[Terrapreta] VM composition

[Richard Haard]

Hi Tom
On Jun 10, 2007, at 10:07 AM, Tom Miles wrote:

>
>> our forest soil here that are mycorrhizal fungus dominated, highly  
>> leached,
> and have abundant annual organic matter input from leaf/needle  
> litter and
> woody debris. What role might charcoal play in such a place?

This will be my study topic for the coming year. Where my home is  
located is forested and the soils are gravel and cobbles yet it  
supports second growth douglas fir with reasonable growth rate. The  
trees are now 92 years old and 18-24" diameter. I was doing some  
reading on symbiotic nitrogen fixation and ran across a web article  
by David Dalton of Reed College on the ecology of nitrogen fixation.

http://academic.reed.edu/biology/Nitrogen/Nfix3.html

Here he shows that interplanting with red alder has a profound effect  
on the growth of douglas fir.

also

Deluca, TH, et al Wildfire-produced charcoal directly influences  
nitrogen cycling in ponderosa pine forests, Soil sci soc Am J  
70:448-453 (2006)

In this lab study, Charcoal had no effect on nitrification with soils  
from a grassland site whereas geatly influenced this process on  
ponderosa forest soils. Important because is in temperate zone and  
conifer source char.

So I think what I will be doing is following n content of my forest  
soil with charcoal additions. Learning about potential for enrichment  
culture of Azotobacter and trying to measure available nitrogen in  
this situation.

This is also my motivation to collecting some wildfire charcoal from  
the recent fires near Winthrop, Wa. Lots of Ponderosa pine there

Rich H