Acid rain has been reduced

The 1990 Clean Air Act required that the amount of sulfur sent up the smokestack in plants burning coal be reduce to reduce the sulfuric acid in the atmosphere. Below is a map indicating how much sulfur was coming from rain.

From Hay&Forage

Many plants in Illinois said they could not afford to add scrubbers so they switched to low-sulfur coal from Wyoming. But I've noticed that plants in Indiana, Kentucky and the southeast did add scrubbers. I don't understand why many plants could afford to install them, but Illinois plants couldn't. Illinois has a lot of coal mines, but it is high-sulfur coal. Illinois mines ended up exporting their coal to China.

Below is a map indicating the 1990 Act successfully reduced acid rain.

From http://industrialscenery.blogspot.com/2016/05/manure-spreader.html

I wondered if the "red dot" on the Wabash River was the Duke Energy/Gibson plant near Princeton, IN. But looking closer at the map, it seems to be upriver near Vincennes, IN.

But alfalfa hay and corn silage need some sulfur.  As long as it was literally raining sulfur, farmers did not have to worry about applying sulfur to their fields. If the farmer raises livestock and spreads manure on the fields, he still doesn't have to worry. Otherwise, he needs to monitor for sulfur deficiency and possibly have to apply sulfur to his fields. (Hay&Forage)

Update: This reference has maps for sulfur deposits for each year from 1985 to 2008. On Facebook, someone commented on their posting "Joke." I read the text, but did not watch any of the videos.

CropLife claims that corn also needs sulfur.