ROTATION OF CROPS 28 1 



340. Long- and Short-course Rotations. Rotations 

 vary in length from 2 to 17 years. Long-course rota- 

 tions are more generally followed in European and 

 other of the older countries. The length of the rotation 

 can be determined only by the conditions existing in 

 different localities. As a general rule, long-course rota- 

 tions should be attempted mainly on large farms and after 

 a careful study of all of the conditions relating to the 

 system of farming that it is desired to follow. For north- 

 ern latitudes a rotation of four or five years gives excel- 

 lent results. In some localities three-course rotations 

 are the most desirable. 



A rotation that is suitable for one locality or kind of 

 farming may be unsuitable for other localities and con- 

 ditions. Because of variations in soil, climate, and rain- 

 fall, no definite standard rotation can be proposed that 

 will be applicable to all cases. 



341. Example of Rotation. In dealing with the sub- 

 ject of rotations it is best to take actual problems as 

 they present themselves and plan rotations that will 

 best meet all of the conditions. For example, a farm 

 of 160 acres is to be rotated with the main object of 

 producing fodder for live stock, and a small amount of 

 grain for sale. To meet these requirements the rotation 

 outlined on pages 282 and 283 is suggested. 83 



The farm is divided into eight fields of 20 acres each; 

 seven fields are brought under the rotation, while one 

 field is left free for miscellaneous purposes. Each year 



