Out of curiosity, in a very quick and thoroughly unscientific study, I thought I would set Mr. Berry's two most widely cited poems against each other—to see which would come out on top (according to Google, The Great Sorter of All Digitally Webbed Things ... quack).
And so ...
"The Peace of Wild Things"
vs.
"Manifesto: The Mad Farmer Liberation Front"
turns out to be both close and not so close.
A search for "Manifesto: The Mad Farmer Liberation Front" produces 329 non-redundant results "of about 2,000" ... while a search for "The Peace of Wild Things" produces 394 non-redundant results "of about 18,800."
Since multiple searches within a ten-minute period for the identical terms produced various numerical outcomes, Google gets the raspberries. But since the results remained proportionally almost the same, we should "in all fairness" (this phrase always kills me) hand the laurel crown to "The Peace of Wild Things" ... unless, of course, you can afford the wasted time it will take to produce some other result.