viii.] RO TA TION OF CROPS. 7 ! 



CHAPTER VIIL 

 ROTATION OF CROPS. 



144. The practice of agriculture has long proved 

 the importance of regulating in proper order, the suc- 

 cession in which crops should be grown. It has been 

 found that if some of our crops be grown upon the 

 same land year after year, difficulties have to be over- 

 come, for the crop to be kept in a healthy and lux- 

 uriant condition. It is commonly remarked by far- 

 mers that the land is " sick" of a crop, and clover 

 is especially referred to in this way. If a field is 

 " clover sick," it is unwise to sow clover again 

 until the land has become ready for it. The same 

 influence has been noticed in connection with other 

 crops; this has led to the crops being changed fre- 

 quently, and experience has taught us much, as to the 

 manner in which we may best make these changes. 



145. The rotation of crops adopted in different 

 districts, represents the experience derived by farmers 

 as to the best order in which our crops should follow 

 each other. The term " rotation of crops" may 

 therefore be taken to mean, the order of succession in 

 which our crops are grown. This is an exceedingly 

 important matter, for it exercises great influence upon 

 the success of farm operations, and it is therefore 

 desirable that the conditions which influence these 

 results should be clearly understood. 



146. At one time it was thought that De Candolle 

 was correct, in his explanation of the cause of land 

 becoming " sick " of a crop. He had observed that 

 when the same crops had been grown repeatedly in 

 direct succession on the same land, they became 

 unhealthy ; that there was a want of vigour, and the 

 produce became small. If, however, another kind of 

 crop were sown, it seemed to thrive luxuriantly, where 



