They could also switch to less fertilizer intensive crops. I think soybeans require less than corn. Farmers commonly switch between the two depending on market prices. Not a farmer but I think I read it somewhere...maybe 80% sure of this...
Legume roots have nodules that cultivate bacteria that fix nitrogen. Farmers rotate their fields between corn and soybeans/legumes because the bacteria on legume roots restores the nitrogen in the soil, thereby lessening their fertilizer costs.
Biological Nitrogen Fixation: https://www.nature.com/scitable/knowledge/library/biological...
This is an inoculant with bacteria for soybeans: https://www.groworganic.com/products/soybean-inoculant?_pos=...
Plants with deep roots pull up nutrients from deep soil. I think corn and soybeans generally don't help with restoring the soil like native plants.
A chart comparing root systems of North American prairie plants and bluegrass: https://www.reddit.com/r/ecology/comments/bxoh43/a_chart_com...
A lot of the other 25% is probably corn syrup.
Burning natural gas to make fertilizer to grow corn (a 2% efficient solar panel) to eventually blend with gasoline is uhhhhh, dumb.