The Raymer enterprise., 1912-01-25
DRY FARMING SOILS
Addition Of Humus Does Not In
crease Availability Of Water.
To Secure Greatest Benefit Barnyard
Manure Should Be Applied In
Small Amounts and at Rath.
Or Frequent Intervals.

Bull III tue uIy'lhIuiu6 Ic6IOuo oo0o
not increase the availability OF water
In the ground and that humusbearing
material-barnyard manure. straw,
leaves, or other vegetable matter
should be added to the soil frequently
in small amounts. are conclusions
drawn from experiments recently con-
Quoted at 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
humus. weighed eighty pounds and
was capable OF absorbing and retain.
ing. without drainage, rs per cent. OF
its weight OF water. or the water. only
1853 pounds could be taken up by
plants. whiting occurring when cubic
foot OF the soil held but 80 pounds OF
water. Seventy-six pounds Of thi0
soil was mixed with four pounds OF
humus, the soil being capable Of hold.
ing 10 pounds OF water. and the humus
four-that is, 100 per cent. OF Its
weight. A cubic foot Of the humus-
bearing soil retained 20 pounds OF wa.
ter, while similar amount OF soil
without humus held but 20 pounds.
Forty per cent OF the water held by
the humus -l.6 pounds-and 3.O4
pounds held by the soil were dnavail-
able to plants.
Since in one cubic foot OF soil with
out humus. containing 20 pounds OF
water, but 1853 pounds were available
for the growth Of plants. in tier OF
three cubic feet OF soil 50.4 pounds Of
water we're available for plants. To
make this amount OF water available
In three cubic feet OF soil without hu.
mus volume of water foot square
and IL inches deep was required. the
amount available-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 i've per cent. OF humus
was put into cubic foot Of soil. In
the bearing soil. as stated, from
% pounds OF moisture retained 1886
pounds were available for the use OF
plants. 1t was found that the soil
containing humus absorbed a greater
amount OF water than did the soil
without humus. two and threefourths
cubic feet OF the former holding as
much water as had been retained by
three cubic feet OF the silt. Since
1886 pounds Of water we're available
for the growth OF plants In a cubic
foot OF the humus-laden soil, two and
threefourths cubic feet held 5O.4y
pounds OF available water-or vol.
ume foot square by 9.7l inches deep.
Hence, with no humus in the soil, 81
inches OF the given volume had been
available for plants. and with humus
added In the amount Indicated, 9.7l
inches Of the same volume were avail
able.
Said Prof. Clark c. Thom, In dis
cussing these results: In 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 be added-does
not increase the availability OF mois-
ture and Is Of no direct benefit In this
respect: indeed. 1t may even be detri.
mental In that It holds the moisture
nearer the surface. where It Is, more
quickly evaporated.
The beneficial results of humus are
in creating new supply OF plant food
and 1t is always advisable. even i'm.
perative. that humus be present in
the soil. Clays are opened up by 1t.
washing Is prevented and nitrogen Is
supplied.
1T Is a common experience among
farmers who add great amounts OF ma
nure to their land to observe on the
following year 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-
tically so, and this amount 1t at once
absorbs from the soil. or the amount
absorbed. however, only about sixty
per cent. is available for the growth
Of plants. the rest being locked up.
Hence the following year the soil ia
actually dried out by the manure,
and burning results. But the second
year will show benefits from the use
OF the fertilizer, since 1t has by this
time stored up Its 40 per cent, re-
serve, retaining this amount OF mois'
ture In excess OF what would other
wise be present In the ground.
1T Is thus made plain why farmers
should not dump great amounts ol
barnyard manure on their land at In
tervals OF from three to ten years. al
some do. To give the greatest bench,
the manure should be added In smal
amounts and at more frequent inter
vals."
0rv Earmlno Reuulrea Work.