22 
Bulletin 1356, U. S. Department of Agriculture 
1918, and 1919 are given in Table 15. These data show that the plats 
which were submerged to the depth of 2, 4. 6. and 8 inches received 
on the average 23.29, 23.31, 24.05, and 37.21 inches of water, respec- 
tively. The average quantity used in the first three depths of sub- 
mergence was approximately the same. The greater quantity used 
on the plats submerged to a depth of 8 inches was very likely due to 
greater seepage. Evaporation and transpiration undoubtedly were 
practically the same for all depths of submergence, so the difference 
must have been due to seepage. 
Table 15. — Seasonal and average irrigation data for the 3-month period of 
July, August, and September and annual and average yields of Wataribune 
rice obtained in the depth-of -submergence experiments on square-rod plats 
at the Bice Experiment Station, Crowley, La., in 1917. 1918, and 1919 
Irrigation water (inches) 
Days of 
submer- 
gence 
Precipi- 
tation 
during 
submer- 
gence 
(inches) 
Quantity 
of water 
used 
(inches) 
Year 
Depth i 
Applied 
to 
maintain 
stated 
depth 
Average 
daily loss 
Esti- 
mated 
total loss 
Yields 
per acre 
(pounds) 
1917 
2 
2 
2 
13.56 
12.21 
3.54 
0.393 
.323 
.233 
27. 510 
22. 610 
12. 815 
70 14. 31 
70 10. 63 
29.87 
24.84 
15.16 
1,520 
1918 
1,520 
1919 
55 
9.62 
3,360 
9.77 
.316 
20.540 
65 
11. 52 1 23. 29 
2. 133 
1917 
4 7.23 
4 1 6. 12 
.299 
.246 
.341 
20. 930 
17.220 
18.755 
70 
70 
55 
14.31 
10.63 
9.62 
25. 54 1. 920 
1918 
20. 75 1, 520 
1919 
Average 
1917 
1918 
1919 
Average 
1917 
1918 
1919 
Average. . .. . 
4 1 10. 01 
23.63 2,080 
7.79 
.295 
19. 175 
65 
11.52 
23. 31 1, 840 
6 8.09 
6 ! 4.73 
6 6.75 
.319 
.232 
.290 
22. 330 
16. 240 
15. 950 
70 
70 
55 
14.31 
10.63 
9.62 
28.40 
21.36 
22.37 
1,760 
1, 360 
2,880 
2,000 
6.53 
.280 
18.200 
65 
11.52 
24.05 
8 
8 
8 
16.85 
26.98 
9.26 
.441 
.517 
.357 
30. 870 
36.190 
19. 635 
70 
70 
55 
14.31 
10.63 
9.62 
39. 16 ! 1, 840 
45.61 1 2,000 
26. 88 3, 020 
17.69 
.438 
28. 470 
65 
11 52 1 37 21 
2,287 

1 Water required for the saturation of the soil prior to submergence was not measured. 
Table 15 shows that for the 3-year period these plats received, 
respectively, exclusive of precipitation, the average quantity of 9.77. 
7.79, 6.53, and 17.69 inches of water to replace losses from evapora- 
tion, transpiration, and seepage. On account of the greater seepage 
from the plat having a submergence of 8 inches, a larger quantity of 
water was applied to it than to the other plats for maintaining" the 
proper depth. 
The data given in Table 15 further show that during the same 
period the average total loss of water from the plats submerged 
2, 4,_ 6, and 8 inches was. respectively, 20.540. 19.175, 18.200, and 
•J^.470 inches. This total loss was based on the respective dailv losses 
of 0.316, 0.295. 0.280. and 0.438 inch of water. 
The loss (if water from the plats and the quantity of water, includ- 
ing precipitation, applied to the plats in the depth-of-submergence 
experiments were accurately measured by a micrometer gauge. The 
gauge was set at the time of reading on the top of a galvanized-iron 
still well. :> inches in diameter, which was firmly placed in the soil 
in each plat among the rice plants about 3 feet from the levee. Per- 
