20 CULTIVATION METHODS AND ROTATIONS FOR GREAT PLAINS. 



nature. The solutions of these problems are also so dependent upon 

 seasonal conditions of soil and climate that no safe generalization 

 concerning them can be made. Each farmer must therefore work 

 out the best practice for his particular farm, crop, and season. It 

 is believed, however, that our investigations a show that fairly deep 

 plowing — about 8 inches — and thorough preparation of the seed bed 

 will give better results than shallower plowing on most soils, whether 

 spring or fall plowing is practiced. The deeper the plowing, the 

 more thorough should be the harrowing in order to form a compact 

 seed bed. 



CROP ROTATION COMPARED WITH CONTINUOUS CROPPING. 



OUTLINE OF THE THREE-YEAR ROTATIONS. 



At the same eleven stations described in the previous pages, a 

 series of nine 3-year rotations were established at the same time that 

 the continuous cropping experiments were begun. The plan of these 

 rotations is described in the accompanying outline and in the explan- 

 atory notes following. These rotations are identical for all of the 

 eleven stations. 



Outline of 3-year rotations. 



Rotation No. 1. 



Plat A. Spring wheat on corn ground disked but not plowed. 

 Plat B. Oats on ground plowed early the preceding fall. 

 Plat C. Corn on ground plowed early the preceding fall. 



Rotation No. 2. 



Plat A. Spring wheat on spring-plowed ground. 

 Plat B. Oats on spring-plowed ground. 

 Plat C. Corn on spring-plowed ground. 



Rotation No. 3. 



Plat A. Spring wheat on ground plowed early the preceding fall. 

 Plat B. Oats on ground plowed early the preceding fall. 

 Plat C. Corn on ground plowed early the preceding fall. 



Rotation No. 4. 



Plat A. Oats on corn ground not plowed but disked. 

 Plat B. Spring wheat on fall-plowed ground. 

 Plat C. Corn on fall-plowed ground. 



Rotation No. 5. 



Plat A. Spring wheat on summer-tilled land. 



Plat B. Oats on ground plowed early the preceding fall. 



Plat C. Summer tilled. 



Rotation No. 6. 



Plat A. Barley on corn ground not plowed but disked. 

 Plat B. Oats on ground plowed early the preceding fall. 

 Plat C. Corn on ground plowed early the preceding fall. 



187 



a See the discussion of crop rotation which follows. 



