EXPERIMENTS WITH FALLOW IN MONTANA 9 
The results reported are for the crop immediately following the 
fallow or the green manures. No marked effects have yet been 
evidenced on succeeding crops, but as the experiment progresses or 
with more favorable seasons the results may become more clear. 
Table 5 gives the annual and average yields of winter wheat and 
oats following fallow and the three green manures in comparable 
rotations for the seven years, 1917 to 1923, inclusive. No great 
difference is evidenced between the three green manures as prepara- 
tions for either oats or winter wheat, although field peas appear to 
have a slight advantage over the other two. Between the green 
manures and the fallow there is a marked difference, the yields on 
green manure being about doubled on fallow. 
As the cost of green manure is much higher than that of fallow, its 
use is a much less profitable practice. 
RESULTS OF PLOWING AT DIFFERENT TIMES FOR FALLOW 
A test of the time of plowing for fallow was started in 1916, but the 
effect could not be seen in the yields until the season of 1918. Winter 
wheat alternates with fallow on four pairs of plats in this experiment. 
In the pair designated H and I the fallow land was plowed in the fall 
as soon as soil conditions permitted after the previous crop was re- 
moved. This was generally during the last of August or early 
September. After plowing, the land was cultivated with a disk and 
harrow, so that it went through the first winter with a smooth cul- 
tivated surface. During the summer of the fallow season it was kept 
cultivated and clean until seeded to winter wheat. 
The fallow plat in the pair designated J and K was also plowed in the 
fall. Instead of being cultivated immediately this plat was left 
rough during the first winter. During the following summer it was 
kept cultivated, the same as the fallow just described. 
The fallow plat in the pair lettered L and M was plowed in May. 
There was no cultivation before plowing; after plowing there was 
sufficient to control weeds. 
The fallow plat in the pair designated N and O was plowed the last 
of June or early in July with no previous cultivation. Weeds and 
volunteer grain made a fair growth before this plat was plowed. 
Sufficient cultivation to prepare a good seed bed was given after 
plowing. 
The four fallows varied in the time of plowing and in the cultivation 
that was given after plowing. Two were plowed in the fall and 
differentiated by working one down smooth at once, while the other 
went through the winter rough, as left by the plow. The other two 
went through the first winter in stubble. One was plowed early, 
before weeds had made much growth, and the other was not plowed 
until well into the summer. 
The results of the four methods for the six years, 1918 to 1923, 
inclusive, are given in Table 6 and shown graphically in Figure 5. 
In 1920 and 1922 winter wheat winterkilled and was reseeded to 
Marquis in the spring. Some winterkilling took place in 1923, and 
the plats were reseeded in the spring. A little wheat grew, but 
Russianthistles were so thick it could not be harvested and the plats 
were mowed. The averages are figured for all six years. 
