[Terrapreta] The Science of Terra Preta Formation

[Greg and April]

Interspaced in Blue.

  ----- Original Message ----- 
  From: Jim Joyner 
  To: Terra Preta 
  Sent: Sunday, April 06, 2008 18:10
  Subject: Re: [Terrapreta] The Science of Terra Preta Formation


  Greg.

  Greg and April wrote: 
    Does not the reports from Glaser et al. (1998 and 2003) and Brodowski et al. (2005) have any merit?    They specifically state that " formation of condensed aromatic structures depends on the manufacture of charcoal ". 

    In which case you can increase the exchange potential, by the addition of char with these compounds, and not just due to different particle size.
  All I know is that when char alone has been added to soil the CEC does not increase. Richard has a set of soil tests that strongly indicate, if not prove, this. Soon I will have a similar set that will probably show the same thing.

  There is a differance between char alone ( especialy if is was produced at high temps ), and char produced at low temps that still has condenced areomatic compounds in it, as Glaser and Brodowski talk about.

  I think you might be confusing CEC with the saturation base. The CEC is the collective ability of the soil to hold nutrient. The saturation base is where the nutrient is actually held (the soup, the electrically charged interstices among soil particles -- inert mineral for the most part). Changing the contents of the saturation base does not change the CEC but it does change the soil nutrient make up..

  Actualy I'm such a bad speller, that the computer can't make sense of what I'm trying to spell, so I have to find words that I can spell well enough that the computer can understand what I'm trying to say.
     Do you have any documentation that show's / suggests that fired clay can not change the soil cation exchange potential, in any way? 


  No. But you are making the claim that it does. The burden of proof is on you. Show us that fired clay has some special quality influencing CEC or even the saturation base. 

  Actualy I'm suggesting that it might, then showing that the pottery shards contain things known to have cation extange potentual, and that at least one company, is marketing a product based on the same theory.

    One major company disagrees with you - even to the point that they are marketing a product, in the form of fired clay intended to raise the CEC of aquarium gravel.
  The CEC of aquarium gravel . . . ? I'm not sure how that is relevant but it's a free country, companies can market snake oil if they like. Do they present proof? Do they indicate how this might be applicable to soil? Do the have "soil" tests?

   
  It's not so much that any aquarium gravel does or does not have any exchange potential - it's that a product ( from a company that has a very good reputation among those that keep aquariums ) is standing as a representation of the theory that a fired clay product has the exchange potential ( at least in part ) of the products it's made from.

  As it is, advanced aquarium hobbyist, have found that ordinary gravel is not enough, and use a clay ( sometimes bentonite ) or more preferably laterite based "soil" ( for lack of a better word ), in the gravel, for the cation exchange potential that permits the plants to do much better.    But the problem is with either the clay or the laterite, as soon as something disturbs the gravel, you have cloudy tank, clogged filters, and generally a real mess on your hands.    

  Seachem developed this fired clay alternative to clay or laterite, to eliminate the mess, and they have been producing it for ~15 yrs now, with no negitive news that I know of ( other than the price and lack of avalability in some markets ).

  I obtained some, and started testing it out in one of my aquariums some 5-6 yrs ago, and I still have better plant growth in that aquarium than I have had before and since, and near as I can tell, most if not all other conditions are the same as with my other aquariums.


  What if the fired clay is inclined to act as a receptor for different ions, than the local unfired clay?    Even if in minute quantities, it could be enough to ensure that long term collection of key trace minerals makes a given piece of land more productive than another piece of land 50-100 yards away.
  "What if" indicates a rather large universe of possibilities. Got any theories?  

  Just gave you a theory, the " What if " was the first two words of the possability.
    I have never stated in any way, that I thought that the shards did more than assist in the beginning of the formation of TP. 

  Sorry, I may have read that into what you were saying.  

    I think the char is catalytic in nature, increasing the potential of the local soil.   

  I think we just don't know what it does at molecular level. It may ultimately indicate re-thinking the way we think about soil structure. Like you, I could guess, but beyond getting some char and putting in the soil I can't do or know much else.

  To an extent but, by passing possibilities back and forth, and talking about them, you can sift through and eliminate some things, from consideration, while other possibilities, you can move higher up on your experiment list.


  Greg H.
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