120 FIRST PRINCIPLES OF AGRICULTURE. 



In No. 4 wheat is dispensed with, and in No. 5, corn. 

 Both are excellent where potatoes or root crops can be 

 grown to advantage; and, if the land is naturally rich, 

 the frequent tillage, and use of clover crops, provide an 

 abundance of available food for maximum crops, provided 

 the second crop of clover is not removed. 



No. 5 may be reduced to a two-year rotation by plow- 

 ing the clover in spring before removing any crop. In 

 these rotations barley may be substituted for oats, rye 

 for wheat, and sweet potatoes or tomatoes for potatoes, 

 without interfering with the usefulness of the rotation. 



Botations on heavy land, where hay is an important 

 crop, differ mainly from those already mentioned in hav- 

 ing a larger number of crops. Timothy is seeded with 

 the wheat in addition to clover in the spring. The first 

 year after wheat, a mixed hay crop is gathered, which 

 becomes almost pure timothy in the next season, and 

 purer still in that following; hay is cut two or three 

 years or longer, as the strength and character of soil per- 

 mit. Cropping in this way is, however, exhaustive, and 

 requires careful manuring. These rotations have refer- 

 ence to what is termed "extensive practice," and do not 

 provide for the manuring of each crop, though it does 

 not follow that it cannot be made "intensive." 



Botations in Market-gardening and on Dairy 

 Farms. In market-gardening and dairy-farming, ma- 

 nures are relied on to a greater extent, and less attention 

 is given to strict rotations. These lines of farming are 

 more on the " intensive plan," the areas are limited, the 

 cropping constant, the manuring liberal, and the crops as 

 large as conditions of climate and season will permit. 



