Monday, August 19, 2013

Too Good To Be True?

Via Big Picture Agriculture, David Bowman is with me in doubting the claims of Allen Savory about improving grasslands with intensive grazing:
In a nutshell, Savory argues that more intensive cattle ranching could simultaneously improve meat production, reverse desertification and turn vast areas of the Earth into massive carbon sinks that would soak up carbon dioxide. This would save the world from climate change. His argument links lots of ideas about ecology that makes for a very inspirational, and for the uninitiated very sensible, narrative.
At the very core of the talk is the idea that rotating grazing animals across rangelands can mimic the migrations of wild animals. This would improve the productivity of pastures and the health of soils. Savory’s message is very positive, a rare a win-win for the environment and the economy.
The catch is Savory’s TED talk is littered with rhetorical devices that paper over problems and exaggerate the effect of grazing. Worse there are just plain errors of fact. In 2008 rangeland scientists undertook a review to determine if “rotation grazing” increased plant and animal productivity compared to other styles of grazing and they could not find any difference.
These authors concluded that “continued advocacy for rotational grazing as a superior strategy of grazing on rangelands is founded on perception and anecdotal interpretations, rather than an objective assessment of the vast experimental evidence”.
Savory’s TED talk builds to the truly astonishing claim that the least biologically productive landscapes on Earth could store so much greenhouse gas pollution it would restore CO2 levels to near pre-industrial levels! This is a dangerous fantasy.
Rangelands are used for cattle grazing for the simple reason there is insufficient water for other more intensive forms or agriculture; more often than not, the soils are infertile. They are some of the least carbon-rich ecosystems on Earth, and no amount of management can get around that fact.
Like Bowman, I think there are ways to improve pasture land, but I think Savory's claims are too good to be true.  Maybe I'll be proven wrong.

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