Book: Clovers and How to Grow Them

T >> Thomas Shaw >> Clovers and How to Grow Them




On the ordinary black soils of the prairie, alfalfa will usually grow
reasonably well if underlaid with clay not too distant nor too
tenacious. When the roots get down into the subsoil, they can usually
find much food in the same, and unless in very dry areas a sufficiency
of moisture, but in many instances it may be necessary to introduce the
requisite bacteria, and to apply farmyard manure to encourage sufficient
growth to carry the roots down quickly to the subsoil. In some prairie
soils the growth will be vigorous from the start, but usually these are
lands that have grown hardwood timber, and that have in them more or
less clay.

In climates where the rainfall is considerable, alfalfa will frequently
grow well on gravelly soils and on those that are stony. Some of the
best alfalfa soils in the State of New York, New England States, and in
the Canadian provinces of Quebec and Ontario are of this character.

Alfalfa will frequently grow fairly well even on stiff clays, and in
some instances on gumbo soils. But these soils must not be so retentive
as to collect and hold water for any considerable time within a few feet
of the surface. Such lands have usually much staying power; hence,
alfalfa grown on them frequently improves for years after it has been
sown. On the reddish soils that cover much of the South, it has been
found, as in growing alfalfa on stiff clays in the North, that where
deep subsoiling is practiced alfalfa is not only more easily
established, but it also grows with added vigor.

On upland soils sandy or gravelly in character where the rainfall is
much less than normal and where the subsoil is not underlaid with sheet
water, alfalfa will not usually succeed, notwithstanding that it may
grow well on these soils where the rainfall is normal. On such soils it
is not easy to get a stand of the plants, as they are much apt to perish
in the dry weather of the first season, but if once established on such
soils the plants have much power to grow even where the rainfall is
considerably less than normal.

Alfalfa will not grow well in soils naturally wet until they are
drained. And when drained it will not grow with normal vigor, on what
may be termed slough soils, where the subsoil is far down and covered
with a deep covering of vegetable mold. What are termed slough soils in
the Western prairies, therefore, are not well fitted for the growth of
alfalfa. On these it may not succeed well, when it may grow with much
vigor on the adjoining upland. When some wet soils are drained, alfalfa
may not succeed well on them for a time and later may grow luxuriantly.
This may arise from the lack of time for proper aeration after being
drained, or from the want of lime to further correct acidity in the
soil, or from the want of the proper bacteria. Notwithstanding that
alfalfa will not grow well on undrained lands that are naturally wet,
and notwithstanding that it will perish if the roots reach standing
water at a distance too near the surface, the best crops by far are
usually grown on irrigated lands. This arises, first, from the ability
to adjust the supplies of water to meet the needs of the plants, and
second, from the congenial character of the soil and subsoil. Next to
these the best crops are grown where congenial soils are underlaid with
ground water, not too near nor too distant from the surface. On these
soils the plants are largely supplied with moisture from the water below
ascending on the principle of capillary attraction. How near or how
distant such water should be will depend somewhat on subsoil conditions.
It would seem correct to say that it ought never to come nearer to the
surface than 3 feet, nor should it be more than 20 feet down. The most
suitable distance would be, say, 8 to 16 feet. When the roots of alfalfa
reach water at too short a depth they will die.

Alfalfa may sometimes be grown satisfactorily on soils subject to
overflow, but usually there is hazard in growing it on these. If the
overflow occurs comparatively early in the season, if it is not of great
depth, if it is of short duration, and if the waters quickly drain out
of the subsoil possessed by the alfalfa, it may receive little or no
harm from such overflow. Instances are on record wherein ice has formed
on alfalfa and yet the plants survived, but such a condition will
usually prove fatal to them. But should the overflow take place in hot
weather, usually it will injure the plants seriously, and may, indeed,
completely destroy them. So great is such hazard, that care must be
taken against the application of an excess of irrigating waters under
such conditions. Overflow waters that are stagnant are more injurious
probably than those that are in motion, owing, it may be, to the less
supply of dissolved oxygen in the former.

Soils suitable in themselves, but lying on stiff clay bottoms or
underlaid with hard pan within two or three feet of the surface, will
not maintain a good stand of alfalfa. The plants in these may grow well
for a time, probably a year or two, after which they will fail. The
roots are not able to go down to gather food. When the subsoils are
simply stiff clays, deep subsoiling, as already intimated, may render
much service, but when composed of hard pan this may not be practicable.
In moist climates, however, reasonably good crops have been obtained
from soils with underlying rock not more than four feet below the
surface.

The fact should not be overlooked that soils may have the requisite
physical conditions for growing alfalfa, and they may possess in fair
supply the essential elements of plant food, and yet alfalfa will not
succeed at the first when sown on these, because of the absence of the
soil bacteria, the presence of which is essential to the vigorous growth
of the plants. Because of this, growers should be slow to conclude that
alfalfa will not flourish on the soils on which they sow it until they
have first tried to grow it on those soils that have been inoculated
with the requisite alfalfa bacteria. For the methods of procedure in
such cases see page 53. Some persons claim that soils which will grow
medium red clover in good form will also grow alfalfa in good form.
This does not necessarily follow. While there is much of similarity in
the soils suitable for the growth of both, alfalfa may fail on lands
that grow red clover luxuriantly until the bacteria proper to alfalfa
have been introduced. Soils may be tested for bacteria, and even in
winter, by sowing some seed in pots and treating them like
well-cared-for house plants. When the plants are 2 to 3 months old, if
tubercles are found on the roots, the conclusion would seem safe that
such soil does not require inoculation.

=Place in the Rotation.=--In a certain sense it can scarcely be said of
alfalfa that it is a rotation plant, because of the long term of years
for which it is grown in an unbroken succession. Nevertheless, in all
places it cannot always be maintained for a long term of successive
years without renewal. In the Eastern States it is frequently, though
not always so crowded by various grasses, that the fields in which it
grows are broken up at some period short of ten years, and not
infrequently at the end of five or six years. When thus grown, it
becomes a rotation plant, though grown in what may be termed long
rotations. But even in the West, where, under irrigation, it may be
grown for a quarter of a century or even for a longer period without
renewal, it may be used when desired in short rotations. In such
situations it grows so readily and becomes established so quickly, that
the fields may be broken with a view to alternate with other crops at
the end of the second year, or of any year subsequently from the sowing
of the seed that may be desired. Alfalfa in these soils will serve even
better than medium red clover in such situations, since while it is
growing, it will produce more hay or soiling food, and consequently
should excel the former in the fertility which it makes available.

East of the Mississippi and north of the Ohio River, alfalfa will
frequently follow cultivated crops, as corn, potatoes and field roots,
and when the fields are broken, it will be followed by crops other than
legumes. On many soils the influence which this crop has on relieving
the surface soil from excessive moisture, through channels opened into
the subsoil by the decaying roots, is so helpful as to considerably
stimulate production in addition to the fertilizing influence which it
exerts directly. Particularly good crops of corn, the small cereal
grains, and even field roots may be grown after alfalfa.

On soils east of the Mississippi and south of the Ohio, the rotation
will be somewhat similar. But on Southern soils alfalfa will frequently
follow immediately crops especially grown to be plowed under as green
manures for the benefit of the alfalfa. These crops include cow peas,
soy beans, crimson clover, and to a limited extent, burr clover. It will
also be followed frequently by crops of cotton and other non-leguminous
plants, the growth of which in the United States is confined to the area
now being considered.

In the area west of the Mississippi and east of the semi-arid region
beside the mountains, alfalfa may follow the small cereal grains, and
may in turn be followed by them and also by millets. It may also follow
and precede corn, or the non-saccharine sorghums, where the climatic
conditions are suitable for growing the latter.

In the irrigated regions of the West, alfalfa may be made to serve
almost any purpose in the rotation that may be desired. By growing it as
a rotation crop in these valleys it may be made to furnish the soil
indefinitely with supplies of nitrogen and humus. In these soils it may
be made to follow directly almost any crop grown on them, and similarly
it may be made to precede the growth of almost any crop for which the
locality has marked adaptation. Small cereal grains, timothy,
vegetables, field roots, potatoes, corn, small fruits and orchards may
be profitably grown on buried alfalfa meadows. This does not imply,
however, that alfalfa meadows should not, as a rule, be maintained for a
long term of years.

=Preparing the Soil.=--In preparing the soil for alfalfa the aim should
be to make a seed-bed clean, rich, fine, moist, even, and sufficiently
firm or friable, according to the conditions. The subsoil should also be
made sufficiently dry and open. From what has just been said, it will be
apparent that in properly preparing the seed-bed, it will be necessary
to study closely the requisite conditions.

The advantage from having a clean seed-bed will be apparent when it is
called to mind that alfalfa is a somewhat delicate plant when young, and
that because of this, it is ill able to overcome in the fight with
weeds. Cleanness in the surface soil may be obtained by summerfallowing
the land, by growing a root crop or a crop of corn or any of the
non-saccharine sorghums. When the seed is spring sown, this preparation
must be given the year previously, but when autumn sown, it may be given
the same season. In preparing the land thus, the aim should be to make
the surface as clean as possible, rather than to get weed seeds out of
the lower strata of the cultivated soil, in which they will likely
perish before the field sown to alfalfa is broken up again.
Summerfallowing makes an excellent preparation for the land, because of
the fine opportunity which it furnishes for cleaning the same perfectly
and leveling it off properly. The excellent condition in which it puts
the seed-bed, viewed from the standpoint of the duration of the years of
cropping that are likely to follow, would seem to more than justify such
preparation of the land. The outcome may more than justify the loss of
the crop for one season when thus summerfallowing the land. But it may
not be necessary to lose the production of one season whether the seed
is sown spring or autumn, as the summerfallowing in the North may follow
the pasturing off of some crop, and in the South the interval for
fallowing the land may be sufficiently long after the harvesting of an
early winter grain crop, before sowing the seed in the autumn. (See page
136.)

When sowing the seed autumn or spring, on land that is filled with weed
seeds near the surface, it is frequently better to defer sowing the seed
for some weeks to give time for sprouting many of these than to sow at
once. This suggestion is specially applicable to spring sowing. It
should also be mentioned that when the weeds infesting the soil are
annual or even biennial in character, the harm done to the alfalfa by
these will be much less than when the land is infested with perennials
at the time of sowing. The former may be prevented from seeding by
clipping back frequently, while the latter remain in the soil, increase
from year to year, and injure the plants by crowding. Where crab grass
grows abundantly, as in some parts of the South, unless the alfalfa is
sown and cultivated, spring sowing ought to be avoided. But it is less
objectionable to sow alfalfa on land that is weedy when the adaptation
of the land for the crop is high than when it is low, as the alfalfa in
the former instance has so much more power to fight its own battle. On
good alfalfa soils, therefore, it may be wiser in some instances to sow
alfalfa in weed-infested land than to defer sowing for a whole year in
order to clean the land.

It is greatly important that the land shall be rich in available plant
food on which the seed is sown. If naturally poor, it should be well
fertilized before sowing. When this cannot be done, it is better not to
sow. A vast preponderance of the land in the Rocky Mountain region, when
first broken, would seem to possess abundantly all the essential foods
required by alfalfa; hence, for a time, at least, it is not necessary to
enrich these before sowing the seed. The sandy and hungry gravelly
soils, which are considerable in the South, in the Atlantic States, and
in some of the Central and Northern States, should be fertilized before
laying them down to alfalfa. Such fertilization usually calls for both
humus and readily available plant food, and these are most cheaply
supplied by growing certain green crops and plowing them under, or by
applying farmyard manure. These may be supplemented when necessary by
commercial fertilizers. Some precede alfalfa on such soils by growing
cow peas or soy beans, followed by crimson clover, both crops being
plowed in, and shortly before sowing the alfalfa they apply more or less
of phosphoric acid and potash, which is usually incorporated in the
surface soil by the harrow. On some soils, as in some parts of Florida,
two successive crops of cow peas should be plowed under before sowing
alfalfa. When farmyard manure can be used in fertilizing those leechy
soils it is well when it can be applied on the surface in a somewhat
decomposed form and also kept near the surface during the subsequent
cultivation given when preparing the seed-bed. In the North it is best
applied in the autumn or winter, and in the South in the summer. But on
loam soils with a reasonably retentive subsoil, the better way to apply
farmyard manure is to make a heavy application of the same to the crop
preceding the alfalfa. It has thus become incorporated with the soil,
and many weed seeds in it will have sprouted before sowing the alfalfa.
The results from applying manure on soil somewhat stiff and not highly
productive have been noticeably marked. This may have been owing in part
to the mechanical influence of the manure on the land. The relation
between the free application of farmyard manure and abundant growth in
alfalfa is so marked in all, or nearly all, soils west of the
Mississippi River that in many instances better crops will be obtained
from poor soils well manured than from good soils unmanured. The
relation between abundant manuring and soil inoculation is worthy of
more careful study, in the judgment of the author, than has yet been
accorded to it.

Fine pulverization of the surface soil is advantageous when sowing
alfalfa, because of the influence which it has upon the retention of
moisture near the surface, and upon the exclusion from the soil of an
overabundance of light. It is in clay soils, of course, that this
condition is most difficult to secure. The agencies in securing it are
the cultivator, the harrow and the roller, and in many instances the
influences of weather, after the land has been plowed, especially when
plowed in the autumn prior to spring seeding.

Moistness in the seed-bed sufficient to promptly sprout the seed is a
prime essential, but it is very much more important where the seasons
are dry than where the lack of rain is but little feared. When the seed
is sown after summerfallow or cultivated crops, it is usually considered
preferable to make the seed-bed without using the plow, but to this
there may be some exceptions. If sowing is deferred for a few weeks in
the spring on such lands, or on other lands autumn plowed or early
spring plowed, a free use of the harrow ought to be made in the
interval, because of the favorable influence which this will have on the
retention of moisture. In preparing some soils for autumn sowing after
a grain crop, as in some parts of Nebraska and Kansas, it is only
necessary to use the harrow; in preparing others the disk and harrow;
and in yet others the disk and harrow and roller. In preparing other
soils, as the clays of the South, it may be necessary first to plow and
subsoil, and subsequently to use sufficiently the harrow and roller.

Evenness in the soil on the surface is important when it is so retentive
that water may collect in the depressions after heavy rain. In such
places the plants are much liable to fail, especially in the early
winter, or even shortly after they may have begun to grow, if moisture
is excessive. In order to smooth and even the land sufficiently, it may
be necessary to run over it some form of leveller. This does not mean,
however, that it will not be necessary sometimes to plow the land in
ridges, or "lands," as they are sometimes called, but it does mean that
the slope from the center of the lands toward the furrows shall be even
and gradual, in order that an excess of surface water, as in rainy
climates, shall be carried away by the latter.

Firmness in the seed-bed is necessary chiefly to prevent too much drying
out near the surface in dry weather, and the holding of too much water
in the spaces between the particles near the surface in wet weather,
followed by freezing of the soil. The less deep the stirring of the
cultivated portion when preparing it, the longer the interval between
such stirring and the sowing of the seed, and the heavier the pressure
when rolling, the more firm will the seed-bed be. The deeper the land
is plowed, therefore, the longer should be the interval before it is
sowed, but ample rainfall will shorten this period. Firmness in the
seed-bed is more important, relatively, in summer or early autumn when
evaporation from the surface soil is the most rapid. On some soils of
the Middle States which border on the Mississippi, the early sown autumn
crop will sometimes perish after the plants have grown some distance
above the ground, because of want of firmness in the soil; hence, in
such locations harrowing the surface of the ground thoroughly may
sometimes be a more suitable preparation than plowing and harrowing.

Friability in the seed-bed is important when the soils are heavy. The
influences which promote it are the presence of humus, liberal
cultivation, and sometimes weather influences, as rain and frost. Unless
heavy clay soils are brought into this condition, the roots of the
alfalfa will not be able to penetrate the soil quickly enough or deeply
enough in search of food.

As has been intimated, it will not avail to sow alfalfa in soils not
sufficiently drained naturally or otherwise. Usually, good alfalfa soils
have sufficient drainage naturally, the subsoil being sufficiently open
to admit of the percolation of water down into the subsoil with
sufficient quickness. But good crops of alfalfa may be grown on subsoils
so retentive that underdrainage is necessary to facilitate the escape of
an excess of moisture with sufficient quickness. The question has been
raised as to whether the roots of the plants will be much liable to
enter and choke the drains at the joints between the tiles. While it
would not be safe to say that this would never happen, it is not likely
to happen, owing to the character of the root growth. Where too much
water is held near the surface, in climates characterized by alternate
freezing and thawing in winter, the young plants will certainly be
thrown out through the heaving of the soil.

The subsoiling of lands not sufficiently open below will be greatly
helpful to the growth of alfalfa. This may also be true of lands not
over-retentive naturally, but made so by the treading of the animals for
successive years on the soil under the furrow when plowing the land. In
some conditions, without subsoiling thus, the growing of alfalfa will
not be successful, but in doing this work, care should be taken not to
bring up raw subsoil to the surface. In subsoiling for alfalfa, usually
the more deeply the ground can be stirred by the subsoiler, the better
will be the results that will follow. Subsoiling is particularly helpful
to the growing of alfalfa on many of the clay soils of the South.

In the far West, toward the mountains, and probably within the same, are
areas in which excellent stands of alfalfa may be obtained by simply
sowing the seed on surfaces stirred with a disk or with a heavy harrow
weighted while it is being driven over the land. The implements should
be driven first one way and then the other, and, of course, the seed is
harrowed after it has been sown. Where the soil is sufficiently level,
this plan of preparing will prove satisfactory, more especially where
water can be put upon the land, but it will also succeed frequently in
the absence of irrigating waters. In some instances the disking and
sowing are both done by the same implement, which is driven both ways
across the field.

Alfalfa is sometimes sown, and with profit, on steep hill sides which
are inclined to wash. When set on these it tends to prevent the washing
of the land. In such situations it is better to sow with a nurse crop,
which will help to hold the soil until the alfalfa becomes rooted. Where
land is so loose as to blow and irrigation cannot be practiced, only as
much should be sown each season as can be covered with stable litter and
well-rotted straw drawn out at the proper season.

=Sowing.=--The best season for sowing alfalfa will depend upon such
conditions as relate to soil, moisture and climate. On rather stiff clay
soils, the other conditions being right, the most satisfactory results
are obtained from sowing the seed in the spring, and on land that has
been plowed in the autumn and exposed to the mellowing influences of
winter. But to this there may be some exceptions. On lands so light as
to lift with the wind, that season should be avoided in sowing, if
possible, when lifting winds prevail. Such winds are common in some
localities in the spring, and may uncover the seed in some places and
bury it too deeply in others.

Where moisture is deficient the seed must be sown at those times when it
is most plentiful. This may be in the autumn, but more commonly it is in
the quite early spring. In some of the mountain States the best results
have been obtained under semi-arid conditions from sowing the seed in
the late autumn, so that it would be ready for germination at the first
commencement of the period of growth in the spring. Under some
conditions the too dry character of the weather may preclude the sowing
of alfalfa in the summer and autumn months. Where moisture is plentiful
all the season of growth, alfalfa may be sown almost any time, except
the early spring or late autumn. Where irrigating waters are plentiful,
the only hindrances to sowing alfalfa at any season of the year are such
as may arise from climate. Far South in very mild areas it may be sown
almost any time.

Where the temperatures are low in winter, the best results are obtained
from sowing alfalfa in the spring and early summer, otherwise the plants
do not become sufficiently well established to withstand the rigors of
the winter following. Under some conditions, sufficiently satisfactory
results follow sowing in the early summer, even in Northern latitudes.
Where the winters are sufficiently mild and the moisture is sufficiently
plentiful, early autumn sowing, as in August or September, according to
the locality, is, all things considered, the most satisfactory, for the
reason, first, that it follows, or may follow, a crop grown the same
season; second, that the plants are less hindered in their growth by
weeds when they are young; and third, that they produce crops of soiling
food or hay the first season after sowing. Many weeds do not grow in
autumn and winter; hence, the less injury done by them to alfalfa
plants, since the latter are so strong by spring that they overshadow
the weeds in their effort to grow. When alfalfa is sown at such a time,
the growth of one year virtually is gained by the process.

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