310 SOILS 



continuous supply of food. The necessity for ac- 

 complishing this may make it necessary to adopt 

 rotations that are not ideal, so far as maintaining 

 the fertility of the farm soil is concerned. The 

 abundance of manure may offset this disadvantage. 

 When either the small grains or hay are me 

 specialties a common rotation is : 



8. Wheat or rye; clover, or clover and mixed 

 grasses, three to six years. 



In the "Cotton Belt" one of the most successful 

 rotations is: 



9. Cotton, rye or clover, corn. 



Catch crops of cowpeas are used between these 

 crops. In addition to main-crop rotation, catch 

 crops and cover crops are used in diverse ways. 



The foregoing are but a few of many rotations 

 in common use on American farms. In the Ap- 

 pendix is a list of the rotations commonly practised 

 or recommended in each of the states. These lists 

 have been prepared by authorities on the subject 

 and are a record of the best current practice^^ 

 crop rotation. 



SINGLE-CROP FARMING 



It must not be inferred that it will never pay to 

 grow a crop continuously on the same land. Often 

 this is the only feasible course as in some Western 

 grain farming; and again it may be best for certain 

 crops, as onions and tobacco. A summer fallow 

 may be introduced instead of another crop. There 

 are numerous instances of wheat and corn being 

 grown continuously, with little diminution of sou 

 Fertility. In the noted experiments of Laws and 

 Gilbert, in England, wheat has been grown con- 

 tinuously on the same land for over sixty years, 



