The true northerner. [volume] (Paw Paw, Mich.) 1855-1920, 1881-02-11
exemption or stay Of execution in the chancery
THR CHEMICALS OF AGRICULTURE.
IL studying the relations OF chemistry TO agri


IL studying the relations OF chemistry to agri
culture was the first endeavor OF the chemist
TO find out how many elementary substances
are found in agricultural plants; then to deter
mine in what form they must be furnished to
promote plant growth and finally why they are
necessary and what office they discharge
Countless as are the forms and products OF veg
etable life, only thirteen elementary substances
enter into the formation OF agricultural plants.
They may be divided into three groups,
or classes: /. Five OF these are metals: potas
stun, sodium, calcium, magnesium and iron.-
ii. Four are non-metalc solids: carbon, sih
con, sulphur and phosphorus. III. Four are
gases: oxygen, hydrogen, nitrogen aud chic
rne. Only these thirteen are necessary for the
formation OF the substance of plants In the
presence OF an adequate supply of these IN an
available form and under favorable physical
conditions, all plants attain perfect develop
ment. The chemistry OF agriculture is primarily
concerned in supplying to the plant sufficient
supply Of these chemicals Of agriculture and in
a form suitable for assimilation by the plant.
RELATIVE IMPORTANCE.
to the plant. Some are required in such small
amounts that the supply from the soil is sufi-
cient, or they are furnished by nature ia such
abundance that the farmer need give himself
no trouble to furnish his crops with artificial
supply. For example: In most soils common
salt sufficient to furnish the small amount Of
sodium and chlorine required by most plants
the amount Of oxide OF iron in nearly all soils
is enough for any plant; the sand and solicates
will supply all the silicon required; the oxygen
and hydrogen which form water are ample sup
plies OF these elements; the air contains one
part Of carbonic acid in $4,000, which seems
small amount, yet the air resting on each acre
contains eight tons of carbon; and if the air
resting on a field should become exhausted OF
it's supply, the next wind would bring eight tons
more, and we may regard the atmospheric sup
ply sufficient for any crop.
This leaves only six substances concerning
which we need feel any agricultural anxiety,
namely: Potassium, calcium, magnesium, sui
phur phosphorus and nitrogen. But these are
OF supellative Importance in agriculture No
plant can grow in the entire absence OF any one
OF them, and the absence or deficiency Of auy
one OF them will correspondingly limit the ac
ton OF all the others.
When a soil has become exhausted by crop
ping, it is because some one or more OF these
substances has become deficient in quality or
does not exist in farm assmilated by plants.
The intelligent farmer Is therefore on the alert
to accumulate on bis farm the materials go es
sentlal for the production OF large crops, and
10 prevent their unnecessary escape. They are
his capital stock, to be expended only when
large profits are to be secured.
Sources OF these six substances: Potassium
is derived from the compound slcates in the
soil. These compound silicates
are entirely insoluble in water, but when de-
composed into silicate OF potassium and OF
aluminium, the silicate OF potassium becomes
soluble in water. and thus available for plant
growth. By decomposition OF feldspar, there
fore, sllicate OF ALUMINIUM or clay is formed and
silicate Of potassium set Free In most clays
this decomposition is incomplete, and az it pro-
ceeds, potash is yielded. This is one reason
why clay soils are go strong and endure long
cultivation. Stirring up the soils hastens de-
composition and consequent supply OF potash,
as does also the presence of caustic lime, plas-
ter, which explains IN part the benefits follow
ing the use OF these materials.
Wood ashes form another and abundant
source Of potassium, soluble in water and hence
Immediately available. One hundred pounds
OF wood ashes contains about Is pounds Of
potash.
Calcium is obtained from carbonate OF lime
mar, plaster, ashes, bones, etc. Plaster is
more active than carbonate because more read
lily soluble in water. Plaster is also the chief
source OF sulphur for plants. The fact that
plaster supplies calcium aud sulphur to plants,
and makes soluble and available an increased
amount of potassium, explains in part the
benefits following the use OF plaster on clover
and leguminous crops in all parts OF our
country,
Magnesium is found in much smaller
amounts in plants than calcium. 1t is obtained
by the plant from the carbonate and sllicate OF
magnesium in the soil, and from bones and
wood ashes.
Phosphorus is obtained from the phosphate
OF calcium, found in minute amount in all fer
tile soils, from bones and animal remains of
every kind, from superphosphates and from
wood ashes. You will observe that wood ashes
is source o; supply OF number Of these
chemicals of agriculture. In fact these ashes
contain nine OF the thirteen chemicals of agri-
culture. No farmer can afford 70 throw il
away. Some farmers sell their ashes to the
soap maker, and their farming is soon clothed
in sack cloth and ashes. Better clothe your fields
with the ashes and keep your sack cloth to
market the surplus Of your crops.
Nitrogen. The great reservoir Of nitrogen is
The air, nearly four -ffths Of which is nitrogen
The leaves OF all plants are therefore constant
ly bathed in nitrogen, and it would seem that
they could easily supply themselves with the
required amount OF this element. But plants
are incapable Of asslmilating the uncombined
or free nitrogen OF the air. 1t is only IN the
combined form that plants can appropriate it.
Repeated and exact experiment has shown that