2 BULLETIN 625, U. S. DEPARTMENT OE AGRICULTURE. 
On the silt loam soils of the Willamette Valley, Oregon, where cli- 
matic conditions are very similar to those of the Bitter Root and 
Blue Mountain regions, summer fallowing has been discontinued, 
without a decrease in yields. This result was accomplished through 
the use of legumes, principally clover, in the rotation. Recent stud- 
ies show that the same result may be accomplished by the use of 
clover in that portion of eastern Washington, eastern Oregon, and 
northern Idaho having an annual precipitation in excess of 20 inches. 
The fact that farmers in this section do not use more clover in the 
crop rotation is due, in large measure, to the prevailing idea that it 
can not be seeded in a nurse crop. In a study of this method of 
seeding clover the author found that in 100 trials, covering a period 
of 11 years, 1,507 acres of land in this region were seeded to clover 
with wheat, oats, or barley. A good stand of clover was secured on 
1,408 acres, or 93.8 per cent of the total acreage seeded. 
It was found that for successfully seeding clover with a nurse crop 
the following rules must be followed: (1) Use good seed; (2) the land 
must be free from weeds, especially wild oats; (3) the seed bed must 
be well prepared; (4) but about two-thirds as much grain (nurse 
crop) should be sown per acre as when no clover is sown; (5) seed 
early in the spring; and (6) inoculate the soil with nitrogen gather- 
ing bacteria, which will grow on the clover plant. 
The per acre crop yields on farms where clover has been grown in 
the crop rotation is from 15 to 25 per cent larger than on farms 
where the summer-fallow method of growing wheat, oats, or barley 
is practiced. Three- and four-year rotations with clover are being 
carried on successfully in different sections of the above-described 
territory. 
FACTORS INFLUENCING FARM PROFITS. 
All farm-management studies show that there are certain factors 
within the control of the farmer which largely determine the profita- 
bleness of his business. As stated above, the most potent factors 
influencing profits on the farms studied in eastern Washington, 
eastern Oregon, and northern Idaho, as shown by the 1915 survey, 
were the amount of idle land in summer fallow and the per-acre 
yield of crops. The greater the percentage of rotation area in summer 
fallow, the smaller were the profits ; the larger the crop yieJds per acre, 
the greater the profits. The effect of these factors on farm profits 
is shown in Tables I and II, which were taken from the 1915 survey 
of the above-described territory. 
It will be seen from Table I that the group of farms having an 
average of 6.4 per cent of their rotation area devoted to summer 
fallow had an average of $490 labor income after deducting 8 per 
cent on capital invested. 1 On the other hand, the group of farms 
>Eight per cent was the current rate on farm loans in this region in 1915. 
