When you travel around the USA you will notice that there are lots of new grain silos - shiny galvanized tanks with elevators and gravity distribution tubes.

The old, much smaller volume, wire enclosed corn cribs are empty - just poison ivy growing on them. 

(I will get some images up here to demonstrate these structures)

What has brought about the vast new storage facilities in our long established agricultural areas?  

Ammonia.   Anhydrous Ammonia.

And how is this ammonia made?  

From natural gas and electricity.   Wikipedia explains ammonia production here.

Here is a University of Minnisota web site which describes the hazzards of ammonia used in the fertilization of crops .

Image above shows anhydrous ammonia pressure tank trailers used for soil injection of ammonia fertilizer in Iowa corn and soy fields. 

Corn ethanol for our autos  is being produced by using natural gas, coal fossil fuel produced electricity, and Diesel fuel for the tractors to plant and harvest.   Makes sense to me....