Joel Salatin, hailed by Time magazine for his prize-winning, pioneering work as a sustainable farmer, is in Sydney to convince farmers that small-scale food producers can be financially successful and rejuvenate the environment.
''That's not happening for many farmers,'' Salatin says. ''Many farmers are going out of business and there's a lot of land degradation. The fact is that industrial agriculture has destroyed a lot of land and destroyed a lot of the food and a lot of the health of people around the world.''
Salatin, 53, the patriarch of Polyface farm in the Shenandoah Valley, Virginia, and well-known for his Oscar-nominated film Food Inc, knows his message about small farming is up against conventional wisdom and the deep pockets of international agribusinesses.
''Our conventional farming neighbours [in Virginia] really believe that if we don't vaccinate and medicate, drug and corn-feed cows we are like Typhoid Mary, we are going to spread disease that will destroy the planet's food supply,'' he says. ''They're being fed pseudo science.
''The large corporate global agendas buy the advertising in the media, they buy positions in parliament and agriculture boards and everything else, and that message just pummels people every day until people actually believe it.''
Salatin says he understands the problems of local farmers. ''Australian farmers are facing low commodity prices and a lack of in-house or in-sourced fertility. In other words, fertility is something you buy from outside rather than fertility being generated on-site.''
Put simply, farmers are not composting. They are not doing what the rest of us are being urged to do in our backyards.
''Composting isn't as sexy as applying petrochemicals from a great big tractor with a boom and wearing a nice HAZMAT suit and gas mask,'' Salatin says.
More seriously, he says our industrial food system is based on chemical technology developed for weapons in World War II. ''The reason industrial food took off is not because we were short of food but because there was cheap left-over stock-piles of N P and K [nitrogen, potassium and phosphorous] after World War II, the materials we make bombs out of,'' he says.
Salatin, who has written seven books, including Everything I Want To Do is Illegal: War Stories From the Local Food Front, wants to change fundamental farming practices. ''Cows should not eat grain,'' he says. ''Yet up to 50 per cent of the grain grown in the world goes to these herbivores which aren't supposed to eat grain anyway.
''If you shift herbivores to a natural diet of perennial plants the way wildebeest on the Serengeti or Cape buffaloes in Botswana graze, not only do you feed the same amount of animals but you do it in a cyclical fashion. The electric fence allows us, for the first time in human history, to manage large herds of herbivores like nature managed them.''
Salatin argues that farmers can build economies of scale in local food systems and feed the planet while we ''shorten the chain of custody between field and fork''.
''There is no question that there are other ways to feed people on a mass scale. We generate plenty of nitrogen, potassium, phosphorus and other things throughout the world to maintain and regenerate soil fertility, and feed everybody on the planet.
''What happens is that through industrial agriculture, animals are concentrated in large and small facilities at a scale that their manure, which should be a blessing to the soil, becomes a liability.''
Despite the heavy opposing guns, this crusading farmer does not see himself as fighting an unwinnable battle.
''It doesn't matter,'' says Salatin. ''Truth is truth. Whether our side actually wins or not before the earth is destroyed, I can't answer that and I don't have a clue. Whether or not people accept it doesn't change the truth of the message.
''At the end of the day, it all comes back to the soil. You and I and every other human being ... depend on literally a couple of inches of earth for our existence. The most dangerous notion is that we can continue creating fertile soil out of petrochemicals.'