ROTATION AND CULTURAL METHODS AT EDGELEY, KT. DAK. 13 



of a bushel more than on the corn ground. There is some evidence 

 of a carry-over effect of the fallow, as the oats following wheat in 

 the fallow rotation have outyielcled the oats in the corn rotation in 8 

 of the 13 years. The average increase for the 13 years is 5 bushels per 

 acre of grain and nearly 200 pounds of straw. The average yield 

 of corn, which occupies in rotation No. 3 the place of the bare fallow 

 in rotation No. 8, has been 6.4 bushels of grain and 3,432 pounds 

 of stover per acre. 



Rotation No. 8 is fallow, oats, and wheat, and rotation No. 4 is 

 corn, oats, and wheat. The heavier yield of oats has been on fallow 

 eight years, and on corn five years. The 13-year average increase on 

 fallow has been 4.2 bushels of grain, but less than 100 pounds of 

 straw per acre. There apparently has been in this case no carry- 

 over effect of the fallow, as the yield of wheat in these rotations 

 differs only by one-tenth of a bushel. 



The yield of corn has averaged 6.3 bushels of grain and 3,344 

 pounds of stover, being practically the same as in rotation No. 3. 



In the same four rotations on section 9 for the three years, 1917 to 

 1919, inclusive, the wheat on fallow has outyielded that on corn 

 ground each year, the average increase being 1.9 bushels. No carry- 

 over effect has been apparent, however, as the average yield of the 

 oats following wheat is a fraction of a bushel less in the fallow than 

 it is in the corn rotation. The oats on fallow have outyielded the 

 oats on corn ground each year, the average increase being 14.3 

 bushels. The wheat following the oats on fallow yielded 1.1 bushels 

 more than the wheat on oats following corn. 



Summing up the evidence from the four rotations on both the main 

 field and section 9, it appears that in a comparison of fallow and 

 corn ground there has been a small advantage in favor of the fallow. 

 The response of oats to the fallow is apparently somewhat greater 

 than that of wheat. Whatever advantage there may be from the fal- 

 low is practically exhausted by the first crop. There is some tend- 

 ency to show a small carry-over effect of fallow on the second crop, 

 but it is so small that the evidence is not very clear. It would appear 

 from the direct comparison of these rotations that the difference in 

 yielding power between fallow and corn ground is so small that a 

 choice between them is really to be determined by the choice between 

 either conducting a bare fallow or raising a crop of corn averaging 

 for 13 years about 6-| bushels of grain and more than 1-| tons of stover 

 per acre. 



Two other rotations in the main field for the period from 1908 to 

 1919 and in section 9 from 1917 to 1919 bear evidence on this subject 

 and lead to the same conclusions. Rotation No. 18 is corn on spring 

 plowing, oats on disked corn ground, fallow, and wheat on fallow. 

 Rotation No. 19 is the same, but with the wheat on disked corn ground 

 and the oats on fallow. 



In the main field the average yield for 12 years of oats on fallow 

 has been 6.1 bushels more than on disked corn ground, but the yield 



