[Terrapreta] Char application negative / delayed benefits

[Robert Klein]

Hi All

It is  best to recall that carbon in the elemental form  is not a nutrient or even in ionic form prepared to enter into a compound.

What we have is a solid crystalline acid that attracts and holds other ions.  These are held until a life form arrives and extracts them.

This also means that it is sufficient to provide a charge of finely divided char that brings the content of the working soil up to the traditional 15%, although I suspect far less is needed,  Once the Indios got going , they never quit.

Any new addition of fertilizer will be acquired and trapped pending use.  This prevents loss into the ground water, and certainly reduces the necessary addition of fresh fertilizer.

An interesting experiment now is to do a pot test in which a char nutrient charge is subjected to several cropping cycles.  This may give us a clue as to how much less fertilizer will be used as a result.  We would love to be able to predict the drop in usage which hits the bottom line.

arclein


----- Original Message ----
From: Greg and April <gregandapril at earthlink.net>
To: Rexm at chaotech.com.au
Cc: Terra Preta <terrapreta at bioenergylists.org>
Sent: Thursday, June 5, 2008 7:21:06 AM
Subject: Re: [Terrapreta] Char application negative / delayed benefits

 
Interspaced in Blue.
 
----- Original Message ----- 
From: Rex  Manderson 
To: terrapreta at bioenergylists.org 
Sent: Wednesday, June 04, 2008 
20:18
Subject: [Terrapreta] Char application  negative / delayed benefits

Hello all – please find below a  couple of delayed responses to earlier posts.
 
	1. following from  Michael Bailes on 1st June.  I am reluctant to talk about  negative effects of char application, but can identify two circumstances  where the outcomes were initially negative,  In a small pot trial we  conducted with radish and “poor” soil the char amended pots with no added  nutrient were 32% less biomass than the control soil sample.  In  contrast the char + nutrient pots were 42% more than the soil + nutrient  counterpart. ( hoop pine sawdust char peak 450deg 80% carbon  ) 
Rank Table:  Soil + Char    68% mass
                   Soil  control   100%
                   Soil +  fertilizer 138%
       Soil + char + fertilizer  196%   ( expressed as 196/138= 1.42  for 42% )
From this we concluded simply that  if there is not enough nutrient to satisfy all the life in the pot, then the  microflora will win the race for the available  nutrient.
 
I have also had discussion with  some other experimenters who admitted to knowledge of negative results, which  may have come from the presence of a large amount of unconverted material  since the char in question had a low carbon  content.
 
In summary lousy soil or lousy  char can both result in nothing gained.
 
 
This is not totally new.    
  
Composters have known for some time that poor results occur if  the compost is not completely finished as the microorganisms directly compete  with plants for nutrients.    
  
I'm actually not surprised that something similar is occurring  with char and soil that doesn't have extra  nutrients.
  
  
2.  following from Greg H on  5th June
“and then trying to  convince farmers to spend the money on something that is not going to return  any benefits for at least the first couple of  years.
 
Greg  H.”
 
In that same pot trial the char  was added the day of planting and the radish harvested 30 days later.   There was absolutely no waiting for the benefit to be realized!   I  can imagine circumstances of application where the results do not appear for  some time, and could probably find references for published work with this  profile.  However this is not a proof that delay in benefit is an  inevitable part of the char process.  We just need to use good stuff with  appropriate attention to the condition of the soil to get an immediate  gain.
 
Let's me ask you this, how long would it take a farmer to reach  the same char level in his fields, as was in your  pot's?    If what I hear is correct, then we can expect  that he would need to obtain at a very minimum a level of 6% char in  the top 6 inches of  soil.    
 
If my math is correct, even if he only owns 100 acres, he still  has to have over 234,000,000 ( that's right, 234 Million ), cubic yards  of char to achieve that level ( assuming .4 inches of char in the first 6  inches of soil ).    How long is it going to take him to  acquire all this char?
 
This is  what I was talking about.    Now I don't doubt that the farmer  can do a portion of his fields one year and another portion of his fields  another year ( and so on ), and see fairly quick results in just  those parts of the fields that he has applied char to ( assuming that his  fields are not nutrient poor ), but for the time and money he is putting into  the char, he is seeing only a fractional increase, until the majority of  his fields are covered - which will probably take a few years ---- does my  comment now make a little more sense?  
 
 
If anyone wonders why this little  10 pot trial is not in some data base or published, I have to say that without  some attempt to characterise the char and the soil it is all just a collection  of anecdotes.
 
I hope to be able to provide more  useful data in future, but we have had our next set of pot trials on hold  since January because I have not invested the time to find a source for a  reasonable fertiliser application schedule to use in the series.  We do  not appear to have attracted too many commercial farmers to this list, and  perhaps that is something that some contributors should take as an indication  of poor input.
  
It might help if we knew just how much char was needed to  make a difference, then estimates can be raised or lowered as needed for any  real improvement in crop production.
  
  
Greg H. 


      
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