THE CHEAPEST MANURE A FARMER CAN USE.
I do not know who first said, “The cheapest manure a farmer can use
is--clover-seed,” but the saying has become part of our agricultural
literature, and deserves a passing remark.
I have heard good farmers in Western New York say, that if they had a
field sown with wheat that they were going to plow the spring after the
crop was harvested, they would sow 10 lbs. of clover-seed on the wheat
in the spring. They thought that the growth of the clover in the fall,
after the wheat was cut, and the growth the next spring, before the land
was plowed, would afford manure worth much more than the cost of the
clover-seed.
“I do not doubt it,” said the Deacon; “but would it not be better to let
the crop grow a few months longer, and then plow it under?”
“But that is not the point,” I remarked; “we sometimes adopt a rotation
when Indian-corn follows a crop of wheat. In such a case, good farmers
sometimes plow the land in the fall, and again the next spring, and then
plant corn. This is one method. But I have known, as I said before, good
farmers to seed down the wheat with clover; and the following spring,
say the third week in May, plow under the young clover, and plant
immediately on the furrow. If the land is warm, and in good condition,
you will frequently get clover, by this time, a foot high, and will have
two or three tons of succulent vegetation to turn under; and the farmer
who first recommended the practice to me, said that the cut-worms were
so fond of this green-clover that they did not molest the young
corn-plants. I once tried the plan myself, and found it to work well;
but since then, I have kept so many pigs and sheep, that clover has been
too useful to plow under. But we will not discuss this point at present.
“What I wanted to say is this: Here we have a field in wheat. Half of it
(A) we seed down with 12 lbs. of clover-seed per acre; the other half
(B) not. The clover-seed and sowing on A, cost, say, $2 per acre. We
plow B in the fall; this will cost us about as much as the clover seed
sown on A. In the spring, A and B are both plowed and planted to corn.
Now, which half of the field will be in the cleanest and best condition,
and which will produce the best corn, and the best barley, or oats,
afterwards?”
“I vote for A,” said the Deacon.
“I vote for A,” said the Doctor.
“I vote for A,” said the Squire.
“I should think,” modestly suggested Charley, “that it would depend
somewhat on the soil,” and Charley is right. On a clean, moderately rich
piece of light, sandy soil, I should certainly expect much better corn,
and better barley or oats, on A, where the clover was grown, than on B.
But if the field was a strong loam, that needed thorough cultivation to
get it mellow enough for corn, I am inclined to think that B would come
out ahead. At any rate, I am sure that on my own farm, moderately stiff
land, if I was going to plant corn after wheat, I should _not_ seed it
down with clover. I would plow the wheat stubble immediately after
harvest, and harrow and cultivate it to kill the weeds, and then, six
weeks or two months later, I would plow it again. I would draw out
manure in the winter, pile it up in the field to ferment, and the next
spring spread it, and plow it under, and then--
“And then what?” asked the Deacon. --“Why the truth is,” said I, “then I
would not plant corn at all. I should either sow the field to barley, or
drill in mangel-wurzel or Swede-turnips. But if I _did_ plant corn,
I should expect better corn than if I had sown clover with the wheat;
and the land, if the corn was well cultivated, would be remarkably
clean, and in fine condition; and the next time the land was seeded down
with clover, we could reasonably expect a great crop.”
The truth is, that clover-seed is sometimes a very cheap manure, and
farmers are in no danger of sowing too much of it. I do not mean sowing
too much seed per acre, but they are in no danger of sowing too many
acres with clover. On this point, there is no difference of opinion. It
is only when we come to explain the action of clover--when we draw
deductions from the facts of the case--that we enter a field bristling
all over with controversy.
“You have just finished threshing,” said the Deacon, “and for my part,
I would rather hear how your wheat turned out, than to listen to any of
your chemical talk about nitrogen, phosphoric acid, and potash.”
“The wheat,” said I, “turned out full as well as I expected. Fourteen
acres of it was after wheat, and eight acres of it after oats. Both
these fields were seeded down with clover last year, but the clover
failed, and there was nothing to be done but to risk them again with
wheat. The remainder was after barley. In all, there was not quite 40
acres, and we had 954 bushels of Diehl wheat. This is not bad in the
circumstances; but I shall not be content until I can average, taking
one year with another, 35 to 40 bushels per acre. If the land had been
rich enough, there would unquestionably have been 40 bushels per acre
this year. That is to say, the _season_ was quite capable of producing
this amount; and I think the mechanical condition of the land was also
equal to it; all that was needed was sufficient available plant-food in
the soil.”
“I can see no reason,” said the Doctor, “why you may not average 40
bushels of wheat per acre in a good season.”
“The field of 14 acres,” said I, “where wheat followed wheat, yielded 23
bushels per acre. Last year it yielded 22 bushels per acre; and so we
got in the two years 45 bushels per acre.”
This field has had no manure of any kind for years. In fact, since the
land was cleared, 40 or 50 years ago, I presume that all the manure that
has been applied would not, in the aggregate, be equal to more than a
good crop of clover-hay. The available plant-food required to produce
these two crops of wheat came from the soil itself, and from the rain,
dews, and atmosphere. The land is now seeded down with clover, and with
the aid of a bushel or two of plaster per acre, next spring, it is not
improbable that, if mown twice for hay next year, it will yield in the
two crops three tons of hay per acre.
Now, three tons of clover-hay contain about 33 lbs. of phosphoric acid,
90 lbs. of potash, and 150 lbs. of nitrogen.
The last crop of wheat, of 22 bushels per acre, and say 1,500 lbs. of
straw, would contain:
In the grain. In the straw. In total crop.
Phosphoric acid 11½ lbs. 3¾ lbs. 15¼ lbs.
Potash 6¾ ” 9¾ ” 16½ ”
Nitrogen 23 ” 9½ ” 32½ ”
It seems very unkind in the wheat-plants not to give me more than 22
bushels per acre, when the clover-plants coming after will find
phosphoric acid enough for 40 bushels of wheat, and potash and nitrogen
enough for nearly 100 bushels of wheat per acre. And these are the three
important constituents of plant-food.
Why, then, did I get only 22 bushels of wheat per acre? I got 23 bushels
on the same land the year previous, and it is not improbable that if I
had sown the same land to wheat again this fall, I should get 12 or 15
bushels per acre again next year. But the clover will find plant-food
enough for 40 bushels of wheat.
“There is not much doubt,” said the Deacon, “that you will get a good
crop of clover, if you will keep the sheep off of the land this fall.
But I do not see what you mean by the clover-plants finding food enough
for 40 bushels of wheat, while in point of fact, if you had sown the
field again to wheat this fall, you would not, as you say, probably get
more than 12 or 15 bushels of wheat.”
“He means this,” said the Doctor. “If he had sown the land to wheat this
fall, without manure, he would probably not get over 15 bushels of wheat
per acre, and yet you both agree that the land will, in all probability,
produce next year, if mown twice, three tons of clover-hay per acre,
without any manure.
“Now, if we admit that the clover gets no more nitrogen from the rain
and dews, and from the atmosphere, than the wheat will get, then it
follows that this soil, which will only produce 15 bushels of wheat per
acre, does, in point of fact, contain plant-food enough for 40 bushels
of wheat, and the usual proportion of straw.
“The two crops take up from the soil as follows:
Phosphoric acid. Potash. Nitrogen.
15 bushels wheat and straw 10¼ lbs. 11¼ lbs. 22 lbs.
3 tons clover-hay 33 ” 90 ” 150 ”
“These facts and figures,” continued the Doctor, “are worth looking at
and thinking about. Why can not the wheat get as much phosphoric acid
out of the soil as the clover?”
“Because,” said the Deacon, “the roots of the clover go down deeper into
the subsoil than the roots of wheat.”
“That is a very good reason, so far as it goes,” said I, “but does not
include all the facts. I have no sort of doubt, that if I had sown this
land to wheat, and put on 75 lbs. of nitrogen per acre, I should have
got a wheat-crop containing, in grain and straw, 30 lbs. of phosphoric
acid. And so the reason I got 15 bushels of wheat per acre, instead of
40 bushels, is not because the roots of wheat do not go deep enough to
find sufficient soluble phosphoric acid.”
“Possibly,” said the Doctor, “the nitrogen you apply may render the
phosphoric acid in the soil more soluble.”
“That is true,” said I; “and this was the answer Liebig gave to Mr.
Lawes. Of which more at some future time. But this answer, like the
Deacon’s, does not cover all the facts of the case; for a supply of
soluble phosphoric acid would not, in all probability, give me a large
crop of wheat. I will give you some facts presently bearing on this
point.
“What we want to find out is, why the clover can get so much more
phosphoric acid, potash, and nitrogen, than the wheat, from the same
soil?”
MORE ABOUT CLOVER.
The Deacon seemed to think the Doctor was going to give a scientific
answer to the question. “If the clover _can_ get more nitrogen,
phosphoric acid, and potash, from the same soil than wheat,” said he,
“why not accept the fact, and act accordingly? You scientific gentlemen
want to explain everything, and sometimes make confusion worse
confounded. We know that a sheep will grow fat in a pasture where a cow
would starve.”
“True,” said the Doctor, “and that is because the cow gathers food with
her tongue, and must have the grass long enough for her to get hold of
it; while a sheep picks up the grass with her teeth and gums, and,
consequently, the sheep can eat the grass down into the very ground.”
“Very well,” said the Deacon; “and how do you know but that the roots of
the clover gather up their food sheep-fashion, while the wheat-roots eat
like a cow?”
“That is not a very scientific way of putting it,” said the Doctor; “but
I am inclined to think the Deacon has the right idea.”
“Perhaps, then,” said I, “we had better let it go at that until we get
more light on the subject. We must conclude that the wheat can not get
food enough from the soil to yield a maximum crop, not because there is
not food enough in the field, but the roots of the wheat are so
constituted that they can not gather it up; while clover-roots, foraging
in the same soil, can find all they want.”
“Clover,” said the Deacon, “is the scavenger of the farm; like a pig, it
gathers up what would otherwise be wasted.”
“Of course, these illustrations,” said the Doctor, “do not give us any
clear idea of _how_ the clover-plants take up food. We must recollect
that the roots of plants take up their food in solution; and it has just
occurred to me that, possibly, Mr. Lawes’ experiments on the amount of
water given off by plants during their growth, may throw some light on
the subject we are discussing.”
“Mr. Lawes found,” continued the Doctor, “that a wheat-plant, from March
19 to June 28, or 101 days, evaporated through its leaves, etc., 45,713
grains of water; while a clover-plant, standing alongside, and in
precisely similar condition, evaporated 55,093 grains. The clover was
cut June 28, when in full bloom. The wheat-plant was allowed to grow
until ripe, Sept. 7. From June 28 to Sept. 7, or 72 days, the
wheat-plant evaporated 67,814 grains.”
“One moment,” said the Deacon; “as I understand, the clover-plant
evaporated more water than the wheat-plant, until the 28th of June, but
that during the next 71 days, the wheat-plant evaporated more water than
it had during the previous 101 days.”
“Yes,” said I, “and if these facts prove nothing else, they at least
show that there is a great difference between wheat and clover. I was at
Rothamsted when these experiments were made. During the first nine days
of the experiment, the clover-plant evaporated 399.6 grains of water;
while the wheat-plant, standing alongside, evaporated only 128.7 grains.
In other words, the clover-plant evaporated three times as much water as
the wheat-plant. During the next 31 days, the wheat-plant evaporated
1,267.8 grains, and the clover-plant 1,643.0 grains; but during the next
27 days, from April 28 to May 25, the wheat-plant evaporated 162.4
grains of water per day, while the clover-plant only evaporated 109.2
grains per day. During the next 34 days, from May 25 to June 28, the
wheat-plant evaporated 1,177.4 grains per day, and the clover-plant
1,473.5 grains per day.”
“In June,” said the Deacon, “the clover evaporates ten times as much
water per day as it did in May. How much water would an acre of clover
evaporate?”
“Let Charley figure it out,” said the Doctor. “Suppose each plant
occupies 10 square inches of land; there are 6,272,640 square inches in
an acre, and, consequently, there would be 627,264 clover-plants on an
acre. Each plant evaporated 1,473.5 grains per day, and there are 7,000
grains in a pound.”
Charley made the calculation, and found that an acre of clover, from May
25 to June 28, evaporated 528,598 lbs. of water, or 15,547 lbs. per day.
A much more accurate way of ascertaining how much water an acre of
clover evaporates is afforded us by these experiments. After the plants
were cut, they were weighed and analyzed; and it being known exactly how
much water each plant had given off during its growth, we have all the
facts necessary to tell us just how much a crop of a given weight would
evaporate. In brief, it was found that for each pound of dry substance
in the wheat-plant, 247.4 lbs. of water had been evaporated; and for
each pound in the clover-plant, 269.1 lbs.
An acre of wheat of 15 bushels per acre of grain, and an equal weight of
straw, would exhale during the spring and summer 177¾ tons of water, or
calculated on 172 days, the duration of the experiment, 2,055 lbs. per
day.
An acre of clover that would make two tons of hay, would pass off
through its leaves, in 101 days, 430 tons of water, or 8,600 lbs. per
day--more than four times as much as the wheat.
These figures show that, from an agricultural point of view, there is a
great difference between, wheat and clover; and yet I think the figures
do not show the whole of the difference. The clover was cut just at the
time when the wheat-plant was entering on its period of most rapid
growth and exhalation, and, consequently, the figures given above
probably exaggerate the amount of water given off by the wheat during
the early part of the season. It is, at any rate, quite clear, and this
is all I want to show, that an acre of good clover exhales a much larger
amount of water from spring to hay-harvest than an acre of wheat.
“And what,” said the Deacon, who was evidently getting tired of the
figures, “does all this prove?”
The figures prove that clover can drink a much greater quantity of water
during March, April, May, and June, than wheat; and, consequently, to
get the same amount of food, it is not necessary that the clover should
have as much nitrogen, phosphoric acid, potash, etc., in the water as
the wheat-plant requires. I do not know that I make myself understood.
“You want to show,” said the Deacon, “that the wheat-plant requires
richer food than clover.”
Yes, I want to show that, though clover requires _more_ food per day
than wheat, yet the clover can drink such a large amount of water, that
it is not necessary to make the “sap of the soil” so rich in nitrogen,
phosphoric acid, and potash, for clover, as it is for wheat. I think
this tells the whole story.
Clover is, or may be, the grandest renovating and enriching crop
commonly grown on our farms. It owes its great value, not to any power
it may or may not possess of getting nitrogen from the atmosphere, or
phosphoric acid and potash from the subsoil, but principally, if not
entirely, to the fact that the roots can drink up such a large amount of
water, and live and thrive on very weak food.
HOW TO MAKE A FARM RICH BY GROWING CLOVER.
Not by growing the clover, and selling it. Nothing would exhaust the
land so rapidly as such a practice. We must either plow under the
clover, let it rot on the surface, or pasture it, or use it for soiling,
or make it into hay, feed it out to stock, and return the manure to the
land. If clover got its nitrogen from the atmosphere, we might sell the
clover, and depend on the roots left in the ground, to enrich the soil
for the next crop. But if, as I have endeavored to show, clover gets its
nitrogen from a weak solution in the soil, it is clear, that though for
a year or two we might raise good crops from the plant-food left in the
clover-roots, yet we should soon find that growing a crop of clover, and
leaving only the roots in the soil, is no way to permanently enrich
land.
I do not say that such a practice will “exhaust” the land. Fortunately,
while it is an easy matter to impoverish land, we should have to call in
the aid of the most advanced agricultural science, before we could
“exhaust” land of its plant-food. The free use of Nitrate of Soda, or
Sulphate of Ammonia, might enable us to do something in the way of
exhausting our farms, but it would reduce our balance at a bank, or send
us to the poor-house, before we had fully robbed the land of its
plant-food.
To exhaust land, by growing and selling clover, is an agricultural
impossibility, for the simple reason that, long before the soil is
exhausted, the clover would produce such a poverty-stricken crop, that
we should give up the attempt.
We can make our land poor, by growing clover, and selling it; or, we can
make our land rich, by growing clover, and feeding it out on the farm.
Or, rather, we can make our land rich, by draining it where needed,
cultivating it thoroughly, so as to develope the latent plant-food
existing in the soil, and then by growing clover to take up and organize
this plant-food. This is how to make land rich by growing clover. It is
not, in one sense, the clover that makes the land rich; it is the
draining and cultivation, that furnishes the food for the clover. The
clover takes up this food and concentrates it. The clover does not
create the plant-food; it merely saves it. It is the thorough
cultivation that enriches the land, not the clover.
“I wish,” writes a distinguished New York gentleman, who has a farm of
barren sand, “you would tell us whether it is best to let clover ripen
and rot on the surface, or plow it under when in blossom? I have heard
that it gave more nitrogen to the land to let it ripen and rot on it,
but as I am no chemist, I do not know.”
If, instead of plowing under the clover--say the last of June, it was
left to grow a month longer, it is quite possible that the clover-roots
and seed would contain more nitrogen than they did a month earlier. It
was formerly thought that there was a loss of nitrogen during the
ripening process, but the evidence is not altogether conclusive on the
point. Still, if I had a piece of sandy land that I wished to enrich by
clover, I do not think I should plow it under in June, on the one hand,
or let it grow until maturity, and rot down, on the other. I should
rather prefer to mow the crop just as it commenced to blossom, and let
the clover lie, spread out on the land, as left by the machine. There
would, I think, be no loss of fertilizing elements by evaporation, while
the clover-hay would act as a mulch, and the second growth of clover
would be encouraged by it. Mow this second crop again, about the first
week in August. Then, unless it was desirable to continue the process
another year, the land might be plowed up in two or three weeks, turning
under the two previous crops of clover that are on the surface, together
with the green-clover still growing. I believe this would be better than
to let the clover exhaust itself by running to seed.