The Genesis Of Soil
Soil primarily had its beginning from rock
together with animal and vegetable decay, if you can imagine long
stretches or periods of time when great rock masses were crumbling
and breaking up. Heat, water action, and friction were largely
responsible for this. By friction here is meant the rubbing and
grinding of rock mass against rock mass. Think of the huge rocks, a
perfect chaos of them, bumping, scraping, settling against one
another. What would be the result? Well, I am sure you all could
work that out. This is what happened: bits of rock were worn off, a
great deal of heat was produced, pieces of rock were pressed
together to form new rock masses, some portions becoming dissolved
in water. Why, I myself, almost feel the stress and strain of it
all. Can you?
Then, too, there were great changes in temperature. First everything
was heated to a high temperature, then gradually became cool. Just
think of the cracking, the crumbling, the upheavals, that such
changes must have caused! You know some of the effects in winter of
sudden freezes and thaws. But the little examples of bursting water
pipes and broken pitchers are as nothing to what was happening in
the world during those days. The water and the gases in the
atmosphere helped along this crumbling work.
From all this action of rubbing, which action we call mechanical, it
is easy enough to understand how sand was formed. This represents
one of the great divisions of soil sandy soil. The sea shores are
great masses of pure sand. If soil were nothing but broken rock
masses then indeed it would be very poor and unproductive. But the
early forms of animal and vegetable life decaying became a part of
the rock mass and a better soil resulted. So the soils we speak of
as sandy soils have mixed with the sand other matter, sometimes
clay, sometimes vegetable matter or humus, and often animal waste.
Clay brings us right to another class of soils clayey soils. It
happens that certain portions of rock masses became dissolved when
water trickled over them and heat was plenty and abundant. This
dissolution took place largely because there is in the air a certain
gas called carbon dioxide or carbonic acid gas. This gas attacks and
changes certain substances in rocks. Sometimes you see great rocks
with portions sticking up looking as if they had been eaten away.
Carbonic acid did this. It changed this eaten part into something
else which we call clay. A change like this is not mechanical but
chemical. The difference in the two kinds of change is just this: in
the one case of sand, where a mechanical change went on, you still
have just what you started with, save that the size of the mass is
smaller. You started with a big rock, and ended with little
particles of sand. But you had no different kind of rock in the end.
Mechanical action might be illustrated with a piece of lump sugar.
Let the sugar represent a big mass of rock. Break up the sugar, and
even the smallest bit is sugar. It is just so with the rock mass;
but in the case of a chemical change you start with one thing and
end with another. You started with a big mass of rock which had in
it a portion that became changed by the acid acting on it. It ended
in being an entirely different thing which we call clay. So in the
case of chemical change a certain something is started with and in
the end we have an entirely different thing. The clay soils are
often called mud soils because of the amount of water used in their
formation.
The third sort of soil which we farm people have to deal with is
lime soil. Remember we are thinking of soils from the farm point of
view. This soil of course ordinarily was formed from limestone. Just
as soon as one thing is mentioned about which we know nothing,
another comes up of which we are just as ignorant. And so a whole
chain of questions follows. Now you are probably saying within
yourselves, how was limestone first formed?
At one time ages ago the lower animal and plant forms picked from
the water particles of lime. With the lime they formed skeletons or
houses about themselves as protection from larger animals. Coral is
representative of this class of skeleton-forming animal.
As the animal died the skeleton remained. Great masses of this
living matter pressed all together, after ages, formed limestone.
Some limestones are still in such shape that the shelly formation is
still visible. Marble, another limestone, is somewhat crystalline in
character. Another well-known limestone is chalk. Perhaps you'd like
to know a way of always being able to tell limestone. Drop a little
of this acid on some lime. See how it bubbles and fizzles. Then drop
some on this chalk and on the marble, too. The same bubbling takes
place. So lime must be in these three structures. One does not have
to buy a special acid for this work, for even the household acids
like vinegar will cause the same result.
Then these are the three types of soil with which the farmer has to
deal, and which we wish to understand. For one may learn to know his
garden soil by studying it, just as one learns a lesson by study.
About the Author: D. Benjamin is the owner of
iapsales.com LLC - a family business specializing in HVAC products. We
are distributors of
Qmark Heaters,
electric tankless water heaters,
bathroom heaters,
patio heaters, electric heaters,
portable air
conditioners & electric towel warmers. Shop on line at
www.heateroutlet.com for these great home improvement products.
Iapsales.com LLC was established in 2003 and is the sister company to
Innovative Air Products located in historical Exeter, NH. We are a 2nd
generation manufacturers’ rep firm dedicated to providing residential &
commercial heating, ventilation and air-conditioning equipment. We offer
a great selection online at the lowest prices anywhere. We can also be
found on Facebook, Twitter and YouTube