CONSERVATION OF ORGANIC MATTER. 



63 



FOUR-YEAR ROTATION (NO. 4). 



Field A, 40 Acres. 



Field C, 40 Acres. 



1910. Corn. 



1911. Wheat, winter or spring. 



1912. Winter rye turned under in spring. 



1913. Oats, barley, emmer, or wheat. 



1910. Winter rye turned under in spring. 



1911. Oats, barley, emmer, or wheat. 



1912. Corn. 



1913. Wheat, winter or spring. 



Field B, 40 Acres. 



Field D, 40 Acres. 



1910. Wheat, winter or spring. 



1911. Winter rye turned under in spring. 



1912. Oats, barley, emmer, or wheat. 



1913. Corn. 



1910. Oats, barley, emmer, or wheat. 



1911. Corn. 



1912. Wheat, winter or spring. 



1913. Winter rye turned under in spring. 



While we feel confident that brome-grass and red clover can be 

 much more commonly grown throughout this area than at present, 

 we recognize that there probably are localities within the area 

 where neither of these crops can be successfully grown, and it is 

 altogether likely that even in those localities where the crops can be 

 successfully grown during favorable seasons there will be unfavor- 

 able seasons when it will be impossible to get a catch of either of 

 them. In order to provide for such emergencies we have included 

 the following 4-year rotation, No. 4, in which we have substituted a 

 crop of winter rye for the clover which occurred in rotation No. 3. 

 The other crops in this rotation will not need further description, as 

 they are to be treated the same as in the rotations described. 



The ground for the winter rye should be prepared by plowing it as 

 soon after the wheat crop is removed as possible. It should then 

 be thoroughly packed and harrowed and kept in good tilth and free 

 from weeds until the proper time for seeding has arrived. The date 

 of seeding, of course, will vary somewhat with the latitude. After 

 the rye is seeded it will require no further attention until the following 

 spring or early summer, when it is to be turned under. The date 

 when this should be done will, of course, vary with the season, but 

 experience has shown that the best results are obtained when the 

 rye is turned under after it has attained nearly its full growth but 

 while it is still young and succulent and has not become hard and 

 woody. This stage will vary somewhat in the same locality on 

 account of the difference in weather conditions from season to season, 

 so that each farmer must use his own judgment in determining 

 whether the grain has reached the proper stage for plowing under. 

 As soon as it is plowed under, the ground should be thoroughly 

 packed and harrowed in order to prevent the rye straw from drying 

 out in the soil instead of rotting. After the rye has been turned 

 under, the field should be treated like summer tillage for the remainder 

 of the season until the following spring, provided a spring crop is to 

 52345°— Bui. 187—10 5 



