Most food would be organic and non-GMO, and much more food would be locally grown, rather than imported and trucked thousands of miles - those things tend to be important to vegetarians.
Processed food would be reduced, because optimum vegetarian nutrition comes from whole foods in their natural state, and most vegetarians are interested in healthy diets.
So, much of the energy that goes into producing, packaging, warehousing and transporting processed food would be saved.
Vegetables and grains need much less land and water than animals, so it wouldn't be necessary to destroy rain forests or irrigate arid land, or create deserts with over pasturing.
Maybe just enough animals could be raised to satisfy the ovo-lacto vegetarians, and those few people who haven't quite made the vegetarian transition, but even they would consume far less meat, for the sake of their health.
This idea isn't necessarily obvious to sustainable ag experts, mainly because they aren't vegetarian, and can't picture agriculture without lots of animals. They are reluctant to be associated with what they regard as a fringe group of cranks, eccentrics and wierdos. In other words, they can't think outside their meat-eating box.
A couple of months ago, I attended a community meeting, held to organize opposition to CAFO's (contained animal feeding operations, or hog lots) in SE Iowa - a serious environmental threat). One of the speakers stated that while he was against having a CAFO anywhere near his country property, of course he himself didn't intend to stop eating pork. The audience was polite - they didn't boo him off the stage!
John Ikerd, Professor Emeritus, U MO, highly respected and passionate sustainability expert, wrote Meeting the Challenge of Peak Oil with Sustainable Agriculture.
In his article, Prof Ikerd states: 'Shifting to a vegetarian diet would be one obvious means of reducing energy use in agriculture, since most food crops are net energy producers - possibly cutting the food energy input/output ratio in half.
However, (and here's where he lost me) processing and distribution would still leave about a five-to-one net fossil energy deficit for total food production. In addition, the 20% fossil fuel equivalent produced by pasture and forage plants - large net energy producers - would be lost.'
I can see that processing and distribution would still be a problem, unless there was no processing, and the food was distributed locally. And I don't see what the 20% fossil fuel equivalent produced by pasture and forage plants has to do with being vegetarian. If you didn't have the animals to pasture and forage in the first place, there would be 100% fossil fuel equivalent, not 20%. Apart from that lapse in logic, attributable to the meat-eating bias, I recommend this article and all of John Ikerd's other writing, available on his website
Another article, by Mary Zanoni, Ph.D., Cornell University, 'The "National Animal Indentification System (NAIS)": A new threat to rural freedom?' appeared in Countryside & Small Stock Journal, a homesteading magazine.
NAIS is a system in the planning stages by the National Institute for Animal Agriculture (NIAA), made up of the big corporate players in U.S. meat production (the National Pork Producers, Monsanto, Cargill, etc), and the makers and marketers of high-tech animal ID equipment.
Any person owning even one agricultural animal, like a horse, cow, chicken or duck would have to register in a federal database, and report any time the animal left the owner's property. The expense of registering, reporting etc, as well as the GPS tracking, would be born by the animal owners. NAIS would be enforced through seizure and fines.
This system would make it difficult and expensive for people who raise their own animals for food, or for small local producers to continue, and strike a heavy blow not only at sustainable agriculture and local organic production, but at individual freedom as well. As the article points out, it will also be completely ineffective in controlling disease and infection in the food supply.
There's a movement afoot, spearheaded by the National Cattlemen's Beef Association, to 'privatize' the database, which means they would have complete access to all the information, and control over enforcement. Since this system is too big and widespread to be effectively enforced, they would most likely just practice selective enforcement, through fines and seizure, against anyone they wanted to drive out of business.
This scheme goes right along with Monsanto's practice of suing farmers for patent violation when their GMO seed propagates uninvited on the farmer's land. NAIS is quite disturbing to anyone who values individual freedom.
After this system goes into effect, I'll no longer be able to buy free-range organic eggs from my neighbor, whose chickens are family pets. And our local organic dairy, with its blissful pampered jersey cows, could be driven out of business. The Amish, who have a separate social and economic system, would also be seriously affected.
What will NAIS do to vegetarian sustainable agriculture? Not a lot, except that there won't be as much organic manure available. And animal manure isn't strictly necessary to organic growing - all you really need are lots of green manure and worms.
Since growing vegetables and grains doesn't require animals, it could be quite tempting for small meat producers to focus instead on raising grains and vegetables, and herbs. There are quite a few high demand organic crops with which small farmers do well.
And the scarcity of organic free range and pastured animal foods will mean that more health conscious and environmentally aware people will turn to vegetarianism. And that local organic production will continue to grow and thrive, as demand for vegetarian foods increases exponentially.
Ms. Zanoni doesn't mention those possibilities, as the silver lining in this black ugly cloud, and the way that NAIS will backfire on these nefarious schemers. But never mind - the less they know about it the better! Of course, if we're forced to go back to horse powered farm machinery, that could be a problem.
(UPDATE: NAIS was scrapped because it was so overwhelmingly unpopular and would have been so burdensome to implement and maintain).