US Study confirms fast Carbon gains with perennials + Mycorrhiza

The irrepressible Tim Wiley sends this news item with his greetings from WA:

"A very interesting paper from the USA on a pot experiment showing that a perennial grass (C3) plus mycorrhiza increased soil carbon from 0.9% to 1.6% in 12 months!!!!! The perennial grass had no affect on soil carbon without the mycorrhiza. There is not enough information to calculate accurately the sequestration rate on a per hectare basis (i.e. the paper gave pot volume not pot depth, no bulk density figures), but my crude sums suggest a rate of about 40 t C/ha/year or about 150 t CO2e/ha/year!!! Of course a pot trial with benonite is a very artificial situations (and my assumptions are crude), but this paper suggest we are
on the right track."

http://www.acresusa.com/toolbox/reprints/Jan09_Amaranthus_etal.pdf