American Falls press. [volume] (American Falls, Idaho) 1907-1937, 1913-01-23
WATER APPLIED TO ALFALFA
eystsms Have essn Planned In Noun.
tain States to Deliver Watsr In
Quite Small Streama.

Flooding from field bitches or later
ais II still the most common method
of applying water to alfalfa out in thil
country. especially in the states oil
Colorado. Montana, Wyoming. Utah,
and to q large extent In Idaho, says
the Denver Field and Farm. This
manner of wetting dry soil originated
here In the mountain states and the
past half century has witnessed q
gradual evolution Of the plan, SO that
now 1t has not only become firmly
established but IL regarded as the best
suited TO the conditions under which
It IL practiced. It a be profitably
used on slopes that are too steep for
other methods. Fields having a firm
soil and a fall of twenty-five to one
hundred feet have been flooded sue
cessfully. From this extreme the
slope may diminish to less than one-
tenth OF a foot in 100 feet. It's cheap
ness IL another feature which recon.
mends 1t to the farmer of limited
means. Ordinary raw land can be pre-
pared for flooding at an expense Of 50
70 20 an acre. Again, 1t is adapted to
The use Of small water supplies. Here
In h mountain states the irrigation
systems have been planned and built
to deliver water in comparatively
small streams for use In flooding or in
burrows. and water users should be
certain that the larger volumes re.
nuItrah fnr nhopLo md hn~Ao.c 800 -
secured before going to the expense
OF preparing their fields for either Of
those systems. In grading the land
for this particular method 1t is not
customary to make many changes In
the natural surface. Only the smaller
knobs are removed and deposited in
the low places. An effort is made al.
ways. however, to make the farm lat
erals fit into the natural slope and con.
f%guration Of the tract to be watered
so as to bring the water to the high
places. = On steep slopes the laterals
may be less than fifty feet apart; on
fatter slopes they may be 200 feet or
more apart. Whatever the spacing 1t
Is always desirable to have the slope
them as nearly uniform as
possible. When the land In It's natural
state Is uneven, the grading can be
done with a scraper. If 1t Is compare
lively smooth and level a homemade
drag or leveler serves the purpose
fairly well. The main lateral Is usual.
ly built to the highest corner Of the
Held and the smaller laterals extend
from 1t, spaced rs to 225 feet
apart. the spacing depending on the
OF the ground and the coarse
Of the soil. The size Of the lat.
erals Is governed by the head which
may be had. but on steep slopes and
soil that erodes readily, small
heads are best. The proper location
or field laterals Is usually evident to
he irrigator without the use Of sur.
instruments. although In fields
where the fall Is slight 1t is often nee
'ssary to have a typographical survey
made and the laterals located by an
engineer. Field laterals are always
70 located that they cover the highest
,arts of the field and their distance
part In alfalfa varies from ten to
wenty rods. The head required for
from field laterals varies from
W to three cubic feet a second and
8 divided between two or three later.
Is. Canvas or coarse dams
re used to check the water in the lat,
rails and to force 1t out over the
and down the slopes Of the
lelds. In less than three hours the
PIPER foot of the soil Is usually thor
ughly moistened. To apply one wa.
In this way costs from fifteen
o thirty cents an acre. In irrigating,
canvas dam Is first inserted in each
itch or set of bitches, rs to 100 feet
Glow the head. The water Is then
lrned into each channel and flows az
as the canvas dam by which 1t IL J
and as a consequence rises
flows over the low places Of the .
,wer bank or through openings made
nth a shovel. When these small +
racts have been watered, the canvas
am Is raised. dragged down the lat. {
raj 75 to 100 feet, and again inserted
, the channel to serve the next tract.
dams sometimes take the
Of the movable canvas dams.
ONE time before a field is to be irri. ,
ated and after the %ditching Is done, :.
oarse anu Is placed in small /,
caps within each ditch channel al /
intervals and each heap is !,
with earth on its upper face ,
, a depth Of n to two inches. When +,
lis check has served It's purpose. II h
broken and the water flows down \
ntil stopped by the next check. In >
instances permanent wooden h
heck boxes are inserted In each lat. II
raj. while in others the canvas dam g
used. The thorough irrigation of :,
'ur acres Is considered a good twelve r
work for one man. BY the use Al
100 inches. two men can i~rrigate ~
even to ten acres In twenty-four !,
ours at a cost Of As to IS cents the n
ire. In summarizing the advantages ,e
the flooding method, 1t may be said Il
lat in first cost 1t is one Of the cheap. at
It, 1t Is adapted to the delivery OF :,