so:me useful plants 337 



largely used as a winter food for cattle under the name of 

 ensilage. Much use is also made of dried com stems, with 

 the leaves, variously known as " corn fodder " and stover. 



The residues left after certain manufacturing processes 

 are of great value as food for horses, cattle, sheep, or hogs. 

 Among these are linseed meal and cotton-seed meal from 

 which all the oil possible has been extracted by pressure. 

 Brewers' grains and distillery swill, the latter consisting 

 of a sort of thin sour gruel of corn meal from which all 

 the alcohol has been distilled, may be fed in moderate 

 quantity to cattle and hogs without ill effects, and are 

 used in the fresh condition and dried for shipment. The 

 refuse from the manufacture of beet-sugar is also consider- 

 ably utilized, both moist and after drying. 



(4) FERTILIZERS OF VEGETABLE ORIGIN 



413. Crops impoverish the soil by removing from it the 

 raw materials for the manufacture of plant food. The 

 most valuable of these are nitrates and potassium com- 

 pounds. It is evident that the fertility of the soil can 

 best be maintained by restoring to it all parts of the plant 

 not to be sold at a profit. For instance, if beans are grown 

 upon a piece of ground, the stems and leaves, after the 

 crop has been gathered, should in some way be restored 

 to the soil and plowed under, — not burned, since burn- 

 ing would destroy much available nitrogen. Cotton-seed 

 meal is much used as a fertilizer and restores to the soil 

 most of the valuable material taken from it by the growth 

 of the cotton crop. 



Wood-ashes is a useful fertilizer, from the amount of 

 potassium salts which it contains. 



