Manures are of two classes--called putrescent and fossil. The putrescent
are composed of decayed, or decaying, vegetable and animal substances.
The fossil are those dug from the earth, as lime, marl, and gypsum. All
vegetable substances not useful for other purposes are valuable for
manure. Rotten wood, leaves, straw, and all the vegetable parts of
stable manure, and any spoiled vegetables or grain, are all valuable. At
the South, their immense quantities of cotton-seed are a mine of wealth,
if properly prepared and applied as manure. Animal manures consist of
the animal parts of stable manure, dry and liquid, parts of bones,
brine, spoiled meat, kitchen slops, soapsuds, and all dead animals. In
decaying, these substances all pass through a process of fermentation.
Left exposed without suitable care, they become unhealthy and offensive.
It is probable that a large share of the diseases suffered in the rural
districts are caused by these impurities; and the impossibility of
keeping large cities free from these substances is the cause of their
increased mortality. In the country, a little timely caution and labor,
in removing these substances and regulating their fermentation, would
save much sickness; while the labor would pay a larger per-cent. profit
than any other performed on the soil. No manures should be allowed to
ferment, or decay, without being mixed or covered with enough common
earth, sand, peat, or muck, to retain all the gases and exhalations of
such putrescence. The smallest quantity that will answer is one load of
earth to two of the decaying substances. The proportions reversed would
be better: put one bushel of lime to two loads, two quarts of ground
plaster, and half a bushel of ashes, and you have the very best compost
heap. The following are brief general rules for the preparation of
manures. It is always most economical to feed cattle in the stable or
under cover, and never have manure exposed to the weather. But if cattle
must be fed outdoor, let them be fed in a yard, lowest in the centre,
that the liquids and washings may run into the centre, and be absorbed
by straw and litter. Put manure on the land, or into heaps for compost,
before very warm weather. Always feed sheep under cover, and keep their
manure from rain; heap it together with earth in the spring, or apply it
to the soil at once. Manure thrown out of a stable should be kept under
cover, out of the rain, and not allowed to heat in winter; its best
qualities are evaporated by fermentation in the yard. Manures often
rained on in winter, or left in large piles without intermixture of
earth, lime, plaster, and ashes, will ferment and waste. Construct your
stables so that the liquid manure will run into a vat filled with earth;
muck is best. Experiments have shown that the liquid manures are at
least one sixth better than the solid. A gentleman dug a pit, thirty-six
feet square and four feet deep, and walled it in on all sides. He filled
his vat from a cultivated field, and so constructed his sewers from the
stables adjoining that the urine saturated the whole. He kept fourteen
head of cattle there for five months, allowing none but the liquid part
of the manure to pass into the vat. He spread forty loads of this on an
acre. For ten years he tried equal quantities of this and well rotted
and prepared stable-manure, side by side, in the same field, and
obtained great crops; but in no stage of their growth could he see that
crops on the land manured from the stable were any better than those
that had received only the soil from the vat. The latter were quite as
good as the former. The contents of his vat manured seven acres, or half
an acre to each creature stabled. The result is proof that one cow
discharges urine sufficient in five months to manure abundantly half an
acre of land. Save the solid manure equally well, and a cow will make
manure enough, in five or six months, to increase a crop sufficiently to
pay for herself. It is certainly safe to say, that a careful man can
make the manure of a cow pay for her body every year. Is not this an
important branch of farming operations? Few pay sufficient attention to
it. Fowls should roost where their droppings may be mixed with common
garden soil or loam. The manure from each fowl, carefully saved and
judiciously applied, will pay for its body twice a year. The hogstye may
be very productive of manure, one fourth better than that from the
stable. Connected with your hogpen, have a yard fifteen feet square for
every five hogs; let that yard have no floor. Throw the straw out of
their sleeping-room frequently to make room for new; throw into the
yard, also, all sorts of weeds, refuse vegetables, corn-husks, peapods,
&c.; also the dirt that will naturally accumulate in the backyard of a
dwelling, including sawdust, fine chips, cleanings of cellars, scrapings
of ditches, and occasionally a load of loam, muck, or clay--and six
loads of manure to each hog may be made, that will prove far better than
any stable manure; it has been known to produce fifty bushels of corn to
the acre, when stable-manure produced but forty bushels. Old wood,
brush, and chips, should never be allowed to remain on uncultivated,
useless land. Wood throws out the same amount of heat in decaying as it
does when consumed as fuel. The action of that heat on the soil is
highly beneficial, retaining it long in a mellow state: hence, all wood,
too old to be of value for any other purpose, should be put in heaps,
covered up till decomposed, and then applied to the soil, as other
manures. For potatoes or vines, but especially melons, it is preferable
to any other manure. Nothing is so good for muskmelons as old chips
from the woodyard. Leaves of fruit and forest trees are also very good;
blood and offal of animals, hair, hoofs, bones, horns, refuse feathers,
woollen rags, mud from sewers, rivers, roads, swamps, or ponds, turf,
ashes, old brine, soapsuds, all kinds of fish, oyster and clam
shells--all are valuable, and no part of them should ever be thrown away
or wasted; they are all good in compost heaps, or applied directly to
the soil. Bones are best ground, but may be used whole, pounded, or
chemically dissolved, or mixed with alternate layers of fresh
horse-manure, they will be decomposed by the fermentation of the manure
(see "Bones"). Perhaps there is as much imprudence in wasting manures as
in any part of American domestic economy. One who leaves his stock
without care, and so exposed to the weather as to lose half of them and
injure the others, is not fit to be a farmer; yet, many waste manure
that would produce plants for man and beast, of far more value than the
loss of stock complained of, and yet no one notices it--it is a matter
of course, exciting no surprise. Wastefulness in a family, if it be of
bread, flour, or meat, is considered wicked and impoverishing; while ten
times that amount may be wasted in manures, that would enrich the soil,
and excite little or no disapprobation. We hope the agricultural
periodicals will keep this subject before the people, until these mines
of wealth will no longer be neglected or wasted.
_Application of Manures_ is a subject that has been much discussed, and
respecting which, intelligent agriculturists differ materially. Some
apply them extensively as a top-dressing for grass lands. This does much
good, but probably one half of their virtues is lost by washing rains,
and by evaporation. A better way is not to keep land down in grass long
at a time, and, when under the plow, manure thoroughly. We knew a piece
of light land that annually produced half a ton of hay per acre. The
owner plowed it up, raised a crop, put a moderate quantity of
stable-manure, and ten loads of leached ashes to the acre. We saw it in
haying time, the third season after it had been manured and subsoiled
and seeded down, and they were then taking fully three tons of timothy
hay from an acre, which was the quantity it had yielded three years in
succession, without any top-dressing. If a top-dressing of manure is to
be applied, harrow the land quite thoroughly, and always apply the
manure in the fall--it is worth twice as much as when applied in the
spring. The rains and snows of winter cause it to sink into the soil,
while the heat of spring and summer evaporate it. A mixture of plaster,
lime, ashes, and a very little salt, sowed on meadows, immediately after
haying, secures a good growth of feed, much sooner than it will come on
other meadows. It also increases, quite considerably, the hay crop of
the following season. It is a universal rule not to allow manure to lie
long on the surface to which it is applied, before plowing in. Place
manure in heaps, as large as will be convenient for spreading, and
spread it just before the plow. Never spread manure one day to be plowed
in the next. When manuring in the hill, have the planters follow the
manure-cart. In manuring potatoes in the hill, drop the potatoes, and
put the manure on them and cover at once. In a dry season, the yield
will be double that of those planted in the usual way. For fall grains,
plow in the manure, just before sowing the seed. This is better than
plowing it in under the sod. If the land be not sod land, and you can
plow the manure in only deep enough to cover it, and then, just before
sowing the seed, plow again very deep, the effect is excellent. Apply
manure to land in the fall, or just after harvest, and plow it in, let
the land remain till spring, and then plow deep, and you get the best
possible effect. On an onion crop, manure does the most good on the
surface. On those raised from sets, or on any onions, after they get
large enough to give room, put fine manure enough to keep down all
weeds, and it will double the crop.
Gypsum is better sowed than in any other way. Mixed with a little lime
and salt, or wood-ashes and salt, the effect on corn is better than from
either alone. To hoed crops apply these articles twice, and always by
sowing, and not by putting it around or upon the hills; the effect is
much greater sowed, besides the labor that is saved. In applying guano,
do not allow it to come in contact with the plants, as it is apt to
destroy them.
It only remains to consider the principles on which manure acts upon
soils, and produces growth in plants. The action of manure on the soil,
by which it is enabled to retain and appropriate moisture, constitutes
its main, if not its whole benefit. It may afford a stimulus to the
roots of plants. Even the specific manures, that are supposed to supply
organic matter to particular plants, may impart their benefits by their
action upon the air and water. Facts are certainly at hand to show that
the great and leading benefits of manures are in their control of
moisture, and where that control is not needed, plants get a great
growth on what we call poor soil. No manures, either fossil or
putrescent, afford any considerable food for plants. Vegetation
receives its growth mainly from water and from the atmosphere. Facts in
support of this theory are abundant.
A trial was made to ascertain whence comes the matter of which a tree is
composed. A quantity of kiln-dried earth was weighed and then put into a
tight vessel. A willow shrub was also weighed and planted in that earth,
and the vessel covered with perforated tin to keep out the dust; for a
year and a half it was supplied only with pure water. The tree was then
taken out, and found, by weight, to have gained one hundred and sixty
pounds. The earth was then kiln-dried, as before, and weighed, and its
weight was found to be only two ounces less than it was a year and a
half before, when it was deposited there. The tree, then, must have
received its growth, not from the soil, but from the water or the
atmosphere, or both.
Another fact: take a load of manure, dry it thoroughly, and weigh it.
Then moisten it and apply it to the soil, and it will increase the
weight of vegetation from ten to thirty or forty times its own weight
when dry, and yet most of that manure may still be found in the soil.
Hence it can only feed plants in a very limited degree. Its action must
be on air and water, or the control it gives the soil over those
elements.
It is also matter of common observation that soil well manured, will
continue moist for a long time after similar land by its side, but which
has not been manured, is dried up. Hard coarse soils dry up very
quickly, while soft, mellow, and friable ones will endure a long
drought. The gases and moisture generated by the decomposition of
manures produce this mellow state. Hence the necessity of having that
decomposition take place under the soil, or of plowing in the manure.
Another important fact bearing on this question is, that what are
regarded very poor soils, such as light sandy or gravelly land, will
produce good crops in a season remarkable for the frequency of showers.
On such soils crops are from twice to four times as large, in a wet
season as in a dry, and yet there is an addition of nothing but
moisture, and in such a manner, as not to have it stand and become
stagnant among the roots of the plants.
Yet another evidence is in the strength of clay soils. A hard clay is
very unproductive. But so disintegrated that plants can grow in it, it
produces a great crop. This is because clay is of so close a texture,
that when mixed with manure, turf, sand, or muck, although friable, it
retains more moisture, than sand or ordinary loam. This is the reason of
the superior fertility of land annually overflowed with water, as Egypt
in the vicinity of the Nile. It is not that the Nile brings down
deposites from the mountains of the Moon, so rich above all that is in
the valleys below. The entire weight of all that a river deposites on
ten acres would not equal in weight the increased vegetation of a single
acre. The cause of the increased fertility is the fact that the deposite
is so fine that it prevents rapid evaporation, and thus causes the soil
to retain moisture for the large growth, and maturity of the plants.
One more evidence is found on our sandy pine plains. Our common
forest-trees, as beech, maple, elm, or linden, will not flourish there.
Such land will produce comparatively no corn, oats, or wheat. But rye
that stands drought better than any other grain, grows tolerably well.
But such plains always produce an enormous growth of pine timber, hardly
equalled in the number of cords to the acre, by the heaviest-timbered
land of the river bottoms. Why is this? Does a maple need so much more
food than a pine, or is it in the habits of the trees? It is not in the
richness or poverty of the soil, but in the adaptation of the trees to
reach and appropriate moisture. The roots of the maple and beech, spread
out near the surface of the ground. And it being a light, porous, sandy
soil, it does not retain moisture enough to promote their growth. But
whoever notices a pine-tree that has been turned up from the roots by
the wind, will see that the roots run down almost perpendicularly ten or
fifteen feet into the sand. There they find plenty of moisture and hence
their great growth. This principle explains the comparative
productiveness of all soils.
A soil composed of light muck, or a kind of peet-soil, will dry up soon.
There is nothing to prevent rapid evaporation; hence it is always
unproductive, for want of suitable moisture. Mix with it clay, to render
its texture more firm, and it will retain the moisture, and be very
productive. Clay alone is too solid to retain moisture; it runs off, as
from a brick. Mix sand with it, and it becomes mellow, and retains
moisture, and produces great growth. Sand allows so free and rapid an
evaporation that it is unproductive. We say it leaches and is hungry,
and so it is, because it has little power to retain water. Our manures
do it good, only as they are calculated to aid it in controlling
moisture. If we apply a light manure as we would to clay, it is
comparatively useless; it adds no firmness to the texture of the soil,
and hence does not increase its capacity for controlling water. On such
land, the only good that manure does, is while decomposition is taking
place in the soil, it renders it more moist, and hence more productive.
Apply clay to such a soil, and it will increase its firmness and
consequent capacity of retaining and appropriating moisture, and thus
render it highly valuable. Dry straw manure is sometimes said to dry up
land, and ruin crops. So of turf in a dry season. In a wet season they
greatly increase the growth of crops. Now they contain just as much food
for plants in one season as another. Hence a soil too easily impervious
to the atmosphere, will be a poor soil, that is, will produce poorly,
simply because it has no power to retain the necessary moisture.
We suppose these facts and reasons to establish our theory, that the
principal benefit of manures, and of mixing different soils, is in the
control they give over the moisture and the atmosphere. Hence the
greatly increased crop of clover from the application of three quarters
of a bushel of plaster to an acre. The increased weight of clover on
five square rods, would outweigh the plaster applied, and still that
plaster remains, in almost its full weight, on the soil. This principle
explains the benefit of mulching trees, plants, or vegetables. This is
the best means of preserving trees, the first year after transplanting,
and of securing a great growth, of any kind of shrubs or plants. This
may be done with common straw or leaves. Now wherein is their utility?
Not in the nourishment they afford the plants, but in the fact that
mulching so covers the surface as to prevent rapid evaporation. In such
cases, it is the more abundant moisture that secures the greater
growth.
Hence the first study of a soil culturist should be to ascertain how he
shall so mix and manage the materials at his command, as to cause them
to retain moisture for the longest time, without leaving water to stand
about the roots of his plants. On this depends the whole importance of
deep plowing and ditching. On this theory we may also account for the
fact that certain plants prefer a certain kind of manure to all others.
It is that those plants act in a certain manner on the soil requiring a
specific action of manure to enable it to appropriate moisture and tax
the atmosphere for their growth. This theory explains why too much
manure is bad. Not because we give too much food to plants, but because
excess of manure dries up the land. But whatever theory we adopt, we all
agree in the utility of fertilizers. And the experience of practical
farmers is of more value in aiding us to reach right conclusions, than
all chemical essays on the subject that have ever been written.