<P> A silo (from the Greek σιρός--siros, "pit for holding grain") is a structure for storing bulk materials . Silos are used in agriculture to store grain (see grain elevators) or fermented feed known as silage . Silos are more commonly used for bulk storage of grain, coal, cement, carbon black, woodchips, food products and sawdust . Three types of silos are in widespread use today: tower silos, bunker silos, and bag silos . </P> <Table> <Tr> <Td> </Td> <Td> This section does not cite any sources . Please help improve this section by adding citations to reliable sources . Unsourced material may be challenged and removed . (November 2010) (Learn how and when to remove this template message) </Td> </Tr> </Table>

What is the purpose of a grain silo