174 ELEMENTS OF AGRICULTURE 



building a silo. The essential point is that it be air-tight 

 at the sides and bottom. Cement, stone, and brick are 

 sometimes used, but they are all more expensive than 

 wood. There are two common methods of wood con- 

 struction. In one, vertical posts are sheathed on the in- 

 side and outside the sheathing acting as hoops to main- 

 tain the circular position. The other type is more common. 

 It is made of two-inch planks that are matched together 

 and held by hoops in the form of a tank. The hoops may 

 be tightened by means of burs. The foundation should 

 be of cement. Wooden silos may be constructed com- 

 plete for $1.50 to $2 per ton of capacity. 



The deeper the silo, the cheaper the construction for 

 a given capacity, and the better the silage keeps, because 

 that in the bottom is packed harder. A silo that is 32 

 feet deep will hold twice as much as one that is 20 feet 

 deep. Ordinarily, a silo should be at least 24 feet deep. 



A silo is not likely to be profitable if there are not 

 at least ten cattle to be fed. Each cow will eat about 

 half a ton a month. The required capacity can therefore 

 be figured from the number of cows. 



163. Growing Corn for the Silo. When corn is grown 

 for the silo, it is usually planted in drills and thicker 

 than when grown for grain. The distance at which the 

 total yield of grain is greatest is probably best. This 

 results in some " nubbins," but they are as desirable as 

 large ears, provided the total yield of grain is not decreased. 

 It is not desirable to plant so thick as to decrease the 

 yield of grain. 



Corn should be cut for the silo when fully glazed. At 

 this time the kernels will all be dented and a few of the 



