268 THE PRINCIPLES OF AGRICULTURE 



nearly all of the manurial constituents of the 

 food are found in the excrements. 



498. This practice of purchasing food would 

 appear to be wise on a farm poorly supplied 

 with plant -food. It may be assumed that the 

 increase in growth, or the products secured from 

 the animals which consume these purchased 

 foods, would equal or exceed the cost of such 

 foods. If so, the value of the excrements would 

 be clear additional profit. 



499. In practice, however, it is found that 

 the purchase of these supplemental foods be- 

 comes necessary largely because a wise use has 

 not been made of the land. If need of these 

 purchased foods arises because but a half crop 

 is secured instead of a full one, then greater 

 attention should be given to making the land 

 more productive. In many cases, the purchased 

 foods are required because the production of 

 grasses and the other forage plants has been 

 neglected. Full crops and wisely purchased 

 concentrated foods lead directly to the im- 

 provement of animals and land, and, therefore, 

 to permanent prosperity. 



500. When the coarser products are used 

 for food and bedding, and a goodly portion of 

 the grains are fed at home, it is possible, with 

 care, to return to the fields three-fourths of all 

 the plant -food which is removed from the fields 



