Tuesday, April 23, 2013

All Sizzle and No Steak

Smoke from a power generating station billows into the air over grazing cattle. Allan Savory?s livestock hypothesis hinges on what he calls ?holistic management and planned grazing.?

Photo by Vyacheslav Oseledko/AFP/Getty Images

When Allan Savory finished his TED talk early last month, foodies worldwide collectively salivated. In roughly 22 minutes, Savory, a biologist and former member of the Rhodesian Parliament, challenged the conventional wisdom blaming livestock for the degradation of global grasslands into hardpan deserts. It has long been a basic tenet of environmentalism that 10,000 years of overgrazing has caused this desertification. Environmentalists insist that to restore degraded landscapes, we must reduce the presence of cattle, eat less meat, and allow ecosystems to repair themselves. Savory, who admits that he?s suggesting ?the unthinkable,? wants humans to do the exact opposite: Add cattle to the deserts, manage them with obsessive precision, and eat more meat. Most of the world?s land, he says (at about 18:40), ?can only feed people with animals.?

Savory?s hypothesis hinges on what he calls ?holistic management and planned grazing.? These methods are designed to re-enact the movements of the prehistoric herds that once nurtured global grasslands with their manure deposits and ?hoof action? (gentle trampling that increases the soil?s ability to hold water). By mimicking the natural symbiosis between plants and animals, holistic grazing would, Savory argues, encourage the regrowth of carbon-sequestering grasslands. These grasses would absorb enough carbon to counteract the methane production that?s associated with cattle husbandry (thanks to cow burps and farts) and halt global warming. (To put that claim in perspective, note that the Earth?s oceans and plants currently absorb only half of the 7 billion metric tons of carbon that human activities release into the atmosphere each year.) In order for Savory?s plan to work, the stocking density of livestock?the number of animals grazing a given area of land?would need to increase, in some cases, by as much as 400 percent. And for ranchers to make a living, they would sell their beef.

Savory?s speech quickly attracted praise. Chris Anderson, the TED host, said to Savory after his show, ?I?m sure everyone here ... wants to hug you.? Michael Pollan, a passionate advocate of pastured beef, called Savory?s talk the ?highlight of TED? in a tweet that provocatively asked, ?Eat MORE meat?? The Organic Consumers Association published an article that used Savory?s presentation to assert that ?what we need is MORE moving, grazing animals, not less,? and to argue that holistic grazing ?would be beneficial for the environment, the health of the animals, and subsequently the health of humans consuming those animals.? The takeaway was clear: If you?re interested in saving the planet, sharpen your steak knives.

Well, not so fast. For all the intuitive appeal of ?holistic management,? Savory?s hypothesis is beset with caveats. The most systematic research trial supporting Savory?s claims, the Charter Grazing Trials, was undertaken in Rhodesia (Zimbabwe today) between 1969 and 1975. Given the ecological vagaries of deserts worldwide, one could certainly question whether Savory?s research on a 6,200-acre spot of semiarid African land holds any relevance for the rest of the world?s 12 billion acres of desert. Extrapolation seems even more dubious when you consider that a comprehensive review of Savory?s trial and other similar trials, published in 2002, found that Savory?s signature high-stocking density and rapid-fire rotation plan did not lead to a perfectly choreographed symbiosis between grass and beast.

Instead, there were problems during the Charter Grazing Trials, ones not mentioned in Savory?s dramatic talk. Cattle that grazed according to Savory?s method needed expensive supplemental feed, became stressed and fatigued, and lost enough weight to compromise the profitability of their meat. And even though Savory?s Grazing Trials took place during a period of freakishly high rainfall, with rates exceeding the average by 24 percent overall, the authors contend that Savory?s method ?failed to produce the marked improvement in grass cover claimed from its application.? The authors of the overview concluded exactly what mainstream ecologists have been concluding for 40 years: ?No grazing system has yet shown the capacity to overcome the long-term effects of overstocking and/or drought on vegetation productivity.?

Source: http://feeds.slate.com/click.phdo?i=c0aca3d8a09ce97b71483d49dcfdf3af

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