[Terrapreta] An off the wall question about a different type of char

[teelws at jmu.edu]

Greg and all,

Dung is not such a good choice.  In general dung from a critter like a steer, if grass fed, has concentrated the nutrient load so that it has a C:N ratio of about 14:1.  This is best left where it falls, spread on agricultural land
or mixed with a carbon source for high quality mulch (that you can then mix with char).  Charring dung would cause a loss of fixed nitrogen that would need replacement.  Chemical fertilizers are energy intensive, using methane as the main energy source, and the source of hyrogen to make the ammonia.  

On the other hand, already dead wood or dried agricultural waste like dried prairie grasses and forbs (don't focus just on switch grass - it sounds like monoculture) have C:N ratios between 100 and 400:1.  Charring these causes very low nutrient losses.  Most nutrients aside from nitrogen based ones, are not lost on charring, they stay embedded in the carbon matrix.  

Wayne 


---- Original message ----
>Date: Thu, 27 Dec 2007 13:30:48 -0700
>From: "Greg and April" <gregandapril at earthlink.net>  
>Subject: [Terrapreta] An off the wall question about a different type of char  
>To: "Terra Preta" <terrapreta at bioenergylists.org>
>
>   Ok, while thinking about the use of TP type char for
>   hydroponics and aquaponic use, I had a really off
>   the wall thought.
>    
>   What would be the result of using a starting
>   material like dung, and charring it ( besides
>   raising a bit of a stink )?
>    
>   Greg H.
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Wayne S. Teel
MSC 4102 ISAT
James Madison University
Harrisonburg, VA 22807
Tel: 540-568-2798
Fax: 540-568-2761