CHAPTER II 

 CROP ROTATION 



By J. F. BARKER 

 New York Agricultural Experiment Station 



WHEN any one crop is grown continuously on the same 

 field for a number of years, the average yield is almost 

 sure to be less than if that crop had been grown in a suit- 

 able rotation with other crops. Thus if corn, oats, wheat, 

 and hay are grown on a farm, the land devoted to these 

 crops may be divided into five fields of equal size and 

 the four crops changed each year in regular order from 

 one field to another, except that hay would always be 

 grown on a field two years in succession. In this way 

 better average yields would result than if each field were 

 devoted to one crop continuously. This principle is 

 recognized in greater or less extent by nearly all practical 

 farmers ; but the following epitomized results of carefully 

 conducted field experiments bearing upon the subject 

 furnish the concrete evidence necessary to a definite 

 understanding of this principle. Such results are of more 

 significance than any amount of theory or generalized 

 experience. It should be said, in explanation, that com- 

 parisons of rotative and continuous cropping are here 

 made between adjoining or near-by fields rather than 

 adjoining plots. The figures therefore are probably 

 not so closely comparable as in fertilizer tests. But con- 



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