6 BULLETIN 253, U. S. DEPARTMENT OF AGRICULTURE. 
Table IV presents the yields of corn from fall-plowed oat stubble 
in two rotations, from spring-plowed oat stubble in one rotation, and 
from both, fall-plowed and spring-plowed wheat stubble in one rota- 
tion each. 
Table IV. — Annual and average yields of com from fall-plowed and spring-plowed 
plats at the Akron Field Station, 1909 to 1914, inclusive. 
Treatment. 
Rota- 
tion 
NO. 
Yield per acre of grain (bushels). 
1909 
1910 
1911 
1912 
1913 
1914 
Average. 
Fall plowed: 
Oat stubble 
1 
3 
4 
26.4 
25.7 
23.1 
7.9 
5.0 
4.6 
9.3 
9.2 
4. 7 
29.1 
34.3 
34.3 
■ 6.0 


16.7 
14.7 
7.6 
1-5.9 
Do 
14.8 
12. 4 
25.1 
5.S 
7. 7 
32.6 
2.0 | 13.0 
14.4 
2 
9 
Spring plowed: 
26.3 
25.3 
7.6 
12.4 
1.2 

33.7 
3i. 5 
10.3 

17.4 
12.6 
16.1 
Wheat stubble 
14.6 
Average lor spring-plowed plats. 
Gain or loss of spring-plowed 
25. S 
..7 
10.0 
4.2 
.6 
-7.1 
35.6 
3.0 
5.2 
3.2 
15.0 
2.0 
15.4 
1.0 
Table V presents the yield of winter wheat from two continuously 
cropped plats, the plowing of which was sometimes early and some- 
times late. 
Table V. — Annual yields of muter wheat from plats plowed at different dates at tlie 
AJzron Field Station, 1909 to 1914, inclusive. 
Plowing date and yield of grain (bushels). 
Plat. 
1909 
1910 
1911 
1912 1913 
1914 
Plowed. 
Yield. 
Plowed. 
Yield. 
Plowed. 
Yield. 
Plowed. 
Yield. 
Plowed. 
Yield. 
Plowed. 
Yield. 
A 
B 
Sept. 14 
Sept. 22 
14.5 
12.9 
Sept. 18 
11.4 
10.3 
Sent. 3 
Aug. 12 
1.7 
6.S 
Sept. 8 
Aug. 15 
25. 8 Sept. 20 
26. 7 Sept. 18 
3. 3 Sept. 30 
2.0 ..do.... 
24.5 
24.8 
SOIL MOISTUEE. 
Some of the factors determining the yields of small grain are 
apparent to the casual observer. One of these is the greater number 
of weeds growing with the grain crop on fall-plowed land at the 
Akron Field Station. 
Another factor not so readily seen is the moisture content of the 
soil at the time of seeding. A knowledge of the exact percentage of 
moisture in the soil is not necessary. TVhile the water-carrying 
capacities of soils vary with their composition and compactness, it 
may be taken as a working hypothesis that on the hard land of 
eastern Colorado the relative depths to which water has penetrated 
on different fields is a fair approximation of the relative amounts of 
