The Lamar register., 1910-08-10
WATER TO ALFALFA
burrows Method Is Confined to
Comparatively Small Area.
II Has Been Shown Water Is Rarely
Distributed Evenly In Furrow
Irrigation and Much Is Lost
by Deep PercoIation.

Alfalfa. native meadows. and grain
are most commonly irrigated by one
of the methods previously described
rather than by the furrow method.
which is the usual method Of irriga-
ting orchards. gardens. root crops and
vegetables The irrigating of alfalfa
from burrows is at present confined
to the Yakima valley. Washington, to
portions of the Snake river valley in
southern Idaho. and to comparatively
small areas In other states. In the
localities named the soil is a fine clay
loan which runs together. puddles
when wet, and bakes and cracks when
dry. Flooding the surfaces by any of
the customary methods tends to phd-
die the top layer of soil. which be-
comes quite hard when the moisture
Is evaporated. writes Samuel Fortier.
chief Of irrigation, United States de-
partment of agriculture. In Irrigation
Age. The pudding and baking pro-
cesses injure alfalfa. and 1t was with
the object of keeping as much as pos
sible of the surface dry that burrows
were introduced. When a small stream
is permitted TO run in the bottom of a
furrow for several hours the soil be-
meath and for some distance on each
side becomes wet, while the surface
may remain nearly dry.
The alfalfa grown in the Yakima
valley In Washington is practically all
irrigated by means of burrows. The
grading is usually done by buck
scrapers. while long rectangular
drag removes most of the surface In
equalities that remain after the sur
face has been leveled roughly by the
scraper. The float is made of two 2
by 6 inch timbers about twenty feet
long. held in position by crosspieces
OF the same size. six feet long.
The common practise is to run the
burrows across the entire width or
length of field. and in consequence
their length varies from 20 rods to
less In small fields to so rods In large
fields. AS rule. the burrows are too
long. Farmers object to cutting up a
field by head bitches, but In a climate
like that Of the Yakima valley In mid
summer. by far the most essential ele-
ment in plant production is water, and
all other considerations should give
place to it. It has been shown that
water is rarely distributed evenly In
furrow irrigation and that much Is
lost by deep percolation. To increase
the length Of a furrow beyond eco
feet. or one-eighth mile. not only In
creases the loss. but renders a uni.
form distribution more dinicult to Sc
cure. Except in rare cases. this dis
lance should be regarded as to the
limit for the length of burrows. In
light. sandy soils. having porous
gravel stratum beneath. the length
may well be reduced to $50 feet.
A good method Of dividing an alfal.
IN field for furrow Irrigation Is by
placing lumber head fumes either 8
by 8 inches or by G inches along the
upper boundary Of each strip Anger
holes are bored through one side Of
the Hume flush with the bottom at
points where water is to be delivered
to the heads Of burrows. A short piece
OF lath revolving In a nail controls the
flow from each opening. On steep
grades a cleat on the bottom of the
inside Of the fiume nailed on crosswise
Just below each opening will dam back
the water and increase the discharge.
When fumes are considered too
costly the water is distributed among
the burrows through wooden spouts
set In the bank OF an ordinary earthen
ditch. These head bitches when in
operation are divided into a series of
level spaces by means of drop boxes
which hold the surface OF the water at
the desired elevation. The spacing of
these drop boxes depends on the
grade OF the head ditch and their cost
averages about $3.50 each. Spouts are
made usually by mailing together four
lath. There is special lath on the
market somewhat heavier than the or.
binary one used for plastering build.
ings. being 05 inch thick. two inches
wide. and three feet long. Four of
these when nailed together cost about
BE- cents and each spout in place costs
about 6.5 cents.