[Terrapreta] Soil microorganisms

[Richard Haard]

Hi Sean

As Alan has stated there are numerous commercial sources of  
mycorrhizial fungi. The most common VAM species, Glomus interadices  
is utilized by crop plants and grown on host plants in greenhouse  
culture then used as harvested roots and a carrier in inocculum. In  
addition, commercial inocculum may contain collected spore material  
of known ectomycorrhizial species such as Rhizopogon, Scleroderma and  
Psilothus.

Depending on the requirements of your crop you can do all or any of  
above. I seem to recall you live in upper midwest and you should be  
able to find Rhizopogon and Scleroderma this summer and fall. I would  
be happy off-list to help you find these if interested.

At our farm, and also as described by Dr. Ogawa, we inocculate  
recently sterilized soil with collected leaf litter, rotting wood and  
surface soil from a  healthy forest understory as my crop plants are  
native trees and shrubs, hosts for ecto and endomycorrhizial (VAM)  
fungi.

As I understand things these organisms do not fix atmospheric  
nitrogen but do make nitrogen available to plants.

Charcoal may indeed be helpful in establishing suitable habitat for  
these beneficial fungi.

There are two additional classes of nitrogen fixing organisms that  
are of interest to me.

Frankia  is an actinomycete that forms nodules on a number of host  
plants including red alder and sweet gale, Ceanothus sp, plants we  
grow at 4CN. We have had interesting results with tests of collected,  
mashed alder roots combined with charcoal. Not conclusive because  
both treatments worked fairly well.

Azotobacter species A. chroococcum,and A. vinelandeii are a class of  
free living bacteria that convert atmospheric nitrogen to ammonia.  
They are aerobic and found in soils and in association with plants.

http://microbewiki.kenyon.edu/index.php/Azotobacter

Azotobacter is interesting to me because in pure culture it can fix  
10 mg of nitrogen/g of sugar and in organic matter rich soils and in  
association with root exudates may be a source of natural fertilizer.

http://www.indiaagronet.com/indiaagronet/Manuers_fertilizers/ 
azotobacter.htm

Charcoal and its cellular structure may provide habitat for this  
beneficial bacterium.

Lastly Sean the status of my tote of charcoal now residing under  
hemlock and douglas fir trees.

We want to age this material in a natural way and use in in some  
tests sometime next year. Right now it is sitting on top of the  
ground. Before 1995 we piled many truck loads of leaves, garden  
debris and it has rotted into a high organic matter layer that the  
conifer tree roots have grown into. Every fall this forested place  
supports heavy fruiting of the mushrooms Lepiota, Collybia and  
Tricholoma and digging into the soil it is easy to find tree roots  
and dense mycelium.

So the plan is to bury our charcoal in this place and let it age in  
this environment. Early next spring I will be moving this organic  
rich soil and charcoal soil mix into raised beds for commercial  
propagation of a native plant, Coryalidis scouleri which occurs in  
moist, organic rich under-story soils in our region.

http://biology.burke.washington.edu/herbarium/imagecollection.php? 
Genus=Corydalis&Species=scouleri

and

>> Learning about potential for enrichment
>> culture of Azotobacter and trying to measure available nitrogen in
>> this situation.


On Jun 11, 2007, at 2:14 PM, Sean K. Barry wrote:

> Hi Richard et. al.
>
>> soil with charcoal additions. Learning about potential for enrichment
>> culture of Azotobacter and trying to measure available nitrogen in
>> this situation.
>
>
> Here you mention promoting the growth of nitrogen fixing  
> Azotobacter.  I
> have always been interested in the possibility of inoculating  
> charcoal with
> mycorrhizal fungi.
>
> Do you think it might be possible that you could isolate, culture, and
> propogate enough of both types of microorganism species from the  
> soil in
> your area, then enrich or inoculate charcoal with it, and put that  
> charcoal
> into plant growth trials?  I have seen some FDA ARS (Agricultural  
> Research
> Service) documentation about developed and patented methods to do this
> (propogate soil fungi) kind of thing.  The charcoal you have on the  
> forest
> floor with the litter (I believe I've seen this picture); is it  
> incorporated
> into the soil containing the fungus? Or just on top with the  
> litter?  Are
> there any plants growing in it?  Are there also Azotobacter in that  
> soil
> (along with the mycorrhizal fungi) ?
>
> Regards,
>
> SKB
>
>