138 CROP ROTATIONS 



Management Required. By rotation of crops is meant the 

 order or arrangement of their succession. On a given field the 

 plan is made to have one crop follow another for the purpose of 

 securing certain definite beneficial results. This is in contrast 

 with the plan of having the same kind of crop grown on the same 

 field for several seasons, with no other crop intervening. 



One of the most important elements in good farm management 

 is to have a. good system of rotation established for each field. 

 The plan should always have for its foundation good scientific 

 reasons which are applicable to the particular case in hand. The 

 rotation should suit the soil, the kinds of crops grown, and also 

 take into consideration the market conditions and money return 

 from the business. 



Many good systems of rotation are in use. No one can hope 

 to specify any definite rotation which would best suit all condi- 

 tions. Each farm manager must become thoroughly acquainted 

 with the underlying principles or reasons, and then make use of 

 them in formulating one rotation course for each field. 



Take, for example, a dairyman in Wisconsin, who has his farm 

 divided into four fields and has on each of these fields a four-year 

 rotation. 



The first year field A has corn; field B has oats, followed by 

 clover just starting; field C has clover with timothy; field D is 

 chiefly timothy with some clover and is used for growing pasture 

 for that year. 



The second year field A is sowed to oats, with clover and 

 timothy seed as B was the year before; field B is now used for 

 clover hay; field C is used for pasture and D is growing corn. 

 Thus each year the rotation is pushed back one and the cycle is 

 complete in four years. The four fields are approximately the 

 same in size. 



It must not be supposed that this identical plan can be followed 

 even by all dairy farmers. 



Underlying Principles. There are a number of fundamental 

 reasons which are applicable in special cases. These should all be 

 borne well in mind by the owner or manager when he is planning 

 any rotation course. 



1 Some crops gather nitrogen from the air and add it to the 

 soil, while others exhaust it or rob this element from the soil. If 

 a rotation be adopted whereby the use of nitrogen-gathering crops 

 of the legume family are used once or perhaps oftener in the rota- 



