p 
SHERIDAN FIELD STATION, 1917 TO 1923 
annually devoted to each are winter wheat, 25; spring wheat, 39; 
oats, 54; barley, 10; corn, 48; flax, 13; sorgo, 4; alfalfa, 3; brome- 
grass, 3; rye for green manure, 4; field peas for green manure, 5; 
sweet clover for hay, 2 ; sweet clover for green manure, 3 ; and pota- 
toes, 1. The plats summer tilled or fallowed number 26 each year. 
Included in the cropping system are 51 rotations, 6 continuously 
cropped series of 6 plats each, 2 plats continuously cropped and 
stubbled in each year, and a series of 8 plats consisting of tests of 
methods of fallow with spring wheat. Six rotations are duplicated 
in different parts of the field. 
The rotations vary in length from two to six years, the various 
lengths being represented as follows : Ten 2-year, twenty-four 3-year, 
eighteen 4-year, two 5-year, and three 6-year rotations, including the 
duplicates. The average yields of all plats of each crop for the 6-year 
period from 1918 to 1923, inclusive, are shown in Table 4. 
Table 4. — Annual and average yields of each crop in the ex-periments with crop 
rotations and tillage methods at the Sheridan Field Station for the six years from 
1918 to 1923, inclusive 
Year 
Winter 
wheat 
Spring 
wheat 
Oats 
Corn 
Barley 
Flax 
Grain 
Stover 
1918 
Bushels 
34.8 
1.7 
28.0 
10.3 
27.1 
17.7 
Bushels 
24.8 
1.4 
23.6 
6.3 
29.5 
21.6 
Bushels 
57.4 
.4 
52.0 
8.1 
48.9 
46.4 
Bushels 
32.2 

17.3 
.6 
23.0 
38.9 
Pounds 
2,607 
236 
1,730 
1,276 
1,835 
2,126 
Bushels 
37.9 
.5 
39.5 
3.1 
47.4 
25.0 
Bushels 
12.8 
1919 

1920 
7.1 
1921 

1922 
10.4 
1923.. 
6.7 
Average 
19.9 
17.9 
35.5 
18.7 
1,635 
25.6 
6.2 
Sorgo 
Alfalfa 
Brome-grass 
Sweet 
clover 
Year 
Second Third 
year year 
Second 
year 
Third 
year 
Potatoes 
1918 
Pounds 
6,200 
480 
4,900 
1,830 
4,788 
5,870 
Pounds Pounds 
2,250 1 2,400 
I 
1,570 i 2,180 
j 580 
2,420 
1,900 2,600 
Pounds 
3,050 
270 

160 
10 
2,430 
Pounds 
2,600 

1,770 
320 

1 1, 340 
Pounds 
Bushels 
1919... 

1920 
1921. _ 
1922.. 
450 
8.0 
120.8 
1923 
2,980 
106.7 
Average 
4,011 
953 1 1,697 
985 
988 
1,715 
2 58.9 
1 1921 seeding a failure; reseeded in 1922. 
4-year average. 
With the four small-grain crops, winter wheat, spring wheat, oats, 
and barley, the differences in average yields when considered in 
Eounds per acre are small. The greatest average yield was produced 
y barley. In the six years barley was exceeded by each of the other 
crops three times. Winter wheat slightly outyielded oats. Spring 
wheat yielded the least of these four crops, but only 120 pounds per 
acre less than winter wheat. Winter wheat did not winterkill to 
any extent in any year, but owing largely to the dry autumns in 1921 
and 1922 emerged with a poor stand in two years. 
The yield of corn is of special interest. With the shelling percent- 
age of corn calculated at 80 per cent of the total ear weight, the grain 
