Quote:
Originally Posted by Michaelangelica
SOM is difficult to study because it is a complex mixture of substances having turnover rates that range from days to millennia ... results are explained if SOM contains components that turn over slower and faster than the several-decade average.
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This is a key point in relation to your beasties, Michael. Models of the soil carbon cycle (e.g. Colorado Uni's Century) usually allow for such pools as fast (1 year), slow (decades) and stable (centuries / millennia) turnover rates. However, even these are approximations: some papers on mycorrhizae suggest their turnover time can be as little as five days, as compared to the glomalin they produce which seems to join the slow pool.
The headline is that, once creatures get hold of carbon, it is as good as gone, back to the air. This implies a trade-off between the two main goals of carbon burial, namely removal from the air and agricultural productivity. The former does not want creatures to access the carbon, the latter does. We have to examine our motivations for making terra preta, and the two camps might choose very different methods as a result. I suggest that atmospheric goals might require high-tech, high-volume, highly recalcitrant carbon while soil goals might require something much closer to Amazonian practices or RBlack's carbon-compost approach.
Your history is in compost, isn't it? How do you feel about the potential conflict of goals between atmosphere and soil?
M
