86 SfSTEM OF ROTATION 



Suppose the farmer to have a soil which requires, 

 asl almost all soils do, the application of manure to 

 render it fertile. He adds a good coating of manure, 

 and then takes a crop of indian corn or wheat : this 

 crop will carry away the largest part of the phosphates 

 that were added in the manure; in most cases a second 

 crop of the same kind would not therefore be so good, 

 and a third still less. There yet remains, however, 

 from the manure, considerable quantities of other sub- 

 stances, which the grain crops did not so particularly 

 require, such as potash and soda; w T ith these a good 

 root crop may be obtained, potatoes or turnips or beets; 

 after this there is probably still enough lime, etc. left 

 to produce an excellent crop of hay, if seeded down 

 with another grain crop of a lighter character than 

 indian corn or w T heat. 



We perceive then that any good system of rotation 

 must be founded upon the principle, that different 

 classes of crops require different proportions of the 

 various substances that are present in soils, and in the 

 numerous fertilizers that are applied for the purpose 

 of enriching them. Thus the crops may be made to 

 succeed each other with the least possible injury to the 

 soil, and with the greatest economy in the use of the 

 manures. It would be useless to recommend here any 

 particular system of rotation as the best; for that is a 

 matter to be decided by experience in each section of 

 country, under the various circumstances of climate, 

 location, and value of certain crops. I wish only to 

 enforce the general principle that rotations are ne- 

 cessary, and that they afford the only means as yet 

 discovered, through w T hich the majority of farmers can 

 regularly obtain heavy crops with profit to themselves; 

 and at the same time can keep up, or even improve 

 tlie value of their land. 



It is to be noti wl, that even a good rotation should 

 not be contjnuoj *a,o long unchanged upon the same 



