Transpiration as a Factor in Crop Production. 
123 
Table 49. — Weekly summary of evaporation from free water sur- 
faces 36 square inches in area at four elevations in an oat 
field. Evaporation expressed as percentage of evaporation from 
the upper jar. 1913. 
Average daily evaporation 
for week ending 7 p. m. 
Elevation of evaporating surface 
0 in. 
15 in. 
30 in. 
45 in. 
(1) 
May 25 
June 1 
8 
" 15 
" 22 
" 29 
July 6 
Per cent 
(2) 
OATS GROW 
46 
32 
40 
31 
35 
37 
34 
Per cent 
(3) 
[NG 
82 
70 
68 
49 
49 
52 
54 
Per cent 
(4) 
90 
86 
84 
88 
79 
73 
75 
Per cent 
(5) 
100 
100 
100 
100 
100 
100 
100 
Average 
July 13 
" 18 
36 
OATS HARVE 
59 
61 
61 
STED 
78 
86 
82 
88 
92 
100 
100 
100 
Average 
60 
82 
90 
100 
Table 50. — Summary showing relative free water evaporation 
ratesfat different elevations in corn and small-grain fields. 
1 91 2-1 9 U. 
PER CENT EVAPORATION BASED ON UPPER JAR 
Corn, 1912 
Corn, 1913 
Corn, 1914 
Spring wheat, 1912 
Oats, 1913 . . . 
Elevation above the ground 
Evap. jar No. 
1 
2 
3 
4 
5 
Inches 
Inches 
Inches 
Inches 
Inches 
(1) 
(2) 
(3) 
(4) 
(5) 
(6) 
Corn, 1912 
6 
24 
42 
60 
108 1 
Corn, 1913 
0 
42 
72 
96 
120 
Corn, 1914 
0 
36 
68 
96 
120 
Spring wheat, 1912 
0 
18 
36 
54 
Oats, 1913 
0 
15 
30 
45 
31 
55 
63 
73 
100 1 
36 
54 
81 
93 
100 
31 
45 
64 
93 
100 
39 
71 
87 
100 
36 
61 
82 
100 
Average'of_two upper jars. 
