On a brisk April day, I was traveling with a group of adventurers through the wilds of the Minnesota country side. We came upon a steep embankment and climbed it so that we might see what lay beyond. When I reached the top, and the crowd around me had parted, I thought for a moment I might suddenly have traded places with Samwise Gamgee, hobbit, because I was gazing out onto a field of what reminded me very much of the steaming slag pits of Mordor.  However, rather than an apocalyptic hell-scape I was instead looking at a premier example of sustainable agriculture.