12 
BULLETIN 10, U. S. DEPAEIMEXI OF AGRICULTURE. 
The following table shows the results obtained from the three 
seasons' work, ai are further illustrated in the diagram i fig. 
•i ) in which the yields of grain in pounds per acre are platted, with 
the corresponding amounts of water applied. 
Summary of results of bai ation, 1910, 1911. and- 1912. 
Rainfall 
rreas :•-. for 
Number of plat. P^L ^ Depth. 
Yield per acre. 
Hay. Grain. 
Cost of 
Value, irriga- 
tion. 
i :-:■:-. 
19U. 
1?12. 
Inches. 
11.90 
:...:> 
,. ,■ ■ 
Unleveled area Xone 
35 
36 
Unleveled a 
(north half J- 
36 
Unleveled a 
(south half). 
35 
Unleveled area 
35i 
36* 
None.. 
do. 
I One... 
Two.. 
Inches. Pounds. Pounds. 
One 
Two 
None 
. 3.6 
- 5.2 
One early 
One late 
Two 
One early 
4.3 
. 6.4 
J 7.0 
J 6.0 
7.35 
3,120 
3,440 
4,460 
1,560 
1,160 
:.4>o 
L,84 
!.:■■> 
2,72 
1,520 
i, 18 
1.S10 
3. 740 
2,146 
680 
345 
1,925 1 
1,040 
2,480 
1.2- ■ 
"• 
1,950 j 
$17. 40 
22.20 
27. 
... 8 
27. " 
32. 19 
■'.> 
19.20 
5L - 
1.56 
2.10 
LSI 
2.20 
5.3S 
1 Green manured. 
Note. — frrig st figured at 30 cents per acre-inch for marking furrows, power, and attendance. 
. values figured at §1.50 per hundred. Value of hay is disregarded. 
Weather records taken over the entire period of the experiment 
show that these three years represented extreme- in rainfall and gen- 
eral weather conditions. Never- 
theless, under all of these vary- 
ing condition- there is not one 
instance where the increase in 
yield did not more than pay for 
the cost of the water which pro- 
duced it. the yield increasing 
with the increased amounts of 
water applied. 
It will be noted that in each 
of these seasons two irrigation-. 
one of which was applied at 
about the time the grain came 
to a head or soon after, or one 
late irrigation, as in 1911, pro- 
duced a heavy yield above the 
single early irrigation. In each 
of these three year- strong, dry- 
ing north winds occurred about 
the time the grain was in the 
dough. The unirriffated and 
I9IO— 1911 1912 
WATER APPLIED.- INCHES 
O 4-6 6.1 OO 735 179. 
lSCC 
< 
± 1400 
UJ 
a. 
IT. '"- 
Q 
| 1000 
c 
a s:: 
z 
^ 
1 
CM 
ui 
> LIZ 
2i: 
- 
Unmanureo ma n jred 
Fig. 4. — Yield of barley with differenl 
tities . on manured and unmanurec 
land. 
early irrigated grain was badly pinched, while the presence of the 
moisture in the checks irrigated late seemed to prevent this, pro- 
ducing full, plump grain. 
