SILOS AND SILAGE 



255 



CAPACITY OF THE ROUND SILO IN TONS 



331 . The height of the silo. The deeper the silo and there- 

 fore the greater the pressure of the silage, the more completely 

 the air will be excluded and the better the silage will keep. 

 With the old-fashioned chain elevator it was not feasible to lift 

 silage to a greater height than thirty feet, but with the modern 

 blower elevator silage can be blown to a height of fifty or more 

 feet. A convenient rule is to estimate the height of the silo 

 at from three to three and one-half times its diameter. Silos 

 of medium size should be between 30 and 40 feet high, and 

 those of large diameter should be 40 or 50 feet high. 



332. What a silo costs. A silo costs from $2.50 to $$ for 

 each ton of capacity, according to the size, the materials used, 

 and the conditions under which it is erected. This means that 

 a loo-ton silo will cost from $250 to $500, and it will hold the 

 forage ordinarily grown on 10 or 12 acres. 



333. When to cut crops for silage. To secure the maximum 

 yield of digestible materials it is necessary to allow corn to 

 become reasonably mature before it is harvested, because the 



