mg sulfate is mg sulfate not mg sulfur, the sulfate is a couple steps down the line from sulfur in the sulfation/transulfuration pathway, hmm but after looking at wikipedia page its got a sulfur atom in it so i guess that makes it a sulfur donor or..? also what happened with the fertilizers? they get detoxed through sulfation sulfoxidation and overburdend ppls systems or somethink?interested to hear full story...