[Terrapreta] Charcoal, Earthworms and Switchgrass

[Larry Williams]

Jeff-------I have a tendency to use unconventional techniques if I  
think that they will work. In your situation I am working off of the  
barest details of what you are looking at. There are far more ways  
for a task not to work than there are for accomplishing the task.

Your suggestion to press the "charcoal into the soil" may cause more  
soil damage with tire compaction that minimum mixing is worth. The  
word "might" seems significant in this case.

I am back to the disc, except instead of using the disc when the  
ground is thawed, can the disc be used when the ground is in some  
stage of freezing or thawing? It sounds like the cutting of the above  
ground switchgrass with a disc with minimal slicing action in the  
soil is a way to do some mixing of soil, charcoal and grass stems.  
Working on frozen ground will do little compaction to the soil or  
damage to the plants. Consider doing a small test area with repeated  
passes, in two direction, using a disc. This should show you if a  
disc will accomplish anything.

My response is to a technical problem for jump-starting a biological  
process and not related to an energy audit for bio-gas.

In the early nineties I used a skid steer to place woody debris in a  
wetland on my property. The wetland was about 1 acre. This land had  
been used to pasture horses. The problem was that the previous owner  
had allow the animals on this wetter portion of his land during the  
wet season (Whatcom County, up against the Canadian border and in the  
Puget Sound basin).

This resulted in soil compaction on the young alder trees. The stress  
occurred twice a year, from what I could see, during the rainy season  
and during our summer droughts which can form 30 to 90 days. Given  
the glacial clays in this area, that meant that the soil saturated  
for the winter months and went bone dry in the late summer. Many  
alder trees, fifteen years old at that time, had died and the  
remaining trees looked stressed when leafed out.

Hooves, wet clay and tree roots do mix and don't work well together.  
I haven't seen any soil type except dune sand that won't puddle under  
the influence of hooves or tires.

In 1990 there was an opportunity to receive the tree prunings of  
trees being cleared from the local power lines. I probably received  
around 5-600 yards, for free, of knife-cut material plus hardwood  
rounds over three year period. Also I was getting Douglas fir planner  
shaving from a saw mill that bought dimension old growth timber  
(Douglas fir) from dismantled mills and warehouses in the Puget Sound  
basis, close to 150 yards. I used a mid-size excavator to create  
several vernal pools for seasonal ponds. Between the tree pruning  
company, lumber mill and the free stumps (replanted---ah, re- 
positioned) I was able to jump-start the biological process in this  
degraded pastureland.

I have since moved and this project has been doing it's thing on it's  
own. The 5-600 yards of wood chips, partly hauled away, has  
disappeared (via oxidation). The 150 yards of Old Growth shavings  
(400 to 1, C/N ratio) is faded on the edges. Basically the shaving  
pile is intact as I left it with some being hauled away. I have  
aerial pictures taken in Jan 06' with the reflected light off the  
constructed vernal pools (which were created with discrete placement  
of the those spoils) match the puddling on adjacent properties while  
the house-looking-back shows the smaller trees currently on this  
property as compared to the adjacent properties. Currently trees are  
replacing the perennial shrubs. Now, I would be managing for perennials.

I have additional prints that show the minimal, detrimental or no  
impacts of woody debris placement. Small machinery was used in the  
driest, wettest and coldness (frozen ground) weather. A dry wheel  
barrow path through a vernal pool is evident in one picture. In this  
project the vernal pools reduced the plant stress going into the  
summer drought and, now, the alder roots are doing nicely. Ya, I played.

I won't tell anyone that it could easily be returned to a degraded  
pastureland. Put animals on it during the wet season, i.e. compacting  
the soil. I can send you some pictures if it helps.

I hope that this gives you some help-------Larry




-----------------------------
On Apr 13, 2007, at 2:26 PM, Jeff Davis wrote:

>
>> In the fall if charcoal was spread over a test patch or a field of
>> switchgrass, could a disc lightly mix it into the top two 2-3 inches
>> without damaging the switchgrass to badly. There must be some
>> existing earthworms down to the microorganisms and micro fauna that
>> would more quickly benefit with the charcoal in the soil rather than
>> on the soil.
>
> What MIGHT work for my field would be to apply it in the spring and  
> use a
> roller to press the charcoal some what into the soil.
>
>
> Jeff
>
>
>
>
> -- 
> Jeff Davis
>
> Some where 20 miles south of Lake Erie, USA
>
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