Reply #6: i.e., before the mass application of artificial fertilizers ... coincidence?

[Nihil]

Maybe not.

> post-refinery corn is too high in sulfates and phosphates

I don't get the impression that it is the refinery that is *adding* the
sulphates and phosphates, merely concentrating them into the "feed",
much as the old poison-in-the-food-chain process does with everything
from mercury to PCBs. As such, the "thousands of years" argument simply
doesn't apply as chemical (=man-made not naturally produced) fertilizers
were not being used then.

(BTW, how come it is "sulfates and phosphates" rather than either a true
US form "sulfates and phosfates" or a true English form "sulphates and
phosphates"?)
:shrug: