The Middlebury register. [volume] (Middlebury, Vt.) 1850-1882, 1872-03-12
agricultural department.
CONDUCTED BY ALBERT CHAPMAN.

CuNDuCIED BY ALBERT CHAPMAN.
The following valuable lecture upon
commercial fertilizers and their compare
two value by Professor Collier Secretary
Of the State Board of Agriculture. We
speak for it not only reading, but a
careful study by all interested. 1t was
delivered at the meetings of the State
board at Burlington, Nliddlcbury and
Montpelier.
Professor Collier said that the applca.
ton Of chemistry to agriculture is of com.
parativcly recent date. The first work on
agricultural chemistry was written by &.
Scotch noblcman in l706. AS late as
1885, prizo was offered for the solution
of the question whether mineral matters
in the soil are Of consequence to the plant.
The ashes Of plant represent the miner
al matters which enter into its compost
ton. Analysing them we find them to
consist chiefly Of potash and phosphoric
acid Now if we can return to the soil
as much of these substances as we take
from 1t in our crops, we shall hold our
own.
English statistics show that the crops
of that country take from the soil each
year $4,000 tons of phosphoric acid, and
that 1000 tons of phosphoric acid,arc re-
turned to the soil in superphosphates ap-
piled as fertilizers. This would not sup
ply the waste. But it is to be remem-
bered that a large proportion Of these
crops are consumed in the country, and
thus return to the soil, and there is a con-
slant process of addition of minerals to
the soil from the "wcathering" Of the
rocks. The fact is that the lands OF
England are increasing in valne and it
may be set down as probably correct, as
\ general rule, that if we return to the
soil in fertilizers, one fourth as much
phcsphoric acid as is taken up in the
crops, we shall retain the fertility of the
SOIL
The phosphoric acid is obtained in va
rious ways. We find it in manures and
guano, and abundantly in the bones Of
animals. In Canada, rocks are found OF
phosphate Of lime. In South Caroline
the phosphatcs are found abundantly in
nodules in the earth, and all of these sub.
stances are used by different manufacture
ers of supcrphosphates. In applying
phosphates, it is important to remember
that plants can take their food only in
solution; and that the phosphatcs exist in
insolublc as well as soluble forms. five
bury the skeleton Of horse it may stay
in some soils almos. unchanged for hun
bred years, but treat it with sulphuric
acid, and it all becomes soluble, and every
atom can be taken up at once by vegeta-
ton. This difference in the phosphates
is all important in. determining the value
of fertilizers. You can buy fertilizer
warranted to contain Is per cent. of phos-
peates, and which yet contains less than
two per cent. of soluble phosphatcs. Some
Of the fertilizers also change or go back,
the Ingredients being such that chemical
changes take place which change the solu-
Bile TO insoluble phosphates, in greater or
less degree, and thus grnatly lessen the
value of the fertilizer.
An idea seems to prevail among many
farmers that fertilizer is not worth
much unless it smells bad ; and some su-
perphosphatc are popular, in which the
makers have secured the ammonia in them
oy using dccayed animal matter, fish
pumice, &C., the result of which is fer
tilizer containing large amount of inso-
luble phosphatcs.
The phosphatcs called Home Made"
in the following table, arc the result of
experiments made by Prof. Collier at the
request of Mr.. G. w. Bcckwiih, of Bur-
lington. Prof. Collier in the course Of
experiments manufactured some twenty
different superphosphatcs, from which
these two were selected as the best.
These he believes can be duplicated with
perfect reliability, and Mr.. Bcckwith in.
tends to manufacture them in quantity.
The popularity in them is that the bones
OF which they are made are calcined be.
fore treating them with the oil of vitriol.
While by this burning of the bones some
substances oc value are destroyed, on the
whole the gain is greater than the loss.
The result is fertilizer which far ex.
ceeds any in the market in amount of
soluble phosphate, and one which will not
"go back" retains its proportions with
out change The Home made No l. is
ammoniated with sulphatc of ammonia,
the mo. ." is simple superphosphate,
without ammonia. Tho first is most ap.
plicable to grain crops, the second to
roots, and especially to turnips.
Prof. Collier presented the following
table showing the results of careful an.
alyses of various fertilizers: