Tuesday, May 21, 2013

What can be taken from Allan Savory's TED talk

Allan Savory recently gave a TED talk in Long Beach, California on desertification and what he thinks the best solution would be to combat this. To briefly summarize, desertification is the process at which land is turning into dessert. Savory's plan to stop diversification is to use "holistic management and planned grazing". Do do this he plans to use livestock to turn this land back to its original state from its current desert form. He believes that the livestock can "mimic nature", with the livestock spreading their feces and urine while naturally tilling the soil with their hooves. This turning the desert into lush green land that would be able to not only absorb the methane produced by the cows but also absorb enough carbon in the atmosphere to halt global warming.

What I have found in response by the critis to this talk and in supporting it, is nothing but a bunch of contradictory data. A loud voice in the opposition of what Savory outlined in his talk was James McWilliams, who questioned the validity, how old much of his research was and the scale of his experiments (among other things). McWilliams sites Dr. Sylbia Fallon who talks about how the land would be deprived of the nutrient cycle that happens when the livestock dies and is taken back in by the earth. This goes against Savory's idea of only having the livestock in one place for a brief amount of time, and would also be used as a food source for income and not dying on the land. In a study by Castellano and Valone. 2007, the authors found that "long-term removal of livestock resulted in increased water filtration rate and reduced soil compaction" both of which encourage growth and in their minds inhibit desertification. This ideas goes against Savory's.

In my opinion there is much confusion on this topic and there does not seem to be a clear trend of which the best options is. Less or more roaming livestock seems to me to still be an unanswered question. The one thing that is strikingly clear to me on this topic is that much more research is needed.  If Savory is correct than his ideas seem extremely beneficial to our planet. If Savory's critics are correct then again, beneficial data will come out of that for stopping desertification. Either way, the results will be important to know. Another interesting fact that was acknowledged in the Castellano and Valone article was that growth generally remains constant after livestock removal for 20 years. Meaning many long term studies will need to be looked at and hopefully a trend will emerge in one way or the other. 

Castellano, M. Valone, T. Livestock, soil compaction and water filtration: Evaluating a potential diversification recovery mechanism. Journal of Arid Environments. 2007. 71(1) p97-108.

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