Yerington times. [volume] (Yerington, Nev.) 1907-1932, 1913-01-11
DRY FARMING SOILS.
Addition of Humus Does Not In
crease Availability of Water.

crease Availability OF w alter.
That the addition Of hurlus to the
sou III dry-tarming regions does not
increase the availability OF water III
the ground and that tie humus-bear-
ing material-barnyard manure, straw,
leaves or other vegetable matter
should be added to the soil frequent
Nv in small amounts, are conclusions
drawn from experiments recently con-
Quoted al the experiment station OF
the State OF Washington, says the
Country Gentleman.
The basis OF the experiments was
soil taken from the dry farming zones,
one cubic foot of which. without hui
mus, weighed eighty pounds and was
capable of absorbing and retaining
without drainage Is per cent OF its
weight OF water. OF the water. oniS
l6S pounds could be taken up by
plants, willing occurring when cubic
foot of soil held but 81 pounds OF
water. Seventy-six pounds OF this soil
was mixed with four pounds OF humus,
the soil being capable ot holding ~
pounds OF water, and the humus four
that is 100 per cent OF its weight A
cubic foot OF the Eumns- bearing soil
retained q pounds of water. while
similar amount OF soil without humus
held but ~ pounds. Forty per cent OF
the water held by the humus-l o
pounds-and 3.04 pounds held by the
soil were unavailable to plants.
Since III one cubic foot OF soil with
out humus. containing 20 pounds OF
water. but los pounds were available
for the growth OF plants, III tier OF
three cubic feet OF soil 504 pounds OF
water were available for plants. To
make this amount of water available
in three cub c feet OF soil without hui
mus a volume OF water foot square
and II inches deep was required, the
amount ayailabe-504 pounds-being
equal to 81 inches of the depth indi-
Gated.
With these facts in mind the next
problem was to find how many inches
OF water would be available to plant
growth when five per cent OF humus
was put into cubic foot OF soil. In
the humus bearing soil. as stated, from
q pounds OF moisture retained 1880
pounds were available for the use OF
plants. Ii was found that the soil
containing humus absorbed a greater
amount OF water than did the soil
without humus. two and three -fourthS
cubic feet OF the former holding a
much water as Lad been retained by
three cubic feet of the silt Since
1896 pounds OF water were available
for the growth OF plants in a cubic
foot OF the humus laden soil, two and
three -fourths cubic feet held 500
pounds OF available water-or a vol
ume foot square by o7l inches deep
Hence. with no humus in the soil. 81
inches OF the given volume had beer
available for plants. and with humus
added in the amount indicated. 97l
inches of the same volume were avail
able
Said Prof. Clark c. Thorn. in dis
GUESSING these results "ln all cases
where humus is added to the soil wa
ter is held nearer the surface and Is
therefore more easily evaporated
Five per cent of humus-which is as
much as is likely to he added-doeS
not increase the availability of moist
ure and is of no direct benefit i'll this
respect; indeed, il may even be detri-
mental in that it holds the moisture
nearer the surface. where ii is more
quickly evaporated
THE beneficial results of humuS are
in creating a new supplv OF plant food
and it is always advisable. even i'm
pcrative. that humus be present in the
soil. Claws are opened up by IT. wash
ING is prevented and nitrogen is sup
Piled
1T is a common experience anon"
farmers who add great amounts OF
manure TO their land to observe on
the following wear that the crop BURNS
where the fertilizer was supplied. The
reason for this is obvious. The ma
nure they have added is able to re
tain its own weight in water or prac-
ticallv so. and this amount is at once
absorbed from the soil. OF the amount
absorbed. however. only about sixty
per cent is available for the growth OF
rlants, the rest being locked No,
Hence the following wear the soil Is
actually dried out nv the manure. and
burning results But the second wear
will show benefits from the use OF the
fertilizer. since it has by this time
stored IN its 40 per cent. reserve. re
tanning this amount of moisture IN
excess of what would otherwise be
present in the ground
at is thus made plain WHY farmers
should not dump great amorntS ct
harvard manure on their land at m
tervals of from three to ten wears. as
some do To give the greatest benefit
the manure should be added in small
amounts and at more frequent inter
walls"