8 
BULI^TIN 1004, U. S. DEPARTMENT OF AGKICULTTJRE. 
water in the soil will be reduced by the required difference. This is 
perhaps best shown by correlations. 
Table 1. — Average daily precipitation, evaporation, and rate of use of water 'by 
the wheat crop, together toith yields per acre, on plats A and G or D during 
a designated period of rapid growth at the several experiment stations for 
the years shown. 
Period. 
Pre- 
cipita- 
tion. 
Evap- 
ora- 
tion. 
Plat A. 
Plate 
orD. 
station and year. 
From— 
To— 
Water 
use. 
Yield. 
Water 
use. 
Yield. 
Huntley: 
1913 
June 11 
June 13 
June 19 
June 8 
June 12 
July 2 
May 29 
June 2 
June 3 
June 4 
June 3 
June 11 
June 29 
July 7 
July 1 
June 3 
June 2 
June 2 
June 5 
June 7 
June 20 
June 23 
June 11 
June 9 
May 29 
June 21 
June 10 
May 27 
June 5 
June 2 
June 18 
June 10 
June 25 
June 10 
June 9 
June 5 
June 19 
May 18 
June 7 
June 3 
June 4 
June 4 
June 9 
June 28 
June 4 
June 9 
June 2 
May 25 
June 4 
June 28 
May 28 
May 22 
May 21 
June 28 
June 27 
Aug. 7 
June 24 
July 29 
July 27 
July 12 
July 22 
Aug. 5 
July 19 
June 16 
Aug. 28 
Aug. 23 
Aug. 8 
July 16 
July 8 
July 19 
June 22 
June 26 
July 2 
July 29 
July 29 
Aug. 13 
July 29 
June 26 
July 9 
July 23 
July 5 
Aug. 3 
June 16 
July 2 
June 27 
Aug. 5 
July 12 
July 9 
June 24 
July 29 
June 18 
July 6 
Aug. 5 
Aug. 2 
Aug. 11 
July 20 
July 28 
July 17 
June 30 
July 28 
June 21 
July 6 
Aug. 12 
June 25 
June 22 
June 13 
Inches. 
0.11 
.14 
.08 
.04 
.10 
.07 
.07 
.09 
.08 
.08 
.05 
.11 
.12 
.11 
.11 
.06 
.06 
.08 
.03 
,15 
.11 
.12 
.13 
.10 
.04 
.13 
.21 
.08 
.13 
.04 
.09 
.06 
.16 
.08 
.02 
.01 
.06 
.06 
.04 
.15 
.17 
.17 
.08 
.04 
.02 
.07 
.12 
.05 
.11 
.10 
.12 
.22 
.05 
Inches. 
0.20 
.18 
.18 
.25 
.20 
.24 
.21 
.22 
.17 
.26 
.22 
.16 
.18 
.23 
.19 
.18 
.14 
.21 
.24 
.16 
.19 
.21 
.15 
.16 
.20 
.25 
.16 
.16 
.23 
.25 
.22 
.24 
.18 
.20 
.27 
.23 
.27 
.25 
.30 
.24 
.24 
.21 
.29 
.21 
.26 
.29 
.27 
..31 
.23 
.21 
.29 
.34 
.30 
Inches. 
0.10 
.16 
.17 
.10 
.16 
.23 
.12 
.19 
.16 
.16 
.13 
.10 
.11 
.18 
.11 
.21 
.16 
.13 
.16 
.23 
.15 
.18 
.17 
.18 
.18 
.15 
.17 
.10 
.20 
.18 
.12 
.13 
.17 
.16 
.11 
.13 
.21 
.16 
.19 
.18 
.25 
.20 
.17 
.17 
.12 
.24 
.18 
.18 
.21 
.17 
.17 
.24 
.23 
Bushels. 
16.0 
18.3 
24.5 
2.7 
25.2 
23.8 
19.3 
24.3 
26.8 
17.4 
5.7 
25.8 
30.5 
19.2 
4.1 
13.3 
28.3 
4.0 

35.0 
16.3 
11.3 
34.8 
5.5 
14.3 
13.8 
40.7 
4.2 
23.8 
2.8 
6.2 
4.0 
56.5 
10.6 
4.4 
8.5 
18.0 
12.0 
9.2 
22.7 
23.0 
22.7 
17.2 
26.8 
15.6 
17.3 
14.3 
11.3 
21.3 
26.3 
2.1 
7.3 
11.0 
Inches. 
0.17 
.23 
.20 
.14 
.21 
.30 
.17 
.20 
.19 
.21 
.21 
.20 
.13 
.18 
.13 
.18 
.15 
.10 
. .16 
.20 
.19 
.18 
.16 
.17 
.22 
.18 
.22 
.14 
.21 
.23 
.14 
.18 
.17 
.21 
.11 
.19 
.20 
.19 
.23 
.22 
.26 
.25 
.20 
.15 
.14 
.23 
.22 
.20 
.21 
.16 
.22 
.33 
.26 
Bushels. 
22.6 
1914 
19.5 
1915 
36.5 
WiUistom: 
1911 
7.6 
1912 
39.7 
1914 . . .. 
31.2 
1915 
27.7 
Dickinson: 
1908 
33.8 
1909 
35.7 
1910 
26.8 
1911 
23.3 
1915 
38.7 
Mandan: 
1915 
39.3 
1916 
21.8 
^"«; 
9.9 
1908 
16.0 
1909 
27.0 
1910 
5.7 
1911 

1912 
30.3 
1913 
16.8 
1914 
13.0 
1915 
40.3 
1916 
6.8 
Hettinger: 
17.5 
1913. . . 
37.0 
1915 .... 
37.4 
1916 .... 
4.2 
BeUe Fourche: 
1909 . 
32.2 
1910 
5.0 
1913 
16.8 
1914 
15.8 
1915 
67.2 
1916 
18.7 
1917 
11.1 
1918 
35.0 
Ardmore: 
1916 
15.8 
Scottsbluff: 
1913 
17.3 
1917 
18.7 
North Platte: 
1908 
40.5 
1909 
18.0 
1915 
27.8 
1916 
19.7 
Archer: 
1915.... .. . 
25.7 
1917 
14.9 
Akron: 
1908. 
13.7 
1909. 
18.5 
1910 
8.5 
1912 
16.0 
1915. 
33.8 
Garden City: 
1909 
6.7 
AmariUo: 
1911 
19.0 
1914 
13.8 
Average 
.09 
.22 
.17 
17.0 
.19 
22.4 
