TIME OF PLOWING SMALL-GEAIN STUBBLE. 3 
Bureau and the Bureau of Plant Industry. A study of these records 
shows the great variation in monthly and annual precipitation. 
The experimental data following are for the past six years, 1909 to 
1914, inclusive. In two of these years the precipitation has been 
above the normal, as determined from the entire record. In 1909 
the total was 2.2 inches less than the recorded maximum. In four 
years of the six it has been below normal, the precipitation of 1911 
being the minimum recorded. Thus, in the six years we have had 
nearly the maximum and the minimum amounts of water that may 
be expected. 
A heavy monthly precipitation usually means that a considerable 
amount falls at one time and penetrates to a depth where it is not 
lost by evaporation but can be used by plants. The exceptions to 
this are when the precipitation falls as torrential showers with a high 
percentage of run-off and shallow penetration, or when it comes as 
light snow, which is blown off. A light monthly precipitation indi- 
cates that the greater part of it falls as light showers or as snow 
flurries. Under such distribution most of the moisture is lost by 
evaporation and very little, if any, penetrates deeply enough in the 
soil to be held until used by the plants. 
Table I. — Monthly and annual precipitation and normal monthly and annual precipi- 
tation at Akron, Colo., 1905 to 1914, inclusive. 
[Precipitation record, in inches, for the years 1905 to 1909, inclusive, from the reports of the United States 
Weather Bureau.] 
Year. 
1905 
1906 
1907 
1908 
1909 
1910 
1911 
1912 
1913 
1914 
Normal 2 . 
Jan. 
Feb. 
Mar. 
Apr. 
May. 
June. 
July. 
Aug. 
Sept. 
Oct. 
Nov. 
Dec. 
0.37 
0.32 
5.45 
4.55 
4.37 
2.14 
3.82 
0.86 
0.83 
1.73 
0.12 

.25 
.26 
1.51 
4.22 
3.32 
1.20 
2.46 
1.26 
1.00 
1.90 
1.56 
0.08 

i T. 
.43 
1.74 
3.30 
3.26 
6.06 
5.13 
1.86 
.02 
1.00 
.60 

.34 
T. 
1.70 
3.57 
2.35 
3.40 
1.62 
.22 
3.20 
2.00 
T. 
T. 
1.38 
3.06 
.40 
1.87 
3.32 
4.61 
3.77 
2.16 
.78 
.48 
.55 
.05 
.16 
.26 
3.96 
2.06 
1.38 
1.47 
3.72 
3.81 
.05 
.12 
.32 
.60 
.44 
.06 
2.63 
1.15 
1.48 
1.34 
1.30 
2.40 
1.47 
.28 
1.36 
.28 
1.43 
.78 
2.49 
2.86 
3.39 
3.58 
1.58 
1.88 
1.99 
.18 
.29 
.22 
.40 
1.57 
2.19 
1.44 
1.35 
1.85 
1.14 
2.08 
.34 
.30 
3.67 
.03 
.32 
.20 
4.01 
1.46 
3.54 
1.66 
1.05 
.23 
2.08 
.10 
.90 
.18 
.51 
1.33 
2.79 
2.54 
2.34 
3.02 
2.14 
1.65 
1.36 
.61 
.78 
Total. 
24.56 
19.02 
23.40 
18.38 
22.38 
17.36 
14.51 
20.73 
16. 55 
15.58 
19.25 
i T.= Trace. 
2 Normal precipitation, October to March, inclusive, is 24.8 per cent of the normal for the year. 
In the consideration of the time of plowing, the great variation in 
time and amount of precipitation must be kept in mind. The winter 
precipitation is usually in the form of snow, and wind is an important 
factor in its local distribution. Heavy rainfall or snows that are not 
disturbed by wind may occur between November 1 and April 1, but 
as the ground is usually frozen the amount of moisture stored in the 
soil from them apparently would not be affected by the time of 
plowing. Generally, the greater part of the snowfall will be blown 
off of a fall-plowed field, while a considerable quantity will be held 
bv stubble land. 
