CROPPING SYSTEMS WASHINGTON", OREGON, IDAHO. O 
Table IV .—Relation of field crop area in legumes to crop yields per acre on 144 silt loam 
soil farms in the Willamette Valley, Oreg. 
[Farms grouped according to percentage of field crop area in legumes, a] 
Item. 
None. 
Under 18 
18 to 33 
Over 33 
per cent. 
percent. 
per cent. 
12.0 
26.0 
44.8 
37 
37 
35 
145.5 
172.0 
183.5 
21.5 
23.8 
23.7 
38.3 
40.9 
44.5 
2.00 
1.86 
2.07 
100.4 
105.0 
111.4 
.\11 farms. 
Average percentage crop area in legumes. 
Number of farms 
Average yields per acre: 
Potatoes (bushels) 
Wheat (bushels) 
Oats (bushels) 
Hay (tons) 
Crop index 
None.... 
35 
132.8 
18.8 
28.5 
1.82 
82.8 
20.4 
144 
150.2 
22.0 
37.7 
1.94 
100.0 
a Clover occupied 58 per cent of the area in legumes. 
Table \ .—Percentage of field crop area in clover in relation to farm profits and 
144 silt loam soil farms in the Willamette Valley, Oreg. 
[Farms grouped according to percentage of field crop area in clover.] 
Item. 
Average percentage of field crop area in clover 
Number of farms 
Average capital 
Average farm income 
Average labor income 
Average per cent made on investment a 
Crop index 
None. 
None. 
64 
$20, 547 
11,098 
-S135 
5.34 
95.8 
Less than 
20 percent. 
11.2 
42 
122,920 
$1,546 
$171 
6.75 
102.7 
More than 
20 per cent. 
32.7 
38 
$21,372 
$1, 834 
$560 
8.63 
110. 7 
All farms. 
11.7 
144 
$21,457 
$1,425 
$138 
6.64 
100.0 
a Per cent made on investment in this table means per cent farm income is of capital. 
The relation of field crop area in legumes to crop yields is shown 
in Table IV. The per acre yields of the four principal crops, potatoes, 
wheat, oats, and hay showed a marked increase on farms devoting 
more than 33 per cent of their rotation area to legumes over the per 
acre yield of those growing no legumes. The increases in yields in 
a comparison of the two groups of farms were as follows: Potatoes, 
38.2 per cent; wheat, 26.1 per cent; oats, 56.2 per cent; hay, 13.7 
per cent. The average increase in yields due to the use of legumes, 
for all crops, as shown by the crop index, was 34.5 per cent. The 
largest increase in crop yields occurred in comparing the group hav- 
ing an average of 12 per cent of the crop area devoted to these crops 
and the group of farms having no legumes. The increase in crop 
yields as between these two groups amounts to 21.3 per cent, while the 
increases as between the second and third and the third and fourth 
groups are 4.7 per cent and 6.1 per cent, respectively. (See Table V.) 
The crop index indicates that those farms having more than 20 
per cent of their field-crop area in clover had 15.5 per cent larger 
yields than farms without clover. The group of farms which grew 
no clover made a minus labor income of $135; that is, the net farm 
profits lacked $135 of amounting to 6 percent of the capital invested. 1 
5 Six per cent was the current rate on farm loans in this region in 1912. 
