The central Presbyterian. [volume] (Richmond, Va.) 1856-1908, 1880-03-10
farm aud Garden.
Commercial Fertilizers.-Continued

the form of ammonia or nitric acid), and
potash are the important. constituents /;
there are some others that are sometimes
advantageous, but these are the principal
ones But all these, as we will hereafter
find, are not necessary for every crop. 10
find out the proportion of constituents In
fertilizer, the farmer must examine the
brand put on the bags as required by law,
and seek for an analysis by the Commits
sioner of Agriculture, or some competent
chemist Farmers frequently have pur
chased fertilizers without knowing what
the manufacturers claim for them, their
application has failed to pay for the out
lay, and payments have been refused on
the ground that they were worthless and
fraudulent The manufacturer comes for
ward and proves that the analysis of his
brand comes up to what he has claimed
on the bags, and the farmer has to pay
for his want of foresight The manufac-'
turer, by the way, we think, frequently
assumes too much margin in stating his
constituents. He cannot always make
his goods uniform but if he gets an anal
ysis from a competent chemist, there need
not be as much margin as we often see.
The next thing the farmer should do, is
to endeavor to find out which of these
three constituents named his crops re-
quire, or whether all of them Of the
three named, phoSphorac acid, in the form
of phosphate of lime, is most universally
required, and is most deficient in soils,
and there is not plant which does not
require it. Besides this, phosphoric acid
occurs In nature almost entirely in forms
not assimilable by plants, and when made
soluble, and converted into organized
bodies, whether animal or vegetable, the
same lnsoluble forms are again assumed
This is apparent when we remember that
the bones-of all animals, and the seed of
all plants have phosphoric acid combined
with lime, as the insoluble tri-basic phos-
phate of lime, ia which form it remains
unasslmllable by plants, unless changed
In the soil by slow chemical action; or ar
tIhclally, by chemical reagents or me-
chanical means. The bones of all animals
must obtain this phosphate of lime, which
IN young animals is obtained through the
milk, and In older animals, through the
food. In the cow, every 80 gallons of
rnllk contains about one pound of phos-
phate of lime, and it is estimated that
COW In milk requires about so pounds of
bone material In a year, and that herd
OF 70 COWS will carry off by pasturage, and
by the hay fed, one ton of bone material
In year. 1t is not to be wondered then
that such a drain upon the resources of
land, II continued, must result in impov-
erlshment. Phosphate of lime must be
returned IN some form to feed the grasses
and plants and give them vigor, that they
may In turn nourish the bodies and form
the bones of our stock, and by the use of
their flesh and milk, nourish our own
bodies and bones. Plants cannot assimi-
late bones and the phosphate rock (the
two principal sources of phosphate OF
llme) In It's ordinary state, and it must be
rendered soluble in water before it can be
taken up by the plant. This is done either
by very tine grinding, making -four OF
bone, or by dissolving it by sulphuric
acid Coil of vitriol This action of sui
phuric acid on bone, or phosphate rock,
obtained principally from South Caro-
hna) forms superphosphate of lime" or
dlssol we'd bone" or acid phosphate,
all OF which mean the same thing Unless
bone is ground very fine its action is too
slow to benefit the growing crop ; it will
benefit the future crops, if it is not too
coarse, but the farmer cannot afford to
wait for this The action of dissolved
bone. or superphosphate is much more
rapid. There is something lost by this in
the expense of the acid, the time, and
labor necessary, and the addition to the
bulk, and loss of percentage of bone One
hundred pounds of South Carolina phog
phate will require about 40 pounds off
sulphuric acid, beside some water, to form
the superphosphate Then, more than
half OF the mass will be gypsum (plaster)
resulting from the action of the acid on
lime. taking up two parts of lime, and
leaving one part in union with the phog-
phate OF lime, or phosphate rock, being
originally tr5-colcic phosphate, or one part
OF phosphorie acid united to three of lime
The gypsum formed is not an entire loss
and indeed on many soils, as it is well
known, it is very valuable, while on many
others, particularly in Eastern Virginia.
1T has no action. The gypsum is useful
when dissolved bone is used in composfs
as 1T prevents the escape of ammonia Of
barn-yard manure used in the compost.
Another loss in dissolving bone is the
ammonia, which amounts to a or S per
cent, and which is driven off by the heat
generally used to prepare the bone for
I1ucolyiuo II r,ory L.. I.--..-l IL