain, and a tiny
plant suffers. A light dressing of manure, well mixed with the soil,
tends to prevent this hardening of the surface and loss of water. There
is no other form of fertility that can fully replace manure, for either
compact or leachy land.
The probable need of lime has been discussed in other chapters. Clovers
and the grasses want an alkaline soil, and there is waste of money and
time in seeding acid land. The lime and the manure must not be mixed
together in the air, but both can be used when fitting land for
seeding, and both should be used if the need exists. One should be
applied early and be well disked into the soil, and then the other
application may be made and covered with the harrow. The soil is an
absorbent, and the contact of manure and lime within the soil only
leads to immediate availability, which is desirable in giving the grass
a start.
CHAPTER VIII
GRASS SODS--(_Continued_)
Seeding in Late Summer.--The natural time of beginning life, in the
case of timothy, blue-grass, red-top, red clover, and alfalfa is in the
summer or autumn. The best conditions of growth are given where no
stronger plants take the plant-food and moisture. Wherever there is any
difficulty in getting heavy grass and clover sods after the lime
deficiency has been met, and wherever a hay crop has more value than a
small-grain crop, the method of seeding alone in August should be
employed. In warmer latitudes the date may be a little later, but in
the northern states it should be in the first half of August for best
results. Seeding alone offers opportunity to make conditions right for
the seeds which are to be used, and in view of the importance of heavy
sods to our agriculture, this reason alone is sufficient. In some
regions the ability to substitute a good hay crop for a cereal that
brings small net income is an item of value, adding to the proportion
of feeding-stuff produced in the rotation and to the resulting supply
of manure. The practice of making seedings to grass and clover alone is
growing, and it is based on sound reasoning.
Crops that may Precede.--Farms that are under common crop-rotations may
adopt the practice of August seeding. The winter wheat comes off in
time for preparation, and this is true of an early variety of oats, and
of rye and barley. Early crops of vegetables get out of the way nicely.
There is a vast total area of thin soil that may be brought up to a
productive stage rapidly by the growth of a green-manuring crop to
precede the grass and clover. Rye may be sown in the fall and plowed
down in May, and cowpeas planted to be disked into the soil. Oats and
Canada peas add organic matter with nitrogen when plowed down. The
summer fallow, which deservedly has fallen into general disuse, may
well be employed when a soil is in an inert state, provided grass and
clover be permitted to appropriate the plant-food made soluble by the
fallowing. The catch crops add organic matter while cleansing the land
of weeds; the fallowing releases plant-food and is peculiarly efficient
in killing out weeds.
Care must be exercised about preserving moisture in the ground, and
therefore a green crop should not be plowed under immediately before
seeding time. When a soil is thin, there may be no better preparatory
crop than the cowpea, which will not make too rank a growth in the
north to prevent its handling with a weighted disk harrow. By this
means the soil below is left firm, and the rich vines are mixed with
the surface soil, where most needed. It is always a mistake to bury
fertility in the bottom of the furrow when a soil is thin and small
seeds are to be sown. The infertile ground lying next the subsoil is
not what is needed at the surface when preparing for a sod.
It is a good practice to use the early summer in making conditions
better for an August seeding, if the land has fallen below a profitable
state of productiveness. A growth may be plowed down in time for
firming the seed-bed, or it may be cut into the surface soil with a
harrow, or the time may be used in freeing inert plant-food and
destroying weed seed. On better soils, and in warm latitudes, a crop
for hay may be removed, especially in the case of the cowpea in the
south, and the stubble prepared for seeding by use of the cutaway or
disk harrow.
Preparation.--A seed-bed for small seeds planted in mid-summer must be
able to retain moisture. Nothing robs a soil of water more surely than
a breaking-plow. Its use is a necessity in farming, but this effect of
plowing must be borne in mind when a seeding is planned for the driest
period of the year. It goes without saying that sods should not be
formed on land that is too solid for admission of air. A thorough
plowing is needed by most soils prior to making a sod that will prevent
further stirring of the ground for a long period of time. It is best
when this plowing can be given in the preceding spring. This enables
the ground to become firm enough to hold moisture. If there is time for
a tilled crop, the cultivation is helpful. When the land must be broken
in the summer, the plowing should be done several weeks before the
seeding to grass must be made. The roller should follow the plow
closely to destroy the spaces that lie open to the hot air, permitting
the land to dry out. All deep harrowings should be given soon after the
plowing, stirring and mixing the ground, and then leaving it to settle
so that moisture can be held. It is bad practice to continue deep
harrowing until the seeding time of any small grain or grass planted in
a dry part of the year. Firmness is wanted in the soil.
The Weed Seed.--The seeds of tilled crops are planted in ground
containing much weed seed, and no harm may result. The cultivation
needed to keep the soil loose, or to prevent evaporation, destroys the
weeds. Grass, clover, alfalfa, and like seeds are put into the ground
to occupy it to the exclusion of other plants for several years, as a
rule, and no tillage can be given. The rule is to sow such seeds after
tilled crops have been grown, and some weed seed has been destroyed,
but there is evidence on every hand that the weed seed remains in
abundance. Summer preparation for grass gives opportunity to destroy a
great part of the seeds in the surface of the ground, and it is only
when they are near the surface that the seeds of most weeds will
germinate. Deep harrowings, continued up to time of planting, not only
rob land of water, but they bring to the surface new lots of seed that
had been safely buried, and become a part of the actual seeding when
the grass, clover, or alfalfa is sown. The obviously right method of
preparing for planting is to use only a surface harrow for a few weeks
previous to seeding time, stirring the ground after every rain to the
depth of three inches, or near that, and destroying the plants soon
after germination of the seed. The process which is right for holding
moisture is right for cleansing the ground.
Summer Grasses.--One of the worst pests is the annual grasses,
springing up in June, July, and August. They are responsible for many
failures to obtain stands of alfalfa, clover, and the valuable grasses.
The delay in seeding until August is due largely to this pest. When
seedings are made in the spring, or in June, failure is invited where
these grasses have a fast hold. The only effective way of combating
them is to make the ground firm enough to encourage germination, and to
stir the surface whenever a growth starts. The late seeding is the one
means of escape, and if there is fertility and moisture, the newly
seeded crop becomes well rooted by winter and takes the ground so
completely that there is little room for weeds to start the next year.
Sowing the Seed.--Partial failure with August seeding is due to faulty
methods. We are accustomed to broadcasting clover seed on top of the
wheat fields and obtaining a stand of plants. A majority of the seeds
do not become buried in the soil, or only very slightly, and yet
germinate. Moisture is necessary, but in the spring, when this method
is used, there is moisture at the surface of the ground under the wheat
plants much of the time. The conditions respecting moisture are not
unfavorable in most springs, and we come to think that a small seed
should not be buried much if any. In the autumn, again, we sow timothy
with the wheat, and while more prompt germination is secured by
covering the timothy seed with the hoes of the drill, we often have
seen a successful seeding made without any covering being given. The
work is done at a time when fall rains may continue for days and, when
the sun's heat does not continue long, the covering given by settling
the seed into the loose earth is sufficient. Moisture does not leave
rapidly because the air is not hot.
Deep Covering.--In August the air is hot, and the surface of the ground
is dry nearly all the time. A shower may be followed by hot sunshine,
and the water at the surface evaporates quickly, leaving the ground
covered with a dry crust. There are two essential things to bear in
mind: the seeding should be made only when there is enough moisture in
the ground to insure quick germination, and preferably as soon as
feasible after a rain, and the seed should be put down where moisture
can be retained. It is poor practice to sow any kind of small seeds
before a rain that seems imminent. If it forms a crust, or causes
weed-seed germination along with that of the grass seeds, only harm
results. When seeds are put into a dry soil, and a light shower comes,
there may be germination without sufficient moisture to continue life
in the plants.
The seeds should be well buried: the soil and air conditions are
different from those of the spring. It is best to wait for moisture,
and to save the seed if it does not come, but when enough water has
fallen to make the firm soil moist, the danger of failure is very small
if the seeds are buried one to two inches deep. A surface harrow will
stir the surface, and then the seeds should be sifted down into the
soil by another harrowing. A light plank float, mashing the little
clods and pressing the soil slightly together, finishes the work. The
plants will appear above ground within a few days, the only danger
being in a beating shower that may puddle the surface before the plants
are up.