THE VALUE OF MANURE DEPENDS ON THE FOOD--NOT ON THE ANIMAL.
“If,” said I, “you should put a ton of cut straw in a heap, wet it, and
let it rot down into manure; and should place in another heap a ton of
cut corn-fodder, and in another heap a ton of cut clover-hay, wet them,
and let them also rot down into manure; and in another heap a ton of
pulped-turnips, and in another heap a ton of corn-meal, and in another
heap a ton of bran, and in another a ton of malt-sprouts, and let them
be mixed with water, and so treated that they will ferment without loss
of ammonia or other valuable plant-food, I think no one will say that
all these different heaps of manure will have the same value. And if
not, why not?”
“Because,” said Charley, “the ton of straw does not contain as much
valuable plant-food as the ton of corn-fodder, nor the ton of
corn-fodder as much as the ton of clover-hay.”
“Now then,” said I, “instead of putting a ton of straw in one heap to
rot, and a ton of corn-fodder in another heap, and a ton of clover in
another heap, we feed the ton of straw to a cow, and the ton of
corn-fodder to another cow, and the ton of clover to another cow, and
save _all_ the solid and liquid excrements, will the manure made from
the ton of straw be worth as much as the manure made from the ton of
corn-fodder or clover-hay?”
“No,” said Charley. --“Certainly not,” said the Doctor. --“I am not so
sure about it,” said the Deacon; “I think you will get more manure from
the corn-fodder than from the straw or clover-hay.”
“We are not talking about bulk,” said the Doctor, “but value.” “Suppose,
Deacon,” said he, “you were to shut up a lot of your Brahma hens, and
feed them a ton of corn-meal, and should also feed a ton of corn-meal
made into slops to a lot of pigs, and should save _all_ the liquid and
solid excrements from the pigs, and all the manure from the hens, which
would be worth the most?” --“The hen-manure, of course,” said the
Deacon, who has great faith in this kind of “guano,” as he calls it.
“And yet,” said the Doctor, “you would probably not get more than half a
ton of manure from the hens, while the liquid and solid excrements from
the pigs, if the corn-meal was made into a thin slop, would weigh two or
three tons.”
“More, too,” said the Deacon, “the way you feed your store pigs.”
“Very well; and yet you say that the half ton of hen-manure made from a
ton of corn is worth more than the two or three tons of pig-manure made
from a ton of corn. You do not seem to think, after all, that mere bulk
or weight adds anything to the value of the manure. Why then should you
say that the manure from a ton of corn-fodder is worth more than from a
ton of straw, because it is more bulky?”
“You, yourself,” said the Deacon, “also say the manure from the ton of
corn-fodder is worth more than from the ton of straw.” --“True,” said I
“but _not_ because it is more bulky. It is worth more because the ton of
corn-fodder contains a greater quantity of valuable plant-food than the
ton of straw. The clover is still richer in this valuable plant-food,
and the manure is much more valuable; in fact, the manure from the ton
of clover is worth as much as the manure from the ton of straw and the
ton of corn-fodder together.”
“I would like to see you prove that,” said the Deacon, “for if it is
true, I will sell no more clover-hay. I can’t get as much for clover-hay
in the market as I can for rye-straw.”
“I will not attempt to _prove_ it at present,” said the Doctor; “but the
evidence is so strong and so conclusive that no rational man, who will
study the subject, can fail to be thoroughly convinced of its truth.”
“The value of manure,” said I, “does not depend on the quantity of water
which it contains, or on the quantity of sand, or silica, or on the
amount of woody fibre or carbonaceous matter. These things add little or
nothing to its fertilizing value, except in rare cases; and the
sulphuric acid and lime are worth no more than the same quantity of
sulphate of lime or gypsum, and the chlorine and soda are probably worth
no more than so much common salt. The real chemical value of the manure,
other things being equal, is in proportion to the nitrogen, phosphoric
acid, and potash, that the manure contains.
“And the quantity of nitrogen, phosphoric acid, and potash found in the
manure is determined, other things being equal, by the quantity of the
nitrogen, phosphoric acid, and potash contained in the food consumed by
the animals making the manure.”