[Terrapreta] Trench Method?

[William Carr]

Hi !

I was reading up on the various charcoal making methods, and I  
recalled something I'd read recently.

I began putting two and two together and then added some guesswork.

Please let me know if this makes any sense.



Apparently the original Terra Preta may have been made in pits, or  
maybe trenches.

Fill the pit with wood, and get it  burning well.

Smother with wet vegetation -- I suppose los indios used banana leaves.


I'm not sure what I'd use yet.



Ahhh... green wood chips?     Leftover straw bales, soaked in water  
for a week ?



Then start shoveling in dirt on top.   Keep doing so until the fire  
smolders for X amount of time, then cover completely.


The objective is usually to come back later and recover the charcoal,  
then break it up into pieces.


Possibly los indios used the big pieces for cooking and just left the  
little bits behind.


The reason this idea suddenly interests me is that my tomato garden  
has a soil infection called Clavibacter Michiganensis spp.  
Michiganensis.


The safest option to kill this stuff off is to solarize the soil.    
Cover with clear plastic in May and June, the months in the Northern  
Hemisphere where the Sunlight is most intense.


Wait two months.   The sunlight gradually heats the soil and dries it  
until temps over 140 degrees are achieved.   That's hot enough to kill  
most bacteria.

I've done this and it works.   You add healthy bacteria back to the  
soil, with horse manure, for example.

Plant late-season stuff in that patch, and next year you'll have  
disease free tomatoes.


Ah .... Unfortunately the infectious bacteria get blown back onto the  
soil when the neighbor plows his fields and it re-establishes itself.


So I need a faster way of heating the soil.   Something that can speed  
up the process to two weeks and can be done in March.

And that's when I thought of doing Terra Preta in a trench.    Use  
some low-value wood, in a deep trench, and repeat firings until the  
trench is full again.

Then... don't dig it up.   Leave in place.

Re-inoculate the soil with healthy bacteria and add symbiotic fungi  
from FungiPerfecti.



The only thing left to work out, is how to buffer the shock the soil  
will experience with the addition of the wood ash.

I always forget this one... I think you add lime to counteract ash  
until you reach neutral pH.

Some organic nitrogen may be necessary if a sample shows the green  
wood chips didn't all burn.   When wood chips decay they suck up  
nitrogen.


If this idea works, it could be repeated whenever necessary.    The  
trench would eventually become a raised bed, higher than the  
surrounding dirt, and a lot richer.


So, any thoughts?

Thanks in advance.


William  Carr