16 BULLETIN 10^ U. S. DEPARTMENT OF AGRICULTURE. 
The following table shows the results of the two seasons' work 
Summary of results of irrigation of Egyptian corn. 
Number 
of plat. 
Number of irrigations. 
Depth- 
Yield per 
Value at 
$1.50 per 
100 pounds. 
Cost of 
irriga- 
tion. 
• 
I 
A ... 
B... 
C. . 
.. None 
.. One 
. Two 
Inches. 
../.....[[ 3.75' 
5. 50 
Pounds. 
1,335 
2,670 
2,700 
2.510 
3.340 
1,100 
1,690 
2,650 
2,965 
S20. 03 
40.05 
40.50 
37.65 
50.10 
16.50 
25. 35 
39. 75 
44.4^ 
1910 
Si. 52 
2 65 
.. One 
Two 
3.10 
5. 35 
\..\\.\.\ LS 
4.6 
5. 7 
1.43 
2.60 
! 
.. None 
.. One 
.. Two 
. . Three 
1911 
1.04 
2.38 
3.20 
Note. — Cost of irrigation is taken as 30 cents per acre-inch for power and attendance, plus 50 cents per acre 
per irrigation for furrowing. 
The accompanying diagram (fig. 5) shows the results for 1911, 
platted graphically, the yields with the corresponding amounts of 
water applied being rdiown. 
With this crop, as with the Indian corn, a greater yield is pro- 
duced in 1910. with less amounts of water applied, than in 1911. due 
entirely to a warmer spring and much 
more favorable growing season. 
The results for 1910 show but a small 
variation in the yields from plats 1-B. 
1-C. and 2. and a large increase in plat 
3. This is due to the time of irriga- 
tion, plat 3 receiving one early and one 
midseason irrigation, the first applied 
before any effects of drought were 
shown, thus keeping more or less of a 
2500 
2000 
1500 
000 
Water Applied,- inches 
i.S 
4.6 
fcl 
c^ 
5.7 
V) 
Fig. 5. — Yield of Egyptian corn 
with different quantities of water. 
500 1 ItcI ^1 I ~^l constant moisture percentage m the 
soil during the entire period of growth. 
In 1911 the yield.- increased quite uni- 
formly with the increased amounts of 
water applied, until the third irriga- 
tion, when there was a slight falling off. When this last irrigation 
was applied the heads were fully formed and the grain ripening, 
and the only effect of this irrigation was probably in preventing any 
pinching or shrinking in the grain. 
Inspection of the value column for each season shows that the 
irrigation of this crop may be made to pay. even if 6 per cent interest 
on an investment of S50 per acre for leveling the land and developing 
water be added to the cost of irrigation. 
Here, as in the irrigation of other grain crops, no definite duty of 
water can be established. The amounts of water required and the 
time of irrigation will always vary with the season, and the intelli- 
