The progressive farmer. [volume] (Winston, N.C.) 1886-1904, 1902-03-11
Nature Study.


One Of the most obvious things 60
any n interested In plants is the
close relation which exists between
the growth Of the plant and the
character Of the soil that produces
1t. For this reason, If for no other,
it is of value TO make q more or less
close examination of the different
soils In which plants are found
growing.
wEATHERED ROCK Is THE BASIS
of soil. By that I mean rock that
has been ~pulverized by the action of
rain, currents, wind, frost, dew,
heat or cold, which accumulates to a
great depth on level land. The
fertility Of the soil depends upon its
physical and chemical nature. A
knowledge of these properties is of
great practical value in determining
what plant food, if any, should be
added 20 the soil and what classes Of
plants T best adapted TO it.
When weathered rocks yield only
angular grains of quartz or silicates
the soil Is pure sand. When a finely
divided silicate of alumina results
from the weathering the soil is clay.
Sand and clay r both produced
from the decay Of most rocks and a
mixture IF these two constituents
form loans
AlmoRt all rocks contain larger or
smaller quantities of carbonate of
lime, iron and BulphRts or phOsphates
of the alkslieS, potash and soda, all
Of which go to form the soil. Rain
adds salts Of amonia derived partly
from the air and partly from decay
ing vegetable matter. These be-
come changed by q process of OEidG-
ton into nitstes. Tho decay of the
vegetation produces n substance
called vegetable mould.
L. would be instructive to select q
given area of q few acres and make
AN EXAMINATION OF THE SOIL
in that region. Is is best TO select
not too large an area. First try to
determine the depth of the soil, the
kind of subsoil underneath. Sub
soil is the layer directly below the
surface soil. Determine the depth
of the subsoil. Has the soil been
formed by the decay of the under
lying rock or has IL been carried to
she spot from q distance by the
action of water or wind? Note the
part the plants Of the region have
had in producing the soil. Take a
small Quantity of the soil: If there
r any pebbles present pick them
out and examine them ; If smooth
and polished, try to determine how
they happened to be present and
how they were polished. Wash the
remainder of the soil, allow 1t TO dry
and burn 1t in q dish. Try to decide
If any of IL Is consumed by the heat.
This is the organic matter of the
soil. Pour the remainder of your
soil very slowly into a jar of water ;
n o the manner in which it is de
posted in the jar. If this expert
ment IS carefully done it will be
easy to distinguish to some extent
the amount of sand coarse and fine
from the clay in your specimens.
THE WATER CONTENT
The amount OF water which soil
Gan hold also affects the growth of
plants If the soil is of a olayey ma
uTe when wet it is of a sticky paste
through which water does not easily
pass When rain falls clay land is
consequently wet and stiff. When
-oil Is of sand, water drains away go
rapidly that no moisture is retained
Clay and sand according TO proper
ton make u mixture retentive OF
moisture and therefor ore valuable.
If scales are accessible it will be
interesting to test the power of vari
Gus soils so Absorb and retain mois
ture Take q quantity of soil, weigh
it then drop by drop add water IN
I'll lie mass Is thoroughly saturated.
then w. Ugh finding hIw mu1h water
nas been taken up by the soil. Spread
sue moist soil on a paper and weigh
at freq rent intervals TO iud out how
rapidly evaporation is taking place.
Animals also assist in the fOrmH
ton OF soil. Darwin observed that
the earth worms we're agents in mix