COMMON VETCH AND ITS VARIETIES 
19 
ROTATIONS WITH VARIOUS CROPS 
From 1915 to 1923 vetch was grown in rotation with oats, wheat, 
corn, and potatoes for comparison with continuous cropping to 
vetch. The data from these experiments are given in Tables 12 
and 13. In considering the relative yields of vetch seed for the 
three years in which data are available it is clear that 75 per cent 
of the rotated plats gave an increased yield. It is also clearly 
indicated that there was no decrease in yield in the continuously 
cropped plats. The yield of vetch seed in 1922 on the continuously 
cropped vetch plat was 60 per cent of the yield in 1916; on the 
plat in rotation with oats, 55 per cent; on the plat in rotation with 
wheat, 64 per cent; on the plat in rotation with corn, 50 per cent; 
and on the plat in rotation with potatoes, 54 per cent. The lower 
yields in all the plats in 1920 and 1922 in comparison with 1916 no 
doubt were due to seasonal climatic conditions. From these data it 
seems apparent that rotation has been beneficial to seed yields of vetch 
and that oats is one of the best crops for this purpose, but at the same 
time continuous cropping to vetch has not decreased the yield. 
In the hay yields given in Table 13 there is a decrease in the vetch 
when rotated with oats and an increase when rotated with corn. 
In the rotation with potatoes and wheat there was an increase in 
1922 but a decrease in 1918 and 1920. 
Table 12. — Yields per acre of Oregon vetch under continuous cropping and in 
rotations with various crops 
[Computed from duplicate twentieth-acre plats; hay yields computed on a dry-matter basis. The asterisk 
(*) marks a year of crop failure] 
' Vetch 
continu- 
ously 
planted 
Crop 
Vetch in rotation with— 
Oats 
Crop 
Wheat 
Crop 
Corn 
Crop 
Potatoes 
grown 
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1914-15. 
Lbs. 
4,900 
Lbs. 
1 . <S50 
Oats... 
Vetch.. 
Oats... 
Vetch.. 
Oats___ 
Vetch. . 
Oats,_- 
Vetch-- 
Oats.__ 
Lbs. 
2,135 
2,305 
2, 695 
(*) 
2. 680 
1,400 
2, 610 
1,280 
2,380 
Lbs. 
4," 920 
2," 180 
6,"020 
4~080 
Wheat-. 
Vetch... 
Wheat.. 
Vetch... 
Wheat. _ 
Vetch... 
Wheat.. 
Vetch... 
Wheat.. 
Lbs. 
(*) 
1,830 
2,268 
(*) 
3, 260 
1,420 
3,130 
1,180 
2,740 
Lbs. 
4," 740 
2, 160 
6," 300 
4,"~466 
Lbs. 
Lbs. 
(*) 
5,760 
15, 340 
2,900 
14, 640 
7,280 
15, 000 
4,560 
14, 240 
Potato.. 
Vetch... 
Potato. . 
Vetch... 
Potato.. 
Vetch... 
Potato.. 
Vetch... 
Potato.. 
Lbs. 
8,280 
2,305 
11, 580 
(*) 
10,210 
1,140 
7,870 
1,260 
5,300 
Lbs. 
1915-16. 
1916-17. 
4,980,1,907 
4, 520;i, 395 
2,580 (*) 
7, 920! 1, 860 
6, 740j 1,310 
7,040!l,080 
4,28011,140 
4, 540 1 040 
Vetch... 
Corn ... 
2,340 
6,220 
1917-18. 
1918-19. 
Vetch... 
Corn ... 
(*) 
2,120 
1919-20. 
1920-21. 
Vetch... 
Corn ... 
1,100 
6,280 
1921-22. 
1922-23. 
Vetch... 
1,180 
4,500 
Table 13. — Relative yields per acre of seed and hay of Oregon vetchHn various 
rotations 
[Computed from data in Table 12, assuming yields on the plats continuously planted to vetch at 1,000 
pounds for seed and 5,000 pounds for hay] 
On plats 
continu- 
ously 
planted 
On plats rotated with— 
Product and year 
Oats 
Wheat 
Corn 
Potatoes 
Seed yields: 
1916 
Pounds 
1,000 
1,000 
1,000 
5,000 
5,000 
5, 000 
5,000 
Pounds 
1,208 
1,068 
1,113 
4,939 
4,225 
4,465 
4,764 
Pounds 
959 
1,084 
1,026 
4,759 
4,186 
4,673 
5,208 
Pounds 
1,227 
847 
1,026 
5,783 
5, 620 
5, 400 
5,324 
Pounds 
1,208 
1920 
870 
1922. . . 
1,095 
Hay yields: 
1916 . 
6,245 
1918. . 
4,108 
1920 
4,658 
1922 
5, 254 
