Vermont watchman and State journal. [volume] (Montpelier, Vt.) 1836-1883, 1880-04-21
Professor Atwater on Fertilizers.
ForRrH ARTICLE.

fully explained in these columns during the
past year in the "Youug Farmers Cate
chism," The following are given as the most
important sources of artificial plant food,
aside from plaster and stable manure " For
phophoric acid with sulphuric acid and
lime), superphosphates i. e., dissolved bone
black and mineral superphosphates. For
phosphoric acid nth a title nitrogen, intro
genous' or ammoniated superphosphates
and ground bone. For nitrogen and phoS-
phoric acid (both in considerable quantities),
Peruvian guano and fish guano. For potash,
German potash salts of the various grades,
of which the muriate,' with fifty per cent
or more of actual potash, is generally pref
cradle"
This list, to be complete and practical for
Vermont, should include both leached and
unleached ashes among the important sources
of potash and phosphoric acid. Also we
advise the collection of all bones easily
accessible and their reduction to fine state
at home. We believe we have tried every
proposed method for effecting this, and have
settled down upon burning them. a few at q
time, in the kitchen stove during the winter.
They are taken up in the ashes, and at
leisure times broken fine upon the barn floor
with FOUNDER or peste made of piece of
lockwood with an old broom.h handle inserted
in an auger-hole bored in one end. OF
course if every farmer should go into this,
the amount that any single one would get
would not be very great; yet even then the
bones left about "promiscuous," and those
of dead horses and other animals buried in
the fields, would yield ten or fifteen dollars
worth OF this valuable fertilizer to every
farmer in the state, annually. But as it is a
sad matter of fact that not one farmer in
dozen will try it, any one who will let the
boys know that he buys bones at half cent
pound can get ton or two every year. A
half ton of this burned and pounded bone
will supply an acre of land with all the
phosphoric acid taken from it by crops in
ten years. In burning, all the ammonia in
the bones is lost but the value of this is not
nearly equal to the charge added for grind
ing in the price asked by dealers in ferti
izers for "pure ground bone" to say nothing
of the chance of its not being pure. Some
times it is nearer to pure oyster-shells than
pure bone. Any one can see that it is
cheaper to buy bones at half a cent pound
and pulverize them as directed than to pay
two cents pound for even the best ground
bone.
Speaking of these matters in detail, the
professor says of the superphosphates proper,
or acid phosphates: 1.-The chief value of
these rests in their phosphoric acid They
are made by treating bone black CLEANED
bone), Canada apatite, and South Carolina
Navassa, and other fossil and mineral phos-
pilates, with sulphuric acid, which renders
their phosphoric acid soluble and hence
available to plants Besides phosphoric
acid they contain sulphuric acid, lime and
other ingredients of less or no value
"Cleaned bone" here in parenthesis is a
gross misprint for chdred bone, mistake
probably caused by the professor not seeing
his proof sheets, and having no one to read
them who knows anything about the sub
ject. In regard to these acid phosphates
made very soluble by the use of sulpburic
acid, we find that grave doubts have arisen
not only among the farmers but among agri
cultural chemists, as to whether this extreme
solubility is worth the cost incurred in pro-
ducing it. DIR. Nichols OF the Boston Jour
nal Of Chemistry, who is not only manu-
facturino chamiet hut m avtapoiva and
skillful farmer who "farms for profit" has
lately expressed the opinion that not only
pure ground bone, but even the mineral
phosphates, when ground fine as flour, will
produce better results, dollars worth for
dollars worth, than the high acid phos-
pilates. These finely ground mineral phos.
pilates can be sold at from $40 to 800 ton.
Applied at the rate of ton to the acre, they
are said to do as well as the acid phosphates
the first year and as the amount of phos-
phoric acid added to the soil is very much
greater than when the same cost in acid
phosphates is incurred, the lasting quality
of such fertilizer is far greater than that
of the quick phosphates. Professor Henry
Tanner of England, an eminent agricultural
chemist says on this subject, in his First
Principles of Agriculture recently pub
lished, that not only are the "over-manu-
featured phosphates too expensive, but
that they have ga higher degree of solu.
bility than is consistent with the healthy
growth of our crops He says, also that
on light soils the use of these acid phos-
pilates is attended with great loss, as the
phosphate, being so very soluble, is apt to be
washed out of the soil by rains before the
plants get hold of it. He recommends the
mixing of these highly acid phosphates with
at least an equal quantity of ground bone
before using. This lessons the cost and in
creases the value of the fertilizer thus pre-.
pared. II finely ground mineral phosphates
were used for mixing, the cost would be yet
more reduced without injury to quality.
OF the socalled heterogeneous or ammoni.
aztec" phosphates, Professor Atwater ex.
plains that their nitrogen is furnished by
the admixture of dried blood and mea,
or fish scraps. They are retailed at from
$40 to $50 per ton, which brings soluble
phosphoric acid at eleven to eighteen cents
and nitrogen at twenty 10 thirty cents per
pound. This is, in our opinion, too higt
a price for their agricultural value on low
priced crops like corn and potatoes. Ye
they are very extensively used, especially il
the hill in connection with moderate dress
ings Of farm manure and many farmer
guess that they pay. Probably in some case
they do; yet good many years of expert
mentation has brought us finally to the us
of pure sulphate of ammonia as the CHEAP
est sort of nitrogen for plant food On pc
tatoes, turnips, beans, peas, clover and sin
liar crops, we do not want any artifca
supply of nitrogen at all Except for yer
early "new" potatoes for village or cit
markets). For those crops plaster and ashe
or ground bone, or not highly acid mineri
phosphate without nitrogen (used in col
nection with ashes) are the most useful i
our experience, and this agrees with the r
suits of the experiments which form tn
text of Professor Atwater's articles FL
corn we want more nitrogen than is fouu