The Idaho Republican. [volume] (Blackfoot, Idaho) 1904-1932, 1912-01-26
Sa@a | HE SU~CCESSFUL FARMERS@ @za /

No.
the nail with an ordinary carpe]
ters | or square. The head mn
be measured within 1900 of IL
length of crest in order to limit Ii
error to IL of n per cent. A We,
accurate measurement of the hea
can only be made with the hoo
guage which consists of a long ro
terminating in an %upturned metallt
hook, the rod sliding up and dow
on a fixed sui port being actuated b
a screw motion, while the head {
water is read from a vernier a,
tached to the rod. The rod is ru
down until the point of the hook
below water and then raised slowl
until the point reaches the surfac
Immediately over the hook.
This method eliminates the effec
of capillary attraction on the rule
but is not practical for farmers
welrs on account of the expense of in
stallion. If care is used, the hea,
can be measured accurately enough
for all practical purposes with an or
binary rule in the manner p~reviousl,
described.
The most frequent cause of erro,
IN weir measurements is excess We
locity of approach and this must be-
guarded against by providing a goot
sized pool above the weirs which
must be kept clean and free from
sediment.
"Don'ts" in Regard to Weirs-
l. Do not set a weir immediately
below a curve in the ditch, for the
curve will cause the water to flow
to the side of the crest.
2. Do not set it immediately be-
low or too close to a head gate where
the water has high velocity, as by
SO doing, it will cause too high a We
loc1ty of approach.
, 3. Don't allow the water below
the weir to back up even with the
crest as it will not allow complete
and will cut down the
4. Do not set the weir any other
way than perpendicular and at right
to the flow of the stream,
D. Do not attempt to use too small
weir. Put in a larger weir where
the water to be measured exceeds a
depth on the crest of 1-3 the crest
6. Do not allow the pool above the
weir to fill up with sediment, as the
'esulting decrease in the cross sec
will increase the velocity of ap-
Duty of Water-To know the
proper amount of irrigation water|
hat should be applied to the differ
mt soils and crops in order to make
greatest possible yield, has al
Ways been a serious problem to all
rrigators. 1t has always been known
nat in order to secure the biggest
osslble crop 1t is necessary to apply
lfferent amounts to different crops
nd to different soils with the same
rop, but just how much this amount
hould be has never been known
My in an indefinite way.
The irrigation Investigations de-
artment, which I represent in the
ate OF Idaho, has, in cooperation
18th the state engineers office, been
lrrylng on a series of experiments .
n the past two years by lei of
Inch 1t is hoped to determine this
ery important factor, and we have
'cured a vast amount of data con- ]
'rn1ng it. These experiments have !
! been carried out on comparative !
large areas and in a practical 1
ay. v
1t does not give any indication of C
w much water is necessary for a
ax1mum crop production on any q
IL to merely measure the amount @
at some farmer applies for the rea- p
that the same or a larger crop r
ght have been produced with either r
)re or less water than that which II
Is really used, so we have been
ing to work out this feature by
Getting a large number Of tracts
typical farms in different parts of
and then divide each tract i'm B
three different parts and apply
ferent amounts of water to each
Water was measured and var al
In this manner on 60 different d.
ms during 1910 and on as many 81
re during the past season. Sew or
Factors in regard to the use of NJ
ter have been very strongly en- so
the principal ones being nc
7 the amount of water required dl
ENDS upon. % The character of ia
soil and sub-soil. The texture er
the soil as regards porosity has ra
to do with the amount of wa m;
used than any other one thing
1T has been found that adobe oil
$ may be irrigated with a total ca
LEGATION of but 2 or 3 acre inches tel
le In some instances from | to 2 loo
, feet are required to spread over tn;
thoroughly irrigate an acre of ov'
7 gravelly soil. At least 2-3 of lin
latter amount is almost invar- Ing
y wasted as it either passes into str
ground water or p~ercolates be- sol
q the reach of the plant roots. l1v'
'oarse soil Is underlaid with an to
erVlous stratum, the amount of gee
Or necessary is materially cut live
while If the impervious stra- tail
is lacking, some irrigation sys- out
must be used which will flood sup
ground quickly before the water ia