Why does a command economy require a large bureaucracy?

Because of the following:
Government ownership of the means of production. In command economies, governments will own some or all of the industries producing goods and services.Government pricing and production decisions. In a command economy, production is decided by government agencies, who decide the most socially efficient goods to produce. Government agencies may also set prices or give consumers rations directly.

In the midwest because it has more moderate climate than the north or south west which makes farming far easier.