Deseret evening news. [volume] (Great Salt Lake City [Utah]) 1867-1920, 1908-01-08

agriculture, were presented yesterday
before the nature study classes at the
state normal by Prof. Hogenson Of the
Agricultural college.
Certain factors In soil fertility was
the theme. The demonstration and lee
ture was a continuation of the previous
lecture, which considered the plant food
in the soil. This lesson deals with the
necessity of having sufficient humus,
oxygen, and heat in the soil.
HuMus IN SOIL
Humus is the product of decaying or
ganic matter 1t is that which usually
gives to the soil it's dark color. Where
the soil is warm during the whole year
and in dry climates where the soil IS
open on account of the small amount OF
moisture received. and also IN sandy
soils, the rate of complete decay is so
rapid that the amount Of humus pro-
duced is very small. Where the soil Is
damp and the rains frequent, the or
ganic matter decays more slowly. ana
the amount OF humus Is relatively
greater. Humus is quite insoluble un-
der field conditions, so that 1t does not
leach away. OF itself It Is of no use to
plants but IL becomes the food of bac-
terra. which by degrees convert 1t into
soluble forms so that plants can use 1t.
The humus of the soil Is Increased by
adding manure and blowing under
green crops and stubble.
FINDING THE HUMus.
Al experiment to determine the
amount of humus in soil may be per-
formed by taking small quantity OF
soil as il Is found in the field. First
weigh the sample and dry it IN mod
crate oven or ON the back of the stove.
When 1t is dry, weigh IL again. Now
place this dry soil upon coal shovel
above hot Goals. The humus in 1t viii
begin to smoke. If the soil is kept very
hot for two or three hours, practically
all of the humus win be burned. leaving
only the mineral part of the soil. What
remains should now be weighed, and
the amount per acre and the per cent
of humus In the soil determined. In
these calculations. take 100000 pounds
as the weight of soil per acre and de-
termine the weight of organic matter in
an acre Of the soil tested.
SOILS NEED OXYGEN
We have already spoken Of the neces-
sity of oxygen in the soil, when consid-
erng both the moisture and the plant
food factors Practically all of our
farm crops need a good supply of oxy-
gen. A soil that Is we'll drained and
OPEN so that air enters II freely has
more bacterial life and consequently n
higher degree of fertility than close
grained, air-tight soil. Air may pene-
| trate the soil TO depth of many feet.
| depending upon the openness or air
| spaces between the soil particles The
rapidity and degree of seed termination
in the soil and growth of the plant later
| depend largely upon the supply of oXy-
gen held by the soil Soils are made
| light and open chiefly by cultivation.
PROVING THE THEORY.
An experiment to show that heavy
clay soils are materially improved by
making them lighter so that air can
enter more freely, can be made by TAX
| ing pair of two-gallon cans, and
| filling both with heavy clay soil. Mix
| the soil In one can with finely cut straw
or coarse sand. which win have ten
| dency to loosen or tighten it. Pack down
| with the hand Let both stand for
week Then plant 10 kernels of oats in
each can, and note the difference in the
growth of the resulting plants, both as
TO the time OF coming up and the ra-
pldity of growth afterwards. The plants
in the can containing the soil llghtened
With straw or sand Will come up first
Will grow more rapidly, and I'm every
way will be better plants than those in
the other can. The oxygen In the looser
soil has aided the growth OF the plants
SOILS SHOULD BE WARM.
A certain degree Of heat is neces-
sary In the soil before any of the
chemical. biological, or physical changes
which are necessary to the develop
ncnt of plant foods in the soil can 70
on. When the temperature falls TO 81
degrees f, nearly all the life processes
cease. Experiments have shown that
with most cultivated crops, growth does
not begin until a temperature of 40 de-
grees II, has been reached. and that
1t does not take place most vigorously
until after a temperature of 6S degrees
+ has been reached. There is certain
degree of temperature at which seeds
terminate most rapidly and produce
the most vigorous plants. Prof. King
has worked out table showing the
best soil temperature for number OF
| crops. 1t is as follows:
Wheat. SO degrees fahrenheit barley
| "a degrees: peas, 80; corn 9S; beans. 10;
squash, 80; clover TO-; turnips SO: mel
| ona 80.
HEAT IN WET AND DRY SOILS.
A dry soil viii become warm In The
| sunshine much more rapidly than a
| moist soil will because from the moist
| soil water is continually being eyapor-
| ated by the sun, and this process keeps
! down it's temperature. Moreover. soil
becomes warm by the application OF
less heat than does water Take 100
pounds Of water at a temperature OF 32
degrees. To raise it's temperature one
degree, certain amount OF heat will
be required N, now. we take this same
amount OF heat and apply II to 100
/ pounds OF loamy soil, It's temperature
win be 3s.6S degrees. II We repeat the
experiment with sand. It's temperature
| VIII be ii.92. This shows that soil Is
more easily heated than wator Is;
hence, a wet soil IL a cold soil.
EFFECT OF GOOD TILLAGE.
Whom a field Is left very uneven ana
umpY. tho heat OF the surface soil Is
rapidly lost In warming the air above
and The result is that the deeper sol
remains cooler Good tlllage prevent,
the escape OF heat by keeping In The
soil moisture, This large amount OF
heat which would ordinarily be used
20 eyaporate water rs then retained IN
the goll, Good tillage, then, saves heat
as well as water.
\ TEMPERATURE EXPERIMENT
10 show that temperature plays an
important part In seed termination and
plant growth get four cans ana III
them with the same kind OF soil; thef
add sufficient water TO bring the sol
10 the best condition for plant growth
Plant wheat In all OF the cans, plnc'
three OF them either IN the warm sun
shine on near the stove; place tn
fourth IN rather cold place Not