re: 2017 Gulf dead zone is largest ever, size of New Jersey

Nope. The US Midwest rotates corn and beans on an every other year cycle. There is usually about 80 million acres of corn and 90 million acres of beans in the US regardless of crop prices or ethanol subsidies.

If ethanol went away you might see 5-10 million acres of corn come out, and move to beans. But that's not enough to have a material effect on the N load going into the MS River.

FTR: Corn uses liquid N that washes downstream. Beans do not.