The Hocking sentinel. [volume] (Logan, Ohio) 1871-1906, 1895-08-29


rainfall which will be held back for
the use of plants and determines large:
ly the amount of moisture which diff
ferent soils maintain. There must be
however some automatic power to
move this water from place to place in
the soil and deliver it to the roots of
plants as it is needed. This power ex-
lists in the soil il the force of surface
tension. or as it is more commonly
call, capillary force. This is due to q
peculiar contracting power of the sur
face of water. the surface particles
of water are under tension, each one
being pulled in toward the center of
the mass of water and the surface
tends to contract to the smallest possi-
bic area. When there is any air in the
soil, therefore. the water surface tends
to contract. As the water around the
roots is used up by the plants the sur
face is extended, and this increased ex-
tent of surface contracts and pulls
water to the plant, so that the very
fact of the plant using the water in
crcases this power, which moves water
automatically to the plant and water
is supplied to the plant as long as there
is an adequate supply in the surround
ing soil to be drawn from. This force
of surface tension may moge water in
any direction in the soil, either up or
down or laterally.
1t was pointed out in this lecture
that different fertilizers affect this
force of surface tension-lime, kainit,
salt, plaster and acid phosphate in
crease the surface tension and increase
the force which moves water to the
plant. This probably explains the
fact SO commonly met with in practice
that an application of lime or of kainit
or of plaster to clover field keeps the
surface soil more moist during a dry
season than it would otherwise have
been. 1t is not that these fertilizers
attract moisture from the air but that
they increase this contracting power
of water and SO pull more water up
from below. Organic matters on the
other hand decrease this surface ten
sion and this probably explains the
fact that the injudicious use Of large
applications of stable manure on light
sandy soils is liable to "burh ant the
land" in dry seasons. The contracting
power of the water surface is material
ly lessened and there is not so much
power to draw wnter to the plant as it
is needed.
While the resistance of the soil to
the descent of the rainfall is due in n
large measure to the relative amount
of sand, silt and clay, as this deter
mines how much the space in the soil
is divided up, the resistance also de-
pepds TO considerable extent upon
the way these soil grains are arranged.
Where the grains are evenly arranged
in the soil and the spaces between the
grains through which the water is
moved are of nearly uniform size, the
resistance is at a maximum and the |
water moves very slowly. This is the
of soil WHICH is puddled
and which is close and impervious to |
water. If the soil grains on the other
hand are grouped in masses, if the |
grains of clay cling closely to the large
grains of sand SO that the mass acts as |
a single grain leaving some of the |
spaces larger and others smaller than
when the grains are uniformly distrib-
uted there will be less friction, the |
soil will be loamy and even leachy and |
will maintain much less moisture than |
before, for the rainfall can move down
ward much faster. This is the condi- |
tion of loamy soil and if this is car
Fied too far it may injure the |
soil, as it will be too |
ieachy aud not sufficiently retentive of |
moisture for the needs of crops. An !
midway between these
two extremes is desire for the most
condition of any soil.
The forces which control the ar
of the soil grains were illus
trated by diagrams shown on lantern
slides and the effect of fertilizers in
modifying these forces and in chang
ing the texture of the soils was ex-
planned. The lectures were illustrated
with number of slides
showing grains of soil highly magni-
fed, and the effect on these grains
Of added lime and other fertilizers,
and by lantern slides showing the tex
ture of different soils aud the amount
IF sand, silt and clay they contain, as
we'll as the average amount of moisture
the different types of soils maintain
for growing plants.
In conclusion il :vas urged that these
soils having such different textures
md maintaing such different conditions
we're naturally adapted to different
kinds of crops and to different agricul-
tural interests and that the highest
type of farming and the most success
fpl farmer must adapt the crops to
the peculiar soil conditions of his farm,
with due regard, OF course, to the
market demands and transportation
facilities. 1t was urged that it was az
senseless to attempt to grow wheat, for
on the light sandy truck
ands as it would be for man to in
vest his money in an iron foundry
with the idea of making woodenware
out of the equipment. His investment
S only suited to iron work, and it
would be folly for him to make such
IN Investment for the sake of going
nto the manufacture of woodenware.
So the intelligent farmer must under
stand what class of crops his soil or
different soils are adapted TO and mako
l speciality of these crops, with sueh
limitations as the markets and trans
oortation facilities may require.
Let the one you would welcome to
your hospitality be the one you would
welcome to your respect and esteem,
# not to your personal friendship.-H.
Bushnell