22 
BULLETIN 1004, U. S. DEPARTMENT OF AGEICULTtTRB. 
Table 3. — Quantity of water used by the wheat crop, etc. — Continued. 
[The column headed "Ratio " shows the number of poimds of water used by the crop per poimd of total yield.] 
Water used. 
Yield. 
Station and year. 
From 
the sou. 
Precipi- 
tation. 
Total. 
Grain. 
Straw. 
Total. 
Ratio. 
North Platte: 
1908 . . 
Inches. 
1.74 
3.24 
3.16 
- .08 
5.74 
3.57 
-1.66 
3.26 
3.35 
3.56 
2.21 
1.26 
4.69 
.86 
4.71 
3.79 
2.76 
.45 
.90 
3.25 
5.15 
4.20 
2.44 
- .36 
2.41 
.86. 
.83 
6.23 
4.23 
2.61 
- .97 
2.39 
5.79 
7.66 
1.81 
1.11 
1.28 
1.88 
6.95 
2.14 
Inches. 
12.96 
13.56 
4.59 
1.55 
3.32 
5.60 
18.12 
6.72 
6.35 
10.66 
11.24 
3.94 
11.32 
4.51 
5.50 
11.18 
5.04 
9.26 
5.35 
6.98 
4.12 
8.79 
2.24 
5.61 
7.05 
3.60 
4.03 
10.41 
10.41 
8.08 
8.68 
11.01 
4.25 
4.17 
4.21 
3.73 
3.91 
9.53 
4.80 
1.98 
Inches. 
14.70 
16.80 
7.75 
1.47 
9.06 
9.17 
16.46 
9.98 
9.70 
14.22 
13.45 
5.20 
16.01 
5.37 
10.21 
14.97 
7.80 
9.71 
6.25 
10.23 
9.27 
12.99 
4.68 
5.25 
9.46 
4.46 
4.86 
16.64 
14.64 
10.69 
7.71 
13.40 
10.04 
11.83 
6.02 
4.84 
5.19 
11.41 
11.75 
4.12 
Bushels. 
22.7 
23.0 
6.8 

12.8 
6.0 
22.7 
17.2 
4.2 
15.5 
14.3 
2.9 
21.3 
4.8 
22.2 
26.3 
9.3 
2.1 

3.5 
1.5 
17.5 





7.8 
8.4 
4.0 

7.3 
6.3 
12.4 
1.7 


13.5 
5.6 

Pounds. 
1,920 
3,060 
1,000 

1,790 
1,600 
2,310 
2,440 
1,290 
3,370 
1,590 
480 
2,760 
660 
2,530 
1,740 
1,140 
560 

1,010 
1,290 
1,950 





1,280 
690 
760 

1,070 
630 
1,800 
480 


1,010 
685 

Pounds. 
3,280 
4,440 
1,410 

2,560 
1,960 
3,670 
3,470 
1,540 
4,300 
2,540 
660 
4,040 
950 
3,860 
3,320 
1,700 
690 

1,220 
1,380 
3,000 





1,750 
1,200 
1,000 

1,510 
1,010 
2,550 
580 


1,820 
1,020 

1,014 
856 
1909 
1910 
1911 
1912 
801 
1,059 
1,015 
651 
1914 
1915 
1916 
1917 
1 426 
1919 
749 
Akron: 
1909 . - 
1,199 
1,783 
897 
1911 
1912 
1913 
1,279 
599 
1914 
1915 
1 021 
1916 
1,'039 
3,185 
Garden City: 
1909 
1911 
1912 
1,898 
1,520 
980 
1914 
1915 
1916 
Dalhart: 
1909 
1910 
1911 
1913 
1914 
2,152 
2,761 
2 420 
Dalhart, new field: 
1914 
1915 
AmarUio: 
1909 
1911 
2,009 
2,250 
1912 
1915 •- 
1,050 
2,349 
1917 
1918 
Tucumcari: 
1913 
1914 
1,419 
2,607 
1915 
1916 
Study of Table 3 shows that, at least so far as the individual sta- 
tions are concerned, a definite relation exists between the total quan- 
tity of water used and the yield of grain, straw, and total weight per 
acre. This relation is not always consistent, but it must be borne in 
mind that when crops are subjected to the varying conditions that 
occur in the field a very close correlation is impossible, and any 
strong correlation, either positive or negative, is highly significant. 
It will be noted from the study of all the stations that high yields 
are always associated with high water use. A high water use does 
not necessarily mean a high yield, because the crop may suffer either 
through poor distribution of rain or through some extreme climatic 
condition that limits the yield. On the other hand, a high yield 
necessitates a high use of water. Table 3 contains data on the use of 
water by 96 wheat crops. Twenty of these crops yielded more than 
20 bushels of grain per acre. Only one of these consumed less than 
11.5 inches of water. At Akron, Colo., in 1914, a yield of 22.2 bushels 
