CHAPTER 

 CONSTRUCTION OF SILOS. 



489. Conditions Essential for Preserving Silage The 



only conditions necessary for preserving good corn and 

 clover silage, are close packing in an air tight structure 

 when the materials have reached the right stage of matur- 

 ity. Whatever means may be adopted to exclude air from 

 these materials will preserve them as silage. If air can 

 find access to it spoiling will be inevitable and the rate and 

 extent will be greater the more readily air can gain access. 



490. Depth of Silage. The depth of silage should be 

 made as great as practicable (1) because in this way the 

 largest amount of feed per cubic foot may be stored. (2) 

 There is less loss relatively at the surface. (3) The strong 

 lateral pressure forces the silage against the walls so 

 closely that less air enters and hence there is less loss. 



491. Silo Walls Must be Rigid and Strong The outward 

 pressure of cut corn silage when settling, at the time of 

 filling, increases with the depth at the rate of 11 Ibs. per 

 square feet for each foot of depth. At a depth of 10 feet 

 the lateral pressure is 110 Ibs. per square foot, at 20 feet it 

 is 220 Ibs. and at 30 feet 330 Ibs. 



Because of this great pressure silo walls must be made 

 very strong when they have a depth of 20 or more feet It 

 is difficult to make deep rectangular silos whose walls will 

 not spread as represented in Fig. 195, and where this takes 

 place the walls are crowd'ed away from the silage so much 

 that air can circulate up and down next to the walls and 

 this results in heavy losses. 



