The farmer and mechanic. [volume] (Raleigh, N.C.) 1877-1885, 1878-03-21

fattened and sold. about sixteen
pounds only of phosphoric acid
viii be exported: this quantity.
distributed through the whole number
of years from the birth of the animal
10 its sale, viii amount toa very small
draft per annum per acre-ceTtainly
not over two pounds. The meaning
of all these figures is 81 plv this. that
if only wheat. milk ana fattened ami
mails are sold Oft the farm. and If
wheat does not ONE too often in the
rotation. the stock Of pEosphOric acid
IN the soil l. not drawn BOZ To an ex-
tent greater than from two TO three
pounds for each acre per year. or less
than a hundreth of the average quaint
" III a good soil. This j. slow eXhaus-
ton. but. after all. il is sure. and even
such careful husbandrv as this cannot
be practiced. if but for half a century,
without making 4 serious inroad on
the native stores of plant food. ON
how many Of our farms. however. l.
such careful husbandry praCtlced-to
say nothing OF the reckless waste OF
manures: IN making these estimates
| have assumed that everything that
is not sold goes back othe farm again
in manur What quantities OF corn
and hay are carried from the country
to the citv-both of them
crops that remove large guam
titles of phosphoric acid, fifteen.
twenty-five orthirty pounds per acre.
instead of only two or three. as III
wheat, milk and fat animals. In res
pect to the waste of manures, fortu-
%nately. phosphoric acid is not easily
lost IN this way. 1t is not volatile,
and 50 it cannot escape intothe atmos-
phere as the ammonia can but If the
manure pile is frequently drenched
with water. as is only too often the
case, the phosphate may be leached out
and carried into the ground under the
pile, far beyond the reach Of the farm
er's spade. In one instance, where an
excavation was made under a manur
pile from seventy head of cattle. 1t
was found that the earth was colored
blue b. phosphate of iron from phos-
phoric acid that had been leached out
of the pile, and it was estimated from
the analysis of this product, that there
were under the manure pile at least
six thousand pounds OF phOsphorlc
acid. worth at least five times as much
as an equal quantity of ~phosDhorlc
acid III the field. because soluble IN
water. The phosphoric acid in the
field, especially of a soil that has been
long under cultivation, is mostly lnsul-
uble: this hat was found under the
manure pile must have been soluble
originally. or it would not have leached
out by the water that soaked through
the manure
If there were time for it, | might
show that lime and potash, ingredients
of the food Of plants, that are always
present in the plant, and in the case
of the latter especially, in quite large
and uniform proportions IN some parts
OF the plant, are exported In much
smaller quantities than the phOsphorlc
acid, in the plants ordinarily sold.
PhOsphoric acid, appears to be the IN
gredient Of plant food above all others
that we have been carrying off from
the soil of our farms in the course of
the fifty years or more that we have
been %cultivating them, and it is only
within the last few years that we have
given any thought to replacing the
loss. In England, where the soil has
been under cultivation for a much
longer period, they began to feel the
deficiency of phosphates many years
ago. ana we are now beginning to fol
low in their track. In Morton'S Cy-
clopRdia of Agriculture we are told
how the farmers Of England began
long ago to be discouraged. Their
soils had been steadily deteriorating
for MANY wears, under somewhat the
same wasteful system Of cultivation.
evidently, that has been SO largely fol
lowed i'll this country, especially in the
west. A point was reached where,
whatever system the farmer followed,
his crops were steadily diminishing;
in some places the condition of things
was SO bad that wheat was not IN
Guided at all in the rotation. 1t was
the introduction of bone manure just
at this point, that saved the agricul-
ture Of England, and entirely changed
the aspect of affairs.
From the consideration Of the rela-
ton between phosphates in the soil
and the phosphoric acid in the crops
that we allow TO leave the farm. we
pass naturally to be continued Of the
important subject Of phosphates as
TO be cOatinucd-If our readers eX-
press a wish To have more Of the adj
I..arc